From 66535e11cef5dfb3d2d444bc2678616a5d1e619e Mon Sep 17 00:00:00 2001
From: Vitor Pamplona <vitor@vitorpamplona.com>
Date: Thu, 13 Mar 2025 17:24:20 -0400
Subject: [PATCH] - Removes the TAG_SIZE constant on all tags because each
 parser might use a different size. There is no minimum size for tags. - Moves
 the tag parsing checks to use ensure. - Explicitly writes matching methods to
 avoid hiding complexity beyond utility functions.

---
 .../audio/header/tags/DownloadUrlTag.kt       |  8 ++-
 .../audio/header/tags/StreamUrlTag.kt         |  8 ++-
 .../audio/header/tags/WaveformTag.kt          |  8 ++-
 .../experimental/audio/track/tags/CoverTag.kt |  8 ++-
 .../experimental/audio/track/tags/MediaTag.kt |  8 ++-
 .../audio/track/tags/ParticipantTag.kt        | 16 ++---
 .../experimental/audio/track/tags/PriceTag.kt |  8 ++-
 .../experimental/audio/track/tags/TypeTag.kt  |  8 ++-
 .../quartz/experimental/bounties/RewardTag.kt |  7 ++-
 .../experimental/forks/MarkedETagExt.kt       |  2 +-
 .../interactiveStories/tags/ReadStatusTag.kt  |  8 ++-
 .../interactiveStories/tags/RootSceneTag.kt   |  1 -
 .../interactiveStories/tags/StoryOptionTag.kt |  1 -
 .../quartz/experimental/nns/tags/IPv4Tag.kt   |  8 ++-
 .../quartz/experimental/nns/tags/IPv6Tag.kt   |  8 ++-
 .../experimental/nns/tags/VersionTag.kt       |  8 ++-
 .../relationshipStatus/tags/PetnameTag.kt     |  8 ++-
 .../relationshipStatus/tags/RankTag.kt        |  8 ++-
 .../relationshipStatus/tags/SummaryTag.kt     |  8 ++-
 .../experimental/zapPolls/tags/ClosedAtTag.kt |  8 ++-
 .../zapPolls/tags/ConsensusThresholdTag.kt    |  7 ++-
 .../experimental/zapPolls/tags/MaximumTag.kt  |  8 ++-
 .../experimental/zapPolls/tags/MinimumTag.kt  |  8 ++-
 .../zapPolls/tags/PollOptionTag.kt            |  9 ++-
 .../quartz/nip01Core/core/Tag.kt              | 58 +------------------
 .../quartz/nip01Core/core/TagArrayBuilder.kt  | 16 +----
 .../nip01Core/tags/addressables/ATag.kt       | 23 ++++----
 .../quartz/nip01Core/tags/events/ETag.kt      | 20 +++++--
 .../nip01Core/tags/hashtags/HashtagTag.kt     | 10 +++-
 .../quartz/nip01Core/tags/kinds/KindTag.kt    | 14 +++--
 .../quartz/nip01Core/tags/people/PTag.kt      | 20 ++++---
 .../nip01Core/tags/references/ReferenceTag.kt | 14 +++--
 .../quartz/nip02FollowList/tags/ContactTag.kt | 26 ++++++---
 .../quartz/nip10Notes/tags/MarkedETag.kt      |  9 ++-
 .../quartz/nip10Notes/tags/Positional.kt      |  6 +-
 .../quartz/nip13Pow/tags/PoWTag.kt            | 13 +++--
 .../quartz/nip14Subject/SubjectTag.kt         | 10 +++-
 .../nip17Dm/files/tags/EncryptionAlgo.kt      | 10 +++-
 .../nip17Dm/files/tags/EncryptionKey.kt       |  9 ++-
 .../nip17Dm/files/tags/EncryptionNonce.kt     |  9 ++-
 .../quartz/nip17Dm/files/tags/FileTypeTag.kt  | 10 +++-
 .../nip18Reposts/quotes/QAddressableTag.kt    | 10 ++--
 .../quartz/nip18Reposts/quotes/QEventTag.kt   | 10 +++-
 .../quartz/nip18Reposts/quotes/QTag.kt        | 23 ++++++--
 .../quartz/nip22Comments/CommentEvent.kt      |  4 +-
 .../nip22Comments/tags/ReplyAddressTag.kt     | 23 +++++---
 .../nip22Comments/tags/ReplyAuthorTag.kt      | 21 ++++---
 .../nip22Comments/tags/ReplyEventTag.kt       | 34 +++++++----
 .../nip22Comments/tags/ReplyIdentifierTag.kt  | 14 +++--
 .../quartz/nip22Comments/tags/ReplyKindTag.kt | 22 +++----
 .../nip22Comments/tags/RootAddressTag.kt      | 25 +++++---
 .../nip22Comments/tags/RootAuthorTag.kt       | 20 +++----
 .../quartz/nip22Comments/tags/RootEventTag.kt | 34 +++++++----
 .../nip22Comments/tags/RootIdentifierTag.kt   | 14 +++--
 .../quartz/nip22Comments/tags/RootKindTag.kt  | 14 +++--
 .../quartz/nip23LongContent/tags/ImageTag.kt  |  8 ++-
 .../nip23LongContent/tags/PublishedAtTag.kt   |  8 ++-
 .../nip23LongContent/tags/SummaryTag.kt       |  8 ++-
 .../quartz/nip23LongContent/tags/TitleTag.kt  |  8 ++-
 .../vitorpamplona/quartz/nip31Alts/AltTag.kt  | 10 +++-
 .../nip34Git/repository/tags/CloneTag.kt      |  8 ++-
 .../repository/tags/DescriptionTag.kt         |  8 ++-
 .../nip34Git/repository/tags/NameTag.kt       |  8 ++-
 .../quartz/nip34Git/repository/tags/WebTag.kt |  8 ++-
 .../quartz/nip35Torrents/tags/BtihTag.kt      |  8 ++-
 .../quartz/nip35Torrents/tags/FileTag.kt      | 13 +++--
 .../quartz/nip35Torrents/tags/InfoHashTag.kt  |  8 ++-
 .../quartz/nip35Torrents/tags/TrackerTag.kt   |  8 ++-
 .../streaming/tags/CurrentParticipantsTag.kt  |  8 ++-
 .../streaming/tags/EndsTag.kt                 |  8 ++-
 .../streaming/tags/ParticipantTag.kt          | 34 ++++++-----
 .../streaming/tags/RelayListTag.kt            |  8 ++-
 .../streaming/tags/StartsTag.kt               |  8 ++-
 .../streaming/tags/StatusTag.kt               |  8 ++-
 .../streaming/tags/StreamingTag.kt            |  8 ++-
 .../streaming/tags/TotalParticipantsTag.kt    |  8 ++-
 .../nip57Zaps/zapraiser/ZapRaiserTag.kt       |  2 +-
 .../quartz/nip71Video/tags/DurationTag.kt     |  8 ++-
 .../quartz/nip71Video/tags/SegmentTag.kt      |  9 ++-
 .../quartz/nip71Video/tags/TextTrackTag.kt    |  7 ++-
 .../definition/tags/DescriptionTag.kt         |  8 ++-
 .../definition/tags/ImageTag.kt               |  8 ++-
 .../definition/tags/ModeratorTag.kt           | 14 +++--
 .../definition/tags/NameTag.kt                |  8 ++-
 .../definition/tags/RelayTag.kt               |  7 ++-
 .../definition/tags/RulesTag.kt               |  8 ++-
 .../quartz/nip75ZapGoals/tags/AmountTag.kt    |  8 ++-
 .../quartz/nip75ZapGoals/tags/ClosedAtTag.kt  |  8 ++-
 .../quartz/nip75ZapGoals/tags/RelayListTag.kt |  8 ++-
 .../quartz/nip84Highlights/tags/ContextTag.kt |  8 ++-
 .../definition/tags/PlatformLinkTag.kt        |  9 +--
 .../recommendation/AppRecommendationEvent.kt  |  2 +-
 .../recommendation/tags/RecommendationTag.kt  | 12 ++--
 .../quartz/nip92IMeta/IMetaTag.kt             |  8 ++-
 .../nip94FileMetadata/tags/BlurhashTag.kt     |  8 ++-
 .../nip94FileMetadata/tags/DimensionTag.kt    |  8 ++-
 .../nip94FileMetadata/tags/FallbackTag.kt     |  8 ++-
 .../nip94FileMetadata/tags/HashSha256Tag.kt   |  8 ++-
 .../quartz/nip94FileMetadata/tags/ImageTag.kt |  7 ++-
 .../nip94FileMetadata/tags/MagnetTag.kt       |  8 ++-
 .../nip94FileMetadata/tags/MimeTypeTag.kt     | 10 +++-
 .../nip94FileMetadata/tags/OriginalHashTag.kt |  8 ++-
 .../nip94FileMetadata/tags/ServiceTag.kt      | 10 +++-
 .../quartz/nip94FileMetadata/tags/SizeTag.kt  |  8 ++-
 .../nip94FileMetadata/tags/SummaryTag.kt      | 10 +++-
 .../quartz/nip94FileMetadata/tags/ThumbTag.kt |  7 ++-
 .../nip94FileMetadata/tags/TorrentInfoHash.kt |  8 ++-
 .../quartz/nip94FileMetadata/tags/UrlTag.kt   | 10 +++-
 .../nip96FileStorage/config/tags/ServerTag.kt |  8 ++-
 .../quartz/nip98HttpAuth/tags/MethodTag.kt    |  8 ++-
 .../nip98HttpAuth/tags/PayloadHashTag.kt      |  7 ++-
 .../quartz/nip98HttpAuth/tags/UrlTag.kt       |  8 ++-
 .../nip99Classifieds/tags/ConditionTag.kt     |  8 ++-
 .../nip99Classifieds/tags/LocationTag.kt      |  8 ++-
 .../quartz/nip99Classifieds/tags/PriceTag.kt  |  7 ++-
 .../quartz/nip99Classifieds/tags/StatusTag.kt |  8 ++-
 116 files changed, 807 insertions(+), 440 deletions(-)

diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/header/tags/DownloadUrlTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/header/tags/DownloadUrlTag.kt
index 5f335b67b..6e69131b7 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/header/tags/DownloadUrlTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/header/tags/DownloadUrlTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.experimental.audio.header.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class DownloadUrlTag {
     companion object {
         const val TAG_NAME = "download_url"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/header/tags/StreamUrlTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/header/tags/StreamUrlTag.kt
index d3bc35de7..2e896aa98 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/header/tags/StreamUrlTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/header/tags/StreamUrlTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.experimental.audio.header.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class StreamUrlTag {
     companion object {
         const val TAG_NAME = "stream_url"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/header/tags/WaveformTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/header/tags/WaveformTag.kt
index 0942299f2..491653632 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/header/tags/WaveformTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/header/tags/WaveformTag.kt
@@ -21,7 +21,9 @@
 package com.vitorpamplona.quartz.experimental.audio.header.tags
 
 import com.fasterxml.jackson.module.kotlin.readValue
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.jackson.EventMapper
+import com.vitorpamplona.quartz.utils.ensure
 
 class WaveformTag(
     val wave: List<Int>,
@@ -30,12 +32,12 @@ class WaveformTag(
 
     companion object {
         const val TAG_NAME = "waveform"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): WaveformTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
-            if (tag[1].isEmpty()) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             val wave = runCatching { EventMapper.mapper.readValue<List<Int>>(tag[1]) }.getOrNull()
             if (wave.isNullOrEmpty()) return null
             return WaveformTag(wave)
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/CoverTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/CoverTag.kt
index e52b81d2e..56488bb95 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/CoverTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/CoverTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.experimental.audio.track.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class CoverTag {
     companion object {
         const val TAG_NAME = "cover"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/MediaTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/MediaTag.kt
index d620dbe45..7ebaacc27 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/MediaTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/MediaTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.experimental.audio.track.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class MediaTag {
     companion object {
         const val TAG_NAME = "media"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/ParticipantTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/ParticipantTag.kt
index 1701e908f..ebc074a71 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/ParticipantTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/ParticipantTag.kt
@@ -23,9 +23,10 @@ package com.vitorpamplona.quartz.experimental.audio.track.tags
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Tag
-import com.vitorpamplona.quartz.nip01Core.core.isNotName
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.tags.people.PubKeyReferenceTag
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
+import com.vitorpamplona.quartz.utils.ensure
 
 @Immutable
 data class ParticipantTag(
@@ -36,26 +37,27 @@ data class ParticipantTag(
 
     companion object {
         const val TAG_NAME = "p"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Tag): ParticipantTag? {
-            if (tag.isNotName(TAG_NAME, TAG_SIZE)) return null
-            if (tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return ParticipantTag(tag[1], tag.getOrNull(2))
         }
 
         @JvmStatic
         fun parseKey(tag: Tag): String? {
-            if (tag.isNotName(TAG_NAME, TAG_SIZE)) return null
-            if (tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return tag[1]
         }
 
         @JvmStatic
         fun assemble(
             pubkey: HexKey,
-            relayHint: String?,
+            relayHint: String? = null,
         ) = arrayOfNotNull(TAG_NAME, pubkey, relayHint)
     }
 }
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/PriceTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/PriceTag.kt
index c0439e8df..dde2c19ae 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/PriceTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/PriceTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.experimental.audio.track.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class PriceTag {
     companion object {
         const val TAG_NAME = "price"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/TypeTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/TypeTag.kt
index fd3a227c6..34bf125a3 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/TypeTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/audio/track/tags/TypeTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.experimental.audio.track.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class TypeTag {
     companion object {
         const val TAG_NAME = "c"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/bounties/RewardTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/bounties/RewardTag.kt
index e8f3acd97..cb514b1d7 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/bounties/RewardTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/bounties/RewardTag.kt
@@ -20,16 +20,19 @@
  */
 package com.vitorpamplona.quartz.experimental.bounties
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
 import java.math.BigDecimal
 
 class RewardTag {
     companion object {
         const val TAG_NAME = "reward"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): BigDecimal? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
 
             return runCatching { BigDecimal(tag[1]) }.getOrNull()
         }
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/forks/MarkedETagExt.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/forks/MarkedETagExt.kt
index 9a3217b0e..fa1a7b02e 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/forks/MarkedETagExt.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/forks/MarkedETagExt.kt
@@ -24,7 +24,7 @@ import com.vitorpamplona.quartz.nip10Notes.tags.MarkedETag
 import com.vitorpamplona.quartz.nip10Notes.tags.MarkedETag.MARKER
 
 fun MarkedETag.Companion.parseFork(tag: Array<String>): MarkedETag? {
-    if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+    if (tag.size < 4 || tag[0] != "e") return null
     if (tag[ORDER_MARKER] != MARKER.FORK.code) return null
     // ["e", id hex, relay hint, marker, pubkey]
     return MarkedETag(
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/interactiveStories/tags/ReadStatusTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/interactiveStories/tags/ReadStatusTag.kt
index c09d4e768..28a5eaf8d 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/interactiveStories/tags/ReadStatusTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/interactiveStories/tags/ReadStatusTag.kt
@@ -20,6 +20,9 @@
  */
 package com.vitorpamplona.quartz.experimental.interactiveStories.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class ReadStatusTag {
     enum class STATUS(
         val value: String,
@@ -34,11 +37,12 @@ class ReadStatusTag {
 
     companion object {
         const val TAG_NAME = "status"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/interactiveStories/tags/RootSceneTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/interactiveStories/tags/RootSceneTag.kt
index 01062321e..ae354c2d0 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/interactiveStories/tags/RootSceneTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/interactiveStories/tags/RootSceneTag.kt
@@ -60,7 +60,6 @@ data class RootSceneTag(
 
     companion object {
         const val TAG_NAME = "A"
-        const val TAG_SIZE = 2
 
         fun assembleATagId(
             kind: Int,
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/interactiveStories/tags/StoryOptionTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/interactiveStories/tags/StoryOptionTag.kt
index 652e68129..a17697642 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/interactiveStories/tags/StoryOptionTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/interactiveStories/tags/StoryOptionTag.kt
@@ -35,7 +35,6 @@ class StoryOptionTag(
 
     companion object {
         const val TAG_NAME = "option"
-        const val TAG_SIZE = 3
 
         @JvmStatic
         fun parse(tag: Array<String>): StoryOptionTag? {
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/nns/tags/IPv4Tag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/nns/tags/IPv4Tag.kt
index c8f7ded13..f6b2024f3 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/nns/tags/IPv4Tag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/nns/tags/IPv4Tag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.experimental.nns.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class IPv4Tag {
     companion object {
         const val TAG_NAME = "ip4"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/nns/tags/IPv6Tag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/nns/tags/IPv6Tag.kt
index 07086b274..db673d7db 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/nns/tags/IPv6Tag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/nns/tags/IPv6Tag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.experimental.nns.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class IPv6Tag {
     companion object {
         const val TAG_NAME = "ip6"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/nns/tags/VersionTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/nns/tags/VersionTag.kt
index 2eca2f76c..7de43e61d 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/nns/tags/VersionTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/nns/tags/VersionTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.experimental.nns.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class VersionTag {
     companion object {
         const val TAG_NAME = "version"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/relationshipStatus/tags/PetnameTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/relationshipStatus/tags/PetnameTag.kt
index df1ccfbfc..ea9b4981a 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/relationshipStatus/tags/PetnameTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/relationshipStatus/tags/PetnameTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.experimental.relationshipStatus.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class PetnameTag {
     companion object {
         const val TAG_NAME = "petname"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/relationshipStatus/tags/RankTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/relationshipStatus/tags/RankTag.kt
index 3525445d0..b39bce3ae 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/relationshipStatus/tags/RankTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/relationshipStatus/tags/RankTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.experimental.relationshipStatus.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class RankTag {
     companion object {
         const val TAG_NAME = "rank"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): Int? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1].toIntOrNull()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/relationshipStatus/tags/SummaryTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/relationshipStatus/tags/SummaryTag.kt
index 8a7696c29..058c58a74 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/relationshipStatus/tags/SummaryTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/relationshipStatus/tags/SummaryTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.experimental.relationshipStatus.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class SummaryTag {
     companion object {
         const val TAG_NAME = "summary"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/ClosedAtTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/ClosedAtTag.kt
index 5b07019a8..21883f052 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/ClosedAtTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/ClosedAtTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.experimental.zapPolls.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class ClosedAtTag {
     companion object {
         const val TAG_NAME = "closed_at"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): Long? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1].toLongOrNull()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/ConsensusThresholdTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/ConsensusThresholdTag.kt
index 87e3967ec..b1d2fce00 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/ConsensusThresholdTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/ConsensusThresholdTag.kt
@@ -20,16 +20,19 @@
  */
 package com.vitorpamplona.quartz.experimental.zapPolls.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
 import kotlin.math.round
 
 class ConsensusThresholdTag {
     companion object {
         const val TAG_NAME = "consensus_threshold"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): Double? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1].toLongOrNull()?.toDouble()?.div(100)
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/MaximumTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/MaximumTag.kt
index bf6381dee..286c9876d 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/MaximumTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/MaximumTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.experimental.zapPolls.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class MaximumTag {
     companion object {
         const val TAG_NAME = "value_maximum"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): Long? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1].toLongOrNull()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/MinimumTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/MinimumTag.kt
index 7f1b8cfe8..5a1fb5ed8 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/MinimumTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/MinimumTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.experimental.zapPolls.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class MinimumTag {
     companion object {
         const val TAG_NAME = "value_minimum"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): Long? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1].toLongOrNull()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/PollOptionTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/PollOptionTag.kt
index f5a74b06d..1ab922f5f 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/PollOptionTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/experimental/zapPolls/tags/PollOptionTag.kt
@@ -20,6 +20,9 @@
  */
 package com.vitorpamplona.quartz.experimental.zapPolls.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class PollOptionTag(
     val index: Int,
     val descriptor: String,
@@ -28,11 +31,13 @@ class PollOptionTag(
 
     companion object {
         const val TAG_NAME = "poll_option"
-        const val TAG_SIZE = 3
 
         @JvmStatic
         fun parse(tag: Array<String>): PollOptionTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(2)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
+            ensure(tag[2].isNotEmpty()) { return null }
 
             val index = tag[1].toIntOrNull() ?: return null
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/core/Tag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/core/Tag.kt
index d97acc9c1..d9273988a 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/core/Tag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/core/Tag.kt
@@ -27,64 +27,12 @@ typealias Tag = Array<String>
  */
 fun Tag.has(index: Int) = size > index
 
-/**
- * Returns if the Tag has less than $index elements.
- */
-fun Tag.lacks(index: Int) = size <= index
-
 fun Tag.name() = this[0]
 
 fun Tag.value() = this[1]
 
-fun Tag.hasValue() = this[1].isNotEmpty()
+fun Tag.hasValue() = if (has(1)) this[1].isNotEmpty() else false
 
-fun Tag.nameOrNull() = if (size > 0) name() else null
+fun Tag.nameOrNull() = if (has(0)) this[0] else null
 
-fun Tag.valueOrNull() = if (size > 1) value() else null
-
-fun Tag.isNameUnsafe(name: String): Boolean = name() == name
-
-fun Tag.isValueUnsafe(value: String): Boolean = value() == value
-
-fun Tag.isValueInUnsafe(values: Set<String>): Boolean = value() in values
-
-fun Tag.match(name: String): Boolean = if (size > 0) isNameUnsafe(name) else false
-
-fun Tag.isValue(value: String): Boolean = if (size > 1) isValueUnsafe(value) else false
-
-fun Tag.match(
-    name: String,
-    value: String,
-    minSize: Int,
-): Boolean = if (size >= minSize) isNameUnsafe(name) && isValueUnsafe(value) else false
-
-fun Tag.match(
-    name: String,
-    values: Set<String>,
-    minSize: Int,
-): Boolean = if (size >= minSize) isNameUnsafe(name) && isValueInUnsafe(values) else false
-
-fun Tag.match(
-    name: String,
-    minSize: Int,
-): Boolean = if (size >= minSize) isNameUnsafe(name) else false
-
-fun Tag.isNotName(
-    name: String,
-    minSize: Int,
-): Boolean = !match(name, minSize)
-
-fun Tag.matchAndHasValue(
-    name: String,
-    minSize: Int,
-): Boolean = if (size >= minSize) isNameUnsafe(name) && hasValue() else false
-
-fun Tag.valueIfMatches(
-    name: String,
-    minSize: Int,
-): String? = if (match(name, minSize)) value() else null
-
-fun Tag.valueToIntIfMatches(
-    name: String,
-    minSize: Int,
-): Int? = if (match(name, minSize)) value().toIntOrNull() else null
+fun Tag.valueOrNull() = if (has(1)) this[1] else null
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/core/TagArrayBuilder.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/core/TagArrayBuilder.kt
index 3d03f667b..aab802bed 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/core/TagArrayBuilder.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/core/TagArrayBuilder.kt
@@ -35,7 +35,7 @@ class TagArrayBuilder<T : IEvent> {
         tagName: String,
         tagValue: String,
     ): TagArrayBuilder<T> {
-        tagList[tagName]?.removeIf { it.value() == tagValue }
+        tagList[tagName]?.removeIf { it.valueOrNull() == tagValue }
         if (tagList[tagName]?.isEmpty() == true) {
             tagList.remove(tagName)
         }
@@ -46,18 +46,8 @@ class TagArrayBuilder<T : IEvent> {
         predicate: (Tag, Tag) -> Boolean,
         toCompare: Tag,
     ): TagArrayBuilder<T> {
-        tagList[toCompare.name()]?.removeIf { predicate(it, toCompare) }
-        if (tagList[toCompare.name()]?.isEmpty() == true) {
-            tagList.remove(toCompare.name())
-        }
-        return this
-    }
-
-    fun removeIf(
-        tagName: String,
-        tagValue: String,
-    ): TagArrayBuilder<T> {
-        tagList[tagName]?.removeIf { it.value() == tagValue }
+        val tagName = toCompare.nameOrNull() ?: return this
+        tagList[tagName]?.removeIf { predicate(it, toCompare) }
         if (tagList[tagName]?.isEmpty() == true) {
             tagList.remove(tagName)
         }
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/addressables/ATag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/addressables/ATag.kt
index 2f8e464d1..07ba6ac59 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/addressables/ATag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/addressables/ATag.kt
@@ -23,9 +23,6 @@ package com.vitorpamplona.quartz.nip01Core.tags.addressables
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.has
-import com.vitorpamplona.quartz.nip01Core.core.match
-import com.vitorpamplona.quartz.nip01Core.core.name
-import com.vitorpamplona.quartz.nip01Core.core.value
 import com.vitorpamplona.quartz.nip01Core.hints.types.AddressHint
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 import com.vitorpamplona.quartz.utils.bytesUsedInMemory
@@ -57,40 +54,44 @@ data class ATag(
 
     companion object {
         const val TAG_NAME = "a"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun isTagged(tag: Array<String>) = tag.size >= 2 && tag[0] == TAG_NAME && tag[1].isNotEmpty()
+        fun isTagged(tag: Array<String>) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
-        @JvmStatic
         fun isSameAddress(
             tag1: Array<String>,
             tag2: Array<String>,
-        ) = tag1.match(tag2.name(), tag2.value(), TAG_SIZE)
+        ): Boolean {
+            ensure(tag1.has(1)) { return false }
+            ensure(tag2.has(1)) { return false }
+            ensure(tag1[0] == tag2[0]) { return false }
+            ensure(tag1[1] == tag2[1]) { return false }
+            return true
+        }
 
         @JvmStatic
         fun isTagged(
             tag: Array<String>,
             addressId: String,
-        ) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && tag[1] == addressId
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] == addressId
 
         @JvmStatic
         fun isTagged(
             tag: Array<String>,
             address: ATag,
-        ) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && tag[1] == address.toTag()
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] == address.toTag()
 
         @JvmStatic
         fun isIn(
             tag: Array<String>,
             addressIds: Set<String>,
-        ) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && tag[1] in addressIds
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] in addressIds
 
         @JvmStatic
         fun isTaggedWithKind(
             tag: Array<String>,
             kind: String,
-        ) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && Address.isOfKind(tag[1], kind)
+        ) = tag.has(1) && tag[0] == TAG_NAME && Address.isOfKind(tag[1], kind)
 
         @JvmStatic
         fun parseIfOfKind(
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/events/ETag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/events/ETag.kt
index 0f59c7897..de7942709 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/events/ETag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/events/ETag.kt
@@ -22,10 +22,12 @@ package com.vitorpamplona.quartz.nip01Core.tags.events
 
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.hints.types.EventIdHint
 import com.vitorpamplona.quartz.nip19Bech32.entities.NEvent
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 import com.vitorpamplona.quartz.utils.bytesUsedInMemory
+import com.vitorpamplona.quartz.utils.ensure
 import com.vitorpamplona.quartz.utils.pointerSizeInBytes
 
 @Immutable
@@ -56,32 +58,38 @@ data class ETag(
 
     companion object {
         const val TAG_NAME = "e"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun isTagged(tag: Array<String>) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && tag[1].length == 64
+        fun isTagged(tag: Array<String>) = tag.has(1) && tag[0] == TAG_NAME && tag[1].length == 64
 
         @JvmStatic
         fun isTagged(
             tag: Array<String>,
             eventId: HexKey,
-        ) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && tag[1] == eventId
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] == eventId
 
         @JvmStatic
         fun parse(tag: Array<String>): ETag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME || tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return ETag(tag[1], tag.getOrNull(2), tag.getOrNull(3))
         }
 
         @JvmStatic
         fun parseId(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME || tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return tag[1]
         }
 
         @JvmStatic
         fun parseAsHint(tag: Array<String>): EventIdHint? {
-            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != 64 || tag[2].isEmpty()) return null
+            ensure(tag.has(2)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
+            ensure(tag[2].isNotEmpty()) { return null }
             return EventIdHint(tag[1], tag[2])
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/hashtags/HashtagTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/hashtags/HashtagTag.kt
index 773b14db2..ac11b4d46 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/hashtags/HashtagTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/hashtags/HashtagTag.kt
@@ -20,17 +20,21 @@
  */
 package com.vitorpamplona.quartz.nip01Core.tags.hashtags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class HashtagTag {
     companion object {
         const val TAG_NAME = "t"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun isTagged(tag: Array<String>) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && tag[1].isNotEmpty()
+        fun isTagged(tag: Array<String>) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME || tag[1].isEmpty()) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/kinds/KindTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/kinds/KindTag.kt
index 051199464..c076c4dee 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/kinds/KindTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/kinds/KindTag.kt
@@ -20,26 +20,30 @@
  */
 package com.vitorpamplona.quartz.nip01Core.tags.kinds
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class KindTag {
     companion object {
         const val TAG_NAME = "k"
-        const val TAG_SIZE = 2
 
-        fun match(tag: Array<String>) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME
+        fun match(tag: Array<String>) = tag.has(1) && tag[0] == TAG_NAME
 
         fun isTagged(
             tag: Array<String>,
             kind: String,
-        ) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && tag[1] == kind
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] == kind
 
         fun isIn(
             tag: Array<String>,
             kinds: Set<String>,
-        ) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && tag[1] in kinds
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] in kinds
 
         @JvmStatic
         fun parse(tag: Array<String>): Int? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1].toInt()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/people/PTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/people/PTag.kt
index 55a2270ac..53e941df9 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/people/PTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/people/PTag.kt
@@ -24,12 +24,14 @@ import android.util.Log
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Tag
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.core.hexToByteArray
 import com.vitorpamplona.quartz.nip01Core.hints.types.PubKeyHint
 import com.vitorpamplona.quartz.nip19Bech32.entities.NProfile
 import com.vitorpamplona.quartz.nip19Bech32.toNpub
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 import com.vitorpamplona.quartz.utils.bytesUsedInMemory
+import com.vitorpamplona.quartz.utils.ensure
 import com.vitorpamplona.quartz.utils.pointerSizeInBytes
 
 @Immutable
@@ -50,24 +52,25 @@ data class PTag(
 
     companion object {
         const val TAG_NAME = "p"
-        const val TAG_SIZE = 2
 
         fun isTagged(
             tag: Array<String>,
             key: HexKey,
-        ): Boolean = tag.size >= 2 && tag[0] == TAG_NAME && tag[1] == key
+        ): Boolean = tag.has(1) && tag[0] == TAG_NAME && tag[1] == key
 
         @JvmStatic
         fun parse(tag: Tag): PTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
-            if (tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return PTag(tag[1], tag.getOrNull(2))
         }
 
         @JvmStatic
         fun parseKey(tag: Array<String>): HexKey? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
-            if (tag[1].length != 64) {
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) {
                 Log.w("PTag", "Invalid `$TAG_NAME` value ${tag.joinToString(", ")}")
                 return null
             }
@@ -76,7 +79,10 @@ data class PTag(
 
         @JvmStatic
         fun parseAsHint(tag: Array<String>): PubKeyHint? {
-            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != 64 || tag[2].isEmpty()) return null
+            ensure(tag.has(2)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
+            ensure(tag[2].isNotEmpty()) { return null }
             return PubKeyHint(tag[1], tag[2])
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/references/ReferenceTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/references/ReferenceTag.kt
index 8c07af9ff..1ad8b8f29 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/references/ReferenceTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip01Core/tags/references/ReferenceTag.kt
@@ -20,34 +20,38 @@
  */
 package com.vitorpamplona.quartz.nip01Core.tags.references
 
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip96FileStorage.HttpUrlFormatter
+import com.vitorpamplona.quartz.utils.ensure
 
 class ReferenceTag {
     companion object {
         const val TAG_NAME = "r"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun isTagged(
             tag: Array<String>,
             reference: String,
-        ): Boolean = tag.size >= 2 && tag[0] == TAG_NAME && tag[1] == reference
+        ): Boolean = tag.has(1) && tag[0] == TAG_NAME && tag[1] == reference
 
         @JvmStatic
         fun isIn(
             tag: Array<String>,
             references: Set<String>,
-        ): Boolean = tag.size >= 2 && tag[0] == TAG_NAME && tag[1] in references
+        ): Boolean = tag.has(1) && tag[0] == TAG_NAME && tag[1] in references
 
         @JvmStatic
         fun hasReference(tag: Array<String>): Boolean {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return false
+            ensure(tag.has(1)) { return false }
+            ensure(tag[0] == TAG_NAME) { return false }
             return tag[1].isNotEmpty()
         }
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip02FollowList/tags/ContactTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip02FollowList/tags/ContactTag.kt
index eab66cef3..d40a858c7 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip02FollowList/tags/ContactTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip02FollowList/tags/ContactTag.kt
@@ -23,11 +23,13 @@ package com.vitorpamplona.quartz.nip02FollowList.tags
 import android.util.Log
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.core.toHexKey
 import com.vitorpamplona.quartz.nip01Core.hints.types.PubKeyHint
 import com.vitorpamplona.quartz.nip19Bech32.decodePublicKey
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 import com.vitorpamplona.quartz.utils.bytesUsedInMemory
+import com.vitorpamplona.quartz.utils.ensure
 import com.vitorpamplona.quartz.utils.pointerSizeInBytes
 
 @Immutable
@@ -56,20 +58,23 @@ data class ContactTag(
 
     companion object {
         const val TAG_NAME = "p"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun isTagged(tag: Array<String>) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && tag[1].isNotEmpty()
+        fun isTagged(tag: Array<String>) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         @JvmStatic
         fun parse(tag: Array<String>): ContactTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME || tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return ContactTag(tag[1], tag.getOrNull(2), tag.getOrNull(3))
         }
 
         @JvmStatic
         fun parseValid(tag: Array<String>): ContactTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME || tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return try {
                 ContactTag(decodePublicKey(tag[1]).toHexKey(), tag.getOrNull(2), tag.getOrNull(3))
             } catch (e: Exception) {
@@ -80,13 +85,17 @@ data class ContactTag(
 
         @JvmStatic
         fun parseKey(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME || tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return tag[1]
         }
 
         @JvmStatic
         fun parseValidKey(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME || tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return try {
                 decodePublicKey(tag[1]).toHexKey()
             } catch (e: Exception) {
@@ -97,7 +106,10 @@ data class ContactTag(
 
         @JvmStatic
         fun parseAsHint(tag: Array<String>): PubKeyHint? {
-            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != 64 || tag[2].isEmpty()) return null
+            ensure(tag.has(2)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
+            ensure(tag[2].isNotEmpty()) { return null }
             return PubKeyHint(tag[1], tag[2])
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip10Notes/tags/MarkedETag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip10Notes/tags/MarkedETag.kt
index dc150479c..15ecd3494 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip10Notes/tags/MarkedETag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip10Notes/tags/MarkedETag.kt
@@ -22,11 +22,13 @@ package com.vitorpamplona.quartz.nip10Notes.tags
 
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.hints.types.EventIdHint
 import com.vitorpamplona.quartz.nip01Core.tags.events.GenericETag
 import com.vitorpamplona.quartz.nip19Bech32.entities.NEvent
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 import com.vitorpamplona.quartz.utils.bytesUsedInMemory
+import com.vitorpamplona.quartz.utils.ensure
 import com.vitorpamplona.quartz.utils.pointerSizeInBytes
 
 @Immutable
@@ -71,7 +73,7 @@ data class MarkedETag(
 
     companion object {
         const val TAG_NAME = "e"
-        const val TAG_SIZE = 4
+        private const val TAG_SIZE = 4
 
         const val ORDER_NAME = 0
         const val ORDER_EVT_ID = 1
@@ -183,7 +185,10 @@ data class MarkedETag(
 
         @JvmStatic
         fun parseAsHint(tag: Array<String>): EventIdHint? {
-            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != 64 || tag[2].isEmpty()) return null
+            ensure(tag.has(2)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
+            ensure(tag[2].isNotEmpty()) { return null }
             return EventIdHint(tag[1], tag[2])
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip10Notes/tags/Positional.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip10Notes/tags/Positional.kt
index 7b0947b38..d21e0d341 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip10Notes/tags/Positional.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip10Notes/tags/Positional.kt
@@ -48,9 +48,9 @@ fun List<String>.positionalMarkedTags(
     }
 }.map {
     when (it) {
-        root -> arrayOf(tagName, it, "", "root")
-        replyingTo -> arrayOf(tagName, it, "", "reply")
-        forkedFrom -> arrayOf(tagName, it, "", "fork")
+        root -> arrayOf(tagName, it, "", MarkedETag.MARKER.ROOT)
+        replyingTo -> arrayOf(tagName, it, "", MarkedETag.MARKER.REPLY)
+        forkedFrom -> arrayOf(tagName, it, "", MarkedETag.MARKER.FORK)
         else -> arrayOf(tagName, it)
     }
 }
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip13Pow/tags/PoWTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip13Pow/tags/PoWTag.kt
index 8c2fd5510..8b2674324 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip13Pow/tags/PoWTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip13Pow/tags/PoWTag.kt
@@ -20,8 +20,10 @@
  */
 package com.vitorpamplona.quartz.nip13Pow.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 import com.vitorpamplona.quartz.utils.bytesUsedInMemory
+import com.vitorpamplona.quartz.utils.ensure
 import com.vitorpamplona.quartz.utils.pointerSizeInBytes
 
 class PoWTag(
@@ -34,20 +36,23 @@ class PoWTag(
 
     companion object {
         const val TAG_NAME = "nonce"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun hasTagWithContent(tag: Array<String>) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && tag[1].isNotEmpty()
+        fun hasTagWithContent(tag: Array<String>) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         @JvmStatic
         fun parse(tag: Array<String>): PoWTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return PoWTag(tag[1], tag.getOrNull(2)?.toIntOrNull())
         }
 
         @JvmStatic
         fun parseCommitment(tag: Array<String>): Int? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag.getOrNull(2)?.toIntOrNull()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip14Subject/SubjectTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip14Subject/SubjectTag.kt
index 8489b1669..4d8becbb8 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip14Subject/SubjectTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip14Subject/SubjectTag.kt
@@ -20,17 +20,21 @@
  */
 package com.vitorpamplona.quartz.nip14Subject
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class SubjectTag {
     companion object {
         const val TAG_NAME = "subject"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun hasTagWithContent(tag: Array<String>) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && tag[1].isNotEmpty()
+        fun hasTagWithContent(tag: Array<String>) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/EncryptionAlgo.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/EncryptionAlgo.kt
index a44727038..8fe35ea2d 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/EncryptionAlgo.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/EncryptionAlgo.kt
@@ -20,17 +20,21 @@
  */
 package com.vitorpamplona.quartz.nip17Dm.files.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class EncryptionAlgo {
     companion object {
         const val TAG_NAME = "encryption-algorithm"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun isTag(tag: Array<String>) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME
+        fun isTag(tag: Array<String>) = tag.has(1) && tag[0] == TAG_NAME
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/EncryptionKey.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/EncryptionKey.kt
index d3ed47c41..6dbfdf91b 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/EncryptionKey.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/EncryptionKey.kt
@@ -20,20 +20,23 @@
  */
 package com.vitorpamplona.quartz.nip17Dm.files.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.core.hexToByteArray
 import com.vitorpamplona.quartz.nip01Core.core.toHexKey
+import com.vitorpamplona.quartz.utils.ensure
 
 class EncryptionKey {
     companion object {
         const val TAG_NAME = "decryption-key"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun isTag(tag: Array<String>) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME
+        fun isTag(tag: Array<String>) = tag.has(0) && tag[0] == TAG_NAME
 
         @JvmStatic
         fun parse(tag: Array<String>): ByteArray? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return runCatching { tag[1].hexToByteArray() }.getOrNull()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/EncryptionNonce.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/EncryptionNonce.kt
index b34eb627e..1a792a3df 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/EncryptionNonce.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/EncryptionNonce.kt
@@ -20,20 +20,23 @@
  */
 package com.vitorpamplona.quartz.nip17Dm.files.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.core.hexToByteArray
 import com.vitorpamplona.quartz.nip01Core.core.toHexKey
+import com.vitorpamplona.quartz.utils.ensure
 
 class EncryptionNonce {
     companion object {
         const val TAG_NAME = "decryption-nonce"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun isTag(tag: Array<String>) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME
+        fun isTag(tag: Array<String>) = tag.has(0) && tag[0] == TAG_NAME
 
         @JvmStatic
         fun parse(tag: Array<String>): ByteArray? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return runCatching { tag[1].hexToByteArray() }.getOrNull()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/FileTypeTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/FileTypeTag.kt
index 38620fd2d..3cae4c9d3 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/FileTypeTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip17Dm/files/tags/FileTypeTag.kt
@@ -20,19 +20,23 @@
  */
 package com.vitorpamplona.quartz.nip17Dm.files.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class FileTypeTag {
     companion object {
         const val TAG_NAME = "file-type"
-        const val TAG_SIZE = 2
 
         fun isIn(
             tag: Array<String>,
             mimeTypes: Set<String>,
-        ) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && tag[1] in mimeTypes
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] in mimeTypes
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip18Reposts/quotes/QAddressableTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip18Reposts/quotes/QAddressableTag.kt
index a0e4ac3a8..cc78b6f5d 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip18Reposts/quotes/QAddressableTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip18Reposts/quotes/QAddressableTag.kt
@@ -59,13 +59,13 @@ data class QAddressableTag(
     override fun toTagArray() = assemble(address, relay)
 
     companion object {
-        const val TAG_SIZE = 2
+        const val TAG_NAME = "q"
 
         @JvmStatic
         fun parse(tag: Array<String>): QAddressableTag? {
             ensure(tag.has(1)) { return null }
-            ensure(tag[0] == QTag.TAG_NAME) { return null }
-            ensure(tag[1].isNotEmpty()) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length != 64) { return null }
             val address = Address.parse(tag[1]) ?: return null
             return QAddressableTag(address, tag.getOrNull(2))
         }
@@ -76,12 +76,12 @@ data class QAddressableTag(
             pubKeyHex: HexKey,
             dTag: String,
             relay: String?,
-        ) = arrayOfNotNull(QTag.TAG_NAME, Address.assemble(kind, pubKeyHex, dTag), relay)
+        ) = arrayOfNotNull(TAG_NAME, Address.assemble(kind, pubKeyHex, dTag), relay)
 
         @JvmStatic
         fun assemble(
             address: Address,
             relay: String?,
-        ) = arrayOfNotNull(QTag.TAG_NAME, address.toValue(), relay)
+        ) = arrayOfNotNull(TAG_NAME, address.toValue(), relay)
     }
 }
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip18Reposts/quotes/QEventTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip18Reposts/quotes/QEventTag.kt
index 511bb12d0..995890fd0 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip18Reposts/quotes/QEventTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip18Reposts/quotes/QEventTag.kt
@@ -22,8 +22,10 @@ package com.vitorpamplona.quartz.nip18Reposts.quotes
 
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 import com.vitorpamplona.quartz.utils.bytesUsedInMemory
+import com.vitorpamplona.quartz.utils.ensure
 import com.vitorpamplona.quartz.utils.pointerSizeInBytes
 
 @Immutable
@@ -47,11 +49,13 @@ data class QEventTag(
     override fun toTagArray() = assemble(eventId, relay, author)
 
     companion object {
-        const val TAG_SIZE = 2
+        const val TAG_NAME = "q"
 
         @JvmStatic
         fun parse(tag: Array<String>): QEventTag? {
-            if (tag.size < TAG_SIZE || tag[0] != QTag.TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return QEventTag(tag[1], tag.getOrNull(2), tag.getOrNull(3))
         }
 
@@ -60,6 +64,6 @@ data class QEventTag(
             eventId: HexKey,
             relay: String?,
             author: HexKey?,
-        ) = arrayOfNotNull(QTag.TAG_NAME, eventId, relay, author)
+        ) = arrayOfNotNull(TAG_NAME, eventId, relay, author)
     }
 }
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip18Reposts/quotes/QTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip18Reposts/quotes/QTag.kt
index 52e6d1490..5feeab571 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip18Reposts/quotes/QTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip18Reposts/quotes/QTag.kt
@@ -20,35 +20,46 @@
  */
 package com.vitorpamplona.quartz.nip18Reposts.quotes
 
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.hints.types.AddressHint
 import com.vitorpamplona.quartz.nip01Core.hints.types.EventIdHint
+import com.vitorpamplona.quartz.nip01Core.tags.addressables.Address
+import com.vitorpamplona.quartz.utils.ensure
 
 interface QTag {
     fun toTagArray(): Array<String>
 
     companion object {
         const val TAG_NAME = "q"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): QTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
             return if (tag[1].length == 64) {
-                QEventTag.parse(tag)
+                QEventTag(tag[1], tag.getOrNull(2), tag.getOrNull(3))
             } else {
-                QAddressableTag.parse(tag)
+                val address = Address.parse(tag[1]) ?: return null
+                QAddressableTag(address, tag.getOrNull(2))
             }
         }
 
         @JvmStatic
         fun parseEventAsHint(tag: Array<String>): EventIdHint? {
-            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != 64 || tag[2].isEmpty()) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
+            ensure(tag[2].isNotEmpty()) { return null }
             return EventIdHint(tag[1], tag[2])
         }
 
         @JvmStatic
         fun parseAddressAsHint(tag: Array<String>): AddressHint? {
-            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length == 64 || !tag[1].contains(':') || tag[2].isEmpty()) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length != 64) { return null }
+            ensure(tag[2].isNotEmpty()) { return null }
+            ensure(!tag[1].contains(':')) { return null }
             return AddressHint(tag[1], tag[2])
         }
     }
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/CommentEvent.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/CommentEvent.kt
index 83e94ac49..14410a207 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/CommentEvent.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/CommentEvent.kt
@@ -107,8 +107,8 @@ class CommentEvent(
             ?: tags.lastNotNullOfOrNull(RootEventTag::parseKey)
 
     fun replyingToAddressId(): String? =
-        tags.lastNotNullOfOrNull(RootAddressTag::parseAddress)
-            ?: tags.lastNotNullOfOrNull(ReplyAddressTag::parseAddress)
+        tags.lastNotNullOfOrNull(RootAddressTag::parseAddressId)
+            ?: tags.lastNotNullOfOrNull(ReplyAddressTag::parseAddressId)
 
     override fun replyingToAddressOrEvent(): HexKey? = replyingToAddressId() ?: replyingTo()
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyAddressTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyAddressTag.kt
index 9e930bbf3..43933ee44 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyAddressTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyAddressTag.kt
@@ -23,11 +23,11 @@ package com.vitorpamplona.quartz.nip22Comments.tags
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Tag
-import com.vitorpamplona.quartz.nip01Core.core.match
-import com.vitorpamplona.quartz.nip01Core.core.valueIfMatches
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.hints.types.AddressHint
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.Address
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
+import com.vitorpamplona.quartz.utils.ensure
 
 @Immutable
 class ReplyAddressTag(
@@ -38,23 +38,32 @@ class ReplyAddressTag(
 
     companion object {
         const val TAG_NAME = "a"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun match(tag: Tag) = tag.match(TAG_NAME, TAG_SIZE)
+        fun match(tag: Tag) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         @JvmStatic
         fun parse(tag: Array<String>): ReplyAddressTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return ReplyAddressTag(tag[1], tag.getOrNull(2))
         }
 
         @JvmStatic
-        fun parseAddress(tag: Array<String>) = tag.valueIfMatches(TAG_NAME, TAG_SIZE)
+        fun parseAddressId(tag: Array<String>): String? {
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
+            return tag[1]
+        }
 
         @JvmStatic
         fun parseAsHint(tag: Array<String>): AddressHint? {
-            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length == 64 || !tag[1].contains(':') || tag[2].isEmpty()) return null
+            ensure(tag.has(2)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
+            ensure(tag[2].isNotEmpty()) { return null }
             return AddressHint(tag[1], tag[2])
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyAuthorTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyAuthorTag.kt
index 1f647c2d5..c6e8598d7 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyAuthorTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyAuthorTag.kt
@@ -23,10 +23,11 @@ package com.vitorpamplona.quartz.nip22Comments.tags
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Tag
-import com.vitorpamplona.quartz.nip01Core.core.match
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.hints.types.PubKeyHint
 import com.vitorpamplona.quartz.nip01Core.tags.people.PubKeyReferenceTag
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
+import com.vitorpamplona.quartz.utils.ensure
 
 @Immutable
 data class ReplyAuthorTag(
@@ -37,28 +38,32 @@ data class ReplyAuthorTag(
 
     companion object {
         const val TAG_NAME = "p"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun match(tag: Tag) = tag.match(TAG_NAME, TAG_SIZE)
+        fun match(tag: Tag) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         @JvmStatic
         fun parse(tag: Tag): ReplyAuthorTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
-            if (tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return ReplyAuthorTag(tag[1], tag.getOrNull(2))
         }
 
         @JvmStatic
         fun parseKey(tag: Tag): HexKey? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
-            if (tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return tag[1]
         }
 
         @JvmStatic
         fun parseAsHint(tag: Array<String>): PubKeyHint? {
-            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != 64 || tag[2].isEmpty()) return null
+            ensure(tag.has(2)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
+            ensure(tag[2].isNotEmpty()) { return null }
             return PubKeyHint(tag[1], tag[2])
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyEventTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyEventTag.kt
index 77f68fbc4..337e6f35b 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyEventTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyEventTag.kt
@@ -23,11 +23,12 @@ package com.vitorpamplona.quartz.nip22Comments.tags
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Tag
-import com.vitorpamplona.quartz.nip01Core.core.match
-import com.vitorpamplona.quartz.nip01Core.core.valueIfMatches
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.hints.types.EventIdHint
 import com.vitorpamplona.quartz.nip01Core.tags.events.EventReference
+import com.vitorpamplona.quartz.utils.Hex
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
+import com.vitorpamplona.quartz.utils.ensure
 
 @Immutable
 class ReplyEventTag(
@@ -39,42 +40,53 @@ class ReplyEventTag(
 
     companion object {
         const val TAG_NAME = "e"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun match(tag: Tag) = tag.match(TAG_NAME, TAG_SIZE)
+        fun match(tag: Tag) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         @JvmStatic
         fun isTagged(
             tag: Array<String>,
             eventId: String,
-        ) = tag.match(TAG_NAME, eventId, TAG_SIZE)
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] == eventId
 
         @JvmStatic
         fun isIn(
             tag: Array<String>,
             eventIds: Set<String>,
-        ) = tag.match(TAG_NAME, eventIds, TAG_SIZE)
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] in eventIds
 
         @JvmStatic
         fun parse(tag: Array<String>): ReplyEventTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return ReplyEventTag(tag[1], tag.getOrNull(2), tag.getOrNull(3))
         }
 
         @JvmStatic
-        fun parseKey(tag: Array<String>) = tag.valueIfMatches(TAG_NAME, TAG_SIZE)
+        fun parseKey(tag: Array<String>): String? {
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
+            return tag[1]
+        }
 
         @JvmStatic
         fun parseValidKey(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
-            if (tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
+            ensure(Hex.isHex(tag[1])) { return null }
             return tag[1]
         }
 
         @JvmStatic
         fun parseAsHint(tag: Array<String>): EventIdHint? {
-            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != 64 || tag[2].isEmpty()) return null
+            ensure(tag.has(2)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
+            ensure(tag[2].isNotEmpty()) { return null }
             return EventIdHint(tag[1], tag[2])
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyIdentifierTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyIdentifierTag.kt
index 9926fa8ff..f0e2299e8 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyIdentifierTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyIdentifierTag.kt
@@ -22,24 +22,28 @@ package com.vitorpamplona.quartz.nip22Comments.tags
 
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.Tag
-import com.vitorpamplona.quartz.nip01Core.core.match
-import com.vitorpamplona.quartz.nip01Core.core.valueIfMatches
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.tags.geohash.GeoHash
 import com.vitorpamplona.quartz.nip73ExternalIds.ExternalId
 import com.vitorpamplona.quartz.nip73ExternalIds.GeohashId
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
+import com.vitorpamplona.quartz.utils.ensure
 
 @Immutable
 class ReplyIdentifierTag {
     companion object {
         const val TAG_NAME = "i"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun match(tag: Tag) = tag.match(TAG_NAME, TAG_SIZE)
+        fun match(tag: Tag) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         @JvmStatic
-        fun parse(tag: Tag) = tag.valueIfMatches(TAG_NAME, TAG_SIZE)
+        fun parse(tag: Tag): String? {
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
+            return tag[1]
+        }
 
         @JvmStatic
         fun assemble(
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyKindTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyKindTag.kt
index f3a0028ed..43647bcb2 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyKindTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/ReplyKindTag.kt
@@ -21,36 +21,36 @@
 package com.vitorpamplona.quartz.nip22Comments.tags
 
 import com.vitorpamplona.quartz.nip01Core.core.Tag
-import com.vitorpamplona.quartz.nip01Core.core.match
-import com.vitorpamplona.quartz.nip01Core.core.matchAndHasValue
-import com.vitorpamplona.quartz.nip01Core.core.valueToIntIfMatches
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip73ExternalIds.ExternalId
+import com.vitorpamplona.quartz.utils.ensure
 
 class ReplyKindTag {
     companion object {
         const val TAG_NAME = "k"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun match(tag: Tag) = tag.match(TAG_NAME, TAG_SIZE)
-
-        @JvmStatic
-        fun isTagged(tag: Tag) = tag.matchAndHasValue(TAG_NAME, TAG_SIZE)
+        fun match(tag: Tag) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         @JvmStatic
         fun isTagged(
             tag: Tag,
             kind: String,
-        ) = tag.match(TAG_NAME, kind, TAG_SIZE)
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] == kind
 
         @JvmStatic
         fun isIn(
             tag: Tag,
             kinds: Set<String>,
-        ) = tag.match(TAG_NAME, kinds, TAG_SIZE)
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] in kinds
 
         @JvmStatic
-        fun parse(tag: Tag) = tag.valueToIntIfMatches(TAG_NAME, TAG_SIZE)
+        fun parse(tag: Tag): String? {
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
+            return tag[1]
+        }
 
         @JvmStatic
         fun assemble(kind: String) = arrayOf(TAG_NAME, kind)
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootAddressTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootAddressTag.kt
index 3241fbfc6..46263abe2 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootAddressTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootAddressTag.kt
@@ -24,8 +24,6 @@ import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Tag
 import com.vitorpamplona.quartz.nip01Core.core.has
-import com.vitorpamplona.quartz.nip01Core.core.match
-import com.vitorpamplona.quartz.nip01Core.core.valueIfMatches
 import com.vitorpamplona.quartz.nip01Core.hints.types.AddressHint
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.Address
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
@@ -40,26 +38,27 @@ class RootAddressTag(
 
     companion object {
         const val TAG_NAME = "A"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun match(tag: Tag) = tag.match(TAG_NAME, TAG_SIZE)
+        fun match(tag: Tag) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         @JvmStatic
         fun isTagged(
             tag: Array<String>,
             addressId: String,
-        ) = tag.match(TAG_NAME, addressId, TAG_SIZE)
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] == addressId
 
         @JvmStatic
         fun isIn(
             tag: Array<String>,
             addressIds: Set<String>,
-        ) = tag.match(TAG_NAME, addressIds, TAG_SIZE)
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] in addressIds
 
         @JvmStatic
         fun parse(tag: Array<String>): RootAddressTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return RootAddressTag(tag[1], tag.getOrNull(2))
         }
 
@@ -72,11 +71,19 @@ class RootAddressTag(
         }
 
         @JvmStatic
-        fun parseAddress(tag: Array<String>) = tag.valueIfMatches(TAG_NAME, TAG_SIZE)
+        fun parseAddressId(tag: Array<String>): String? {
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
+            return tag[1]
+        }
 
         @JvmStatic
         fun parseAsHint(tag: Array<String>): AddressHint? {
-            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length == 64 || !tag[1].contains(':') || tag[2].isEmpty()) return null
+            ensure(tag.has(2)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
+            ensure(tag[2].isNotEmpty()) { return null }
             return AddressHint(tag[1], tag[2])
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootAuthorTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootAuthorTag.kt
index dcae0d9f9..e548f60bc 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootAuthorTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootAuthorTag.kt
@@ -24,11 +24,11 @@ import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.PUBKEY_LENGTH
 import com.vitorpamplona.quartz.nip01Core.core.Tag
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.hints.types.PubKeyHint
 import com.vitorpamplona.quartz.nip01Core.tags.people.PubKeyReferenceTag
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
-import kotlin.contracts.ExperimentalContracts
-import kotlin.contracts.contract
+import com.vitorpamplona.quartz.utils.ensure
 
 @Immutable
 data class RootAuthorTag(
@@ -41,7 +41,7 @@ data class RootAuthorTag(
         const val TAG_NAME = "P"
 
         @JvmStatic
-        fun match(tag: Tag) = tag.size > 1 && tag[0] == TAG_NAME
+        fun match(tag: Tag) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         @JvmStatic
         fun parse(tag: Tag): ReplyAuthorTag? {
@@ -65,19 +65,13 @@ data class RootAuthorTag(
 
         @JvmStatic
         fun parseAsHint(tag: Array<String>): PubKeyHint? {
-            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != PUBKEY_LENGTH || tag[2].isEmpty()) return null
+            ensure(tag.has(2)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
+            ensure(tag[2].isNotEmpty()) { return null }
             return PubKeyHint(tag[1], tag[2])
         }
 
-        @OptIn(ExperimentalContracts::class)
-        inline fun ensure(
-            condition: Boolean,
-            exit: () -> Nothing,
-        ) {
-            contract { returns() implies condition }
-            if (!condition) exit()
-        }
-
         @JvmStatic
         fun assemble(
             pubkey: HexKey,
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootEventTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootEventTag.kt
index c0d546f92..9796e5ec6 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootEventTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootEventTag.kt
@@ -23,11 +23,12 @@ package com.vitorpamplona.quartz.nip22Comments.tags
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Tag
-import com.vitorpamplona.quartz.nip01Core.core.match
-import com.vitorpamplona.quartz.nip01Core.core.valueIfMatches
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.hints.types.EventIdHint
 import com.vitorpamplona.quartz.nip01Core.tags.events.EventReference
+import com.vitorpamplona.quartz.utils.Hex
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
+import com.vitorpamplona.quartz.utils.ensure
 
 @Immutable
 class RootEventTag(
@@ -39,42 +40,53 @@ class RootEventTag(
 
     companion object {
         const val TAG_NAME = "E"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun match(tag: Tag) = tag.match(TAG_NAME, TAG_SIZE)
+        fun match(tag: Tag) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         @JvmStatic
         fun isTagged(
             tag: Array<String>,
             eventId: String,
-        ) = tag.match(TAG_NAME, eventId, TAG_SIZE)
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] == eventId
 
         @JvmStatic
         fun isIn(
             tag: Array<String>,
             eventIds: Set<String>,
-        ) = tag.match(TAG_NAME, eventIds, TAG_SIZE)
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] in eventIds
 
         @JvmStatic
         fun parse(tag: Array<String>): RootEventTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return RootEventTag(tag[1], tag.getOrNull(2), tag.getOrNull(3))
         }
 
         @JvmStatic
-        fun parseKey(tag: Array<String>) = tag.valueIfMatches(TAG_NAME, TAG_SIZE)
+        fun parseKey(tag: Array<String>): String? {
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
+            return tag[1]
+        }
 
         @JvmStatic
         fun parseValidKey(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
-            if (tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
+            ensure(Hex.isHex(tag[1])) { return null }
             return tag[1]
         }
 
         @JvmStatic
         fun parseAsHint(tag: Array<String>): EventIdHint? {
-            if (tag.size < 3 || tag[0] != TAG_NAME || tag[1].length != 64 || tag[2].isEmpty()) return null
+            ensure(tag.has(2)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
+            ensure(tag[2].isNotEmpty()) { return null }
             return EventIdHint(tag[1], tag[2])
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootIdentifierTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootIdentifierTag.kt
index 34aa37a9d..d896b3e66 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootIdentifierTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootIdentifierTag.kt
@@ -22,24 +22,28 @@ package com.vitorpamplona.quartz.nip22Comments.tags
 
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.Tag
-import com.vitorpamplona.quartz.nip01Core.core.match
-import com.vitorpamplona.quartz.nip01Core.core.valueIfMatches
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.tags.geohash.GeoHash
 import com.vitorpamplona.quartz.nip73ExternalIds.ExternalId
 import com.vitorpamplona.quartz.nip73ExternalIds.GeohashId
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
+import com.vitorpamplona.quartz.utils.ensure
 
 @Immutable
 class RootIdentifierTag {
     companion object {
         const val TAG_NAME = "I"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun match(tag: Tag) = tag.match(TAG_NAME, TAG_SIZE)
+        fun match(tag: Tag) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         @JvmStatic
-        fun parse(tag: Tag) = tag.valueIfMatches(TAG_NAME, TAG_SIZE)
+        fun parse(tag: Tag): String? {
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
+            return tag[1]
+        }
 
         @JvmStatic
         fun assemble(
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootKindTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootKindTag.kt
index bbbe5861d..7a1a31767 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootKindTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip22Comments/tags/RootKindTag.kt
@@ -21,20 +21,24 @@
 package com.vitorpamplona.quartz.nip22Comments.tags
 
 import com.vitorpamplona.quartz.nip01Core.core.Tag
-import com.vitorpamplona.quartz.nip01Core.core.match
-import com.vitorpamplona.quartz.nip01Core.core.valueIfMatches
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip73ExternalIds.ExternalId
+import com.vitorpamplona.quartz.utils.ensure
 
 class RootKindTag {
     companion object {
         const val TAG_NAME = "K"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun match(tag: Tag) = tag.match(TAG_NAME, TAG_SIZE)
+        fun match(tag: Tag) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         @JvmStatic
-        fun parse(tag: Tag) = tag.valueIfMatches(TAG_NAME, TAG_SIZE)
+        fun parse(tag: Tag): String? {
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
+            return tag[1]
+        }
 
         @JvmStatic
         fun assemble(kind: String): Tag = arrayOf(TAG_NAME, kind)
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/tags/ImageTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/tags/ImageTag.kt
index d7e74286e..0ab6c6714 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/tags/ImageTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/tags/ImageTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip23LongContent.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class ImageTag {
     companion object {
         const val TAG_NAME = "image"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/tags/PublishedAtTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/tags/PublishedAtTag.kt
index 671348f27..21f33adb4 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/tags/PublishedAtTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/tags/PublishedAtTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip23LongContent.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class PublishedAtTag {
     companion object {
         const val TAG_NAME = "published_at"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): Long? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1].toLongOrNull()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/tags/SummaryTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/tags/SummaryTag.kt
index 1e04d3b56..6acbac79d 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/tags/SummaryTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/tags/SummaryTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip23LongContent.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class SummaryTag {
     companion object {
         const val TAG_NAME = "summary"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/tags/TitleTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/tags/TitleTag.kt
index 409c4eb1d..77b6ab6d6 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/tags/TitleTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip23LongContent/tags/TitleTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip23LongContent.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class TitleTag {
     companion object {
         const val TAG_NAME = "title"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip31Alts/AltTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip31Alts/AltTag.kt
index b28d37465..8a7df1c4a 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip31Alts/AltTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip31Alts/AltTag.kt
@@ -20,18 +20,22 @@
  */
 package com.vitorpamplona.quartz.nip31Alts
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class AltTag {
     companion object {
         const val TAG_NAME = "alt"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
         @JvmStatic
-        fun assemble(altDescriptor: String = "") = arrayOf(TAG_NAME, altDescriptor)
+        fun assemble(altDescriptor: String) = arrayOf(TAG_NAME, altDescriptor)
     }
 }
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/repository/tags/CloneTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/repository/tags/CloneTag.kt
index 47b1e1f18..b4a95634e 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/repository/tags/CloneTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/repository/tags/CloneTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip34Git.repository.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class CloneTag {
     companion object {
         const val TAG_NAME = "clone"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/repository/tags/DescriptionTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/repository/tags/DescriptionTag.kt
index 4256d7efe..faea7e0d8 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/repository/tags/DescriptionTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/repository/tags/DescriptionTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip34Git.repository.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class DescriptionTag {
     companion object {
         const val TAG_NAME = "description"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/repository/tags/NameTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/repository/tags/NameTag.kt
index 8fc6aff04..147b52d35 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/repository/tags/NameTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/repository/tags/NameTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip34Git.repository.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class NameTag {
     companion object {
         const val TAG_NAME = "name"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/repository/tags/WebTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/repository/tags/WebTag.kt
index 5c5445856..3dae53fa3 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/repository/tags/WebTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip34Git/repository/tags/WebTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip34Git.repository.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class WebTag {
     companion object {
         const val TAG_NAME = "web"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/tags/BtihTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/tags/BtihTag.kt
index 85697ae11..47feee58c 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/tags/BtihTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/tags/BtihTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip35Torrents.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class BtihTag {
     companion object {
         const val TAG_NAME = "btih"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/tags/FileTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/tags/FileTag.kt
index 895eb423c..0639907fe 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/tags/FileTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/tags/FileTag.kt
@@ -21,7 +21,9 @@
 package com.vitorpamplona.quartz.nip35Torrents.tags
 
 import androidx.compose.runtime.Immutable
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip46RemoteSigner.getOrNull
+import com.vitorpamplona.quartz.utils.ensure
 
 @Immutable
 class FileTag(
@@ -32,18 +34,21 @@ class FileTag(
 
     companion object {
         const val TAG_NAME = "file"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): FileTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return FileTag(tag[1], tag.getOrNull(2)?.toLongOrNull())
         }
 
         @JvmStatic
         fun parseBytes(tag: Array<String>): Long? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
-            return tag.getOrNull(2)?.toLongOrNull()
+            ensure(tag.has(2)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[2].isNotEmpty()) { return null }
+            return tag[2].toLongOrNull()
         }
 
         @JvmStatic
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/tags/InfoHashTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/tags/InfoHashTag.kt
index 744aad94d..1e0786ebf 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/tags/InfoHashTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/tags/InfoHashTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip35Torrents.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class InfoHashTag {
     companion object {
         const val TAG_NAME = "x"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/tags/TrackerTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/tags/TrackerTag.kt
index 8282c3670..4e154418e 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/tags/TrackerTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip35Torrents/tags/TrackerTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip35Torrents.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class TrackerTag {
     companion object {
         const val TAG_NAME = "tracker"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/CurrentParticipantsTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/CurrentParticipantsTag.kt
index 934a4637b..fb1b44148 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/CurrentParticipantsTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/CurrentParticipantsTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip53LiveActivities.streaming.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class CurrentParticipantsTag {
     companion object {
         const val TAG_NAME = "current_participants"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): Int? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1].toIntOrNull()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/EndsTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/EndsTag.kt
index 0597b1d54..26d212547 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/EndsTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/EndsTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip53LiveActivities.streaming.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class EndsTag {
     companion object {
         const val TAG_NAME = "ends"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): Long? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1].toLongOrNull()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/ParticipantTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/ParticipantTag.kt
index a77348d0d..c48c004c3 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/ParticipantTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/ParticipantTag.kt
@@ -23,9 +23,10 @@ package com.vitorpamplona.quartz.nip53LiveActivities.streaming.tags
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Tag
-import com.vitorpamplona.quartz.nip01Core.core.isNotName
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.tags.people.PubKeyReferenceTag
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
+import com.vitorpamplona.quartz.utils.ensure
 
 enum class ROLE(
     val code: String,
@@ -43,40 +44,43 @@ data class ParticipantTag(
 ) : PubKeyReferenceTag {
     companion object {
         const val TAG_NAME = "p"
-        const val TAG_SIZE = 2
 
         fun isIn(
             tag: Array<String>,
             keys: Set<HexKey>,
-        ) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && tag[1] in keys
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] in keys
 
         @JvmStatic
         fun isHost(tag: Tag): Boolean {
-            if (tag.isNotName(TAG_NAME, TAG_SIZE)) return false
-            if (tag[1].length != 64) return false
-            if (tag.getOrNull(3).equals(ROLE.HOST.code)) return true
-            return false
+            ensure(tag.has(3)) { return false }
+            ensure(tag[0] == TAG_NAME) { return false }
+            ensure(tag[1].length == 64) { return false }
+            ensure(tag[3] == ROLE.HOST.code) { return false }
+            return true
         }
 
         @JvmStatic
         fun parse(tag: Tag): ParticipantTag? {
-            if (tag.isNotName(TAG_NAME, TAG_SIZE)) return null
-            if (tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return ParticipantTag(tag[1], tag.getOrNull(2), tag.getOrNull(3), tag.getOrNull(4))
         }
 
         @JvmStatic
         fun parseHost(tag: Tag): ParticipantTag? {
-            if (tag.isNotName(TAG_NAME, TAG_SIZE)) return null
-            if (tag[1].length != 64) return null
-            if (!tag.getOrNull(3).equals(ROLE.HOST.code)) return null
-            return ParticipantTag(tag[1], tag.getOrNull(2), tag.getOrNull(3), tag.getOrNull(4))
+            ensure(tag.has(3)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
+            ensure(tag[3] == ROLE.HOST.code) { return null }
+            return ParticipantTag(tag[1], tag[2], tag[3], tag.getOrNull(4))
         }
 
         @JvmStatic
         fun parseKey(tag: Tag): String? {
-            if (tag.isNotName(TAG_NAME, TAG_SIZE)) return null
-            if (tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/RelayListTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/RelayListTag.kt
index fda64e467..70627f607 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/RelayListTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/RelayListTag.kt
@@ -20,16 +20,20 @@
  */
 package com.vitorpamplona.quartz.nip53LiveActivities.streaming.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class RelayListTag(
     val relayUrls: List<String>,
 ) {
     companion object {
         const val TAG_NAME = "relays"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): RelayListTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             val relays =
                 tag.mapIndexedNotNull { index, s ->
                     if (index == 0) null else s
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/StartsTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/StartsTag.kt
index 8c6cb4488..7a094d643 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/StartsTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/StartsTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip53LiveActivities.streaming.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class StartsTag {
     companion object {
         const val TAG_NAME = "starts"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): Long? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1].toLongOrNull()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/StatusTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/StatusTag.kt
index d6e651b9e..f41dcfc05 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/StatusTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/StatusTag.kt
@@ -20,6 +20,9 @@
  */
 package com.vitorpamplona.quartz.nip53LiveActivities.streaming.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class StatusTag {
     enum class STATUS(
         val code: String,
@@ -34,11 +37,12 @@ class StatusTag {
 
     companion object {
         const val TAG_NAME = "status"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/StreamingTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/StreamingTag.kt
index 7303e1a44..667cf742e 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/StreamingTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/StreamingTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip53LiveActivities.streaming.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class StreamingTag {
     companion object {
         const val TAG_NAME = "streaming"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/TotalParticipantsTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/TotalParticipantsTag.kt
index 52bbeac76..ac34c4bf6 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/TotalParticipantsTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip53LiveActivities/streaming/tags/TotalParticipantsTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip53LiveActivities.streaming.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class TotalParticipantsTag {
     companion object {
         const val TAG_NAME = "total_participants"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): Int? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1].toIntOrNull()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip57Zaps/zapraiser/ZapRaiserTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip57Zaps/zapraiser/ZapRaiserTag.kt
index 192ade51d..66feb1396 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip57Zaps/zapraiser/ZapRaiserTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip57Zaps/zapraiser/ZapRaiserTag.kt
@@ -31,7 +31,7 @@ class ZapRaiserTag(
     fun toTagArray() = assemble(amountInSats)
 
     companion object {
-        val TAG_NAME = "zapraiser"
+        const val TAG_NAME = "zapraiser"
 
         @JvmStatic
         fun parse(tags: Array<String>): ZapRaiserTag? {
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip71Video/tags/DurationTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip71Video/tags/DurationTag.kt
index 4e4fed010..fc378cc8a 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip71Video/tags/DurationTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip71Video/tags/DurationTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip71Video.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class DurationTag {
     companion object {
         const val TAG_NAME = "duration"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): Int? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1].toIntOrNull()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip71Video/tags/SegmentTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip71Video/tags/SegmentTag.kt
index 6feb0fea0..2d4a09bd4 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip71Video/tags/SegmentTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip71Video/tags/SegmentTag.kt
@@ -20,7 +20,9 @@
  */
 package com.vitorpamplona.quartz.nip71Video.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
+import com.vitorpamplona.quartz.utils.ensure
 
 class SegmentTag(
     val start: String, // HH:MM:SS.sss
@@ -32,11 +34,14 @@ class SegmentTag(
 
     companion object {
         const val TAG_NAME = "segment"
-        const val TAG_SIZE = 4
 
         @JvmStatic
         fun parse(tag: Array<String>): SegmentTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(3)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
+            ensure(tag[2].isNotEmpty()) { return null }
+            ensure(tag[3].isNotEmpty()) { return null }
             return SegmentTag(tag[1], tag[2], tag[3], tag.getOrNull(4))
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip71Video/tags/TextTrackTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip71Video/tags/TextTrackTag.kt
index 1f0680f46..a624e0c09 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip71Video/tags/TextTrackTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip71Video/tags/TextTrackTag.kt
@@ -21,8 +21,10 @@
 package com.vitorpamplona.quartz.nip71Video.tags
 
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 import com.vitorpamplona.quartz.utils.bytesUsedInMemory
+import com.vitorpamplona.quartz.utils.ensure
 import com.vitorpamplona.quartz.utils.pointerSizeInBytes
 
 data class TextTrackTag(
@@ -38,11 +40,12 @@ data class TextTrackTag(
 
     companion object {
         const val TAG_NAME = "text-track"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): TextTrackTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return TextTrackTag(tag[1], tag.getOrNull(2))
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/DescriptionTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/DescriptionTag.kt
index 84a2edb9d..5e76b7ed9 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/DescriptionTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/DescriptionTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip72ModCommunities.definition.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class DescriptionTag {
     companion object {
         const val TAG_NAME = "description"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/ImageTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/ImageTag.kt
index 9bae1d46a..2f3a7dbe3 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/ImageTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/ImageTag.kt
@@ -20,8 +20,10 @@
  */
 package com.vitorpamplona.quartz.nip72ModCommunities.definition.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip94FileMetadata.tags.DimensionTag
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
+import com.vitorpamplona.quartz.utils.ensure
 
 class ImageTag(
     val imageUrl: String,
@@ -29,12 +31,12 @@ class ImageTag(
 ) {
     companion object {
         const val TAG_NAME = "image"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): ImageTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
-            if (tag[1].isEmpty()) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             val dims = tag.getOrNull(2)?.let { DimensionTag.parse(it) }
             return ImageTag(tag[1], dims)
         }
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/ModeratorTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/ModeratorTag.kt
index 08d901cc2..ddd2b46a2 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/ModeratorTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/ModeratorTag.kt
@@ -23,9 +23,10 @@ package com.vitorpamplona.quartz.nip72ModCommunities.definition.tags
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
 import com.vitorpamplona.quartz.nip01Core.core.Tag
-import com.vitorpamplona.quartz.nip01Core.core.isNotName
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.tags.people.PubKeyReferenceTag
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
+import com.vitorpamplona.quartz.utils.ensure
 
 @Immutable
 data class ModeratorTag(
@@ -37,19 +38,20 @@ data class ModeratorTag(
 
     companion object {
         const val TAG_NAME = "p"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Tag): ModeratorTag? {
-            if (tag.isNotName(TAG_NAME, TAG_SIZE)) return null
-            if (tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return ModeratorTag(tag[1], tag.getOrNull(2), tag.getOrNull(3))
         }
 
         @JvmStatic
         fun parseKey(tag: Tag): String? {
-            if (tag.isNotName(TAG_NAME, TAG_SIZE)) return null
-            if (tag[1].length != 64) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].length == 64) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/NameTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/NameTag.kt
index 0c66da66d..5f23b0f82 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/NameTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/NameTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip72ModCommunities.definition.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class NameTag {
     companion object {
         const val TAG_NAME = "name"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/RelayTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/RelayTag.kt
index a70f2f7d9..6e5c4dd14 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/RelayTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/RelayTag.kt
@@ -20,7 +20,9 @@
  */
 package com.vitorpamplona.quartz.nip72ModCommunities.definition.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
+import com.vitorpamplona.quartz.utils.ensure
 
 class RelayTag(
     val url: String,
@@ -30,11 +32,12 @@ class RelayTag(
 
     companion object {
         const val TAG_NAME = "relay"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): RelayTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return RelayTag(tag[1], tag.getOrNull(2))
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/RulesTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/RulesTag.kt
index 467216f8f..3908eca08 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/RulesTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip72ModCommunities/definition/tags/RulesTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip72ModCommunities.definition.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class RulesTag {
     companion object {
         const val TAG_NAME = "rules"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip75ZapGoals/tags/AmountTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip75ZapGoals/tags/AmountTag.kt
index e5c24cae3..177c985ab 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip75ZapGoals/tags/AmountTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip75ZapGoals/tags/AmountTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip75ZapGoals.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class AmountTag {
     companion object {
         const val TAG_NAME = "amount"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): Long? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1].toLongOrNull()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip75ZapGoals/tags/ClosedAtTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip75ZapGoals/tags/ClosedAtTag.kt
index 2fbd2a885..2af7ec8d6 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip75ZapGoals/tags/ClosedAtTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip75ZapGoals/tags/ClosedAtTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip75ZapGoals.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class ClosedAtTag {
     companion object {
         const val TAG_NAME = "closed_at"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): Long? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1].toLongOrNull()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip75ZapGoals/tags/RelayListTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip75ZapGoals/tags/RelayListTag.kt
index bb5c0811a..9f49ce761 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip75ZapGoals/tags/RelayListTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip75ZapGoals/tags/RelayListTag.kt
@@ -20,16 +20,20 @@
  */
 package com.vitorpamplona.quartz.nip75ZapGoals.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class RelayListTag(
     val relayUrls: List<String>,
 ) {
     companion object {
         const val TAG_NAME = "relays"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): RelayListTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             val relays =
                 tag.mapIndexedNotNull { index, s ->
                     if (index == 0) null else s
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip84Highlights/tags/ContextTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip84Highlights/tags/ContextTag.kt
index 6e46a32e7..80daa368f 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip84Highlights/tags/ContextTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip84Highlights/tags/ContextTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip84Highlights.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class ContextTag {
     companion object {
         const val TAG_NAME = "context"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip89AppHandlers/definition/tags/PlatformLinkTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip89AppHandlers/definition/tags/PlatformLinkTag.kt
index 94f5f798d..8c18bf480 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip89AppHandlers/definition/tags/PlatformLinkTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip89AppHandlers/definition/tags/PlatformLinkTag.kt
@@ -21,6 +21,7 @@
 package com.vitorpamplona.quartz.nip89AppHandlers.definition.tags
 
 import com.vitorpamplona.quartz.nip01Core.core.Tag
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip89AppHandlers.PlatformType
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 
@@ -32,14 +33,10 @@ class PlatformLinkTag(
     fun toTagArray() = assemble(platform, uri, entityType)
 
     companion object {
-        const val TAG_SIZE = 3
-
         @JvmStatic
         fun match(tag: Tag): Boolean =
-            if (tag.size >= TAG_SIZE) {
-                tag[0] == PlatformType.IOS.code ||
-                    tag[0] == PlatformType.WEB.code ||
-                    tag[0] == PlatformType.ANDROID.code
+            if (tag.has(2)) {
+                tag[0] == PlatformType.IOS.code || tag[0] == PlatformType.WEB.code || tag[0] == PlatformType.ANDROID.code
             } else {
                 false
             }
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip89AppHandlers/recommendation/AppRecommendationEvent.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip89AppHandlers/recommendation/AppRecommendationEvent.kt
index 0b3db29b5..4b98181e7 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip89AppHandlers/recommendation/AppRecommendationEvent.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip89AppHandlers/recommendation/AppRecommendationEvent.kt
@@ -43,7 +43,7 @@ class AppRecommendationEvent(
 ) : BaseAddressableEvent(id, pubKey, createdAt, KIND, tags, content, sig) {
     fun recommendations() = tags.mapNotNull(RecommendationTag::parse)
 
-    fun recommendationAddresses() = tags.mapNotNull(RecommendationTag::parseAddress)
+    fun recommendationAddresses() = tags.mapNotNull(RecommendationTag::parseAddressId)
 
     companion object {
         const val KIND = 31989
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip89AppHandlers/recommendation/tags/RecommendationTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip89AppHandlers/recommendation/tags/RecommendationTag.kt
index 045510e69..22c8fea76 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip89AppHandlers/recommendation/tags/RecommendationTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip89AppHandlers/recommendation/tags/RecommendationTag.kt
@@ -23,8 +23,6 @@ package com.vitorpamplona.quartz.nip89AppHandlers.recommendation.tags
 import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.nip01Core.core.Tag
 import com.vitorpamplona.quartz.nip01Core.core.has
-import com.vitorpamplona.quartz.nip01Core.core.match
-import com.vitorpamplona.quartz.nip01Core.core.valueIfMatches
 import com.vitorpamplona.quartz.nip01Core.tags.addressables.Address
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
 import com.vitorpamplona.quartz.utils.ensure
@@ -39,10 +37,9 @@ class RecommendationTag(
 
     companion object {
         const val TAG_NAME = "a"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun match(tag: Tag) = tag.match(TAG_NAME, TAG_SIZE)
+        fun match(tag: Tag) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         @JvmStatic
         fun parse(tag: Array<String>): RecommendationTag? {
@@ -54,7 +51,12 @@ class RecommendationTag(
         }
 
         @JvmStatic
-        fun parseAddress(tag: Array<String>) = tag.valueIfMatches(TAG_NAME, TAG_SIZE)
+        fun parseAddressId(tag: Array<String>): String? {
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
+            return tag[1]
+        }
 
         @JvmStatic
         fun assemble(
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip92IMeta/IMetaTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip92IMeta/IMetaTag.kt
index 7f8c1c8d1..1c7d89153 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip92IMeta/IMetaTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip92IMeta/IMetaTag.kt
@@ -20,6 +20,9 @@
  */
 package com.vitorpamplona.quartz.nip92IMeta
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class IMetaTag(
     val url: String,
     val properties: Map<String, List<String>>,
@@ -38,10 +41,11 @@ class IMetaTag(
     companion object {
         const val TAG_NAME = "imeta"
         const val ANCHOR_PROPERTY = "url"
-        const val TAG_SIZE = 2
 
         fun parse(tag: Array<String>): IMetaTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
 
             val allTags = parseIMeta(tag)
             val url = allTags.get(ANCHOR_PROPERTY)?.firstOrNull()
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/BlurhashTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/BlurhashTag.kt
index 329314d84..57c646976 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/BlurhashTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/BlurhashTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip94FileMetadata.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class BlurhashTag {
     companion object {
         const val TAG_NAME = "blurhash"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/DimensionTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/DimensionTag.kt
index dcfd011ca..515b7c916 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/DimensionTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/DimensionTag.kt
@@ -20,6 +20,9 @@
  */
 package com.vitorpamplona.quartz.nip94FileMetadata.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class DimensionTag(
     val width: Int,
     val height: Int,
@@ -34,11 +37,12 @@ class DimensionTag(
 
     companion object {
         const val TAG_NAME = "dim"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): DimensionTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return parse(tag[1])
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/FallbackTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/FallbackTag.kt
index 4eca6fd06..b00bfc43c 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/FallbackTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/FallbackTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip94FileMetadata.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class FallbackTag {
     companion object {
         const val TAG_NAME = "fallback"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/HashSha256Tag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/HashSha256Tag.kt
index 9880e9162..adf394c3a 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/HashSha256Tag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/HashSha256Tag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip94FileMetadata.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class HashSha256Tag {
     companion object {
         const val TAG_NAME = "x"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME || tag[1].isEmpty()) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/ImageTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/ImageTag.kt
index 7aa7274a2..f8423bd3e 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/ImageTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/ImageTag.kt
@@ -21,7 +21,9 @@
 package com.vitorpamplona.quartz.nip94FileMetadata.tags
 
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
+import com.vitorpamplona.quartz.utils.ensure
 
 class ImageTag(
     val imageUrl: String,
@@ -29,11 +31,12 @@ class ImageTag(
 ) {
     companion object {
         const val TAG_NAME = "image"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): ImageTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return ImageTag(tag[1], tag.getOrNull(2))
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/MagnetTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/MagnetTag.kt
index 9bd916cd7..d608a6f64 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/MagnetTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/MagnetTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip94FileMetadata.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class MagnetTag {
     companion object {
         const val TAG_NAME = "magnet"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/MimeTypeTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/MimeTypeTag.kt
index 416b3f0a1..c0555f089 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/MimeTypeTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/MimeTypeTag.kt
@@ -20,19 +20,23 @@
  */
 package com.vitorpamplona.quartz.nip94FileMetadata.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class MimeTypeTag {
     companion object {
         const val TAG_NAME = "m"
-        const val TAG_SIZE = 2
 
         fun isIn(
             tag: Array<String>,
             mimeTypes: Set<String>,
-        ) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME && tag[1] in mimeTypes
+        ) = tag.has(1) && tag[0] == TAG_NAME && tag[1] in mimeTypes
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/OriginalHashTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/OriginalHashTag.kt
index 6cc31f954..f17d01e75 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/OriginalHashTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/OriginalHashTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip94FileMetadata.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class OriginalHashTag {
     companion object {
         const val TAG_NAME = "ox"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/ServiceTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/ServiceTag.kt
index ca4703c05..18c6a9315 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/ServiceTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/ServiceTag.kt
@@ -20,17 +20,21 @@
  */
 package com.vitorpamplona.quartz.nip94FileMetadata.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class ServiceTag {
     companion object {
         const val TAG_NAME = "service"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun isTag(tag: Array<String>) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME
+        fun isTag(tag: Array<String>) = tag.has(0) && tag[0] == TAG_NAME
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/SizeTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/SizeTag.kt
index 4548ea5f5..645a77d1f 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/SizeTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/SizeTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip94FileMetadata.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class SizeTag {
     companion object {
         const val TAG_NAME = "size"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): Int? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1].toIntOrNull()
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/SummaryTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/SummaryTag.kt
index b854ab7a6..b0a405fca 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/SummaryTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/SummaryTag.kt
@@ -20,17 +20,21 @@
  */
 package com.vitorpamplona.quartz.nip94FileMetadata.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class SummaryTag {
     companion object {
         const val TAG_NAME = "summary"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun isTag(tag: Array<String>) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME
+        fun isTag(tag: Array<String>) = tag.has(1) && tag[0] == TAG_NAME
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/ThumbTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/ThumbTag.kt
index e11faa1be..52e53e202 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/ThumbTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/ThumbTag.kt
@@ -21,7 +21,9 @@
 package com.vitorpamplona.quartz.nip94FileMetadata.tags
 
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
+import com.vitorpamplona.quartz.utils.ensure
 
 class ThumbTag(
     val imageUrl: String,
@@ -29,11 +31,12 @@ class ThumbTag(
 ) {
     companion object {
         const val TAG_NAME = "thumb"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): ThumbTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return ThumbTag(tag[1], tag.getOrNull(2))
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/TorrentInfoHash.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/TorrentInfoHash.kt
index 93b87b03e..4ea1a7d4b 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/TorrentInfoHash.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/TorrentInfoHash.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip94FileMetadata.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class TorrentInfoHash {
     companion object {
         const val TAG_NAME = "i"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/UrlTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/UrlTag.kt
index 4be128be8..05bcd0a91 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/UrlTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip94FileMetadata/tags/UrlTag.kt
@@ -20,17 +20,21 @@
  */
 package com.vitorpamplona.quartz.nip94FileMetadata.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class UrlTag {
     companion object {
         const val TAG_NAME = "url"
-        const val TAG_SIZE = 2
 
         @JvmStatic
-        fun isTag(tag: Array<String>) = tag.size >= TAG_SIZE && tag[0] == TAG_NAME
+        fun isTag(tag: Array<String>) = tag.has(1) && tag[0] == TAG_NAME && tag[1].isNotEmpty()
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip96FileStorage/config/tags/ServerTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip96FileStorage/config/tags/ServerTag.kt
index 4e326bb9d..2b926fb6e 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip96FileStorage/config/tags/ServerTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip96FileStorage/config/tags/ServerTag.kt
@@ -20,16 +20,20 @@
  */
 package com.vitorpamplona.quartz.nip96FileStorage.config.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class ServerTag {
     companion object {
         const val TAG_NAME = "server"
-        const val TAG_SIZE = 2
 
         fun isTag(tag: Array<String>) = tag[0] == TAG_NAME
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip98HttpAuth/tags/MethodTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip98HttpAuth/tags/MethodTag.kt
index 5459cfdf5..bd127fd4f 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip98HttpAuth/tags/MethodTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip98HttpAuth/tags/MethodTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip98HttpAuth.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class MethodTag {
     companion object {
         const val TAG_NAME = "method"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip98HttpAuth/tags/PayloadHashTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip98HttpAuth/tags/PayloadHashTag.kt
index f8ae6d583..1c342f818 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip98HttpAuth/tags/PayloadHashTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip98HttpAuth/tags/PayloadHashTag.kt
@@ -21,17 +21,20 @@
 package com.vitorpamplona.quartz.nip98HttpAuth.tags
 
 import com.vitorpamplona.quartz.nip01Core.core.HexKey
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.nip01Core.core.toHexKey
+import com.vitorpamplona.quartz.utils.ensure
 import com.vitorpamplona.quartz.utils.sha256.sha256
 
 class PayloadHashTag {
     companion object {
         const val TAG_NAME = "payload"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): HexKey? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip98HttpAuth/tags/UrlTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip98HttpAuth/tags/UrlTag.kt
index a8f1afd40..1895606d7 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip98HttpAuth/tags/UrlTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip98HttpAuth/tags/UrlTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip98HttpAuth.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class UrlTag {
     companion object {
         const val TAG_NAME = "u"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip99Classifieds/tags/ConditionTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip99Classifieds/tags/ConditionTag.kt
index 658a694c6..2071cf817 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip99Classifieds/tags/ConditionTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip99Classifieds/tags/ConditionTag.kt
@@ -20,6 +20,9 @@
  */
 package com.vitorpamplona.quartz.nip99Classifieds.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class ConditionTag {
     enum class CONDITION(
         val value: String,
@@ -35,11 +38,12 @@ class ConditionTag {
 
     companion object {
         const val TAG_NAME = "condition"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip99Classifieds/tags/LocationTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip99Classifieds/tags/LocationTag.kt
index 1d8966ef1..1a7efcd9e 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip99Classifieds/tags/LocationTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip99Classifieds/tags/LocationTag.kt
@@ -20,14 +20,18 @@
  */
 package com.vitorpamplona.quartz.nip99Classifieds.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class LocationTag {
     companion object {
         const val TAG_NAME = "location"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip99Classifieds/tags/PriceTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip99Classifieds/tags/PriceTag.kt
index 48c2e4801..e432aef23 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip99Classifieds/tags/PriceTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip99Classifieds/tags/PriceTag.kt
@@ -20,7 +20,9 @@
  */
 package com.vitorpamplona.quartz.nip99Classifieds.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
 import com.vitorpamplona.quartz.utils.arrayOfNotNull
+import com.vitorpamplona.quartz.utils.ensure
 
 data class PriceTag(
     val amount: String,
@@ -31,11 +33,12 @@ data class PriceTag(
 
     companion object {
         const val TAG_NAME = "price"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): PriceTag? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return PriceTag(tag[1], tag.getOrNull(2), tag.getOrNull(3))
         }
 
diff --git a/quartz/src/main/java/com/vitorpamplona/quartz/nip99Classifieds/tags/StatusTag.kt b/quartz/src/main/java/com/vitorpamplona/quartz/nip99Classifieds/tags/StatusTag.kt
index d4365b82f..149cc9c74 100644
--- a/quartz/src/main/java/com/vitorpamplona/quartz/nip99Classifieds/tags/StatusTag.kt
+++ b/quartz/src/main/java/com/vitorpamplona/quartz/nip99Classifieds/tags/StatusTag.kt
@@ -20,6 +20,9 @@
  */
 package com.vitorpamplona.quartz.nip99Classifieds.tags
 
+import com.vitorpamplona.quartz.nip01Core.core.has
+import com.vitorpamplona.quartz.utils.ensure
+
 class StatusTag {
     enum class STATUS(
         val value: String,
@@ -33,11 +36,12 @@ class StatusTag {
 
     companion object {
         const val TAG_NAME = "status"
-        const val TAG_SIZE = 2
 
         @JvmStatic
         fun parse(tag: Array<String>): String? {
-            if (tag.size < TAG_SIZE || tag[0] != TAG_NAME) return null
+            ensure(tag.has(1)) { return null }
+            ensure(tag[0] == TAG_NAME) { return null }
+            ensure(tag[1].isNotEmpty()) { return null }
             return tag[1]
         }