diff --git a/negentropy/negentropy.go b/negentropy/negentropy.go
index adf8b75..0a66f4f 100644
--- a/negentropy/negentropy.go
+++ b/negentropy/negentropy.go
@@ -6,7 +6,6 @@ import (
 	"fmt"
 	"math"
 	"os"
-	"slices"
 	"unsafe"
 
 	"github.com/nbd-wtf/go-nostr"
@@ -26,15 +25,16 @@ type Negentropy struct {
 	isInitiator      bool
 	lastTimestampIn  nostr.Timestamp
 	lastTimestampOut nostr.Timestamp
-	haveIds          []string
-	needIds          []string
+
+	Haves    chan string
+	HaveNots chan string
 }
 
-func NewNegentropy(storage Storage, frameSizeLimit int) (*Negentropy, error) {
+func NewNegentropy(storage Storage, frameSizeLimit int) *Negentropy {
 	return &Negentropy{
 		storage:        storage,
 		frameSizeLimit: frameSizeLimit,
-	}, nil
+	}
 }
 
 func (n *Negentropy) Insert(evt *nostr.Event) {
@@ -55,8 +55,8 @@ func (n *Negentropy) Initiate() []byte {
 	n.seal()
 	n.isInitiator = true
 
-	n.haveIds = make([]string, 0, n.storage.Size()/2)
-	n.needIds = make([]string, 0, n.storage.Size()/2)
+	n.Haves = make(chan string, n.storage.Size()/2)
+	n.HaveNots = make(chan string, n.storage.Size()/2)
 
 	output := bytes.NewBuffer(make([]byte, 0, 1+n.storage.Size()*32))
 	output.WriteByte(protocolVersion)
@@ -65,22 +65,22 @@ func (n *Negentropy) Initiate() []byte {
 	return output.Bytes()
 }
 
-func (n *Negentropy) Reconcile(step int, query []byte) (output []byte, haveIds []string, needIds []string, err error) {
+func (n *Negentropy) Reconcile(step int, query []byte) (output []byte, err error) {
 	n.seal()
 	reader := bytes.NewReader(query)
 
 	output, err = n.reconcileAux(step, reader)
 	if err != nil {
-		return nil, nil, nil, err
+		return nil, err
 	}
 
 	if len(output) == 1 && n.isInitiator {
-		slices.Sort(n.haveIds)
-		slices.Sort(n.needIds)
-		return nil, n.haveIds, n.needIds, nil
+		close(n.Haves)
+		close(n.HaveNots)
+		return nil, nil
 	}
 
-	return output, nil, nil, nil
+	return output, nil
 }
 
 func (n *Negentropy) reconcileAux(step int, reader *bytes.Reader) ([]byte, error) {
@@ -178,7 +178,7 @@ func (n *Negentropy) reconcileAux(step int, reader *bytes.Reader) ([]byte, error
 				id := item.ID
 				if _, exists := theirElems[id]; !exists {
 					if n.isInitiator {
-						n.haveIds = append(n.haveIds, id)
+						n.Haves <- id
 					}
 				} else {
 					delete(theirElems, id)
@@ -189,7 +189,7 @@ func (n *Negentropy) reconcileAux(step int, reader *bytes.Reader) ([]byte, error
 			if n.isInitiator {
 				skip = true
 				for id := range theirElems {
-					n.needIds = append(n.needIds, id)
+					n.HaveNots <- id
 				}
 			} else {
 				doSkip()
diff --git a/negentropy/whatever_test.go b/negentropy/whatever_test.go
index 3eaddda..4f4bb89 100644
--- a/negentropy/whatever_test.go
+++ b/negentropy/whatever_test.go
@@ -3,7 +3,9 @@ package negentropy
 import (
 	"encoding/hex"
 	"fmt"
+	"slices"
 	"strings"
+	"sync"
 	"testing"
 
 	"github.com/nbd-wtf/go-nostr"
@@ -73,7 +75,7 @@ func runTestWith(t *testing.T,
 	}
 
 	{
-		n1, _ = NewNegentropy(NewVector(), 1<<16)
+		n1 = NewNegentropy(NewVector(), 1<<16)
 		for _, r := range n1Ranges {
 			for i := r[0]; i < r[1]; i++ {
 				n1.Insert(events[i])
@@ -84,14 +86,14 @@ func runTestWith(t *testing.T,
 	}
 
 	{
-		n2, _ = NewNegentropy(NewVector(), 1<<16)
+		n2 = NewNegentropy(NewVector(), 1<<16)
 		for _, r := range n2Ranges {
 			for i := r[0]; i < r[1]; i++ {
 				n2.Insert(events[i])
 			}
 		}
 
-		q, _, _, err = n2.Reconcile(1, q)
+		q, err = n2.Reconcile(1, q)
 		if err != nil {
 			t.Fatal(err)
 			return
@@ -103,36 +105,64 @@ func runTestWith(t *testing.T,
 		n2: n1,
 	}
 	i := 1
-	for n := n1; q != nil; n = invert[n] {
-		i++
-		var have []string
-		var need []string
 
-		q, have, need, err = n.Reconcile(i, q)
-		if err != nil {
-			t.Fatal(err)
-			return
-		}
+	wg := sync.WaitGroup{}
+	wg.Add(3)
 
-		if q == nil {
-			expectedNeed := make([]string, 0, 100)
-			for _, r := range expectedN1NeedRanges {
-				for i := r[0]; i < r[1]; i++ {
-					expectedNeed = append(expectedNeed, events[i].ID)
-				}
+	go func() {
+		wg.Done()
+		for n := n1; q != nil; n = invert[n] {
+			i++
+
+			q, err = n.Reconcile(i, q)
+			if err != nil {
+				t.Fatal(err)
+				return
 			}
 
-			expectedHave := make([]string, 0, 100)
-			for _, r := range expectedN1HaveRanges {
-				for i := r[0]; i < r[1]; i++ {
-					expectedHave = append(expectedHave, events[i].ID)
-				}
+			if q == nil {
+				return
 			}
-
-			require.ElementsMatch(t, expectedNeed, need, "wrong need")
-			require.ElementsMatch(t, expectedHave, have, "wrong have")
 		}
-	}
+	}()
+
+	go func() {
+		defer wg.Done()
+		expectedHave := make([]string, 0, 100)
+		for _, r := range expectedN1HaveRanges {
+			for i := r[0]; i < r[1]; i++ {
+				expectedHave = append(expectedHave, events[i].ID)
+			}
+		}
+		haves := make([]string, 0, 100)
+		for item := range n1.Haves {
+			if slices.Contains(haves, item) {
+				continue
+			}
+			haves = append(haves, item)
+		}
+		require.ElementsMatch(t, expectedHave, haves, "wrong have")
+	}()
+
+	go func() {
+		defer wg.Done()
+		expectedNeed := make([]string, 0, 100)
+		for _, r := range expectedN1NeedRanges {
+			for i := r[0]; i < r[1]; i++ {
+				expectedNeed = append(expectedNeed, events[i].ID)
+			}
+		}
+		havenots := make([]string, 0, 100)
+		for item := range n1.HaveNots {
+			if slices.Contains(havenots, item) {
+				continue
+			}
+			havenots = append(havenots, item)
+		}
+		require.ElementsMatch(t, expectedNeed, havenots, "wrong need")
+	}()
+
+	wg.Wait()
 }
 
 func hexedBytes(o []byte) string {