diff --git a/server/internal/handler/runtime.go b/server/internal/handler/runtime.go
index 2cfc44cd3..90b9d8429 100644
--- a/server/internal/handler/runtime.go
+++ b/server/internal/handler/runtime.go
@@ -343,14 +343,20 @@ func (h *Handler) DeleteAgentRuntime(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// Check if any agents are bound to this runtime (ON DELETE RESTRICT).
-	agentCount, err := h.Queries.CountAgentsByRuntime(r.Context(), rt.ID)
+	// Check if any active (non-archived) agents are bound to this runtime.
+	activeCount, err := h.Queries.CountActiveAgentsByRuntime(r.Context(), rt.ID)
 	if err != nil {
 		writeError(w, http.StatusInternalServerError, "failed to check runtime dependencies")
 		return
 	}
-	if agentCount > 0 {
-		writeError(w, http.StatusConflict, "cannot delete runtime: it has agents bound to it. Reassign or remove the agents first.")
+	if activeCount > 0 {
+		writeError(w, http.StatusConflict, "cannot delete runtime: it has active agents bound to it. Archive or reassign the agents first.")
+		return
+	}
+
+	// Remove archived agents so the FK constraint (ON DELETE RESTRICT) won't block deletion.
+	if err := h.Queries.DeleteArchivedAgentsByRuntime(r.Context(), rt.ID); err != nil {
+		writeError(w, http.StatusInternalServerError, "failed to clean up archived agents")
 		return
 	}
 
diff --git a/server/pkg/db/generated/runtime.sql.go b/server/pkg/db/generated/runtime.sql.go
index e605fc1ec..683d97b8d 100644
--- a/server/pkg/db/generated/runtime.sql.go
+++ b/server/pkg/db/generated/runtime.sql.go
@@ -11,12 +11,12 @@ import (
 	"github.com/jackc/pgx/v5/pgtype"
 )
 
-const countAgentsByRuntime = `-- name: CountAgentsByRuntime :one
-SELECT count(*) FROM agent WHERE runtime_id = $1
+const countActiveAgentsByRuntime = `-- name: CountActiveAgentsByRuntime :one
+SELECT count(*) FROM agent WHERE runtime_id = $1 AND archived_at IS NULL
 `
 
-func (q *Queries) CountAgentsByRuntime(ctx context.Context, runtimeID pgtype.UUID) (int64, error) {
-	row := q.db.QueryRow(ctx, countAgentsByRuntime, runtimeID)
+func (q *Queries) CountActiveAgentsByRuntime(ctx context.Context, runtimeID pgtype.UUID) (int64, error) {
+	row := q.db.QueryRow(ctx, countActiveAgentsByRuntime, runtimeID)
 	var count int64
 	err := row.Scan(&count)
 	return count, err
@@ -31,6 +31,15 @@ func (q *Queries) DeleteAgentRuntime(ctx context.Context, id pgtype.UUID) error
 	return err
 }
 
+const deleteArchivedAgentsByRuntime = `-- name: DeleteArchivedAgentsByRuntime :exec
+DELETE FROM agent WHERE runtime_id = $1 AND archived_at IS NOT NULL
+`
+
+func (q *Queries) DeleteArchivedAgentsByRuntime(ctx context.Context, runtimeID pgtype.UUID) error {
+	_, err := q.db.Exec(ctx, deleteArchivedAgentsByRuntime, runtimeID)
+	return err
+}
+
 const failTasksForOfflineRuntimes = `-- name: FailTasksForOfflineRuntimes :many
 UPDATE agent_task_queue
 SET status = 'failed', completed_at = now(), error = 'runtime went offline'
diff --git a/server/pkg/db/queries/runtime.sql b/server/pkg/db/queries/runtime.sql
index 1b80eb354..1e70a5372 100644
--- a/server/pkg/db/queries/runtime.sql
+++ b/server/pkg/db/queries/runtime.sql
@@ -73,5 +73,8 @@ ORDER BY created_at ASC;
 -- name: DeleteAgentRuntime :exec
 DELETE FROM agent_runtime WHERE id = $1;
 
--- name: CountAgentsByRuntime :one
-SELECT count(*) FROM agent WHERE runtime_id = $1;
+-- name: CountActiveAgentsByRuntime :one
+SELECT count(*) FROM agent WHERE runtime_id = $1 AND archived_at IS NULL;
+
+-- name: DeleteArchivedAgentsByRuntime :exec
+DELETE FROM agent WHERE runtime_id = $1 AND archived_at IS NOT NULL;