diff --git a/internal/providers/codex.go b/internal/providers/codex.go
index cfb04b7b..27dc7caa 100644
--- a/internal/providers/codex.go
+++ b/internal/providers/codex.go
@@ -30,7 +30,7 @@ func NewCodexProvider(name string, tokenSource TokenSource, apiBase, defaultMode
 	apiBase = strings.TrimRight(apiBase, "/")
 
 	if defaultModel == "" {
-		defaultModel = "gpt-5.3-codex"
+		defaultModel = "gpt-5.4"
 	}
 
 	return &CodexProvider{
diff --git a/internal/providers/codex_build.go b/internal/providers/codex_build.go
index 94eeb950..9449b0e6 100644
--- a/internal/providers/codex_build.go
+++ b/internal/providers/codex_build.go
@@ -7,9 +7,13 @@ import (
 	"fmt"
 	"io"
 	"net/http"
+	"regexp"
 	"strings"
 )
 
+// invalidFcIDChars matches characters not allowed in Responses API tool call IDs.
+var invalidFcIDChars = regexp.MustCompile(`[^a-zA-Z0-9_-]`)
+
 // buildRequestBody converts internal ChatRequest to Responses API format.
 func (p *CodexProvider) buildRequestBody(req ChatRequest, stream bool) map[string]any {
 	model := req.Model
@@ -164,16 +168,17 @@ func (p *CodexProvider) doRequest(ctx context.Context, body any) (io.ReadCloser,
 	return resp.Body, nil
 }
 
-// toFcID ensures a tool call ID starts with "fc_" as required by the Responses API.
+// toFcID ensures a tool call ID starts with "fc_" and contains only
+// letters, numbers, underscores, or dashes as required by the Responses API.
 func toFcID(id string) string {
-	if strings.HasPrefix(id, "fc_") {
-		return id
-	}
 	if strings.HasPrefix(id, "tool_") {
-		return "fc_" + id[len("tool_"):]
-	}
-	if strings.HasPrefix(id, "call_") {
-		return "fc_" + id[len("call_"):]
+		id = id[len("tool_"):]
+	} else if strings.HasPrefix(id, "call_") {
+		id = id[len("call_"):]
+	} else if strings.HasPrefix(id, "fc_") {
+		id = id[len("fc_"):]
 	}
+	// Replace invalid characters (e.g. colons from session keys) with underscores.
+	id = invalidFcIDChars.ReplaceAllString(id, "_")
 	return "fc_" + id
 }
diff --git a/internal/providers/codex_test.go b/internal/providers/codex_test.go
index 0dbd3e09..fec97a10 100644
--- a/internal/providers/codex_test.go
+++ b/internal/providers/codex_test.go
@@ -47,8 +47,8 @@ func TestCodexProviderName(t *testing.T) {
 
 func TestCodexProviderDefaultModel(t *testing.T) {
 	p := NewCodexProvider("test", &staticTokenSource{token: "test"}, "", "")
-	if p.DefaultModel() != "gpt-5.3-codex" {
-		t.Errorf("DefaultModel() = %q, want %q", p.DefaultModel(), "gpt-5.3-codex")
+	if p.DefaultModel() != "gpt-5.4" {
+		t.Errorf("DefaultModel() = %q, want %q", p.DefaultModel(), "gpt-5.4")
 	}
 
 	p2 := NewCodexProvider("test", &staticTokenSource{token: "test"}, "", "o3")
diff --git a/internal/store/pg/memory_docs.go b/internal/store/pg/memory_docs.go
index e9af2215..ccacb5a7 100644
--- a/internal/store/pg/memory_docs.go
+++ b/internal/store/pg/memory_docs.go
@@ -85,16 +85,25 @@ func (s *PGMemoryStore) PutDocument(ctx context.Context, agentID, userID, path,
 
 func (s *PGMemoryStore) DeleteDocument(ctx context.Context, agentID, userID, path string) error {
 	aid := mustParseUUID(agentID)
+	var res sql.Result
+	var err error
 	if userID == "" {
-		_, err := s.db.ExecContext(ctx,
+		res, err = s.db.ExecContext(ctx,
 			"DELETE FROM memory_documents WHERE agent_id = $1 AND path = $2 AND user_id IS NULL",
 			aid, path)
+	} else {
+		res, err = s.db.ExecContext(ctx,
+			"DELETE FROM memory_documents WHERE agent_id = $1 AND path = $2 AND user_id = $3",
+			aid, path, userID)
+	}
+	if err != nil {
 		return err
 	}
-	_, err := s.db.ExecContext(ctx,
-		"DELETE FROM memory_documents WHERE agent_id = $1 AND path = $2 AND user_id = $3",
-		aid, path, userID)
-	return err
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		return fmt.Errorf("document not found: %s", path)
+	}
+	return nil
 }
 
 func (s *PGMemoryStore) ListDocuments(ctx context.Context, agentID, userID string) ([]store.DocumentInfo, error) {
diff --git a/ui/web/src/pages/memory/hooks/use-memory.ts b/ui/web/src/pages/memory/hooks/use-memory.ts
index df466591..e445a10e 100644
--- a/ui/web/src/pages/memory/hooks/use-memory.ts
+++ b/ui/web/src/pages/memory/hooks/use-memory.ts
@@ -95,10 +95,15 @@ export function useMemoryDocuments(filters: MemoryDocFilters) {
   );
 
   const deleteDocument = useCallback(
-    async (path: string, userId?: string) => {
+    async (path: string, userId?: string, agentId?: string) => {
+      const aid = agentId || filters.agentId;
+      if (!aid) {
+        toast.error(i18n.t("memory:toast.docDeleteFailed"), "No agent selected");
+        return;
+      }
       try {
         const qs = userId ? `?user_id=${encodeURIComponent(userId)}` : "";
-        await http.delete(`/v1/agents/${filters.agentId}/memory/documents/${path}${qs}`);
+        await http.delete(`/v1/agents/${aid}/memory/documents/${path}${qs}`);
         await invalidate();
         toast.success(i18n.t("memory:toast.docDeleted"), path);
       } catch (err) {
diff --git a/ui/web/src/pages/memory/memory-page.tsx b/ui/web/src/pages/memory/memory-page.tsx
index 9b1cf9b5..d958c723 100644
--- a/ui/web/src/pages/memory/memory-page.tsx
+++ b/ui/web/src/pages/memory/memory-page.tsx
@@ -82,7 +82,7 @@ export function MemoryPage() {
     if (!deleteTarget) return;
     setDeleteLoading(true);
     try {
-      await deleteDocument(deleteTarget.path, deleteTarget.user_id);
+      await deleteDocument(deleteTarget.path, deleteTarget.user_id, deleteTarget.agent_id);
       setDeleteTarget(null);
     } finally {
       setDeleteLoading(false);
diff --git a/ui/web/src/pages/providers/hooks/use-provider-models.ts b/ui/web/src/pages/providers/hooks/use-provider-models.ts
index 7d4681dd..f8f855da 100644
--- a/ui/web/src/pages/providers/hooks/use-provider-models.ts
+++ b/ui/web/src/pages/providers/hooks/use-provider-models.ts
@@ -8,13 +8,15 @@ export type { ModelInfo };
 // Hardcoded models for ChatGPT OAuth provider.
 // OAuth token lacks api.model.read scope, so we can't call /v1/models.
 const CODEX_MODELS: ModelInfo[] = [
+  { id: "gpt-5.4", name: "GPT-5.4" },
+  { id: "gpt-5.4-mini", name: "GPT-5.4 Mini" },
   { id: "gpt-5.3-codex", name: "GPT-5.3 Codex" },
   { id: "gpt-5.3-codex-spark", name: "GPT-5.3 Codex Spark" },
   { id: "gpt-5.2-codex", name: "GPT-5.2 Codex" },
   { id: "gpt-5.2", name: "GPT-5.2" },
+  { id: "gpt-5.1-codex", name: "GPT-5.1 Codex" },
   { id: "gpt-5.1-codex-max", name: "GPT-5.1 Codex Max" },
   { id: "gpt-5.1-codex-mini", name: "GPT-5.1 Codex Mini" },
-  { id: "gpt-5.1-codex", name: "GPT-5.1 Codex" },
   { id: "gpt-5.1", name: "GPT-5.1" },
 ];