diff --git a/.devcontainer/codespaces/agent-worker.mjs b/.devcontainer/codespaces/agent-worker.mjs
index 5c716a6ad5d..65ad2d556e2 100644
--- a/.devcontainer/codespaces/agent-worker.mjs
+++ b/.devcontainer/codespaces/agent-worker.mjs
@@ -51,6 +51,10 @@ for (const [k, v] of Object.entries({
 	}
 }
 
+// Not fatal, but box pinning needs it: without a box id every turn routes by
+// owner, so a thread cannot follow the box holding its session.
+if (!BOX_ID) console.error('CODESPACE_NAME is not set — box pinning disabled; turns route by githubUser only.');
+
 function runClaude({ message, sessionId, cwd }) {
 	const safeCwd = resolvePath(typeof cwd === 'string' && cwd ? cwd : `${ROOT}/n8n`);
 	if (safeCwd !== ROOT && !safeCwd.startsWith(ROOT + sep))
diff --git a/.devcontainer/codespaces/docker-compose.yml b/.devcontainer/codespaces/docker-compose.yml
index 8a792dcf35b..cab52a55f1d 100644
--- a/.devcontainer/codespaces/docker-compose.yml
+++ b/.devcontainer/codespaces/docker-compose.yml
@@ -28,3 +28,6 @@ services:
       DB_POSTGRESDB_PASSWORD: password
       # Prompt-cache TTL in seconds. 1 hour keeps the cache warm between turns.
       ANTHROPIC_PROMPT_CACHE_TTL: "3600"
+      # Compose does not inherit the codespace env. Pass the box name through so
+      # the worker can stamp boxId and dev:up can print the forwarded URL.
+      CODESPACE_NAME: ${CODESPACE_NAME:-}