Context

When trying to access Fleet feature in LangSmith, you may find that the dropdown option is not visible in the interface. This typically occurs when the required ConfigMap that provides the frontend with the Agent Builder deployment URL is missing from your Kubernetes namespace.

Answer

The Agent Builder dropdown requires the langsmith-agent-builder-config ConfigMap to be present in your namespace. If this ConfigMap is missing, the feature will not be accessible through the UI.

To resolve this issue:

1. Verify the ConfigMap is missing:

   Check if the ConfigMap exists in your namespace:

   kubectl get configmap langsmith-agent-builder-config -n <your-namespace> -o yaml

   If this returns nothing, the ConfigMap is missing and needs to be created.

2. Run a Helm upgrade to recreate the ConfigMap:

   Execute a Helm upgrade with your existing values file:

   helm upgrade langsmith langchain/langsmith -n <your-namespace> -f <your-values-file>.yaml

   This re-triggers the bootstrap job which creates the missing ConfigMap.

3. Verify the ConfigMap was created:

   After the upgrade completes, confirm the ConfigMap now exists:

   kubectl get configmap langsmith-agent-builder-config -n <your-namespace> -o yaml

4. Restart frontend pods if needed:

   The bootstrap job normally restarts the frontend automatically, but if you still see errors like "No deployment URL specified for 'deepagents-public' deployment type," restart the frontend pods manually:

   kubectl rollout restart deployment/langsmith-frontend -n <your-namespace>

If the ConfigMap is still not created after the Helm upgrade, capture the bootstrap job logs immediately (the pod is cleaned up within seconds):

kubectl logs -n <your-namespace> -l app.kubernetes.io/component=agent-bootstrap --tail=100

Note: The configuration key agent_builder_encryption_key maintains full backward compatibility even though the feature is now called "Fleet" in the documentation.