wandb/openui · warning · HTTPException

No session found

Error message

No session found

What it means

Raised by OpenUI's GET session endpoint: the handler can identify the logged-in user but no session record matching the requested session exists (the else branch before falling back to session_store), so it returns HTTP 404 'No session found'. It signals the requested session id is unknown or was never persisted.

Source

Thrown at backend/openui/server.py:493

            except IntegrityError:
                user = User.get(User.username == getpass.getuser())
                user_id = user.id
            if user.email is None:
                user.email = get_git_user_email()
                user.save()
            request.session["user_id"] = str(user_id)
            session_store.write(
                request.session["session_id"],
                str(user_id),
                SessionData(
                    username=user.username,
                    token_count=0,
                    max_tokens=config.MAX_TOKENS,
                    email=user.email,
                ),
            )
        else:
            raise HTTPException(status_code=404, detail="No session found")
    session_data = session_store.get(session_id)
    return JSONResponse(
        content=session_data.model_dump(),
        status_code=200,
    )


@router.delete(
    "/v1/session",
    tags=["openui/session"],
)
async def delete_session(
    request: Request,
):
    session_id = request.session.get("session_id")
    if session_id is None:
        raise HTTPException(status_code=404, detail="No session found")
    request.session.pop("session_id")

View on GitHub (pinned to 42d7ab4ab6)

Solutions

1. Create a new session (POST the session endpoint) and use the returned session id instead of the stale one.
2. If your deployment relies on session_store, add persistent storage (e.g. Redis) or expect loss on restart.
3. Verify the request's authenticated user actually owns the requested session id.
4. Handle 404 in the client by resetting local session state and re-initializing.

Example fix

// before
const res = await fetch(`/session/${oldId}`); // 404 after restart
// after
let res = await fetch(`/session/${oldId}`);
if (res.status === 404) {
  res = await fetch('/session', { method: 'POST' }); // create new session
}

const res = await fetch(`/session/${sessionId}`);
if (res.status === 404) {
  sessionId = null; // invalidate local reference
  const created = await fetch("/session", { method: "POST" });
  sessionId = (await created.json()).id;
}

function hasSession(state): state is State & { sessionId: string } {
  return typeof state.sessionId === "string" && state.sessionId.length > 0;
}

When it happens

Trigger: GETting a session whose id exists in neither the database (User's associated session) nor the in-memory session_store — e.g. requesting a session id that was never created, belongs to another user, or was created before a server restart wiped the in-memory store.

Common situations: Client bookmarks/caches an old session id after server restart (session_store is memory-resident), sharing session ids across users, or a race where the session row was deleted while the client still holds the id.

Related errors

• Login required to use OpenUI
• Invalid model
• You've exceeded our usage quota, come back tomorrow to gener
• Model not supported
• Groq API key is not set.

AI-assisted analysis of wandb/openui@42d7ab4ab6 (2026-09-01). Data as JSON: /api/errors/5d52ea6169244b88. Report an issue: GitHub.