langflow-ai/langflow · error · HTTPException

response.model_dump()

Error message

response.model_dump()

What it means

Raised as HTTP 500 by the health-check endpoint when any subsystem check fails: response.has_error() is true after probing the database, the chat/cache service (set_cache/get_cache round-trip), or other registered checks. The detail is response.model_dump() — a dict of per-subsystem statuses, so the failing subsystem is named in the body.

Source

Thrown at src/backend/base/langflow/api/health_check_router.py:63

    user_id = "da93c2bd-c857-4b10-8c8c-60988103320f"
    try:
        # Check database to query a bogus flow
        stmt = select(Flow).where(Flow.id == uuid.uuid4())
        (await session.exec(stmt)).first()
        response.db = "ok"
    except Exception:  # noqa: BLE001
        await logger.aexception("Error checking database")

    try:
        chat = get_chat_service()
        await chat.set_cache("health_check", str(user_id))
        await chat.get_cache("health_check")
        response.chat = "ok"
    except Exception:  # noqa: BLE001
        await logger.aexception("Error checking chat service")

    if response.has_error():
        raise HTTPException(status_code=status.HTTP_500_INTERNAL_SERVER_ERROR, detail=response.model_dump())
    response.status = "ok"
    return response

View on GitHub (pinned to 976ec789d2)

Solutions

1. Inspect the 500 body: response.model_dump() lists exactly which check (db/cache/chat) is 'error'
2. Verify connectivity to the failing service (psql/ping the DB host, redis-cli ping)
3. Check env vars LANGFLOW_DATABASE_URL, LANGFLOW_CACHE_TYPE and Redis settings in .env
4. If the database check fails on startup, apply pending migrations (make alembic-upgrade) after DB connectivity is restored

Example fix

# before: LANGFLOW_DATABASE_URL=postgresql://langflow:wrongpw@db:5432/langflow
# after
LANGFLOW_DATABASE_URL=postgresql://langflow:correctpw@db:5432/langflow
# then: curl -s localhost:7860/health_check | jq  # expect status 'ok'

const healthy = await fetch('/health_check').then(r => r.ok); // deploy gates
// inspect body on failure: { database: 'error', cache: 'ok', ... }

try { const h = await healthCheck(); } catch (e) { const failed = e.response.data.detail; // dict naming the failing subsystem
  pageOncall(failed); }

When it happens

Trigger: GET /health_check returning 500 when: the database is unreachable, the cache (Redis) backend is down, or chat service cache round-trip fails. Each failed probe logs 'Error checking database' / 'Error checking chat service' with tracebacks.

Common situations: Misconfigured LANGFLOW_DATABASE_URL or Redis URL, database container not started, network partitions between services, wrong credentials after rotation.

Related errors

• Flow creation failed.
• Database error while activating version. Please try again.
• An internal error occurred while listing flows.
• An internal error occurred while creating the flow.
• Error deleting knowledge base.

AI-assisted analysis of langflow-ai/langflow@976ec789d2 (2026-08-14). Data as JSON: /api/errors/6298bef2108286db. Report an issue: GitHub.