Rate limits & errors

Rate limits

Rate limits are enforced by slowapiwith Redis as the backend. They protect both the infrastructure and the user's LLM budget. When a limit is hit the API responds with 429 Too Many Requests and a small JSON body describing the offending limit.

Concurrency limits

• One active pipeline per repository. Creating a second issue while a previous one is in progress on the same repo responds with 409 Conflict.
• Five active pipelines per VPS. Once the global semaphore is saturated, new issues stay queued in pending until a slot frees. Issues are still visible immediately; only their execution waits.

HTTP status codes

• 200 OK — the request succeeded and the response body carries the result.
• 201 Created — a new resource was created (e.g. an issue or a repo).
• 204 No Content — the request succeeded but there is nothing to return (e.g. cancel or delete operations).
• 400 Bad Request — validation failed on the request body or query parameters. The JSON body contains a detail field with a human-readable message.
• 401 Unauthorized — the session cookie is missing or expired. The frontend treats this as a redirect to /login on every endpoint except /api/auth/login and /api/auth/register, where it means “bad credentials”.
• 403 Forbidden — the session is valid but the resource belongs to another user.
• 404 Not Found — the resource does not exist or is not visible to the current user.
• 409 Conflict — a state precondition was violated. Examples: cancelling a terminal issue, deleting an active issue, starting a second pipeline on the same repo, approving an issue that is not awaiting_approval.
• 429 Too Many Requests — a rate limit was hit. Wait and retry.
• 500 Internal Server Error — an unhandled failure on the backend. The body has a short detail but full diagnostics live in the server logs.
• 503 Service Unavailable — the readiness probe failed: one of Postgres, Redis or Qdrant is unreachable.

Error body shape

Errors always come as JSON with at least a detail field:

{
  "detail": "Another issue is already in progress for this repo"
}