Reference

Errors

The error envelope and every error code the gateway and Functions return, with what each means and what to do.

Every error returns an HTTP status and a JSON envelope:

JSON

{
  "error": "no_policy_compliant_provider",
  "message": "no provider satisfies the requested data policy",
  "correlation_id": "6f1c2d4e-0b7a-4f53-9a51-3d2e8c7b9a10"
}

error is a stable code. Branch on it, not on message.
message is human-readable and may change.
400 responses may include reason, an upstream cause shared by every provider that rejected the request.
schema_validation_failed includes detail.attempts.

Errors never include stack traces or internal paths. When you contact support, include the code, the time and the X-Seldon-Trace-Id header if the response had one.

Gateway

400invalid_request: The body is malformed (for example, missing model or messages, or a provider, cache, preset or reasoning field has the wrong type), or every provider rejected the request as invalid. When providers agree, a reason field names the upstream cause.; What to do: Read message; it names the failing field. Remove options the model does not accept.
400unknown_model: The model ID is not in the catalog.; What to do: Pick an ID from /models or GET /v1/models.
400model_not_routable: The model exists but has no routable provider right now.; What to do: Choose a routable model or add a fallback in models.
400invalid_sort: provider.sort is not price, latency or throughput.; What to do: Use one of the three supported values.
400feature_unsupported: The model cannot honor a requested feature such as tools, vision, audio, JSON output or streaming.; What to do: Check the model's capabilities on /models or choose another model.
400invalid_response_schema: response_format.json_schema is malformed.; What to do: Send a valid JSON Schema under response_format.json_schema.schema.
400schema_streaming_unsupported: stream: true was combined with a json_schema response format.; What to do: Send structured-output requests without streaming.
400invalid_correlation: A session, span or trace header is malformed or conflicts with another header.; What to do: See Attribution and sessions for header formats.
401UNAUTHORIZED: The API key is missing, revoked or copied with extra characters.; What to do: Send Authorization: Bearer with an active key from API keys.
402PAYMENT_REQUIRED: The workspace has no available credit or has reached a spend limit.; What to do: Add credits in Billing. Cached responses can still be served.
402price_cap_exceeded: No provider is available under provider.max_price.; What to do: Raise the cap or remove it.
404preset_not_found: The preset slug or version does not exist in this workspace.; What to do: Check the preset reference. Presets are coming soon.
409idempotency_conflict: An Idempotency-Key was reused with a different body or correlation headers.; What to do: Use a new key for each distinct request.
409duplicate_span_id: X-Seldon-Span-Id was already used in this workspace.; What to do: Generate a unique span ID per request, or omit it.
422no_policy_compliant_provider: No provider satisfies the requested zdr, data_collection or data_residency policy, including when provider policy metadata is unknown.; What to do: Relax the policy or choose a model with compliant providers.
422data_policy_loosening_forbidden: The request tries to loosen a data policy your workspace enforces.; What to do: Remove the conflicting provider policy field.
422structured_output_unsupported: No selected provider supports response_format json_schema.; What to do: Choose a model that supports structured outputs.
422schema_validation_failed: Provider output did not satisfy your json_schema after retries. detail.attempts reports how many calls were made.; What to do: Simplify the schema or make the instructions more explicit.
429rate_limited: Every eligible provider is rate limited.; What to do: Retry after the Retry-After delay, or allow more providers.
502no_available_provider: All eligible providers failed.; What to do: Retry with backoff. Send X-Seldon-Trace-Id to support if it persists.
503RATE_LIMITER_UNAVAILABLE: Provider admission is temporarily unavailable.; What to do: Retry after the Retry-After delay.
503catalog_unavailable: The model catalog is temporarily unavailable.; What to do: Retry with backoff.
503provider_not_configured: No provider credentials are configured for this request.; What to do: Choose another model or contact support.
504request_deadline_exceeded: The request did not finish within its 55-second budget, including queueing and fallback.; What to do: Retry, shorten the request or lower max_tokens.

Functions

Returned by calls whose model is a function alias.

400invalid_function_alias: The model is not seldon/function/<function-id> or seldon/function/<function-id>@<revision-id>, or Idempotency-Key is not a UUID.; What to do: Copy the alias from the function's Use section. Use UUID idempotency keys.
400invalid_function_request: The request does not match the function's input contract: fixed messages changed, an unsupported option such as stream or tools was sent, response_format, temperature or max_tokens was overridden, or a workflow input was not one JSON object in one user message.; What to do: Send the request shown in the Use section and vary only the declared input.
400function_requires_managed_funding: BYOK credentials or a BYOK policy apply to this request. Functions use workspace credits.; What to do: Call the function without x-byok-key, using a key that has no BYOK policy.
401api_key_revoked: The API key was revoked.; What to do: Use an active key.
402spend_limit_exceeded: This call could exceed the API key's spend limit.; What to do: Raise the key's limit or use another key.
404function_not_found: No function with this ID exists in the key's workspace.; What to do: Check the function ID and that the key belongs to the same workspace.
404revision_not_available: The function has no active revision, or the pinned revision was never activated.; What to do: Activate a revision, or pin a revision you have activated.
409function_disabled: The function is disabled.; What to do: Activate a revision to serve again.
409qualification_expired: The requested revision has expired.; What to do: Activate a current revision.
409idempotency_conflict: An Idempotency-Key was reused with different inputs.; What to do: Use a new UUID for each distinct call.
409execution_in_progress: A retry arrived while the original call with the same Idempotency-Key is still running.; What to do: Wait, then retry with the same key to receive the stored result.
409execution_disabled: Function execution is temporarily turned off.; What to do: Retry later or route the original request instead.
413request_too_large: The request is larger than 256 KiB.; What to do: Send a smaller input.
429api_key_rate_limit: The API key's requests-per-minute limit was reached.; What to do: Slow down or raise the key's limit.
429execution_capacity: Workspace or service concurrency for Functions is saturated.; What to do: Retry with backoff and jitter.
502execution_failed: The function could not produce a valid result, including after any fallback.; What to do: Retry, or inspect the call under Recent executions.
504execution_deadline_exceeded: The call did not finish within 55 seconds.; What to do: Retry with the same Idempotency-Key, or send a smaller input.

Bring your own key

Bring your own key is coming soon.

400byok_provider_required: x-byok-key was sent without provider.only naming exactly one supported provider.; What to do: Set provider.only to the provider the key belongs to.
400byok_credential_unsupported: That provider does not accept a per-request key header.; What to do: Use a stored connection for this provider.
400byok_credential_conflict: A transient key was sent while a stored BYOK policy also applies.; What to do: Use either the stored connection or the header, not both.
402byok_budget_exceeded: The request would exceed a BYOK budget.; What to do: Raise the budget or wait for the next budget window.
403byok_not_enabled: BYOK is not enabled for this workspace.; What to do: Contact us to request access.
422byok_no_eligible_connection: No authorized stored connection can serve this model and feature set.; What to do: Check the connection's models and status under Providers.
422byok_budget_unquotable: A BYOK budget applies, but Seldon cannot price this request to check it.; What to do: Choose a model with known pricing for this connection.

Gateway#

Functions#

Bring your own key#

Gateway

Functions

Bring your own key