> ## Documentation Index > Fetch the complete documentation index at: https://docs.auriko.ai/llms.txt > Use this file to discover all available pages before exploring further. # Error Codes > Machine-readable error codes returned by the Auriko API OpenAI-compatible endpoints return the `code` field in the error envelope. Anthropic-compatible endpoints (`/v1/messages`) use a different envelope without `code` (see [Errors](/api-reference/errors#anthropic-error-envelope)). The 62 codes below apply to OpenAI-format responses. | Error Code | HTTP Status | Description | | -------------------------------------------- | ----------- | ------------------------------------------------------------------------------------------------------------- | | `batch_only` | `400` | Model is batch-only and cannot serve real-time requests | | `budget_exhausted` | `429` | Account or project budget reached | | `byok_keys_required` | `400` | BYOK keys required but none are configured | | `client_disconnected` | `0` | Client closed the connection before the response completed | | `content_filtered` | `400` | The upstream provider's content filter rejects the request | | `context_length_exceeded` | `400` | Token count exceeds the model's context window | | `cost_constraint_exceeded` | `400` | No provider meets the cost constraint | | `duplicate_resource` | `409` | A resource with this identifier already exists | | `expired_api_key` | `401` | API key has expired | | `feature_disabled` | `403` | Feature is not available for this account or plan | | `field_immutable` | `400` | Field cannot be modified after resource creation | | `hosted_tool_not_supported` | `400` | Model does not support the requested hosted tool on available providers | | `idempotency_conflict` | `409` | Idempotency key reused with a different payload | | `idempotency_replay_unavailable` | `409` | Idempotency key matched a completed request but replay data was not captured | | `input_requires_responses_endpoint` | `400` | Request input contains types served only via the native Response API, and no provider for the model offers it | | `insufficient_permissions` | `403` | Caller authenticated but lacks the required scope | | `insufficient_quota` | `429` | No quota remaining on the current plan | | `internal_error` | `500` | Unexpected server error | | `invalid_api_key` | `401` | API key is missing, malformed, revoked, or unrecognized | | `invalid_parameter_value` | `400` | Field present, value outside allowed range or set | | `invalid_recovery_code` | `401` | MFA recovery code is invalid or already used | | `invalid_request` | `400` | Malformed or invalid request | | `json_mode_not_supported` | `400` | Model does not support JSON mode | | `latency_constraint_exceeded` | `400` | No provider meets the latency constraint | | `method_not_allowed` | `405` | HTTP method not supported on this endpoint | | `mfa_required` | `403` | Action requires multi-factor authentication step-up | | `mfa_verification_failed` | `401` | TOTP verification code is incorrect or expired | | `missing_required_parameter` | `400` | Required parameter not provided | | `model_not_found` | `404` | Requested model ID isn't in the catalog | | `model_unavailable` | `503` | The requested model is temporarily unavailable | | `no_compatible_endpoint` | `400` | No provider supports the required API endpoint for this model | | `no_provider_available` | `503` | No provider can serve this request right now | | `no_responses_endpoint` | `400` | Request requires the Response API but no provider supports it for this model | | `non_streaming_not_supported` | `400` | Model requires streaming | | `operation_not_allowed` | `400` | Operation not permitted for current resource state or role | | `payload_too_large` | `413` | Request body exceeds the size limit | | `payment_declined` | `400` | Card declined, expired, insufficient funds, or incorrect details | | `payment_method_invalid` | `400` | Payment method is invalid, expired, or incompatible | | `platform_keys_unavailable` | `400` | No platform keys available for this model | | `provider_blocked` | `400` | All providers for this model are in the blocklist | | `provider_not_in_allowlist` | `400` | No provider in the allowlist supports this model | | `rate_limit_exceeded` | `429` | Requests-per-minute cap hit | | `reasoning_not_supported` | `400` | Model does not support reasoning/extended thinking | | `required_params_not_supported` | `400` | No provider supports all required parameters | | `resource_not_found` | `404` | Requested resource not found | | `response_api_only` | `400` | Model is only available via the Response API | | `service_unavailable` | `503` | Planned or temporary capacity shortage | | `state_precondition_failed` | `409` | Resource is not in the required state for this operation | | `stream_duration_exceeded` | `0` | Stream exceeded the maximum allowed duration and was terminated by the gateway | | `streaming_not_supported` | `400` | Model does not support streaming | | `structured_output_not_supported` | `400` | Model does not support structured output | | `thinking_disable_not_supported` | `400` | Model does not support disabling thinking | | `throughput_constraint_not_met` | `400` | No provider meets the throughput constraint | | `tier_opt_in_required` | `400` | Model requires explicit tier opt-in (e.g., priority tier for fast mode) | | `tool_choice_required_not_supported` | `400` | Model does not support tool\_choice="required" | | `tools_not_supported` | `400` | Model does not support tool/function calling | | `tools_with_structured_output_not_supported` | `400` | Model does not support tools with structured output | | `unknown_field` | `400` | Request contains an unrecognized field | | `unsupported_modalities` | `400` | Audio output is not supported | | `upstream_error` | `502` | An upstream provider returned an invalid or unparseable response | | `upstream_timeout` | `504` | Upstream exceeded the request deadline | | `vision_not_supported` | `400` | Model does not support vision/image input |