Schemas

Request schemas & validation

This page documents the validation logic enforced by the API server so examples here match real behavior.

Common rules

  • model is required and must be one of the allowed models. The normalized model name is used internally.
  • messages must be a non-empty array.
  • tools (if provided) must be valid per the tool spec; otherwise the request is rejected.
  • max_tokens/max_completion_tokens must be between 1 and the model context window.
  • stream (if provided) must be a boolean.
  • Rate limit and size checks apply: payload too large returns 413.

OpenAI-style messages

  • Allowed roles: system, developer, user, assistant, tool, function.
  • A user message must be present somewhere in the array.
  • message.content can be a string or an array of content parts. Unknown shapes are rejected.

Anthropic-style messages

  • Allowed roles: user, assistant, system, tool.
  • At least one text segment must be present across messages.
  • Content blocks support text, image, tool_use, tool_result as commonly used shapes.

Provider-specific parameters

The unified endpoint enforces parameter compatibility based on the model provider.

  • For OpenAI models, Anthropic-only parameters (e.g. top_k, stop_sequences, cache_control) are rejected with HTTP 400.
  • For Anthropic models, OpenAI-only parameters (e.g. max_completion_tokens, logit_bias, n, seed, user, function_call, functions, parallel_tool_calls, store, response_format) are rejected with HTTP 400.

response_format (OpenAI)

response_format must be one of:

{ "type": "text" }
{ "type": "json_object" }
{ "type": "json_schema", "json_schema": { "name": "MySchema", "schema": {"type":"object"}, "strict": true } }

Invalid shapes (missing name for json_schema, wrong types) cause a 400 error.

Error responses

  • 400 – invalid request parameters (message describes the exact issue)
  • 401 – missing or invalid API key
  • 413 – payload too large
  • 429 – rate limit exceeded (key or IP)

These rules are applied consistently across:

  • Unified: POST /api/v1/messages
  • OpenAI: POST /api/openai/v1/chat/completions
  • Anthropic: POST /api/anthropic/v1/messages
PricingSdk Examples