Create an Anthropic message
Anthropic-compatible Messages endpoint supporting system prompts, tool calling, and streaming (SSE).
Authorizations
Bearer authentication header of the form Bearer <token>, where <token> is your auth token.
Headers
Anthropic-compatible idempotency header. Same semantics as Idempotency-Key; used on the /messages endpoint to match Anthropic's conventions.
255Body
x >= 11System prompt: a string, or an array of text blocks.
0 <= x <= 10 <= x <= 1Tool definitions the model may call. Responses include tool_use blocks; return outcomes as tool_result content blocks in a follow-up message.
Controls tool use: auto, any, tool, or none.
Extended thinking configuration; translated to the model's reasoning.
When true, the response streams as Anthropic Server-Sent Events (message_start, content_block_delta, message_stop, …).
Optional string metadata. completion_window controls scheduling; completion_webhook/webhook_token configure completion webhooks.
Anthropic server-side context-editing config (Claude Code sends it automatically). Accepted for compatibility but ignored — Sail forwards the full context each turn.
Response
Anthropic-compatible message response. Returns a single JSON object by default, or an Anthropic Server-Sent Events stream when stream: true.
message assistant 1- Option 1
- Option 2
- Option 3
end_turn, max_tokens, tool_use, stop_sequence, refusal