The unified surface. - Sideren

Base URL

All endpoints below are relative to:

https://api.sideren.io

Authentication is one key across the whole surface — see Authentication for which header each dialect expects.

Endpoints

Endpoint	What it does
`POST` `/v1/chat/completions`	OpenAI Chat Completions dialect — messages in, completion out. SSE streaming.
`POST` `/v1/messages`	Anthropic Messages dialect — content blocks, tools, vision + PDFs. SSE streaming.
`POST` `/v1/responses`	OpenAI Responses dialect — the surface Codex CLI speaks. SSE streaming, stored conversations.
`POST` `/v1/completions`	Legacy text completions for older clients — prompt in, text out.
`POST` `/v1/embeddings`	Seven embedding models, 384 to 2048 dimensions — memory and retrieval next to chat.
`POST` `/v1/messages/count_tokens`	Token estimate for a Messages request body, for context budgeting.
`POST` `/v1/messages/batches`	Async batches — up to 1,000 requests per submission, results as JSONL.
`GET` `/v1/models`	The self-describing model catalog: ids, capabilities, limits, list pricing.

GET /v1/models/{id} returns a single catalog entry. Batches also exist in an OpenAI flavor at /v1/batches with the same lifecycle — see Batches.

Also on the surface

Endpoint	What it does
`GET` `/v1/responses/{id}`	Replay a stored Responses envelope.
`GET` `/healthz`	Unauthenticated liveness probe. Returns `ok`.

Conventions

Errors are standard HTTP status codes with a JSON body shaped for the protocol you called (Errors). Responses carry a small, fixed set of sideren- and x-ratelimit- headers (Headers). Streaming is Server-Sent Events on every chat endpoint (Streaming).