One API. Every model. Built for agent loops.
Sideren is a model API built for agents: point your tool at a single endpoint, authenticate with one key, and reach the entire sdn model catalog through the protocols your stack already speaks.
What is Sideren
Sideren serves its own catalog of sdn- models through a single gateway that is wire-compatible with the Anthropic Messages API, the OpenAI Chat Completions API, and the OpenAI Responses API. Swap your base URL and key; keep the rest of your stack exactly as it is.
What you get on the other side of that swap:
- The whole catalog, one key — from fast, near-free small models to premium reasoning and vision, all included on every plan. See Models.
- Every protocol your tools speak — Messages, Chat Completions, Responses, legacy Completions, embeddings, and batches, with streaming on every chat surface.
- Sessions that keep moving— if a model can't answer, the engine keeps your session moving. See Reliability.
- Predictable plans — a monthly pool of included usage measured in dollars at public list rates, with published rate limits. See Plans & limits.
Base URL
The gateway lives at a single origin. Every endpoint is served under /v1.
https://api.sideren.ioAPI keys are created in the dashboard and are prefixed sdn_. The Anthropic-style endpoints accept the key as x-api-key; the OpenAI-style endpoints accept it as a bearer token. See Authentication for the details.
curl https://api.sideren.io/v1/messages \
-H "x-api-key: sdn_your_key" \
-H "content-type: application/json" \
-d '{"model":"sdn-gpt-oss-120b","max_tokens":256,"messages":[{"role":"user","content":"Hello"}]}'