Synrouter Docs

API reference

Synrouter exposes OpenAI-compatible, Anthropic-compatible, and Synrouter-specific public endpoints for model inference and pricing metadata.

Authentication

Authenticate API calls with a Synrouter key in the Authorization header.

http
1Authorization: Bearer sk-sr-...

Public endpoints

GET /v1/models

Returns the current OpenAI-compatible model list.

POST /v1/chat/completions

Creates a chat completion through the OpenAI-compatible API.

POST /anthropic/v1/messages

Creates a message through the Anthropic-compatible API.

GET /api/sr/pricing

Returns Synrouter pricing metadata for configured models.

Chat Completions

Use this endpoint with OpenAI-compatible SDKs and clients. The production base URL is https://synrouter.ai/api/v1.

bash
1curl https://synrouter.ai/api/v1/chat/completions \
2 -H "Authorization: Bearer sk-sr-..." \
3 -H "Content-Type: application/json" \
4 -d '{
5 "model": "deepseek/deepseek-v4-flash",
6 "messages": [
7 { "role": "user", "content": "Return a JSON object with one greeting." }
8 ]
9 }'

Anthropic Messages

Use this endpoint with Anthropic-compatible clients. The production base URL is https://synrouter.ai/api/anthropic.

bash
1curl https://synrouter.ai/api/anthropic/v1/messages \
2 -H "Authorization: Bearer sk-sr-..." \
3 -H "Content-Type: application/json" \
4 -d '{
5 "model": "anthropic/claude-sonnet-4.6",
6 "max_tokens": 256,
7 "messages": [
8 { "role": "user", "content": "Explain session-aware caching." }
9 ]
10 }'

Models

bash
1curl https://synrouter.ai/api/v1/models \
2 -H "Authorization: Bearer sk-sr-..."

Pricing

Pricing data is returned in USD per million tokens. Use it for display and estimation; the final bill is based on actual request usage.

bash
1curl https://synrouter.ai/api/sr/pricing

Synrouter response headers

  • x-synrouter-session-id: session identifier assigned by Synrouter.
  • x-synrouter-cache-savings-usd: estimated savings from cache reads.
  • x-synrouter-trim-savings-usd: estimated savings from tool-result reduction.
  • x-synrouter-trimmed-tokens: estimated number of input tokens removed before routing.