Claude Sonnet API - pay per call, no API key. OpenAI-format chat completions on anthropic/claude-sonnet-5.5, pinned to Anthropic's own OpenRouter endpoint for reliability. You sign a fixed price computed from your max_tokens; unused tokens are not refunded. 20s server-side timeout - never charged if it fires; set your client timeout to 30s. Try GET /llm/claude-sonnet/sample.
| Network | Scheme | Amount | Pay To |
|---|---|---|---|
| Base | exact | $0.001892 USDC | 0xb3F3...A69d |