# LLM Wallet Router

Pay for model-selected text answers in USDC using x402. No router account or router API key. Text-only, bounded JSON responses; not full OpenAI feature parity.

## When to use

Call for a short answer or a continued text conversation. Supply a supported model and ordered role/content messages. Keep a private per-request UUIDv4 recovery key.

## Circle Gateway API

- [OpenAPI 3.1](https://402.paymentrequired.com/openapi.json): fully described fixed-price request and response contract.
- [Usage and recovery docs](https://402.paymentrequired.com/docs): examples, payment requirements and error handling.
- [Fixed-price Gateway chat](https://402.paymentrequired.com/v1/gateway/chat/completions): POST, exactly 0.010000 USDC per successful answer, requested max_tokens 1–128. Requires funded Circle Gateway balance on a network actually advertised by its 402 challenge. An unsigned Gateway request performs no model work.

## Existing direct-wallet alternative

- [Models and direct-wallet tariffs](https://402.paymentrequired.com/v1/models): free discovery.
- [Direct-wallet chat](https://402.paymentrequired.com/v1/chat/completions): POST, privately prepares an answer and then invoices actual tokens on Base via x402 exact/EIP-3009, with no Gateway deposit. Do not confuse this variable invoice with the separate fixed Gateway tariff.
- [Native MCP](https://402.paymentrequired.com/mcp): Streamable HTTP, free list_models/quote, usage-priced chat. Ordinary MCP registration does not sign payments; use a payment-aware wallet bridge.
- [Direct-wallet paid proof](https://402.paymentrequired.com/proof.json): actual answers, token usage and receipts, not fixtures.

A paid result contains choices[0].message.content and a payment receipt. Preserve the exact body and private Idempotency-Key (HTTP) or request_id (MCP) across retries. Confirmed response recovery charges zero. Unknown/pending payment requires reconciliation, never automatic repayment. The Gateway transfer ID is not necessarily an on-chain transaction hash.

Contact: support@nuri.com. Never submit wallet keys or private recovery capabilities in public reports.