x402 LLM API: pay per call in USDC on Base
Updated 25 October 2026.
Short answer: send a request to /v1/chat/completions with no key: you get HTTP 402 with x402 requirements (scheme exact, network base, asset USDC). Retry with the X-PAYMENT header. Settlement only happens after a successful completion.
Details
- payTo
0x5beB45770465cBd7BDb8517b64fB52F6dD6607cf - Asset USDC
0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913 - Minimum per request: $0.001
| Model id | Input $/1M | Output $/1M | Context | vs maker list price |
|---|---|---|---|---|
deepseek-v4.1-flash | $0.15 | $0.6 | 1,048,576 | at list price |
glm-5.3-flash | $0.15 | $0.5 | 1,048,576 | at list price |
qwen3-235b | $0.9 | $0.9 | 262,144 | at list price |
gpt-oss-120b | $0.1 | $0.5 | 128,000 | at list price |
qwen3.7-flash | $0.03 | $0.13 | 1,000,000 | at list price |
Prices from /v1/models, snapshot 25 Oct 2026; refreshed daily.
FAQ
Do I need an account or a card?
No. POST /v1/topup returns a deposit address and a tai_ key; send USDC or USDT on Base, Solana or BNB Chain from $1. Or pay per call with x402 (USDC on Base).
Is it OpenAI-compatible?
Yes. Base URL https://pay.trustai.center/v1, POST /v1/chat/completions, streaming supported.