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Quickstart

Send your first paid AI request in under a minute.

Basic Usage​

from x402_openai import X402OpenAI
from x402_openai.wallets import EvmWallet

client = X402OpenAI(wallet=EvmWallet(private_key="0x…"))

res = client.chat.completions.create(
    model="openai/gpt-4o-mini",
    messages=[{"role": "user", "content": "Hello!"}],
)
print(res.choices[0].message.content)

That's it. If the server returns 402 Payment Required, the SDK automatically signs a payment and retries — you only see the final response.

What Happens Under the Hood​

  1. The SDK sends your request to https://llm.qntx.fun/v1 (default).
  2. The server responds with 402 and includes payment requirements in the headers.
  3. The SDK parses the requirements and finds a compatible wallet.
  4. A payment payload is signed using your wallet's private key.
  5. The request is retried with the X-PAYMENT header attached.
  6. The server verifies the payment via a facilitator and returns the content.

Custom Base URL​

Point the client at any x402-compatible endpoint:

client = X402OpenAI(
    wallet=EvmWallet(private_key="0x…"),
    base_url="https://your-server.example.com/v1",
)

Using Solana​

Swap the wallet adapter — the API is identical:

from x402_openai.wallets import SvmWallet

client = X402OpenAI(wallet=SvmWallet(private_key="base58…"))

Next Steps​

  • Wallets — BIP-39 mnemonics, multi-chain setups
  • Streaming — async streaming responses
  • Policies — control chain and amount preferences