x402-anthropic 0.1.0

x402 payment transport for the Anthropic Python SDK

x402-anthropic-python

x402 payment transport for the Anthropic Python SDK.

Server returns 402 → client signs a USDC authorization → retries with payment header. Your code doesn't change. Follows the pattern introduced by qntx/x402-openai-python.

Install

pip install x402-anthropic           # base
pip install "x402-anthropic[evm]"    # + Base/Ethereum
pip install "x402-anthropic[svm]"    # + Solana

Usage

from x402_anthropic import X402Anthropic, EVMWallet

wallet = EVMWallet(private_key="0x...")
client = X402Anthropic(wallet=wallet, base_url="https://your-x402-gateway.example.com")

message = client.messages.create(
    model="claude-opus-4-5",
    max_tokens=1024,
    messages=[{"role": "user", "content": "Hello, Claude!"}],
)
print(message.content[0].text)

Async + streaming:

from x402_anthropic import AsyncX402Anthropic, EVMWallet
import asyncio

async def main():
    wallet = EVMWallet(private_key="0x...")
    async with AsyncX402Anthropic(wallet=wallet, base_url="...") as client:
        async with client.messages.stream(...) as stream:
            async for text in stream.text_stream:
                print(text, end="", flush=True)

asyncio.run(main())

Policy configuration

from x402 import preferNetwork, maxAmount

client = X402Anthropic(
    wallet=wallet,
    policies=[preferNetwork("eip155:8453"), maxAmount(1_000_000)],  # Base, max $1 USDC
    base_url="...",
)

Related

• qntx/x402-openai-python — OpenAI SDK equivalent
• coinbase/x402 — x402 protocol spec and reference implementation
• @x402/fetch — TypeScript equivalent

License

MIT