v0.2.0 — x402 Payment Support

What's New

x402 (HTTP 402 Payment Required) support

Handle paywalled APIs automatically:

response = requests.get("https://api.example.com/data")
if response.status_code == 402:
    result = client.x402_handle_payment_required(dict(response.headers))
    data = requests.get(url, headers={"PAYMENT-SIGNATURE": result.payment_signature})

• client.x402_handle_payment_required(headers) — full flow: parse header → fund bot EOA from vault → sign EIP-3009 (USDC) or Permit2 (any ERC-20) → return PAYMENT-SIGNATURE header
• client.x402_fund(amount, token?) — fund bot EOA from vault for manual flows
• EIP-3009 signing (eip3009.py) — USDC-specific gasless transfer authorization
• Permit2 signing (permit2.py) — universal ERC-20 via Uniswap Permit2
• x402 header parsing, chain matching, metadata extraction (x402.py)
• Full Axon pipeline applies (spending limits, AI scan, human review)

Other changes

• x402_funding flag on pay() — audit/context flag for x402 self-payments
• relayer_url config option on client

Previous versions

• 0.1.6: Add relayer_url to client config
• 0.1.5: Add swap(), execute(), token resolution, amount parsing
• 0.1.0: Initial release — pay(), EIP-712 signing, sync wrapper