x402 agentic payments (Coinbase's HTTP 402 protocol). Custody-free tools to pay x402-protected endpoints (build the EIP-3009 transferWithAuthorization the payer signs, assemble the X-PAYMENT header), call a facilitator (verify/settle/supported), and monetize your own API by generating PaymentRequirements. USDC on Base. Triggers: x402, HTTP 402, pay per request, agentic payment, machine payment, X-PAYMENT, transferWithAuthorization, EIP-3009, facilitator, monetize API, pay for API, agent pays.
How to install x402?
chaingpt-org/chaingpt-claude-skill/x402
$npx -y skills add chaingpt-org/chaingpt-claude-skill --skill x402Installs into the current project.
›Prefer a prompt? Paste this to your agent
Run `npx skills use "https://github.com/chaingpt-org/chaingpt-claude-skill" --skill "chaingpt-org/chaingpt-claude-skill/x402"` and follow the generated skill instructions now. Read its complete output, redirecting it to a temporary file first if necessary. Resolve relative paths from the supporting-files directory it provides.
Use the skills in "https://github.com/chaingpt-org/chaingpt-claude-skill" that are relevant to the current task. Run `npx skills add "https://github.com/chaingpt-org/chaingpt-claude-skill"` and select the relevant skills, then follow their instructions.
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