The x402 wrapper could advertise a 402 and verify a payment, but never
settled it (the "exact" scheme needs verify + settle to actually move
funds), and its HTTPFacilitator sent no auth, so it could not use the
Coinbase CDP facilitator — the only one that settles Base mainnet. It
also passed the raw base64 X-PAYMENT string where facilitators expect the
decoded payload object.
- Add an optional Settler interface; HTTPFacilitator now implements
Verify and Settle (POST /verify then /settle), and Require settles a
verified payment and emits the settlement reference.
- HTTPFacilitator.Authorize hook + x402.CDP(keyID, secret) constructor:
mint a short-lived Ed25519 Bearer JWT (stdlib crypto only, no chain
code, no new dependency) so verify/settle authenticate to CDP.
- Decode the X-PAYMENT payload to the object facilitators expect, with
passthrough for non-JSON payloads.
- Requirements gains extra (EIP-712 domain) and mimeType; the asset and
its {name,version} are auto-filled for known networks so clients can
sign. NormalizeNetwork maps base/base-sepolia to CAIP-2 ids.
- Accept the v2 PAYMENT-SIGNATURE request header and emit both
X-PAYMENT-RESPONSE and PAYMENT-RESPONSE.
Backward compatible: the default network stays "base", the Facilitator
interface is unchanged (Settler is additive), and gateway/mcp builds and
tests unchanged. Adds tests for settle, CDP JWT, header aliases, extra,
and payload decoding.
Follow-up to the merged x402 integration (#2964). Drop the commerce-y
'price' vocabulary for the protocol's own 'amount', and add per-tool
pricing as an operator concern (the way scopes/rate-limits are set at the
gateway).
- x402.Config: Price -> Amount (default), plus Amounts map for per-tool
overrides; AmountFor(tool) resolves per-tool -> default. Add a Require
primitive (per-request enforcement) and LoadConfig for an operator
config file.
- MCP gateway: enforce payment per-tool inside /mcp/call (where scopes
are enforced) using AmountFor, instead of a flat path-based middleware.
- CLI: --x402-price -> --x402-amount; add --x402-config (per-tool file)
to micro mcp serve and micro-mcp-gateway.
- docs: new Payments (x402) guide + nav + README section; blog/22
updated to Amount/Amounts and the config-file model.
Co-authored-by: Claude <noreply@anthropic.com>
Integrate the x402 payment protocol (HTTP 402) so a tool can require a
stablecoin payment and an agent can settle it — the next step after
autonomous agents (blog 21): agents that act, and pay.
- wrapper/x402: HTTP middleware enforcing the 402 challenge/verify flow,
with a pluggable Facilitator interface. Go Micro carries no chain or
crypto code — verification/settlement is delegated to a facilitator
(Coinbase CDP, Alchemy, self-hosted), so Base and Solana are just
different facilitators behind one interface. HTTPFacilitator default;
tests cover challenge / accept / reject via a mock facilitator.
- MCP gateway: optional Options.Payment gates /mcp/call (listing tools
and health stay free); off unless configured.
- micro mcp serve and micro-mcp-gateway: opt-in --x402-pay-to/-price/
-network/-facilitator flags (env vars on the standalone binary).
- blog/22 'Integrating x402: Payments for Agents'; README feature row.
Pricing is flat per call for now; richer models and an agent-side spend
cap (next to MaxSteps/ApproveTool) are follow-ups.
Co-authored-by: Claude <noreply@anthropic.com>
Asim Aslam