* feat(mcp): advertise x402 payment requirements in the tool catalog
/mcp/tools now includes each priced tool's payment requirements (amount,
network, asset, payTo) when payments are enabled, so an agent can see the
cost before calling and choose by price — a shoppable catalog, the
foundation for a tool marketplace. Free tools carry no payment block; the
shared Tool struct is copied when pricing so it isn't mutated. Tests cover
priced/free tools and payments-disabled. Documented in the payments guide.
* feat(x402): consumer client with a spend budget (pay-and-retry)
Add x402.Client, the consumer counterpart to Middleware: it settles 402
challenges automatically via a pluggable Payer, up to a spend Budget. A
call that would exceed the budget is refused before any payment is made,
and spend accumulates across calls — the spend cap that keeps an
autonomous, paying caller in bounds. Tests cover pay-within-budget,
refuse-over-budget, budget accumulation, and free endpoints, end to end
against the server Middleware with a mock facilitator and payer. Guide
documents the consumer side; agent-level AgentMaxSpend is the next step.
* chore: gofmt gateway/mcp/benchmark_test.go (trailing newline)
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Co-authored-by: Claude <noreply@anthropic.com>
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