Put a price on any endpoint

How it works

One router in front of your API

Payments verify locally and debit a prepaid balance. Facilitators only see real money moving.

request served from credit settle — refills the balance

served 0 facilitator calls 0 ratio —

demo runs ~8 requests per settle so you can see it — production is ~1,000

Features

Everything a paid API needs

Credit rail

One settle, ~1,000 requests

Verify locally, debit a balance. No facilitator in your hot path.

Router

Protocols are routes, not bets

x402 and MPP in one 402. New chains and facilitators plug in.

Failsafe

Failover, budgets, breakers

Throttled facilitator reroutes. A lying one gets benched.

Live pricing

No deploy to change a price

Versioned config in your DB. Apply from CI, roll back instantly.

Fail dials

Experiments can't cause outages

Shadow mode prices traffic before charging. Fail-open per route.

Ledger

Revenue you can audit

Atomic units, reconciled against the facilitator. Per-payer statements.

Agent-native

Agents find and pay you

Discovery endpoints, built-in MCP, spend-capped payer tools.

Observability

Metrics and dashboards, wired

Prometheus, OTel traces, Grafana packs included.

Enterprise

SOC 2 evidence built in

SSO, RBAC, tamper-evident audit chain, one-command audit pack.

Quickstart

Charging in five minutes

No wallet. No signup. No real money. goldrail dev ships a mock facilitator and funded test wallets.

brew install goldsky-io/tap/goldrail # or cargo, or docker goldrail init # scaffold a priced route goldrail dev # mock money, admin panel, chaos API goldrail serve # production, same binary

npm install goldrail import { goldrail } from "goldrail"; app.use(goldrail()); // that's it app.use("/ops", goldrail.admin()); // optional panel

cargo add goldrail-tower let app = Router::new() .merge(api) .layer(GoldrailLayer::from_env()?); // prices live in config

go get github.com/goldsky-io/goldrail/sdk/go handler = goldrail.Middleware(handler)

goldrail mcp # one tool: paid_fetch(url) const fetch = paidFetch(wallet, { maxPerRequest: 5000n }); # selling? your catalog is already published: # /.well-known/x402 · llms.txt · MCP

✅ Prove it works without writing a test: goldrail conformance --against localhost:3000 — and it refuses to run against mainnet.

Compare

Who owns your payment path?

	Coinbase middleware	Cloudflare gateway	Goldrail
model	embed the protocol	rent the gateway	own the layer
protocols	x402 only	x402 only	x402 + MPP
funding	settle every request	settle every request	prepaid credit
price changes	redeploy	their dashboard	live, versioned
ledger	none	their analytics	built in
runs where	in your app	their edge	anywhere
lock-in	facilitator	platform	none

Full comparison in docs/comparison.md.

Born in production

Every rule was paid for with real money

Goldrail runs Goldsky's edge — ~1M paid requests a day. The scars are the spec.

A hidden rate limit refused 96% of settles.→ credit rail + auto-tuned budgets.

A price change clients couldn't converge on.→ every 402 says exactly what to sign.

A revenue dashboard wrong by 1000×.→ revenue counted in units settled.

A timeout is not a failure.→ ambiguous settles resolve, never blind-retry.