Planned as a stretch payment rail integration, allowing payment instructions and quotes for services via Lightning.
Provides a prepaid Mastercard payment rail for payable services. Supports payment quotes and can expose card credentials when configured.
Provides EV charging station search using OpenStreetMap/Overpass data, returning chargers near a point with default central Berlin.
Click on "Deploy Server".
Wait a few minutes for the server to deploy. Once ready, it will show a "Started" state.
In the chat, type @ followed by the MCP server name and your instructions, e.g., "@mcp.cashu.exchange find EV chargers near central Berlin and quote the payment"
That's it! The server will respond to your query, and you can continue using it as needed.
Here is a step-by-step guide with screenshots.
A modular MCP service exchange: one registry, one gateway, and swappable payment rails for payable services — EV charging, food, and more. Built as a hackathon project (Berlin, 2026) to let AI agents discover and pay for real-world services.
Live: https://mcp.cashu.exchange · MCP endpoint: POST https://mcp.cashu.exchange/mcp
Route | What |
| redirects to the flagship chat demo at chat.cashu.exchange |
| Berlin cinema box-office chat (Cashu-settled, Yorck programme) |
| Leaflet map of Berlin EV chargers (OSM/Overpass, KV-cached) |
| MCP server (streamable HTTP, stateless) |
| JSON surfaces for the map/other clients |
An exchange, not a monolith. Three moving pieces:
Native plugins (public, in this repo) — safe to open-source: OpenStreetMap data, checkout-handoff payment instructions, generic contracts.
Federated downstreams (private, yours) — existing MCP servers
(oda-mcp, vipps-mcp, …) mounted through the gateway. Their code and
personal data never enter this repo; only their URL + token (secrets).
Payment rails — interchangeable PaymentRail implementations:
2fiat-card (own-card checkout handoff — no card ever touches this repo),
Cashu (via pecan for alternative
numeraires), Lightning (stretch). See docs/PAYMENT.md.
Related MCP server: remit.md MCP Server
packages/
contracts/ The two contracts: ServiceProvider, PaymentRail
core/ Registry + MCP server + downstream gateway + catalog
plugin-berlin-charging/ OSM/Overpass charging stations (native plugin)
plugin-pay-2fiat/ Own-card checkout handoff rail (holds no card)
map/ Map frontend (placeholder: worker serves Leaflet page)
chat/ Chat frontend (placeholder: any MCP client works today)
apps/
worker/ Composition root → deploys to mcp.cashu.exchangeTool | What it does |
| Catalog + native providers + payment rails |
| Tools from federated downstream MCP servers (europark parking) |
| EV chargers near a point (defaults: central Berlin) |
| Berlin cinema programme (category |
| Payment instructions for an amount, per rail |
npm install
npm test # vitest
npm run typecheck # tsc --noEmit (strict)
npm run check # biome
npm run dev # wrangler dev on :8787Copy .dev.vars.example → .dev.vars for local secrets (gitignored).
Continuous deployment on push to main (.github/workflows/deploy.yml) via
wrangler. Required repo secrets (never committed — this repo is public):
CLOUDFLARE_API_TOKEN — scoped token: Workers Scripts:Edit +
Zone:Read (+ DNS:Edit in the cashu.exchange zone for the custom domain)
CLOUDFLARE_ACCOUNT_ID
Worker runtime secrets (wrangler secret put, per-name):
DOWNSTREAMS — JSON array [{"name":"oda-mcp","url":"https://…/mcp"}]
(plus a TOKEN-style secret per downstream if you extend the env parsing)
There are no card secrets, on purpose: participants pay with their own card on the merchant's hosted checkout page. See docs/PAYMENT.md.
Secrets only via wrangler secret / .dev.vars (gitignored) / GitHub
Actions secrets. Never in code, commits, or issues.
Fixtures are synthetic. No real names, PANs, cookies, or order histories.
Reverse-engineered API knowledge lives in private kits; this repo consumes them through the gateway. A plugin that needs personal data is a private kit implementing the same MCP surface — not a plugin here.
No tool returns card details — there is no payment.card_details and no
card in any secret. The payment boundary is the merchant's hosted checkout
URL, opened by the person paying (see docs/PAYMENT.md).
What may be public: contracts/types, synthetic fixtures (inline in tests, with a provenance comment), architecture, infrastructure config that carries no credential material.
What never enters this repo:
Card numbers, license plates, phone numbers, tokens, cookies, session captures — in code, fixtures, docs, or comments.
Captured/sample payloads. **/fixtures/captures/, **/captures/,
*.har, *.pcap are gitignored. If a test needs a response shape, write a
synthetic fixture and say so in a comment.
Reverse-engineered API knowledge stays in private kits — this repo consumes it over MCP (the gateway), it does not vendor it.
Enforcement: node scripts/leak-scan.mjs . --history runs in CI on every PR
and push — PAN (Luhn-validated), Norwegian/German plates, phones, JWTs, Cashu
tokens, GitHub tokens, secret-shaped key/value pairs. Exceptions live in
scripts/leak-scan-allowlist.txt and require a # because: justification
line above each entry; unjustified entries fail the build.
New provider → new package implementing ServiceProvider, register it in
apps/worker/src/index.ts. Tools appear automatically (<id>.search).
New rail → implement PaymentRail, add to exchangeDeps.
Federate an existing MCP server → append to DOWNSTREAMS. Done.
MIT — see LICENSE. Map data © OpenStreetMap contributors (ODbL).
This server cannot be deployed
AI service marketplace — agents discover, call, and pay for API services automatically.
Marketplace and payment rail for AI agents: list, buy and settle with signed receipts.
Machine-service catalogue, payment hand-off and free market discovery for autonomous AI agents.
Directory of APIs, merchants, and tools AI agents can actually use.