peage-mcp — give your agent a wallet

An MCP server that puts a prepaid fiat wallet in any MCP-capable agent (Claude Code, Claude Desktop, anything speaking MCP stdio). The agent can then pay APIs per call on the peage rail — cents at a time, no crypto, no subscriptions, with spending caps you control.

One ~120 KB static binary, pure machin (MFL). No Node, no Python.

Install

Grab the binary (or ./build.sh with machin on PATH), then register it:

Claude Code (.mcp.json in your project, or ~/.claude.json for user scope):

config.json

{"mcpServers": {"peage": {"command": "/path/to/peage-mcp", "args": ["serve"]}}}

Claude Desktop (claude_desktop_config.json): same snippet under mcpServers.

What the agent gets (7 tools)

tool	what it does
`peage_setup`	mint the wallet once; token stored at `~/.peage-mcp.json`
`peage_status`	balance, escrow, caps, recent charges
`peage_topup`	Stripe Checkout URL → the agent hands it to you, you pay once
`peage_paid_request`	call any peage-metered API with the wallet attached
`peage_set_limits`	per-call + per-merchant daily spending caps
`peage_verify_receipt`	publicly verify any signed charge receipt
`peage_solvency`	audit the rail's live ledger invariant

The human appears exactly once in the loop: paying the top-up link. Everything else is the agent's business.

The 60-second demo

Ask your agent: "set up a peage wallet, then fetch https://peage.intrane.fr/demo/fortune as a paid request" — it mints a wallet that comes with free starter credit, so it pays the 1-cent toll and gets its fortune on the first try, no human needed. When the free credit runs out, peage_topup hands you a Stripe link to fund more. That's the whole agent-payment loop — and the agent completes it before you touch your card.

Security model

The wallet token lives in ~/.peage-mcp.json (or PEAGE_WALLET_TOKEN). Sharing it with a merchant API is how they charge you — the caps bound the exposure: default 1€ per call / 10€ per merchant per day, adjustable via peage_set_limits.
The rail stores only a hash of the token; every charge returns an HMAC-signed receipt anyone can verify; the ledger invariant is public (peage_solvency).
PEAGE_URL points the server at a different rail instance (self-hosted, staging).

Sibling repos: peage (the rail, docs, skills) · x402: peage is a live x402 facilitator. An intrane.fr product. Contact: javi@intrane.fr