@slippay/mcp

Give your agent's checkout a limit it can prove.

One tool to let an AI agent pay. One tool to re-verify the limit it can't break — locally, offline, in seconds. SlipPay runs on Stellar/Soroban: settlement in ~5s for a fraction of a cent, and the agent's wallet enforces a machine-proved spending bound on-chain.

Most agent-checkout tools gate spend with a configured guard — "abort if the total drifts more than 5%." That's a number someone typed. SlipPay's bound is a theorem, and slippay_verify hands it to you as an object you re-check yourself — no install, no trust.

Install

// Claude Desktop / any MCP client — mcpServers config
{
  "mcpServers": {
    "slippay": {
      "command": "npx",
      "args": ["-y", "@slippay/mcp"],
      "env": {
        "SLIPPAY_API_KEY": "sk_live_..."   // for slippay_pay / slippay_status
      }
    }
  }
}

slippay_verify needs no key and no network — it works the moment the server loads.

Tools

slippay_verify · the one that matters

Re-verify a SlipPay proof-carrying certificate against the agent spec it covers. Returns:

• the spec ↔ certificate SHA-256 binding (tamper-evidence — change a byte, it goes red),
• structural coherence of the certificate,
• the exact SMT-LIB proof obligations the compiler discharged (copy-runnable in any z3).

Call it before trusting any counterparty agent's claimed limit. Nothing is sent anywhere.

slippay_verify(certificate: <cert JSON>, spec: <the .axl spec>)

slippay_pay

Send a payment from your SlipPay agent wallet. Executes only if it stays within the proved per-transaction and sliding-window limits.

slippay_pay(recipient: "G…", amount: "0.50", asset: "USDC", memo?: "order-123")

slippay_status

Look up a payment by reference / transaction hash. Returns settlement status and the on-chain link.

slippay_status(reference: "<tx hash>")

Env

| var | default | used by | |---|---|---| | SLIPPAY_API_KEY | — | slippay_pay, slippay_status | | SLIPPAY_API_BASE | https://api.slippay.cc/api/v1 | slippay_pay, slippay_status |

Why a proved bound

A configured guard fails open: misconfigure it, or let an attacker influence the inputs it reads, and the cap is whatever the runtime says it is. A proved bound holds for every reachable state of the contract — the proof is over the state machine, not over one execution. slippay_verify is what lets a third party confirm that without taking our word for it. The day a config-guard competitor ships a real proof, they've conceded their guard was never enough.

Re-verify in the browser too: app.slippay.cc/verify.

Built on Stellar · proofs discharged by z3 · part of SlipPay.