Payments for MCP servers

Gate the HTTP transport

Serve your MCP server over HTTP (rather than stdio) and put the paygate middleware — or the hosted proxy — in front of the endpoint. Express example:

import express from "express";
import { paygate } from "paygate/express";

const app = express();
const pw = paygate({ merchantId: process.env.PAYGATE_MERCHANT_ID });

// Each MCP request (tool call) pays 2 cents.
app.post("/mcp", pw({ priceCents: 2 }), mcpHttpHandler);

app.listen(3000);

Get discovered by paying agents

List the server in the ArisPay agent marketplace (agentmarketplace.arispay.app). Listings carry transport, capabilities, and pricing metadata that agents query programmatically via /v1/marketplace/discover — a budget-bounded search that favors paid, healthy, verified endpoints.

On the buyer side, any AI agent can pay your endpoint with `npx payagent pay <url>` or the payagent SDK — the 402 challenge your route now returns is the whole integration contract.

Pricing guidance

• Price per tool call, in integer cents. Tools with an upstream cost (search, enrichment, inference) should be priced cost-plus; pure-compute tools can start at 1 cent.
• If different tools have very different costs, split them across routes so each carries its own price rather than averaging.

FAQ

Does this work with stdio MCP servers?

Payment gating happens at an HTTP boundary. Publish an HTTP transport for the paid surface; a stdio distribution can stay free for local use.

How do agents find the price?

The 402 challenge carries it. Marketplace listings also expose pricing metadata so agents can budget before they ever call you.