@meter-mcp/mcp

Drop-in prepaid billing wrappers for Model Context Protocol tools.

Install

npm install @meter-mcp/sdk @meter-mcp/mcp

Register a paid tool

import { MeterPublicApiClient } from "@meter-mcp/sdk";
import { registerPaidTool } from "@meter-mcp/mcp";

const meter = new MeterPublicApiClient({
  baseUrl: process.env.METER_API_URL!,
  serviceId: process.env.METER_SERVICE_ID!,
  serviceApiKey: process.env.METER_SERVICE_API_KEY!,
});

registerPaidTool({
  server,
  meter,
  name: "knowledge_search",
  definition: { description: "Search knowledge", inputSchema },
  billing: {
    customer: ({ extra }) => extra.auth.subject,
    credits: 8,
    provider: ({ input }) => `creator:${input.creatorId}`,
    product: ({ input }) => input.productId,
    aiUsage: (result) => result.aiUsage,
  },
  handler: searchKnowledge,
});

The wrapper reserves credits before invoking the tool, commits after success, and releases on failure. Payment-required and suspended-account responses are returned as MCP tool errors with structured billing details in _meta.meter. Unexpected errors continue to throw.

Use paidTool when your MCP framework has a different registration API, and use meterErrorToMcpResult when you need to translate errors yourself.

Both ESM import and CommonJS require are supported on Node.js 20 or newer.

License

MIT