neverminedio/weather-mcp-agent repository overview

src/
├── main.ts                  # MCP server with Nevermined Payments
└── services/
    └── weather.service.ts   # Weather API service (Open-Meteo)

# Install
yarn install

# Configure environment
export NVM_API_KEY=...
export NVM_PLAN_ID=...
export NVM_ENVIRONMENT=sandbox
export OPENAI_API_KEY=...

# Run
yarn start

import { Payments, EnvironmentName } from "@nevermined-io/payments";

const payments = Payments.getInstance({
  nvmApiKey: process.env.NVM_API_KEY!,
  environment: process.env.NVM_ENVIRONMENT! as EnvironmentName,
});

import { z } from "zod";

const schema = z.object({
  city: z.string().describe("City name"),
}) as any;

payments.mcp.registerTool(
  "weather.today",
  {
    title: "Today's Weather",
    description: "Get weather for a city",
    inputSchema: schema,
  },
  async (args) => {
    const { city } = args as { city: string };
    return {
      content: [{ type: "text", text: `Weather for ${city}: Sunny, 25C` }],
    };
  },
  { credits: 1n }
);

payments.mcp.registerResource(
  "Weather Data",
  "weather://today",
  {
    title: "Today's Weather",
    description: "JSON weather data",
    mimeType: "application/json",
  },
  async (uri) => {
    return {
      contents: [{ uri: uri.href, text: "{...}", mimeType: "application/json" }],
    };
  },
  { credits: 5n }
);

payments.mcp.registerPrompt(
  "weather.ensureCity",
  {
    title: "Ensure city",
    description: "Guide to call weather.today",
    argsSchema: schema,
  },
  (args) => {
    return {
      messages: [{ role: "user", content: { type: "text", text: "..." } }],
    };
  },
  { credits: (ctx) => ctx.result.length > 100 ? 2n : 1n }  // Dynamic credits
);

const PORT = parseInt(process.env.PORT || "3000", 10);
const BASE_URL = process.env.BASE_URL || `http://localhost:${PORT}`;

const { info, stop } = await payments.mcp.start({
  port: PORT,
  baseUrl: BASE_URL,  // External URL for OAuth metadata
  planId: process.env.NVM_PLAN_ID!,  // required — the plan tool calls settle against
  serverName: "weather-mcp",
  version: "0.1.0",
});

// Fixed credits
{ credits: 1n }
{ credits: 5n }

// Dynamic credits based on input
{ credits: (ctx) => ctx.args.premium ? 5n : 1n }

// Dynamic credits based on result
{ credits: (ctx) => ctx.result.length > 1000 ? 3n : 1n }

// Tiered pricing
{ credits: (ctx) => {
  const size = JSON.stringify(ctx.result).length;
  if (size > 1000) return 5n;
  if (size > 500) return 3n;
  return 1n;
}}

import { Payments } from "@nevermined-io/payments";

const payments = Payments.getInstance({
  nvmApiKey: process.env.NVM_API_KEY!,
  environment: "sandbox",
});

// agentId is optional under the plan-centric model — the plan id is all you need
const { accessToken } = await payments.agents.getAgentAccessToken(
  process.env.NVM_PLAN_ID!
);

import { Client } from "@modelcontextprotocol/sdk/client";
import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/streamableHttp";
import { decodeAccessToken } from "@nevermined-io/payments";

const transport = new StreamableHTTPClientTransport(
  new URL("http://localhost:3002/mcp"),
  // The MCP session is an OAuth-protected resource: authenticate it with the
  // access token (without it, `initialize` returns 401). The per-call payment
  // is sent in band via `_meta` below.
  { requestInit: { headers: { Authorization: `Bearer ${accessToken}` } } }
);

const client = new Client({ name: "my-client" });
await client.connect(transport);

const result = await client.callTool({
  name: "weather.today",
  arguments: { city: "London" },
  // In-band payment (x402 v2 MCP transport): plain-JSON PaymentPayload, not base64.
  _meta: { "x402/payment": decodeAccessToken(accessToken) },
});

NVM_API_KEY=...            # Builder/agent owner API key
NVM_PLAN_ID=...            # Plan tool calls settle against (required)
# NVM_AGENT_ID=...         # Optional — informational only (plan-centric)
NVM_ENVIRONMENT=sandbox    # sandbox, live
PORT=3000                  # Optional, defaults to 3000
OPENAI_API_KEY=...         # For LLM-enhanced forecasts
BASE_URL=...               # External URL (required for production/Docker)

NVM_API_KEY=...            # Subscriber's API key
NVM_PLAN_ID=...            # Subscription plan ID
# NVM_AGENT_ID=...         # Optional — informational only (plan-centric)