Frontrun MCP Server

Instructions

Implementation Reference

• index.js:200-214 (handler)

  The 'frontrun_account_activity' tool handler implementation. Makes a GET request to /v1/vc/:username/activity endpoint to retrieve a tracked account's activity profile including follow velocity, sector distribution, and recent follows.

  server.tool(
    'frontrun_account_activity',
    'Get activity profile for a tracked account: follow velocity, sector distribution, snapshot coverage, and recent follows with classification. Use this to analyze a specific VC\'s recent behavior.',
    {
      username: z.string().describe('Twitter/X username of the tracked account'),
      since: z.string().optional().describe('Time window: "7d", "30d", "90d", or ISO date. Default: "30d"'),
    },
    async ({ username, since }) => {
      const params = new URLSearchParams();
      if (since) params.set('since', since);
      const qs = params.toString();
      const result = await apiCall('GET', `/vc/${encodeURIComponent(username)}/activity${qs ? '?' + qs : ''}`);
      return { content: [{ type: 'text', text: JSON.stringify(result, null, 2) }] };
    }
  );

• index.js:203-206 (schema)

  Input schema definition using Zod for 'frontrun_account_activity' tool. Defines two parameters: 'username' (required Twitter/X username) and 'since' (optional time window for filtering activity data).

  {
    username: z.string().describe('Twitter/X username of the tracked account'),
    since: z.string().optional().describe('Time window: "7d", "30d", "90d", or ISO date. Default: "30d"'),
  },

• index.js:29-73 (helper)

  The apiCall helper function used by the tool handler to make HTTP requests to the Frontrun API. Handles authentication, timeouts, rate limiting, and error responses.

  async function apiCall(method, path, body = null) {
    const url = `${API_URL}/v1${path}`;
    const options = {
      method,
      headers: {
        'X-API-Key': API_KEY,
        'Content-Type': 'application/json',
      },
    };
    if (body) {
      options.body = JSON.stringify(body);
    }
  
    const controller = new AbortController();
    const timeout = setTimeout(() => controller.abort(), 60000);
    options.signal = controller.signal;
  
    let response;
    try {
      response = await fetch(url, options);
    } catch (err) {
      clearTimeout(timeout);
      if (err.name === 'AbortError') return { error: 'Request timed out (60s). Try a narrower query.' };
      return { error: `Network error: ${err.message}` };
    }
    clearTimeout(timeout);
  
    if (response.status === 429) {
      const retry = response.headers.get('Retry-After') || '60';
      return { error: `Rate limited. Retry in ${retry}s.` };
    }
    if (response.status === 401) {
      return { error: 'Invalid API key. Check FRONTRUN_API_KEY.' };
    }
    if (response.status === 402) {
      const data = await response.json();
      return { error: 'Insufficient balance', ...data };
    }
    if (!response.ok) {
      const text = await response.text();
      return { error: `HTTP ${response.status}: ${text.slice(0, 500)}` };
    }
  
    return response.json();
  }