Marketo MCP Server

Implementation Reference

• src/index.ts:416-445 (registration)

  Registration of the 'marketo_get_lead_by_email' tool using server.tool(). Includes Zod input schema (email required, fields optional) and inline async handler that performs a GET request to Marketo's lead lookup endpoint, returning JSON response or error text.

  server.tool(
    'marketo_get_lead_by_email',
    {
      email: z.string().email(),
      fields: z.array(z.string()).optional(),
    },
    async ({ email, fields }) => {
      try {
        const params = new URLSearchParams();
        if (fields) {
          params.append('fields', fields.join(','));
        }
  
        const response = await makeApiRequest(
          `/rest/v1/lead/${email}.json${params.toString() ? `?${params.toString()}` : ''}`,
          'GET'
        );
  
        return {
          content: [{ type: 'text', text: JSON.stringify(response, null, 2) }],
        };
      } catch (error: any) {
        return {
          content: [
            { type: 'text', text: `Error: ${error.response?.data?.message || error.message}` },
          ],
        };
      }
    }
  );

• src/index.ts:22-52 (helper)

  Utility function makeApiRequest that performs authenticated API calls to Marketo endpoints using axios and bearer token from TokenManager. Called by the tool handler.

  async function makeApiRequest(
    endpoint: string,
    method: string,
    data?: any,
    contentType: string = 'application/json'
  ) {
    const token = await tokenManager.getToken();
    const headers: any = {
      Authorization: `Bearer ${token}`,
    };
  
    if (contentType) {
      headers['Content-Type'] = contentType;
    }
  
    try {
      const response = await axios({
        url: `${MARKETO_BASE_URL}${endpoint}`,
        method: method,
        data:
          contentType === 'application/x-www-form-urlencoded'
            ? new URLSearchParams(data).toString()
            : data,
        headers,
      });
      return response.data;
    } catch (error: any) {
      console.error('API request failed:', error.response?.data || error.message);
      throw error;
    }
  }

• src/auth.ts:11-52 (helper)

  TokenManager class handles OAuth2 client credentials flow to obtain and cache access tokens for Marketo API authentication. Used indirectly by the tool via makeApiRequest.

  class TokenManager {
    private clientId: string;
    private clientSecret: string;
    private accessToken: string | null = null;
    private tokenExpiry: number = 0;
  
    constructor(clientId: string, clientSecret: string) {
      this.clientId = clientId;
      this.clientSecret = clientSecret;
    }
  
    async getToken(): Promise<string> {
      // Check if we have a valid token
      if (this.accessToken && Date.now() < this.tokenExpiry) {
        return this.accessToken;
      }
  
      try {
        // Extract the identity URL from the base URL
        // Convert from https://instance.mktorest.com/rest to https://instance.mktorest.com/identity
        const identityUrl = MARKETO_BASE_URL.replace('/rest', '/identity');
  
        const response = await axios.get(`${identityUrl}/oauth/token`, {
          params: {
            grant_type: 'client_credentials',
            client_id: this.clientId,
            client_secret: this.clientSecret,
          },
        });
  
        const data = response.data as TokenResponse;
        this.accessToken = data.access_token;
        // Set expiry to slightly before the actual expiry to ensure we don't use an expired token
        this.tokenExpiry = Date.now() + (data.expires_in - 60) * 1000;
  
        return this.accessToken;
      } catch (error: any) {
        console.error('Failed to get Marketo access token:', error.response?.data || error.message);
        throw new Error('Failed to authenticate with Marketo');
      }
    }
  }