Money Lover MCP Server

Instructions

Implementation Reference

• src/server.js:295-314 (handler)

  The handler function for the 'login' MCP tool. It authenticates using email/password via MoneyloverClient.getToken, caches the token, updates environment cache if matching, and returns formatted success/error response.

  async ({ email, password }) => {
    try {
      const token = await MoneyloverClient.getToken(email, password);
      try {
        await writeToken(email, token);
      } catch (error) {
        console.warn('Failed to persist Money Lover token:', error);
      }
      const { email: envEmail } = getEnvConfig();
      if (email === envEmail && envEmail) {
        cachedEnvEmail = envEmail;
        cachedEnvToken = token;
        cacheLoaded = true;
        cachedEnvUsesDirectToken = false;
      }
      return formatSuccess({ token });
    } catch (error) {
      return formatError(error instanceof Error ? error : new Error(String(error)));
    }
  }

• src/server.js:287-293 (schema)

  Zod schemas defining input (email, password) and output (token) for the 'login' tool.

  inputSchema: {
    email: z.string().email().describe('Money Lover account email'),
    password: z.string().min(1).describe('Money Lover account password')
  },
  outputSchema: {
    token: z.string()
  }

• src/server.js:282-315 (registration)

  Registers the 'login' tool on the MCP server with title, description, schemas, and handler.

  server.registerTool(
    'login',
    {
      title: 'Login to Money Lover',
      description: 'Authenticate using Money Lover credentials to retrieve a JWT token.',
      inputSchema: {
        email: z.string().email().describe('Money Lover account email'),
        password: z.string().min(1).describe('Money Lover account password')
      },
      outputSchema: {
        token: z.string()
      }
    },
    async ({ email, password }) => {
      try {
        const token = await MoneyloverClient.getToken(email, password);
        try {
          await writeToken(email, token);
        } catch (error) {
          console.warn('Failed to persist Money Lover token:', error);
        }
        const { email: envEmail } = getEnvConfig();
        if (email === envEmail && envEmail) {
          cachedEnvEmail = envEmail;
          cachedEnvToken = token;
          cacheLoaded = true;
          cachedEnvUsesDirectToken = false;
        }
        return formatSuccess({ token });
      } catch (error) {
        return formatError(error instanceof Error ? error : new Error(String(error)));
      }
    }
  );

• src/moneyloverClient.js:66-116 (helper)

  Core helper method implementing the Money Lover login flow: fetches login initiation URL and request token, parses client param, then POSTs credentials to oauth endpoint to obtain JWT access token.

  static async getToken(email, password) {
    const loginResponse = await fetch(LOGIN_URL, { method: 'POST' });
    if (!loginResponse.ok) {
      throw new Error(`Failed to initiate login: HTTP ${loginResponse.status}`);
    }
  
    const loginPayload = await readJson(loginResponse);
    const requestToken = loginPayload?.data?.request_token;
    const loginUrl = loginPayload?.data?.login_url;
  
    if (!requestToken || !loginUrl) {
      throw new Error('Login response missing request_token or login_url');
    }
  
    let clientParam = '';
    try {
      const parsed = new URL(loginUrl);
      clientParam = parsed.searchParams.get('client') ?? '';
    } catch (error) {
      throw new Error(`Unable to parse login URL: ${error.message}`);
    }
  
    if (!clientParam) {
      throw new Error('Login URL missing client parameter');
    }
  
    const form = new URLSearchParams();
    form.set('email', ensureString(email, 'email'));
    form.set('password', ensureString(password, 'password'));
  
    const tokenResponse = await fetch(TOKEN_URL, {
      method: 'POST',
      headers: {
        Authorization: `Bearer ${requestToken}`,
        Client: clientParam,
        'Content-Type': 'application/x-www-form-urlencoded'
      },
      body: form.toString()
    });
  
    if (!tokenResponse.ok) {
      throw new Error(`Failed to retrieve access token: HTTP ${tokenResponse.status}`);
    }
  
    const tokenPayload = await readJson(tokenResponse);
    const accessToken = tokenPayload?.access_token;
    if (!accessToken) {
      throw new Error('Access token not present in response');
    }
    return accessToken;
  }