Authenticator App MCP Server

Instructions

Implementation Reference

• src/mcp.ts:51-75 (registration)

  Registers the 'get_password' MCP tool with name, description, Zod input schema, and handler function that delegates to Authenticator.getPassword and formats the response.

  this.tool(
    'get_password',
    'Retrieve the password for a username when logging into a website.',
    {
      website: z
        .string()
        .describe('The domain name of the website you need to login, e.g. "github.com"'),
      username: z
        .string()
        .describe(
          'The username or email of the account you need to login, e.g. "john.doe@example.com"'
        ),
    },
    async ({ website, username }, extra) => {
      const res = await this.authenticator.getPassword(website, username);
      return {
        content: [
          {
            type: 'text',
            text: `The password is ${res.password}.`,
          },
        ],
      };
    }
  );

• src/authenticator.ts:53-67 (handler)

  Core handler function in Authenticator class that performs HTTP GET request to the backend API endpoint '/password' to retrieve the password for given website and username.

  async getPassword(website: string, username: string): Promise<GetPasswordResponse> {
    const url = `${this.baseUrl}/password?website=${encodeURIComponent(website)}&username=${encodeURIComponent(username)}`;
    const response = await fetch(url, {
      headers: {
        Authorization: `Bearer ${this.accessToken}`,
      },
    });
  
    if (!response.ok) {
      const errorBody = await response.text();
      console.error(`HTTP error ${response.status} from ${url}: ${errorBody}`);
      throw new Error(`HTTP error ${response.status}: ${errorBody}`);
    }
    return (await response.json()) as GetPasswordResponse;
  }

• src/authenticator.ts:21-23 (schema)

  TypeScript interface defining the response structure from the password retrieval API.

  export interface GetPasswordResponse {
    password: string;
  }

• src/mcp.ts:54-63 (schema)

  Zod schema defining the input parameters for the 'get_password' tool: website and username.

  {
    website: z
      .string()
      .describe('The domain name of the website you need to login, e.g. "github.com"'),
    username: z
      .string()
      .describe(
        'The username or email of the account you need to login, e.g. "john.doe@example.com"'
      ),
  },