DhanHQ MCP Server

Instructions

Implementation Reference

• src/index.ts:382-404 (handler)

  MCP CallToolRequest handler case that implements the get_login_instructions tool. Handles input arguments, retrieves consentAppId from state if not provided, calls the helper function, and formats the response.

  case 'get_login_instructions': {
    console.error('[Tool] Executing: get_login_instructions');
    const authState = getAuthState();
    const consentAppId =
      (args as Record<string, unknown>).consentAppId ||
      authState.consentAppId;
  
    if (!consentAppId) {
      throw new Error(
        'No consentAppId available. Please run start_authentication first.'
      );
    }
  
    const instructions = getStep2Instructions(consentAppId as string);
    return {
      content: [
        {
          type: 'text' as const,
          text: JSON.stringify(instructions, null, 2),
        },
      ],
    };
  }

• src/index.ts:55-70 (schema)

  Tool metadata including name, description, and input schema definition used for tool discovery and validation.

  {
    name: 'get_login_instructions',
    description:
      'Gets the login instructions and URL for Step 2 (browser-based login). You must complete this step manually by opening the URL in your browser.',
    inputSchema: {
      type: 'object' as const,
      properties: {
        consentAppId: {
          type: 'string' as const,
          description:
            'The consentAppId from Step 1 (start_authentication). If not provided, the latest one from the current session will be used.',
        },
      },
      required: [],
    },
  },

• src/index.ts:359-361 (registration)

  Registers the tool list (including get_login_instructions) with the MCP server via ListToolsRequestSchema handler.

  server.setRequestHandler(ListToolsRequestSchema, async () => ({
    tools,
  }));

• src/authentication.ts:101-114 (helper)

  Helper function that constructs the login URL and multi-step instructions for browser-based authentication step 2.

  export function getStep2Instructions(
    consentAppId: string
  ): { loginUrl: string; instruction: string } {
    const loginUrl = `${AUTH_BASE_URL}/login/consentApp-login?consentAppId=${consentAppId}`;
  
    return {
      loginUrl,
      instruction: `1. Open this URL in your browser: ${loginUrl}
  2. Log in with your Dhan credentials
  3. Complete 2FA verification (OTP/PIN/Password)
  4. You will be redirected to: ${dhanConfig.redirectUrl}?tokenId=<TOKEN_ID>
  5. Copy the tokenId from the URL and use it in the 'consumeConsent' tool`,
    };
  }