This MCP server exposes JustCall telephony capabilities to your language models and AI agents via the MCP interface. It provides tools for real-time voice calls, call management, and messaging (SMS) through JustCall’s APIs, all accessible through the standard MCP endpoints. You can initiate calls, fetch call histories, manage call journeys, send and retrieve SMS, and work with contacts and tags, enabling your agents to operate in a contextually aware voice and messaging environment. The server also includes authentication via OAuth2 and token-based access to secure endpoints, ensuring that only authorized clients can invoke JustCall operations.

To use it, connect your MCP-enabled LLM or orchestrator to the JustCall MCP server at the provided MCP URL. Once connected, you can browse and call tools under categories like Calls, SMS & Messaging, Contacts, Analytics, Webhooks, Phone Numbers, User Groups, and Appointments. Each tool corresponds to a JustCall API action (for example, list_calls, send_sms, list_contacts, get_account_analytics, and create_webhook). The tools are designed to be composable in prompts or within function-calling workflows, allowing your agent to decide which operation to perform based on the conversation context. Ensure you provide a valid OAuth2 Bearer token in requests, as the server requires authentication for MCP and SSE endpoints.

Prerequisites:

• Node.js and npm installed on the host
• Access to the JustCall API with an API Key and Secret
• Network access to reach the MCP server endpoint

1. Clone the MCP server repository: git clone https://example.com/saaslabsco-justcall-mcp-server.git cd saaslabsco-justcall-mcp-server

2. Install dependencies: npm install

3. Configure environment variables:

   • Create a .env file or export variables in your environment: JUSTCALL_API_KEY=your_key JUSTCALL_API_SECRET=your_secret JUSTCALL_MCP_URL=https://mcp.justcall.host/mcp

4. Run the server: npm start

   Alternatively, if using a direct node start:

   node server.js

5. Verify the server is running by hitting the health endpoint or the MCP root: curl -H "Authorization: Bearer <token>" https://mcp.justcall.host/mcp/health

Note: If your deployment uses Docker, you can containerize this by mapping the environment variables into the container and exposing the MCP URL as needed.

Tips and common issues:

• Ensure your JustCall API credentials have the required scopes for calls, messaging, and contacts.
• The server uses OAuth2 with PKCE; obtain and pass a valid Bearer token in all requests to MCP endpoints.
• Public endpoints include /health and the OAuth2 metadata at /.well-known/oauth-authorization-server; keep these accessible for health checks and discovery.
• When using Streamable HTTP transport, include the Bearer token in the Authorization header: Authorization: Bearer <JWT_TOKEN>.
• If you see rate-limit errors, review your JustCall API key’s quota and adjust request rates accordingly.
• For local development, you can stub credentials and use a test JustCall sandbox environment if available.
• The MCP server exposes a comprehensive set of 66 tools across Calls, SMS & Messaging, Contacts, Analytics, Webhooks, Phone Numbers, User Groups, and Appointments; use function-calling prompts to select specific tools based on your use case.