Model Context Protocol (MCP) is a standard way for AI clients to connect to external systems. An MCP server acts as the bridge between an AI client and the tools, data, or workflows that the client can use. Instead of hard-coding every integration into an AI client, you connect the client to an MCP server. The server then describes what it can do and handles requests from the client.
How an MCP server works?
An MCP server is a service that exposes capabilities to an AI client through the Model Context Protocol. These capabilities can include:
- Tools: Actions the client can ask the server to run, such as creating a record or fetching data.
- Resources: Readable context the client can access, such as files, records, or documentation.
- Prompts: Reusable prompt templates that help the client perform a specific task.
The AI client does not directly access your systems. It sends MCP requests to the server, and the server decides how to process those requests.
An MCP connection typically follows this flow:
- Start or register the server. The MCP server becomes available to the AI client through a local command, remote endpoint, or configured connection.
- Connect the client. The AI client opens a connection using the server configuration.
- Discover capabilities. The client asks the server which tools, resources, and prompts are available.
- Send requests. The client calls a tool, reads a resource, or uses a prompt through the MCP connection.
- Return results. The server processes the request and returns structured results that the client can use in the conversation.
This keeps the client focused on reasoning while the MCP server owns access control, business logic, and integration details.
Troubleshooting
If the client cannot connect to the MCP server:
- Confirm the server command or URL is correct.
- Check that required environment variables are set.
- Verify any API keys or tokens are valid.
- Make sure the server process is running and reachable from the client.
- Review the client logs for connection, authentication, or permission errors.
If the server connects but no capabilities appear, confirm that the server is exposing tools, resources, or prompts and that the connected user has permission to access them.