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MCP basics

Initialisation​

The MCP server initialisation process is consistent for all MCP servers

Initialize​

Request:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "initialize",
  "params": {
    "protocolVersion": "2024-11-05",
    "capabilities": {},
    "clientInfo": { "name": "manual-client", "version": "0.1.0" }
  }
}

Response:

{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "protocolVersion": "2024-11-05",
    "capabilities": {},
    "serverInfo": { "name": "rmcp", "version": "0.14.0" }
  }
}

Initialized notification​

Request:

{ "jsonrpc": "2.0", "method": "notifications/initialized" }

No response.

List available tools​

Request:

{ "jsonrpc": "2.0", "id": 2, "method": "tools/list", "params": {} }

Response:

{
  "jsonrpc": "2.0",
  "id": 2,
  "result": {
    "tools": [
      {
        "name": "search",
        "description": "Search the web using a configured search engine",
        "inputSchema": {
          "type": "object",
          "properties": {
            "query": { "type": "string" },
            "engine": { "type": "string" },
            "page": { "type": "integer", "default": 1 },
            "max_results": { "type": "integer", "default": 10 },
            "region": { "type": ["string", "null"] }
          },
          "required": ["query", "engine"]
        }
      },
      {
        "name": "fetch",
        "description": "Fetch a URL and return its content as markdown",
        "inputSchema": {
          "type": "object",
          "properties": {
            "uri": { "type": "string" },
            "max_length": { "type": "integer", "default": 8000 },
            "start_index": { "type": "integer", "default": 0 },
            "format": { "type": "string", "default": "markdown" }
          },
          "required": ["uri"]
        }
      },
      {
        "name": "list-search-engines",
        "description": "List all available search engines and their configuration status",
        "inputSchema": { "type": "object", "properties": {} }
      }
    ]
  }
}

After this, implementations get a little more specific.