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Documentation Index

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The initialize method is the first request an AI client must send after connecting. It negotiates the protocol version and returns the server’s capabilities, name, and version.

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MCP Endpoint

POST https://yoursite.com/mcp/{slug}
Content-Type: application/json

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Request

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jsonrpc
string
required
Must be "2.0".
​
id
integer | string
required
Arbitrary request identifier echoed back unchanged in the response.
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method
string
required
Must be "initialize".
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params.protocolVersion
string
required
The MCP protocol version the client supports (e.g. "2024-11-05").
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params.capabilities
object
Client-declared capabilities object (e.g. roots, sampling). Can be empty {}.
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params.clientInfo.name
string
Human-readable name of the connecting client (e.g. "claude-desktop").
​
params.clientInfo.version
string
Version string of the connecting client (e.g. "1.0.0").
curl --request POST \
     --url https://yoursite.com/mcp/my-weather-tools \
     --header 'content-type: application/json' \
     --data '
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "initialize",
  "params": {
    "protocolVersion": "2024-11-05",
    "capabilities": {
      "roots": {"listChanged": true},
      "sampling": {}
    },
    "clientInfo": {
      "name": "claude-desktop",
      "version": "1.0.0"
    }
}
}
'

​
Response

​
result.protocolVersion
string
The protocol version the server selected (matches or falls back from the client’s requested version).
​
result.capabilities
object
Server-declared capabilities. GetMCP reports tools.listChanged: true.
​
result.serverInfo.name
string
The server’s display name as configured in GetMCP admin.
​
result.serverInfo.version
string
The GetMCP plugin version string.
{
  "jsonrpc": "2.0",
  "id": 1,
  "result": {
    "protocolVersion": "2024-11-05",
    "capabilities": {
      "tools": {
        "listChanged": true
      }
    },
    "serverInfo": {
      "name": "My Weather Tools",
      "version": "1.0.0"
    }
  }
}

​
Response Headers

HeaderDescription
Mcp-Session-IdSession ID to use in subsequent requests
Content-Typeapplication/json

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Follow-up Notification

After receiving the initialize response, the client should send the notifications/initialized notification to signal it’s ready: 
{
  "jsonrpc": "2.0",
  "method": "notifications/initialized",
  "params": {}
}
This is a notification (no id field), so no response is expected.

​
Capabilities

GetMCP currently reports:
CapabilityValue
tools.listChangedtrue — server can notify when tool list changes