### 1. Client sends initialize request with protocol version and capabilities
POST http://127.0.0.1:8000/mcp/
accept: application/json, text/event-stream
content-type: application/json
accept-encoding: gzip, deflate
{
"jsonrpc": "2.0",
"id": 0,
"method": "initialize",
"params": {
"protocolVersion": "2025-03-26",
"capabilities": {
"sampling": {},
"roots": {
"listChanged": true
}
},
"clientInfo": {
"name": "mcp-inspector",
"version": "0.14.0"
}
}
}
> {% client.global.set("mcp_session_id", response.headers.valueOf("mcp-session-id")); %}
### 2. Client sends initialized notification as acknowledgment
POST http://127.0.0.1:8000/mcp/
accept: application/json, text/event-stream
content-type: application/json
accept-encoding: gzip, deflate
mcp-session-id: {{mcp_session_id}}
{
"jsonrpc": "2.0",
"method": "notifications/initialized"
}
### 3. Normal message exchange begins
POST http://127.0.0.1:8000/mcp/
accept: application/json, text/event-stream
content-type: application/json
accept-encoding: gzip, deflate
mcp-session-id: {{mcp_session_id}}
{
"jsonrpc": "2.0",
"id": 1,
"method": "tools/list"
}
