| Value | Meaning |
|---|---|
| protocolVersion"io.modelcontextprotocol/protocolVersion" | |
| clientInfo"io.modelcontextprotocol/clientInfo" | |
| clientCapabilities"io.modelcontextprotocol/clientCapabilities" | |
| logLevel"io.modelcontextprotocol/logLevel" | |
| subscriptionId"io.modelcontextprotocol/subscriptionId" |
Reserved _meta keys defined by the draft (2026-07-28) revision.