protocolVersion property

String? get protocolVersion

The MCP Protocol Version being used for this request. Required.

For the HTTP transport, this value MUST match the MCP-Protocol-Version header; otherwise the server MUST return a 400 Bad Request. If the server does not support the requested version, it MUST return an UnsupportedProtocolVersionError.

Implementation

String? get protocolVersion => $optional('io.modelcontextprotocol/protocolVersion', $string);