OptionaleffortMJ-normalized effort level (the ChatParams.effortLevel vocabulary: numeric 1–100 or a
named level). Providers with reasoning realtime models (OpenAI gpt-realtime-2.x) map it to
their native literals; others scrub it.
OptionalinputPer-session input-transcription model override (OpenAI-protocol providers).
OptionalmcpRemote MCP server tool declarations (provider-native { type:'mcp', server_label, server_url|connector_id, … } objects) for providers that support MCP in session.tools.
Until an approval UX exists, declare servers with require_approval: 'never' — an approval
request is auto-denied by the driver.
OptionalparallelWhether the model may run tool calls in parallel (GA reasoning realtime models).
Provider-session tuning for a Realtime co-agent — the config-cascade source for the driver feature keys (GetSessionTuningSettings projects these onto the flat bag keys the drivers consume). Every field is optional; absent fields contribute NOTHING to the bag.