> ## Documentation Index
> Fetch the complete documentation index at: https://agentclientprotocol.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Session Config Options are stabilized

> Announcement that session-level configuration selectors are now part of the stable ACP protocol.

**Published:** February 4, 2026

The Session Config Options RFD has moved to Completed and is stabilized.

Session Config Options give agents a flexible way to expose session-level configuration such as models, modes, reasoning levels, and other selectors. Instead of hard-coding a small set of protocol-level controls, clients can render the options an agent provides and keep them in sync as they change.

The stable protocol documentation is available in [Session Config Options](/protocol/session-config-options), and the design history remains in the [Session Config Options RFD](/rfds/session-config-options).