Switch engines

Different tasks suit different agents. Switch engines on the fly — use Claude Code for deep refactors, Codex for quick fixes — without restarting or reconfiguring anything.

Use an engine for one message

Prefix the first non-empty line with an engine directive:

/codex hard reset the timeline
/claude shrink and store artifacts forever
/opencode hide their paper until they reply
/pi render a diorama of this timeline
/gemini analyse the codebase architecture
/amp review recent changes

Directives are only parsed at the start of the first non-empty line.

Untether working · codex · 5s · step 1

✓ Read `src/timeline.py`

🏷 codex

Set a default engine for the current scope

Use /agent:

/agent
/agent set claude
/agent clear

• Inside a forum topic, /agent set affects that topic.
• In normal chats, it affects the whole chat.
• In group chats, only admins can change defaults.

Selection precedence (highest to lowest): resume token → /<engine-id> directive → topic default → chat default → project default → global default.

Engine installation

Untether shells out to engine CLIs. Install them and make sure they’re on your PATH (codex, claude, opencode, pi, gemini, amp). Authentication is handled by each CLI.

Feature differences

Not all features are available on every engine. See the engine compatibility matrix in the README for a full breakdown of which features (interactive permissions, plan mode, reasoning levels, etc.) each engine supports.

Related

• Commands & directives
• Config reference
• Multi-engine workflows — tutorial on using multiple engines