Extended Thinking

Aura supports extended thinking/reasoning, allowing models to reason before responding.

Thinking Levels

Level	Description
`off` / `false`	No thinking — direct response
`on` / `true`	Enable thinking at the default level (medium)
`low`	Minimal reasoning
`medium`	Moderate reasoning
`high`	Maximum reasoning effort

Set per-agent in the agent frontmatter via model.think.

Controls

Method	Description
`/think [level]` or `/effort`	Set thinking level (off, on, low, medium, high)
`Ctrl+R`	Toggle thinking off ↔ on (true)
`Ctrl+E`	Cycle all levels (off → on → low → medium → high → off)
`--think` flag	Set starting level from CLI

Thinking Display

Thinking blocks are rendered in faint gray in the TUI. Toggle visibility:

/verbose command
Ctrl+T keybinding

Prior Turn Handling

Each agent configures how thinking blocks from prior conversation turns are handled:

Mode	Description
`""` (default)	Keep thinking blocks as-is in history
`"strip"`	Strip thinking from older messages that exceed the token threshold
`"rewrite"`	Condense older thinking via a dedicated agent or self-rewrite

Set in agent frontmatter: thinking: "strip"

Both strip and rewrite respect configurable thresholds in features/thinking.yaml:

thinking:
  agent: Thinking        # dedicated agent for rewriting
  prompt: ""             # named prompt for self-rewrite (overrides agent)
  keep_last: 5           # recent messages whose thinking is preserved
  token_threshold: 300   # minimum tokens for a block to be affected

keep_last — the N most recent messages always keep their thinking blocks unchanged.
token_threshold — blocks below this threshold are left alone (small thinking blocks are cheap to keep).
prompt — when set, uses the current agent’s model with a named system prompt instead of delegating to a separate agent. Mirrors compaction’s self-compact pattern.

Agent resolution follows the same three-tier pattern as compaction:

prompt: set → self-rewrite with current model
agent: set → use dedicated Thinking agent
Neither → use pre-built thinking agent (error if nil)

Both modes mutate the builder in place — what the LLM sees is what gets saved to sessions and shown in /export.

If thinking: rewrite is configured and the agent or prompt cannot be resolved, it fails with an error. No silent fallback to stripping.