Problem:
When users execute `/think off`, they still receive `reasoning_content`
from models configured with `reasoning: true` (e.g., GLM-4.7, GLM-4.6,
Kimi K2.5, MiniMax-M2.1).
Expected: `/think off` should completely disable reasoning content.
Actual: Reasoning content is still returned.
Root Cause:
The directive handlers delete `sessionEntry.thinkingLevel` when user
executes `/think off`. This causes the thinking level to become undefined,
and the system falls back to `resolveThinkingDefault()`, which checks the
model catalog and returns "low" for reasoning-capable models, ignoring the
user's explicit intent.
Why We Must Persist "off" (Design Rationale):
1. **Model-dependent defaults**: Unlike other directives where "off" means
use a global default, `thinkingLevel` has model-dependent defaults:
- Reasoning-capable models (GLM-4.7, etc.) → default "low"
- Other models → default "off"
2. **Existing pattern**: The codebase already follows this pattern for
`elevatedLevel`, which persists "off" explicitly to override defaults
that may be "on". The comment explains:
"Persist 'off' explicitly so `/elevated off` actually overrides defaults."
3. **User intent**: When a user explicitly executes `/think off`, they want
to disable thinking regardless of the model's capabilities. Deleting the
field breaks this intent by falling back to the model's default.
Solution:
Persist "off" value instead of deleting the field in all internal directive handlers:
- `src/auto-reply/reply/directive-handling.impl.ts`: Directive-only messages
- `src/auto-reply/reply/directive-handling.persist.ts`: Inline directives
- `src/commands/agent.ts`: CLI command-line flags
Gateway API Backward Compatibility:
The original implementation incorrectly mapped `null` to "off" in
`sessions-patch.ts` for consistency with internal handlers. This was a
breaking change because:
- Previously, `null` cleared the override (deleted the field)
- API clients lost the ability to "clear to default" via `null`
- This contradicts standard JSON semantics where `null` means "no value"
Restored original null semantics in `src/gateway/sessions-patch.ts`:
- `null` → delete field, fall back to model default (clear override)
- `"off"` → persist explicit override
- Other values → normalize and persist
This ensures backward compatibility for API clients while fixing the `/think off`
issue in internal handlers.
Signed-off-by: Liu Yuan <namei.unix@gmail.com>
