---
id: T01
parent: S02
milestone: M003
provides: []
requires: []
affects: []
key_files: ["backend/config.py", "backend/pipeline/stages.py", ".env.example"]
key_decisions: ["8 new Settings fields: llm_stage{2-5}_model (Optional[str]) and llm_stage{2-5}_modality (str, default 'chat')"]
patterns_established: []
drill_down_paths: []
observability_surfaces: []
duration: ""
verification_result: "Settings loads with default values (model=None, modality=chat)"
completed_at: 2026-03-30T01:46:57.859Z
blocker_discovered: false
---

# T01: Added per-stage LLM model/modality config fields to Settings and _get_stage_config helper

> Added per-stage LLM model/modality config fields to Settings and _get_stage_config helper

## What Happened
---
id: T01
parent: S02
milestone: M003
key_files:
  - backend/config.py
  - backend/pipeline/stages.py
  - .env.example
key_decisions:
  - 8 new Settings fields: llm_stage{2-5}_model (Optional[str]) and llm_stage{2-5}_modality (str, default 'chat')
duration: ""
verification_result: passed
completed_at: 2026-03-30T01:46:57.859Z
blocker_discovered: false
---

# T01: Added per-stage LLM model/modality config fields to Settings and _get_stage_config helper

**Added per-stage LLM model/modality config fields to Settings and _get_stage_config helper**

## What Happened

Added 8 per-stage config fields to Settings (model override + modality for stages 2-5), added _get_stage_config helper to stages.py, updated .env.example with commented examples showing recommended model assignments.

## Verification

Settings loads with default values (model=None, modality=chat)

## Verification Evidence

| # | Command | Exit Code | Verdict | Duration |
|---|---------|-----------|---------|----------|
| 1 | `cd backend && python3 -c "from config import Settings; s = Settings(); print(s.llm_stage2_model, s.llm_stage2_modality)"` | 0 | ✅ pass — None chat | 300ms |


## Deviations

None.

## Known Issues

None.

## Files Created/Modified

- `backend/config.py`
- `backend/pipeline/stages.py`
- `.env.example`


## Deviations
None.

## Known Issues
None.
