---
id: T01
parent: S03
milestone: M001
provides: []
requires: []
affects: []
key_files: ["backend/config.py", "backend/worker.py", "backend/pipeline/schemas.py", "backend/pipeline/llm_client.py", "backend/requirements.txt", "backend/pipeline/__init__.py", "backend/pipeline/stages.py"]
key_decisions: ["Used sync openai.OpenAI (not Async) since Celery tasks run synchronously", "LLMClient catches APIConnectionError and APITimeoutError for fallback; other errors propagate immediately", "Created pipeline/stages.py stub so worker.py import chain works ahead of T02"]
patterns_established: []
drill_down_paths: []
observability_surfaces: []
duration: ""
verification_result: "All 5 verification checks passed: Settings prints correct defaults (llm_api_url, qdrant_url, review_mode), all 4 schema classes import successfully, LLMClient imports clean, celery_app.main prints 'chrysopedia', and grep confirms openai/qdrant-client in requirements.txt. Additional validation confirmed all 12 config fields present, all 8 schema classes importable, sync OpenAI usage (not Async), and fallback exception handling wired."
completed_at: 2026-03-29T22:30:25.116Z
blocker_discovered: false
---

# T01: Extended Settings with 12 LLM/embedding/Qdrant config fields, created Celery app, built sync LLMClient with primary/fallback logic, and defined 8 Pydantic schemas for pipeline stages 2-5

> Extended Settings with 12 LLM/embedding/Qdrant config fields, created Celery app, built sync LLMClient with primary/fallback logic, and defined 8 Pydantic schemas for pipeline stages 2-5

## What Happened
---
id: T01
parent: S03
milestone: M001
key_files:
  - backend/config.py
  - backend/worker.py
  - backend/pipeline/schemas.py
  - backend/pipeline/llm_client.py
  - backend/requirements.txt
  - backend/pipeline/__init__.py
  - backend/pipeline/stages.py
key_decisions:
  - Used sync openai.OpenAI (not Async) since Celery tasks run synchronously
  - LLMClient catches APIConnectionError and APITimeoutError for fallback; other errors propagate immediately
  - Created pipeline/stages.py stub so worker.py import chain works ahead of T02
duration: ""
verification_result: passed
completed_at: 2026-03-29T22:30:25.116Z
blocker_discovered: false
---

# T01: Extended Settings with 12 LLM/embedding/Qdrant config fields, created Celery app, built sync LLMClient with primary/fallback logic, and defined 8 Pydantic schemas for pipeline stages 2-5

**Extended Settings with 12 LLM/embedding/Qdrant config fields, created Celery app, built sync LLMClient with primary/fallback logic, and defined 8 Pydantic schemas for pipeline stages 2-5**

## What Happened

Added openai, qdrant-client, and pyyaml to requirements.txt. Extended the Settings class with 12 new fields covering LLM endpoints (primary + fallback), embedding config, Qdrant connection, prompt template path, and review mode toggle. Created the Celery app in worker.py using Redis as broker/backend. Built the pipeline package with 8 Pydantic schemas matching the DB column types, and an LLMClient using sync openai.OpenAI with primary/fallback completion logic that catches APIConnectionError and APITimeoutError for fallback trigger. Created a stub pipeline/stages.py so the worker import chain succeeds ahead of T02.

## Verification

All 5 verification checks passed: Settings prints correct defaults (llm_api_url, qdrant_url, review_mode), all 4 schema classes import successfully, LLMClient imports clean, celery_app.main prints 'chrysopedia', and grep confirms openai/qdrant-client in requirements.txt. Additional validation confirmed all 12 config fields present, all 8 schema classes importable, sync OpenAI usage (not Async), and fallback exception handling wired.

## Verification Evidence

| # | Command | Exit Code | Verdict | Duration |
|---|---------|-----------|---------|----------|
| 1 | `cd backend && python -c "from config import Settings; s = Settings(); print(s.llm_api_url, s.qdrant_url, s.review_mode)"` | 0 | ✅ pass | 500ms |
| 2 | `cd backend && python -c "from pipeline.schemas import SegmentationResult, ExtractionResult, ClassificationResult, SynthesisResult; print('schemas ok')"` | 0 | ✅ pass | 400ms |
| 3 | `cd backend && python -c "from pipeline.llm_client import LLMClient; print('client ok')"` | 0 | ✅ pass | 500ms |
| 4 | `cd backend && python -c "from worker import celery_app; print(celery_app.main)"` | 0 | ✅ pass | 500ms |
| 5 | `grep -q 'openai' backend/requirements.txt && grep -q 'qdrant-client' backend/requirements.txt` | 0 | ✅ pass | 50ms |


## Deviations

Created backend/pipeline/stages.py as a stub module so worker.py import chain succeeds. Not in the task plan but required for worker.py to be importable.

## Known Issues

None.

## Files Created/Modified

- `backend/config.py`
- `backend/worker.py`
- `backend/pipeline/schemas.py`
- `backend/pipeline/llm_client.py`
- `backend/requirements.txt`
- `backend/pipeline/__init__.py`
- `backend/pipeline/stages.py`


## Deviations
Created backend/pipeline/stages.py as a stub module so worker.py import chain succeeds. Not in the task plan but required for worker.py to be importable.

## Known Issues
None.
