---
id: T01
parent: S07
milestone: M001
provides:
  - PipelineContext dataclass for runtime dependency injection
  - build_pipeline() returning compiled 5-node linear StateGraph
  - analyze_stage function querying DuckDB and calling LLM
  - ANALYZE_SYSTEM_PROMPT and format_analyze_user_message prompt layer
  - run_pipeline() async entry point with PipelineError wrapping
  - Stub stages (assess, generate, validate, decide) for Plan 02
requires: []
affects: []
key_files: []
key_decisions: []
patterns_established: []
observability_surfaces: []
drill_down_paths: []
duration: 10min
verification_result: passed
completed_at: 2026-03-11
blocker_discovered: false
---
# T01: 07-pipeline-core 01

**# Phase 7 Plan 1: Pipeline Graph + Analyze Stage Summary**

## What Happened

# Phase 7 Plan 1: Pipeline Graph + Analyze Stage Summary

**LangGraph 1.1.0 StateGraph with context_schema DI, working Analyze stage consuming 4 DuckDB queries, and pipeline runner with PipelineError wrapping**

## Performance

- **Duration:** 10 min
- **Started:** 2026-03-11T18:22:31Z
- **Completed:** 2026-03-11T18:32:58Z
- **Tasks:** 2
- **Files modified:** 15

## Accomplishments
- Installed LangGraph 1.1.0 and wired 5-node linear StateGraph with context_schema for dependency injection
- Implemented Analyze stage (Stage 1) that queries all 4 DuckDB analytics functions, formats results as JSON, and calls LLM with TrafficAnalysis response model
- Created pipeline runner with PipelineError wrapping on stage failure
- Built comprehensive test suite: 29 pipeline tests covering prompts, stages, graph construction, and error handling

## Task Commits

Each task was committed atomically:

1. **Task 1 (RED): Failing tests for graph, analyze stage, prompts** - `a9de53c` (test)
2. **Task 1 (GREEN): Pipeline graph, analyze stage, runner, prompts** - `607afc9` (feat)
3. **Task 2: Expand conftest with pipeline context and security assessment fixtures** - `62bb931` (test)

_Note: Task 1 followed TDD flow (RED then GREEN). Task 2 expanded the test infrastructure._

## Files Created/Modified
- `src/policyfoundry/pipeline/graph.py` - PipelineContext dataclass + build_pipeline() returning compiled StateGraph
- `src/policyfoundry/pipeline/runner.py` - run_pipeline() async entry point with PipelineError wrapping
- `src/policyfoundry/pipeline/stages/analyze.py` - Analyze stage querying 4 DuckDB functions and calling LLM
- `src/policyfoundry/pipeline/stages/assess.py` - Stub stage (Plan 02)
- `src/policyfoundry/pipeline/stages/generate.py` - Stub stage (Plan 02)
- `src/policyfoundry/pipeline/stages/validate.py` - Stub stage (Plan 02)
- `src/policyfoundry/pipeline/stages/decide.py` - Stub stage (Plan 02)
- `src/policyfoundry/pipeline/prompts/analyze.py` - ANALYZE_SYSTEM_PROMPT + format_analyze_user_message()
- `tests/test_pipeline/test_prompts.py` - 4 tests for prompt formatting
- `tests/test_pipeline/test_stages.py` - 7 tests for stages, graph, and runner
- `tests/test_pipeline/conftest.py` - Expanded with mock_adapter, mock_llm_client, mock_pipeline_context, sample data fixtures
- `pyproject.toml` - Added langgraph>=1.1.0 dependency

## Decisions Made
- Used LangGraph `context_schema` with `PipelineContext` dataclass for type-safe dependency injection -- avoids putting non-serializable objects (LLMClient, FirewallAdapter) in TypedDict state
- Targeted `type: ignore[reportUnknownVariableType]` comments for LangGraph dynamic types, consistent with Phase 06 precedent for litellm/instructor
- Stage functions return `dict[str, Any]` instead of bare `dict` to satisfy pyright strict mode
- Analyze stage uses temperature=0.1 (precision over creativity, per RESEARCH.md recommendation)
- System prompt instructs LLM to report "no data available" rather than hallucinate when data is empty

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered
- LangGraph multi-line import formatting with `type: ignore` comments caused ruff I001 (unsorted imports) -- resolved by using `ruff check --fix` and placing type: ignore on the specific import name line rather than the `from` line

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness
- Graph skeleton with 5 nodes compiled and tested -- Plan 02 replaces stub stages with real implementations
- PipelineContext pattern established for all future stages to follow
- Prompt separation pattern (prompts/stage.py) ready for assess, generate, decide prompts
- Full test infrastructure in place with mock fixtures for LLM, adapter, and DuckDB queries

## Self-Check: PASSED

All 10 created files verified present. All 3 task commits (a9de53c, 607afc9, 62bb931) verified in git log.

---
*Phase: 07-pipeline-core*
*Completed: 2026-03-11*
