---
phase: 01.5-evaluation-framework-for-gsd-lite
plan: 01
subsystem: testing
tags: [python, etl, sqlite, standard-library]

# Dependency graph
requires: []
provides:
  - "Simulation sandbox for GSD-lite evaluation"
  - "Standard library ETL pipeline (CSV -> SQLite)"
  - "Unit test suite for transformation logic"
affects:
  - "01.5-02-PLAN.md"

# Tech tracking
tech-stack:
  added: []
  patterns:
    - "Standard library only constraint"
    - "Modular ETL structure (extract/transform/load)"

key-files:
  created:
    - tests/eval_gsd_lite/src/pipeline.py
    - tests/eval_gsd_lite/src/etl/transform.py
    - tests/eval_gsd_lite/tests/test_transform.py
  modified: []

key-decisions:
  - "Used standard library only to avoid dependency management in evaluation"
  - "Implemented full ETL pattern despite simplicity to provide adequate surface area for agents"

patterns-established:
  - "Evaluation subject-under-test isolation in tests/eval_gsd_lite"

# Metrics
duration: 3 min
completed: 2026-01-26
---

# Phase 01.5 Plan 01: Simulation Sandbox Setup Summary

**Created dependency-free Python ETL pipeline to serve as evaluation subject-under-test**

## Performance

- **Duration:** 3 min
- **Started:** 2026-01-26
- **Completed:** 2026-01-26
- **Tasks:** 6
- **Files modified:** 9

## Accomplishments
- Established isolated simulation environment in `tests/eval_gsd_lite`
- Implemented working ETL pipeline (CSV -> SQLite) using only Python standard library
- Created unit tests verifying transformation logic
- Documented environment usage and constraints for agents

## Task Commits

Each task was committed atomically:

1. **Task 1 & 2: Create Simulation Structure & Data** - `77264d1` (feat)
2. **Task 3: Create Source Modules (ETL)** - `74987b1` (feat)
3. **Task 4: Create Pipeline Orchestrator** - `abff27e` (feat)
4. **Task 5: Create Unit Test** - `19c4203` (test)
5. **Task 6: Create Context README** - `ec5b204` (docs)

## Files Created/Modified
- `tests/eval_gsd_lite/src/pipeline.py` - Orchestrator script
- `tests/eval_gsd_lite/src/etl/extract.py` - CSV reading logic
- `tests/eval_gsd_lite/src/etl/transform.py` - Currency cleaning and record shaping
- `tests/eval_gsd_lite/src/etl/load.py` - SQLite schema init and data insertion
- `tests/eval_gsd_lite/data/input.csv` - Sample data
- `tests/eval_gsd_lite/tests/test_transform.py` - Unit tests
- `tests/eval_gsd_lite/README.md` - Context documentation

## Decisions Made
- **Standard Library Only:** Enforced no external dependencies to make the evaluation environment portable and fast to setup for agents.
- **Idempotent Load:** Implemented `DELETE FROM transactions` in load step to allow repeated pipeline runs during testing.

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered
None.

## Next Phase Readiness
- Sandbox is ready for creating the evaluation prompts and scenarios in Plan 02.
