---
phase: 03-vault
plan: 01
subsystem: api
tags: [python, logging, vault, deanonymize, pii, scan_output, refactor]

# Dependency graph
requires:
  - phase: 02-scanners
    provides: scan_input() with vault accumulation scaffolded, ScanResult.placeholders field
  - phase: 01-foundation
    provides: Guard class, _build_session, exceptions, models
provides:
  - _scan() private method (shared HTTP+vault logic for scan_input and scan_output)
  - scan_output(text, scanners) fully implemented (delegates to _scan, same as scan_input)
  - deanonymize() enhanced with debug logging (empty vault and no-match paths)
  - Module-level logger via logging.getLogger(__name__)
affects:
  - 03-vault demo (Gemini chatbot integration)
  - Future phases that test the full anonymize → LLM → deanonymize workflow

# Tech tracking
tech-stack:
  added: [Python stdlib logging]
  patterns:
    - Private _scan() extraction for DRY HTTP+vault logic shared across scan_input/scan_output
    - Module-level logger = logging.getLogger(__name__) for SDK observability
    - Longest-first sort in deanonymize() as defensive measure against placeholder prefix overlap

key-files:
  created: []
  modified:
    - src/meshulash_guard/guard.py

key-decisions:
  - "scan_output(text, scanners) matches scan_input signature -- both delegate to _scan()"
  - "deanonymize uses sorted(vault.items(), key=len, reverse=True) for longest-first replacement"
  - "debug level (not warning) for deanonymize log -- empty vault and no-match are normal non-error conditions"

patterns-established:
  - "DRY scan pattern: scan_input and scan_output both delegate to _scan() private method"
  - "Debug-level logging for expected non-error conditions in SDK flow"
  - "Longest-first replacement order in deanonymize() as defensive anti-prefix-overlap measure"

# Metrics
duration: 1min
completed: 2026-02-26
---

# Phase 3 Plan 01: Vault Workflow Summary

**Completed vault workflow: _scan() private method DRY-extracts HTTP+vault logic, scan_output() implemented with (text, scanners) signature, deanonymize() enhanced with stdlib debug logging for empty vault and no-match paths**

## Performance

- **Duration:** 1 min
- **Started:** 2026-02-26T19:11:30Z
- **Completed:** 2026-02-26T19:12:54Z
- **Tasks:** 2
- **Files modified:** 1

## Accomplishments
- Extracted _scan() private method from scan_input() -- all HTTP, error handling, and vault accumulation logic lives in one place
- Replaced scan_output() NotImplementedError stub with a real implementation using the same (text, scanners) signature as scan_input()
- Enhanced deanonymize() with two debug log paths: empty vault early return and no-match warning after replacements
- Added module-level logger = logging.getLogger(__name__) -- SDK is now observable at DEBUG level
- Verified complete vault workflow end-to-end without live server: accumulation, multi-occurrence replacement, clear_cache, debug logging

## Task Commits

Each task was committed atomically:

1. **Task 1: Refactor guard.py -- extract _scan(), implement scan_output(), enhance deanonymize()** - `6dede59` (feat)

_Task 2 was a verification-only task (no file changes); all assertions passed in-process._

**Plan metadata:** (docs commit follows)

## Files Created/Modified
- `src/meshulash_guard/guard.py` - Added import logging, module-level logger, _scan() private method, working scan_output(), enhanced deanonymize() with debug paths and longest-first sort

## Decisions Made
- scan_output(text, scanners) signature matches scan_input -- same endpoint, same payload, same vault accumulation
- deanonymize sorts vault by placeholder length descending (longest first) as a defensive measure against prefix overlap -- cost is negligible (vault is small), correctness benefit is real
- debug level for deanonymize logs: empty vault and no-match are expected in normal non-PII flows, not error conditions

## Deviations from Plan

None - plan executed exactly as written.

## Issues Encountered

None.

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness
- Vault workflow is complete: scan_input, scan_output, deanonymize, clear_cache all work together
- Module-level logger provides observability when developers enable DEBUG logging
- Ready for the Gemini chatbot demo (Phase 3.1) and any end-to-end integration tests
- Server integration still requires the /api/security/scan endpoint to be deployed and reachable (pre-existing concern, not introduced here)

---
*Phase: 03-vault*
*Completed: 2026-02-26*
