---
phase: 08-stack-upgrade-backend-decomposition
plan: "02"
subsystem: api
tags: [pydantic, schemas, refactor, cross-package, backend]

# Dependency graph
requires:
  - phase: none
    provides: "Wave 0 prerequisite — no prior plan dependency"
provides:
  - "backend/api/schemas.py: new cross-package Pydantic schemas module with CloudConnectionOut"
  - "backend/api/cloud.py: no longer imports from api/admin (coupling eliminated)"
affects:
  - "08-04-admin-split: plan 08-04 will delete original CloudConnectionOut from admin.py and import from api.schemas"

# Tech tracking
tech-stack:
  added: []
  patterns:
    - "api/schemas.py as top-level home for Pydantic models shared across 2+ API packages (D-10)"

key-files:
  created:
    - backend/api/schemas.py
  modified:
    - backend/api/cloud.py

key-decisions:
  - "CloudConnectionOut stays duplicated in admin.py until plan 08-04 admin split (intentional transient state)"
  - "credentials_enc excluded from CloudConnectionOut field set — SEC-08 whitelist preserved verbatim"
  - "coerce_id_to_str field_validator preserved byte-identically to prevent any UUID serialization regression"

patterns-established:
  - "backend/api/schemas.py: shared Pydantic models for 2+ packages live here, not in any single package"

requirements-completed: [CODE-08]

# Metrics
duration: 5min
completed: 2026-06-08
---

# Phase 8 Plan 02: Shared Schemas Module Summary

**New `backend/api/schemas.py` cross-package module with `CloudConnectionOut` extracted from `api/admin.py`; `api/cloud.py` import switched from `api.admin` to `api.schemas`, eliminating cross-package coupling (Pitfall 3)**

## Performance

- **Duration:** ~5 min
- **Started:** 2026-06-08
- **Completed:** 2026-06-08
- **Tasks:** 2 / 2
- **Files modified:** 2 (1 created, 1 modified)

## Accomplishments

- Created `backend/api/schemas.py` as the canonical home for Pydantic response models shared across 2+ API packages (D-10)
- `CloudConnectionOut` copied verbatim from `api/admin.py` including SEC-08 docstring, 7-field whitelist, `from_attributes` config, and `coerce_id_to_str` field_validator
- Switched `backend/api/cloud.py` line 35 from `from api.admin import CloudConnectionOut` to `from api.schemas import CloudConnectionOut`
- All 51 cloud and admin tests continue to pass after the import switch
- Original `CloudConnectionOut` definition in `api/admin.py` left untouched — plan 08-04 owns the deletion during the admin split

## Task Commits

Each task was committed atomically:

1. **Task 1: Create backend/api/schemas.py with CloudConnectionOut** - `10e0900` (feat)
2. **Task 2: Switch backend/api/cloud.py import to api.schemas** - `61fa6e2` (refactor)

**Plan metadata:** (SUMMARY committed separately)

## Files Created/Modified

- `backend/api/schemas.py` — New cross-package Pydantic schemas module; contains `CloudConnectionOut` with SEC-08 whitelist, 7 fields, `coerce_id_to_str` validator
- `backend/api/cloud.py` — Single-line import change: `from api.admin` → `from api.schemas`

## Decisions Made

- Original `CloudConnectionOut` in `api/admin.py` is intentionally left in place until plan 08-04. Both definitions coexist temporarily; only `api/cloud.py` imports from `api/schemas`. This avoids a two-plan cascading dependency and is explicitly documented in T-08-02-03 as accepted transient duplication.
- No changes to any other file — plan scope held exactly.

## Deviations from Plan

None — plan executed exactly as written.

## Issues Encountered

- `tests/test_admin.py` does not exist; the correct file is `tests/test_admin_api.py`. Plan's verify command referenced the wrong filename, but the test run with the correct filename confirmed all 51 tests pass. No code change needed.

## User Setup Required

None — no external service configuration required.

## Next Phase Readiness

- `backend/api/schemas.py` is ready for plan 08-04 (admin split) to import from it and delete the original `CloudConnectionOut` from `api/admin.py`
- No blockers. Verification output: `51 passed, 5 warnings` from `pytest tests/test_cloud.py tests/test_admin_api.py -x -v`
- Final check: `grep -rn "from api.admin import CloudConnectionOut" backend/` returns no matches

---
*Phase: 08-stack-upgrade-backend-decomposition*
*Completed: 2026-06-08*