# Implementation Plan: [FEATURE]

**Branch**: `[###-feature-name]` | **Date**: [DATE] | **Spec**: [link]
**Input**: Feature specification from `/specs/[###-feature-name]/spec.md`

**Note**: This template is filled in by the `/speckit.plan` command. See `.specify/templates/commands/plan.md` for the execution workflow.

## Summary

[Extract from feature spec: primary requirement + technical approach from research]

## Technical Context

<!--
  ACTION REQUIRED: Replace the content in this section with the technical details
  for the project. The structure here is presented in advisory capacity to guide
  the iteration process.
-->

**Language/Version**: Python 3.13
**Primary Dependencies**: FastAPI, garth, garminconnect, httpx, pydantic
**Storage**: centralDB (PostgreSQL/SQLite with SQLAlchemy)
**Testing**: pytest
**Target Platform**: Linux server
**Project Type**: Web (backend service)
**Performance Goals**: SC-001: Login within 10s; SC-003: Error response within 2s.
**Constraints**: Stateless API caller (no cookies); Single-user system; Automatic token refresh.
**Scale/Scope**: Single user, managing Garmin Connect data.

## Constitution Check

*GATE: Must pass before Phase 0 research. Re-check after Phase 1 design.*

- **Python Modernization**: Compliant (Python 3.13, type hints, dataclasses for schemas).
- **Virtual Environment Isolation**: Compliant (project uses .venv, dependencies pinned).
- **Test-Driven Development**: Compliant (spec includes tests, pytest is used).
- **Containerization Standards**: Compliant (project uses Docker Compose).
- **Project Structure Standards**: Compliant (modifies existing src/api and src/services).
- **Service-Specific Standards (garmin_sync_service)**: Compliant (implements Garmin Connect OAuth flow).
- **API Standards**: Compliant (FastAPI, OpenAPI, structured errors).
- **Code Quality Standards**: Compliant (Black, Flake8, Mypy, Isort).

No violations detected.

## Project Structure

### Documentation (this feature)

```
specs/[###-feature]/
├── plan.md              # This file (/speckit.plan command output)
├── research.md          # Phase 0 output (/speckit.plan command)
├── data-model.md        # Phase 1 output (/speckit.plan command)
├── quickstart.md        # Phase 1 output (/speckit.plan command)
├── contracts/           # Phase 1 output (/speckit.plan command)
└── tasks.md             # Phase 2 output (/speckit.tasks command - NOT created by /speckit.plan)
```

### Source Code (repository root)
<!--
  ACTION REQUIRED: Replace the placeholder tree below with the concrete layout
  for this feature. Delete unused options and expand the chosen structure with
  real paths (e.g., apps/admin, packages/something). The delivered plan must
  not include Option labels.
-->

```
# [REMOVE IF UNUSED] Option 1: Single project (DEFAULT)
src/
├── models/
├── services/
├── cli/
└── lib/

tests/
├── contract/
├── integration/
└── unit/

# [REMOVE IF UNUSED] Option 2: Web application (when "frontend" + "backend" detected)
backend/
├── src/
│   ├── models/
│   ├── services/
│   └── api/
└── tests/

frontend/
├── src/
│   ├── components/
│   ├── pages/
│   └── services/
└── tests/

# [REMOVE IF UNUSED] Option 3: Mobile + API (when "iOS/Android" detected)
api/
└── [same as backend above]

ios/ or android/
└── [platform-specific structure: feature modules, UI flows, platform tests]
```

**Structure Decision**: [Document the selected structure and reference the real
directories captured above]

## Complexity Tracking

*Fill ONLY if Constitution Check has violations that must be justified*

| Violation | Why Needed | Simpler Alternative Rejected Because |
|-----------|------------|-------------------------------------|
| [e.g., 4th project] | [current need] | [why 3 projects insufficient] |
| [e.g., Repository pattern] | [specific problem] | [why direct DB access insufficient] |