Files
resolutionflow/backend
Michael Chihlas da93ae55c3 feat(ai): opt-in structured-system-block caching for one-shot generators (Phase 0.3)
Wraps each static system prompt in a single-block list so Phase 0.1's
AnthropicProvider applies cache_control: ephemeral automatically (policy α,
first block gets marked when no caller-authored cache_control is present).

Call sites:
- ai_tree_generator.scaffold_branches: SCAFFOLD_SYSTEM_PROMPT (~1k tokens)
- ai_tree_generator.generate_branch_detail: BRANCH_DETAIL_SYSTEM_PROMPT
  (~2.5k tokens with few-shot example); retries inside the same function
  re-read the cached block instead of paying full input cost on each attempt
- kb_conversion.convert_document: TROUBLESHOOTING or PROCEDURAL prompt
  (each caches independently by text content)
- ai_fix.generate_fixes: FIX_SYSTEM_PROMPT on first attempt + corrective retry
- script_builder.send_message: SYSTEM_PROMPT_TEMPLATE (per-session language
  substitution — same-language sessions share cache entries)

Each edit includes an inline comment explaining why the block is cacheable
(stable-constant, retry-reuse, per-language variant) so a future dev can
see the intent at the cache_control marker site.

script_builder history caching deliberately deferred — per Phase 0.1
decision (option i), AnthropicProvider does not automatically cache the
message list. If script_builder's growing 20-message history turns out
to be a visible cost driver via the anthropic.cache telemetry, route
that caller through the 0.4 chat wrapper which handles history caching.

No runtime verification from code-server; cache-hit behavior will be
confirmed against the new dev environment when it's up, per the inline
TODO(phase0-verify) in ai_provider.py.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-17 16:29:45 +00:00
..

Troubleshooting Decision Tree - Backend API

FastAPI backend for the Troubleshooting Decision Tree application.

Quick Start

1. Set up Python environment

cd backend
python -m venv venv

# Windows
venv\Scripts\activate

# macOS/Linux
source venv/bin/activate

pip install -r requirements.txt

2. Start PostgreSQL database

Using Docker:

docker-compose up -d

Or install PostgreSQL locally and create a database:

CREATE DATABASE decision_tree;

3. Configure environment

Copy the example env file and update as needed:

cp .env.example .env

4. Run database migrations

alembic upgrade head

5. Start the server

uvicorn app.main:app --reload --host 0.0.0.0 --port 8000

The API will be available at:

API Endpoints

Authentication

  • POST /api/v1/auth/register - Register new user
  • POST /api/v1/auth/login - Login (form data)
  • POST /api/v1/auth/login/json - Login (JSON body)
  • POST /api/v1/auth/refresh - Refresh token
  • GET /api/v1/auth/me - Get current user
  • POST /api/v1/auth/logout - Logout

Trees

  • GET /api/v1/trees - List all trees
  • GET /api/v1/trees/categories - List categories
  • GET /api/v1/trees/search?q=query - Search trees
  • GET /api/v1/trees/{id} - Get specific tree
  • POST /api/v1/trees - Create tree (engineer/admin)
  • PUT /api/v1/trees/{id} - Update tree (engineer/admin)
  • DELETE /api/v1/trees/{id} - Delete tree (admin)

Sessions

  • GET /api/v1/sessions - List user's sessions
  • GET /api/v1/sessions/{id} - Get specific session
  • POST /api/v1/sessions - Start new session
  • PUT /api/v1/sessions/{id} - Update session
  • POST /api/v1/sessions/{id}/complete - Complete session
  • POST /api/v1/sessions/{id}/export - Export session

Development

Create new migration

alembic revision --autogenerate -m "description"

Run migrations

alembic upgrade head

Rollback migration

alembic downgrade -1

Project Structure

backend/
├── alembic/              # Database migrations
│   └── versions/
├── app/
│   ├── api/
│   │   ├── endpoints/    # API route handlers
│   │   ├── deps.py       # Dependencies (auth, etc.)
│   │   └── router.py     # Main router
│   ├── core/
│   │   ├── config.py     # Settings
│   │   ├── database.py   # DB connection
│   │   └── security.py   # JWT, password hashing
│   ├── models/           # SQLAlchemy models
│   ├── schemas/          # Pydantic schemas
│   └── main.py           # FastAPI app
├── tests/
├── alembic.ini
├── docker-compose.yml
├── requirements.txt
└── README.md