LongLink Applications / SDK

The LongLink SDK is the runtime and tooling layer for LongLink Applications. It provides the application factory, route registration, database helpers, storage access, XML page discovery, page manifest endpoint, testing defaults, and image labels expected by the LongLink Platform.

Application code owns the process-specific behavior: models, validation, workflows, actions, API routes, integrations, and XML pages. The SDK provides the runtime contract that lets the LongLink Platform run the application consistently across local development, tests, and production.

The packaged container image is the handoff from the SDK to the LongLink Platform. Local development uses the SDK runtime and local services, while production receives platform-managed database, storage, routing, identity, and deployment configuration.

Create a Project

Install LongLink:

bash
pip install longlink

Create the application scaffold:

bash
longlink init

longlink init creates an application scaffold with separate directories for routes, schemas, database models and services, XML pages, translations, migrations, environment declarations, and tests:

├── src/
│   ├── database/         # Database models and services
│   ├── i18n/             # Translation catalogs
│   ├── pages/            # XML page definitions
│   ├── routes/           # FastAPI route modules
│   ├── schemas/          # Pydantic request and response schemas
│   └── envs.py           # Environment settings
├── migrations/           # Alembic application migrations
├── tests/                # Application tests
├── main.py               # Application entry point
├── pyproject.toml        # Project configuration
├── .env.sample           # Environment template
├── .gitignore
├── AGENTS.md             # Application agent guide
└── README.md

Local Runtime

Install development dependencies:

bash
pip install .[dev]

Run the development server against main:app with the embedded SDK web bundle:

bash
longlink dev

The development server listens on 127.0.0.1 by default. Use --host only when you intentionally need access from another host.

For a small working application, see the LongLink sample repository(opens in new tab).