> ## Documentation Index
> Fetch the complete documentation index at: https://docs.backant.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Seeding

> Replacing mock data with real database logic in BackAnt.

BackAnt's code generator lets you scaffold routes with mock data so your API is immediately testable without a database. Seeding in BackAnt means replacing that generated mock data with real repository calls.

## How mock data is generated

When you run `ant generate route users --mock '[{"id": 1, "name": "Alice"}]'`, the generated service returns the mock data directly:

```python theme={null}
# api/services/users_service.py (generated with mock)
class UsersService:
    def get_users(self):
        mock_data = [{"id": 1, "name": "Alice"}]
        return mock_data
```

## Replacing mock data with real logic

Open the service file and replace the mock return with a repository call:

```python theme={null}
class UsersService:
    def get_users(self):
        return self.users_repository.get_all_users()
```

Then implement `get_all_users()` in the repository:

```python theme={null}
# api/repositories/users_repository.py
from sqlalchemy import select
from models.Users_model import Users
from helper.DBSession import myDB

class UsersRepository(Repository):
    def get_all_users(self):
        stmt = select(Users)
        return myDB.execute(stmt).scalars().all()
```

## Seeding initial data

To seed the database with initial records, add a seed function to a repository and call it from `init_db()` in `startup/Alchemy.py`:

```python theme={null}
# api/repositories/users_repository.py
def seed(self):
    if myDB.execute(select(Users)).scalars().first():
        return  # already seeded
    users = [
        Users(name="Alice", email="alice@example.com"),
        Users(name="Bob", email="bob@example.com"),
    ]
    myDB.add_all(users)
```

```python theme={null}
# api/startup/Alchemy.py — inside init_db()
def init_db():
    import models.Users_model
    Base.metadata.create_all(engine)

    from repositories.users_repository import myUsersRepository
    myUsersRepository.seed()
```

## Using the dry-run flag

Before generating a project, you can validate a spec without creating any files:

```bash theme={null}
ant generate api my-api --json api-spec.json --dry-run
```

This lets you iterate on your spec (including mock data) until it's correct, then generate for real.

## Mock data formats

Mock data can be any valid JSON value:

```bash theme={null}
# Array of objects (most common)
ant generate route users --mock '[{"id": 1, "name": "Alice"}]'

# Single object
ant generate route health --mock '{"status": "ok"}'

# String
ant generate route ping --mock '"pong"'
```

Mock data is embedded directly in the generated Python file as a literal — replace it with real repository calls when you are ready to connect to the database.