Seeding - 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:

# 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:

class UsersService:
    def get_users(self):
        return self.users_repository.get_all_users()

Then implement get_all_users() in the repository:

# 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:

# 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)

# 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:

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:

# 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.

​How mock data is generated

​Replacing mock data with real logic

​Seeding initial data

​Using the dry-run flag

​Mock data formats

How mock data is generated

Replacing mock data with real logic

Seeding initial data

Using the dry-run flag

Mock data formats