alembic-migrations

name	alembic-migrations
description	Alembic migration patterns for SQLAlchemy 2.0 async. Use when creating database migrations, managing schema versions, handling zero-downtime deployments, or implementing reversible database changes.
context	fork
agent	database-engineer
version	2.0.0
tags	["alembic","migrations","sqlalchemy","database","schema","python","async",2026]
allowed-tools	["Read","Write","Edit","Bash","Grep","Glob"]
author	SkillForge
user-invocable	false

Alembic Migration Patterns (2026)

Database migration management with Alembic for SQLAlchemy 2.0 async applications.

When to Use

• Creating or modifying database tables and columns
• Auto-generating migrations from SQLAlchemy models
• Implementing zero-downtime schema changes
• Rolling back or managing migration history
• Adding indexes on large production tables
• Setting up Alembic with async PostgreSQL (asyncpg)

Quick Reference

Initialize Alembic (Async Template)

# Initialize with async template for asyncpg
alembic init -t async migrations

# Creates:
# - alembic.ini
# - migrations/env.py (async-ready)
# - migrations/script.py.mako
# - migrations/versions/

Async env.py Configuration

# migrations/env.py
import asyncio
from logging.config import fileConfig

from sqlalchemy import pool
from sqlalchemy.engine import Connection
from sqlalchemy.ext.asyncio import async_engine_from_config

from alembic import context

# Import your models' Base for autogenerate
from app.models.base import Base

config = context.config
if config.config_file_name is not None:
    fileConfig(config.config_file_name)

target_metadata = Base.metadata

def run_migrations_offline() -> None:
    """Run migrations in 'offline' mode - generates SQL."""
    url = config.get_main_option("sqlalchemy.url")
    context.configure(
        url=url,
        target_metadata=target_metadata,
        literal_binds=,
        dialect_opts={: },
    )
     context.begin_transaction():
        context.run_migrations()

 () -> :
    context.configure(connection=connection, target_metadata=target_metadata)
     context.begin_transaction():
        context.run_migrations()

  () -> :
    
    connectable = async_engine_from_config(
        config.get_section(config.config_ini_section, {}),
        prefix=,
        poolclass=pool.NullPool,
    )

      connectable.connect()  connection:
         connection.run_sync(do_run_migrations)

     connectable.dispose()

 () -> :
    
    asyncio.run(run_async_migrations())

 context.is_offline_mode():
    run_migrations_offline()
:
    run_migrations_online()