# Alembic

> >-

- **Type:** Skill
- **Install:** `agentstack add skill-terminalskills-skills-alembic`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [TerminalSkills](https://agentstack.voostack.com/s/terminalskills)
- **Installs:** 0
- **Category:** [Agent Skills](https://agentstack.voostack.com/c/agent-skills)
- **Latest version:** 0.1.0
- **License:** Apache-2.0
- **Upstream author:** [TerminalSkills](https://github.com/TerminalSkills)
- **Source:** https://github.com/TerminalSkills/skills/tree/main/skills/alembic
- **Website:** https://terminalskills.io/

## Install

```sh
agentstack add skill-terminalskills-skills-alembic
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Alembic

## Overview

Alembic is the migration tool for SQLAlchemy. It tracks database schema changes as versioned Python scripts — like Git for your database. Supports autogeneration from model changes, branching, and data migrations.

## Instructions

### Step 1: Setup

```bash
pip install alembic
alembic init alembic
```

```python
# alembic/env.py — Configure with async SQLAlchemy
from alembic import context
from sqlalchemy.ext.asyncio import create_async_engine
from models import Base
import asyncio

config = context.config
target_metadata = Base.metadata

def run_migrations_online():
    connectable = create_async_engine(config.get_main_option("sqlalchemy.url"))

    async def do_run():
        async with connectable.connect() as connection:
            await connection.run_sync(do_migrations)

    def do_migrations(connection):
        context.configure(connection=connection, target_metadata=target_metadata)
        with context.begin_transaction():
            context.run_migrations()

    asyncio.run(do_run())

run_migrations_online()
```

### Step 2: Create Migrations

```bash
# Auto-generate from model changes
alembic revision --autogenerate -m "add projects table"

# Create empty migration (for data migrations)
alembic revision -m "backfill user roles"
```

```python
# alembic/versions/001_add_projects.py — Generated migration
def upgrade():
    op.create_table('projects',
        sa.Column('id', sa.String(36), primary_key=True),
        sa.Column('name', sa.String(100), nullable=False),
        sa.Column('owner_id', sa.String(36), sa.ForeignKey('users.id')),
        sa.Column('created_at', sa.DateTime, server_default=sa.func.now()),
    )
    op.create_index('ix_projects_owner_id', 'projects', ['owner_id'])

def downgrade():
    op.drop_index('ix_projects_owner_id')
    op.drop_table('projects')
```

### Step 3: Data Migrations

```python
# alembic/versions/002_backfill_roles.py — Data migration
from alembic import op
import sqlalchemy as sa

def upgrade():
    # Add column
    op.add_column('users', sa.Column('role', sa.String(20), server_default='member'))

    # Backfill existing rows
    conn = op.get_bind()
    conn.execute(sa.text("UPDATE users SET role = 'admin' WHERE email LIKE '%@mycompany.com'"))

def downgrade():
    op.drop_column('users', 'role')
```

### Step 4: Commands

```bash
alembic upgrade head          # apply all pending migrations
alembic downgrade -1          # rollback one migration
alembic history               # show migration history
alembic current               # show current revision
alembic upgrade +1            # apply next migration only
```

## Guidelines

- Always review autogenerated migrations — they may miss renames (detected as drop+create).
- Run migrations in CI before deploying — catch schema issues early.
- Data migrations should be idempotent — safe to run multiple times.
- Use `op.batch_alter_table()` for SQLite (which doesn't support ALTER TABLE well).
- Never edit applied migrations — create new ones instead.

## Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [TerminalSkills](https://github.com/TerminalSkills)
- **Source:** [TerminalSkills/skills](https://github.com/TerminalSkills/skills)
- **License:** Apache-2.0
- **Homepage:** https://terminalskills.io/

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/skill-terminalskills-skills-alembic
- Seller: https://agentstack.voostack.com/s/terminalskills
- Browse the marketplace: https://agentstack.voostack.com/browse

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