schema-alignment
Detect and report drift between database schema and code data models. Works with SQLAlchemy, Django ORM, Prisma, TypeORM, and other ORMs. Generic across any project.
When & Why to Use This Skill
The Schema Alignment skill is a powerful, framework-agnostic tool designed to detect and report 'drift' between database schemas and application code models. By supporting a wide range of ORMs including SQLAlchemy, Django, Prisma, and TypeORM, it ensures data integrity and consistency across the entire development lifecycle. It automatically identifies missing columns, data type mismatches, orphaned migrations, and naming inconsistencies, providing actionable fix suggestions to prevent runtime errors and deployment failures.
Use Cases
- Pre-deployment Validation: Automatically verify that database migrations are perfectly aligned with code models before merging pull requests to prevent production crashes.
- Legacy System Auditing: Quickly map and identify discrepancies in older projects where the live database schema may have diverged from the original source code or documentation.
- Automated Migration Generation: Use the drift detection report to automatically generate the necessary migration scripts (e.g., Alembic or Django migrations) for missing columns or type changes.
- Cross-Stack Consistency: Maintain schema synchronization in polyglot architectures where multiple services written in different languages (e.g., Python/SQLAlchemy and TypeScript/Prisma) share the same database.
- CI/CD Quality Gate: Integrate into continuous integration pipelines as a mandatory check to ensure no code changes are committed without corresponding database schema updates.
| name | schema-alignment |
|---|---|
| description | "Detect and report drift between database schema and code data models. Works with SQLAlchemy, Django ORM, Prisma, TypeORM, and other ORMs. Generic across any project." |
Schema Alignment Skill
Detect drift between database schemas and code data models. This skill identifies missing columns, type mismatches, orphaned migrations, and naming inconsistencies.
Design Principle
This skill is framework-generic. It works with any ORM or database:
- SQLAlchemy (Python)
- Django ORM (Python)
- Prisma (TypeScript/JavaScript)
- TypeORM (TypeScript)
- Drizzle (TypeScript)
- Alembic migrations
- Prisma migrations
- Django migrations
Variables
| Variable | Default | Description |
|---|---|---|
| SCHEMA_SOURCE | auto | Schema source: auto, migrations, live_db, models |
| SEVERITY_THRESHOLD | medium | Report issues at this level or higher |
| AUTO_FIX | false | Attempt to generate fix suggestions |
| INCLUDE_TYPES | true | Include type mismatch detection |
Instructions
MANDATORY - Follow the Workflow steps below in order.
- Detect database technology and ORM in use
- Extract schema from migrations or live database
- Extract data models from code
- Compare and identify drift
- Generate alignment report
Red Flags - STOP and Reconsider
If you're about to:
- Modify the database schema directly without a migration
- Assume a column exists without checking the schema
- Skip type checking because "it works in tests"
- Ignore nullable/not-null mismatches
STOP -> Check schema alignment -> Generate migration if needed -> Then proceed
Workflow
1. Detect Stack
Identify the database and ORM:
Check for these indicators:
| File/Dependency | Technology |
|-----------------|------------|
| alembic.ini, alembic/ | Alembic (SQLAlchemy) |
| prisma/schema.prisma | Prisma |
| manage.py + migrations/ | Django |
| ormconfig.json | TypeORM |
| drizzle.config.ts | Drizzle |
| supabase/migrations/ | Supabase (PostgreSQL) |
2. Extract Database Schema
Option A: From Migrations (Preferred)
Parse migration files to reconstruct current schema:
# Alembic example
from alembic.script import ScriptDirectory
from alembic.config import Config
config = Config("alembic.ini")
scripts = ScriptDirectory.from_config(config)
# Walk revisions to build schema
Option B: From Live Database
Query information_schema (if accessible):
SELECT table_name, column_name, data_type, is_nullable
FROM information_schema.columns
WHERE table_schema = 'public';
Option C: From Model Definitions
Parse ORM model files directly.
3. Extract Code Models
Parse model definitions from code:
SQLAlchemy
# Look for patterns like:
class User(Base):
__tablename__ = 'users'
id = Column(Integer, primary_key=True)
email = Column(String(255), nullable=False)
Prisma
model User {
id Int @id @default(autoincrement())
email String @unique
name String?
}
Pydantic/TypeScript Types
Also extract related types:
- Pydantic models
- TypeScript interfaces
- BAML type definitions
4. Compare and Detect Drift
Run comparisons:
| Check | Source A | Source B | Issue Type |
|---|---|---|---|
| Missing column | DB schema | ORM model | MISSING_IN_MODEL |
| Missing column | ORM model | DB schema | MISSING_IN_DB |
| Type mismatch | DB type | Code type | TYPE_MISMATCH |
| Nullable mismatch | DB nullable | Model nullable | NULLABLE_MISMATCH |
| Name mismatch | snake_case | camelCase | NAMING_DRIFT |
| Missing migration | Model change | Migration files | MISSING_MIGRATION |
| FK constraint | DB constraint | ORM relationship | FK_MISMATCH |
5. Generate Report
Output format:
# Schema Alignment Report
**Generated**: 2025-12-24T10:00:00Z
**Database**: PostgreSQL (via Supabase)
**ORM**: SQLAlchemy 2.0
## Summary
| Severity | Count |
|----------|-------|
| HIGH | 2 |
| MEDIUM | 3 |
| LOW | 5 |
## Issues
### 1. MISSING_IN_MODEL (HIGH)
**Table**: `curation_jobs`
**Column**: `retry_count` (INTEGER NOT NULL DEFAULT 0)
**Model**: `src/models/curation_job.py:CurationJob`
The column exists in the database but is not defined in the ORM model.
**Fix**:
```python
retry_count: Mapped[int] = mapped_column(Integer, default=0)
2. TYPE_MISMATCH (MEDIUM)
Table: books
Column: isbn (VARCHAR(13))
Model: src/models/book.py:Book.isbn -> str
Database constrains to 13 characters but model allows unbounded string.
Fix:
isbn: Mapped[str] = mapped_column(String(13))
3. MISSING_MIGRATION (LOW)
Model Change: User.preferences added (JSONB)
Migration: Not found
A new column was added to the model but no migration exists.
Fix:
alembic revision --autogenerate -m "add user preferences"
## Cookbook
### SQLAlchemy Detection
- IF: Parsing SQLAlchemy models
- THEN: Read and execute `./cookbook/sqlalchemy-detection.md`
### Prisma Detection
- IF: Parsing Prisma schema
- THEN: Read and execute `./cookbook/prisma-detection.md`
### Alembic Migrations
- IF: Generating migration fix
- THEN: Read and execute `./cookbook/alembic-migration.md`
## Issue Severity Matrix
| Issue Type | Default Severity | Upgrade If |
|------------|-----------------|------------|
| MISSING_IN_MODEL | HIGH | Column is NOT NULL |
| MISSING_IN_DB | MEDIUM | Model references it |
| TYPE_MISMATCH | MEDIUM | Could cause data loss |
| NULLABLE_MISMATCH | LOW | NOT NULL in code, nullable in DB |
| NAMING_DRIFT | LOW | - |
| MISSING_MIGRATION | LOW | - |
| FK_MISMATCH | MEDIUM | Causes ORM errors |
## Integration
### With /ai-dev-kit:check-schema
Direct invocation:
```bash
# Full check
/ai-dev-kit:check-schema
# Check specific tables
/ai-dev-kit:check-schema --tables=users,orders
# Generate fixes
/ai-dev-kit:check-schema --auto-fix
# Output to file
/ai-dev-kit:check-schema --output=alignment-report.md
With /ai-dev-kit:execute-lane
Runs as pre-flight check for database-related lanes:
Lane: SL-DB (Database Schema)
Pre-flight checks:
1. ✓ Git worktree clean
2. ✗ Schema alignment check failed
- 2 HIGH severity issues found
- See alignment-report.md
Action: Resolve schema issues before proceeding.
With /ai-dev-kit:plan-phase
Runs during phase planning:
Planning Phase P1...
Schema Alignment: ⚠️ 3 issues detected
- 1 missing migration
- 2 type mismatches
Recommendation: Add schema alignment task to SL-DB lane.
Output Schema
{
"$schema": "http://json-schema.org/draft-07/schema#",
"type": "object",
"properties": {
"generated_at": {"type": "string", "format": "date-time"},
"database": {"type": "string"},
"orm": {"type": "string"},
"summary": {
"type": "object",
"properties": {
"high": {"type": "integer"},
"medium": {"type": "integer"},
"low": {"type": "integer"}
}
},
"issues": {
"type": "array",
"items": {
"type": "object",
"properties": {
"type": {"type": "string"},
"severity": {"enum": ["HIGH", "MEDIUM", "LOW"]},
"table": {"type": "string"},
"column": {"type": "string"},
"model_location": {"type": "string"},
"description": {"type": "string"},
"fix": {"type": "string"}
}
}
}
}
}
Best Practices
- Run regularly: Check schema alignment before each PR
- CI integration: Add to CI pipeline for automatic detection
- Migration hygiene: Always generate migrations for model changes
- Type consistency: Use explicit types in models matching DB constraints
- Document drift: If drift is intentional, document why