---
name: pydantic-models-py
description: "Create Pydantic models following the multi-model pattern with Base, Create, Update, Response, and InDB variants. Use when defining API request/response schemas, database models, or data validation ..."
risk: unknown
source: community
---
# Pydantic Models
Create Pydantic models following the multi-model pattern for clean API contracts.
## Quick Start
Copy the template from assets/template.py and replace placeholders:
- `{{ResourceName}}` → PascalCase name (e.g., `Project`)
- `{{resource_name}}` → snake_case name (e.g., `project`)
## Multi-Model Pattern
| Model | Purpose |
|-------|---------|
| `Base` | Common fields shared across models |
| `Create` | Request body for creation (required fields) |
| `Update` | Request body for updates (all optional) |
| `Response` | API response with all fields |
| `InDB` | Database document with `doc_type` |
## camelCase Aliases
```python
class MyModel(BaseModel):
workspace_id: str = Field(..., alias="workspaceId")
created_at: datetime = Field(..., alias="createdAt")
class Config:
populate_by_name = True # Accept both snake_case and camelCase
```
## Optional Update Fields
```python
class MyUpdate(BaseModel):
"""All fields optional for PATCH requests."""
name: Optional[str] = Field(None, min_length=1)
description: Optional[str] = None
```
## Database Document
```python
class MyInDB(MyResponse):
"""Adds doc_type for Cosmos DB queries."""
doc_type: str = "my_resource"
```
## Integration Steps
1. Create models in `src/backend/app/models/`
2. Export from `src/backend/app/models/__init__.py`
3. Add corresponding TypeScript types
## When to Use
This skill is applicable to execute the workflow or actions described in the overview.