generate-crud-apis

Generate REST APIs from Prisma Schema

Generates complete API modules for ALL models in a Prisma schema with Supabase-compatible database operations — in one shot.

Supported Frameworks:

• NestJS (default): TypeScript, decorators, modules, dependency injection
• NodeJS: Express or Fastify, plain JavaScript/TypeScript routers
• FastAPI: Python, Pydantic models, async/await

Database Support:

• PostgreSQL: Full mode: 'insensitive' support for case-insensitive search
• SQLite: Case-insensitive LIKE by default, no mode argument needed

---

Framework Selection

Auto-Detection

The skill auto-detects the framework from the project structure:

Indicator	Framework
package.json with @nestjs/core	NestJS
package.json with express or fastify	NodeJS (Express/Fastify)
requirements.txt or pyproject.toml with fastapi	FastAPI

Manual Override

Specify explicitly in the prompt:

• generate APIs for NestJS
• generate APIs for Express
• generate APIs for FastAPI
• generate APIs for Fastify

---

Workflow

Step 1: Read Prisma Schema

Read {project}/back/prisma/schema.prisma and parse ALL models:

• Fields + types, Relations, Attributes, Enums, Provider

Step 2: Detect Framework

Check project structure to determine framework:

1. Look for package.json with NestJS/Express/Fastify dependencies
2. Look for requirements.txt or pyproject.toml with FastAPI
3. Default to NestJS if no clear indicator

Step 3: Check Existing Structure

Check existing API modules in the framework-appropriate location:

• NestJS: {project}/back/src/
• NodeJS: {project}/back/src/
• FastAPI: {project}/back/

Step 4: Generate Module for EACH Model

For every model in the schema, generate framework-specific files:

NestJS:

{project}/back/src/{modelName}/
  ├── {modelName}.controller.ts
  ├── {modelName}.service.ts
  ├── {modelName}.module.ts
  └── dto/
      ├── create-{modelName}.dto.ts
      └── query-{modelName}.dto.ts

NodeJS (Express/Fastify):

{project}/back/src/{modelName}/
  ├── {modelName}.router.js        # or .ts
  ├── {modelName}.service.js        # or .ts
  └── {modelName}.validation.js      # optional, for input validation

FastAPI:

{project}/back/
  ├── routers/
  │   └── {modelName}.py
  ├── services/
  │   └── {modelName}.py
  └── schemas/
      └── {modelName}.py

Step 5: Update App/Entry Point

Update the framework-specific entry point:

• NestJS: app.module.ts
• NodeJS: app.js or index.js
• FastAPI: main.py

---

Key Implementation Details

Database Detection (Shared)

The service auto-detects PostgreSQL vs SQLite from DATABASE_URL:

// TypeScript (NestJS/NodeJS)
function getDbProvider(connectionString: string): 'postgresql' | 'sqlite' {
  if (connectionString.startsWith('sqlite') || connectionString.includes('.db')) {
    return 'sqlite';
  }
  return 'postgresql';
}

# Python (FastAPI)
def get_db_provider(connection_string: str) -> str:
    if connection_string.startswith('sqlite') or '.db' in connection_string:
        return 'sqlite'
    return 'postgresql'

Filter Operators (Same Across All Frameworks)

Full reference: See references/filter-operators.md

Operator	PostgreSQL	SQLite	Description
ilike_{field}	{ contains: value, mode: 'insensitive' }	{ contains: value }	Case-insensitive (PG only)
textSearch_{field}	{ contains: value, mode: 'insensitive' }	{ contains: value }	Case-insensitive search
rangegt/gte/lt/lte/adjacent	Supported	Not supported	Range operators (PG only)
rpc	Supported	Throws error	Postgres function calls

API Response Format (Consistent Across All Frameworks)

All frameworks return the same pagination format:

{
  "data": [...],
  "count": 100,
  "page": 1,
  "perPage": 20
}

Controller/Router Implementation

Full implementation by framework:

• NestJS: See references/nestjs-controller.md
• NodeJS: See references/nodejs-implementation.md
• FastAPI: See references/fastapi-implementation.md

Service Implementation

Full implementation by framework:

• NestJS: See references/nestjs-service.md
• NodeJS: See references/nodejs-implementation.md
• FastAPI: See references/fastapi-implementation.md

---

Pagination (Same Across All Frameworks)

Always use Number() for skip and take (or equivalent):

// TypeScript
const skip = offset !== undefined ? Number(offset) : (Number(page) - 1) * Number(perPage);
const take = limit !== undefined ? Number(limit) : Number(perPage);

# Python
skip = offset if offset is not None else (page - 1) * per_page
take = limit if limit is not None else per_page

---

Error Handling (Same Across All Frameworks)

HTTP Code	Condition
200	Success
201	Created
400	Validation error, bad filter, RPC not supported
404	Record not found
409	Unique constraint violation
500	Server error

P2025 error code: Record not found

---

Quick Reference

Query Examples (Same Across All Frameworks)

GET /products?page=1&perPage=20
GET /products?sortBy=price,createdAt&order=asc,desc
GET /products?eq_category=electronics&lt_price=1000
GET /products?ilike_name=laptop
GET /products?in_category=electronics,books
GET /products?or=category.eq.electronics,price.lt.500

RPC Call (PostgreSQL only)

POST /products/rpc/my_function
Body: { "param1": "value1", "param2": 123 }

---

Database-Specific Features

Details: See references/database-specifics.md

PostgreSQL

• mode: 'insensitive' for case-insensitive search
• Full range operators
• RPC / function calls

SQLite

• LIKE is case-insensitive by default
• Range operators not supported
• RPC not supported

---

Field Type Mapping

Details: See references/field-types.md

Prisma Type	TypeScript/Python Type
String	string / str
Int	number / int
BigInt	bigint / int
Float	number / float
Decimal	string / str
Boolean	boolean / bool
DateTime	Date / datetime
Json	object / dict
Bytes	Buffer / bytes

---

Framework-Specific Notes

NestJS

Uses @Controller, @Injectable, @Get, @Post, decorators with full DI system.

Reference: references/nestjs-controller.md, references/nestjs-service.md

NodeJS (Express/Fastify)

Plain router pattern with express.Router() or Fastify's plugin system. Service layer is shared Prisma logic.

Reference: references/nodejs-implementation.md

FastAPI

Python with async/await, Pydantic for request/response validation, APIRouter for routing, Depends for DI.

Reference: references/fastapi-implementation.md

---

SQL Dev Endpoint (Optional)

For development convenience, add a raw SQL execution endpoint controlled by MODE=dev.

NestJS Implementation: See references/sql-dev-endpoint.md

For NodeJS/FastAPI, implement similar endpoint with MODE=dev check.