pg-codegen

Generate fully-typed TypeScript classes and interfaces from a live PostgreSQL schema via introspection.

Converts your PostgreSQL tables into idiomatic TypeScript code — fast, predictable, and schema-aware.

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✨ Features

🧠 Intelligent Introspection Pulls schema structure using native SQL introspection — no GraphQL required.

🧱 Interface + Class Output Generates matching interface + class pairs for each table using PascalCase naming.

🧹 Schema-Aware Output Writes files into schemas/<schema>.ts, grouped and re-exported from an index.ts.

🔗 Type Mapping for Postgres Primitives Supports UUID, Timestamp, Boolean, Text, Int, and nullable detection.

🪴 Auto Imports from _common.ts Deduplicates and imports shared scalar types intelligently.

🧪 Snapshot-Ready for Testing Babel AST-based output is stable and perfect for inline snapshot tests.

🛠️ Install

npm install pg-codegen

🚀 Usage

import { generateCodeTree } from 'pg-codegen';
import getIntrospectionRows from 'pg-codegen/introspect';

const rows = await getIntrospectionRows({
  client: pgClient,
  introspectionOptions: {
    pgLegacyFunctionsOnly: false,
    pgIgnoreRBAC: true
  },
  namespacesToIntrospect: ['my_schema'],
  includeExtensions: false
});

const output = generateCodeTree(rows, {
  includeUUID: true,
  includeTimestamps: true
});

// Example: write output['schemas/my_schema.ts'] to disk

📟 Example Output

// schemas/_common.ts
export type UUID = string;
export type Timestamp = string;

// schemas/my_schema.ts
import { UUID, Timestamp } from './_common';

export interface Users {
  id: UUID;
  email: string;
  created_at: Timestamp;
}

export class Users implements Users {
  id: UUID;
  email: string;
  created_at: Timestamp;

  constructor(data: Users) {
    this.id = data.id;
    this.email = data.email;
    this.created_at = data.created_at;
  }
}