@memberjunction/sqlglot-ts

A TypeScript wrapper for Python's sqlglot SQL transpiler. Provides deterministic, verifiable SQL dialect conversion via a managed local Python FastAPI microservice.

Features

• 31 SQL dialects supported (T-SQL, PostgreSQL, MySQL, Snowflake, BigQuery, etc.)
• Deterministic conversion — no LLM randomness, reproducible results
• Zero MemberJunction dependencies — standalone community package
• Ephemeral port binding — microservice runs on 127.0.0.1 with auto-assigned port
• Managed lifecycle — automatic startup/shutdown of the Python process
• Statement-by-statement mode — individual statement tracking, one failure doesn't block others

Prerequisites

• Python 3.9+ with sqlglot, fastapi, and uvicorn installed:

pip install sqlglot fastapi uvicorn

Usage

import { SqlGlotClient } from '@memberjunction/sqlglot-ts';

const client = new SqlGlotClient();
await client.start();

// Transpile T-SQL to PostgreSQL
const result = await client.transpile(
  "SELECT ISNULL(col, 0) FROM [dbo].[MyTable]",
  { fromDialect: 'tsql', toDialect: 'postgres' }
);
console.log(result.sql);
// Output: SELECT COALESCE(col, 0) FROM "dbo"."MyTable";

// Statement-by-statement mode
const stmtResult = await client.transpileStatements(
  "SELECT TOP 10 * FROM Users; SELECT GETDATE();",
  { fromDialect: 'tsql', toDialect: 'postgres' }
);
console.log(stmtResult.statements);

// Parse SQL to AST
const ast = await client.parse(
  "SELECT 1",
  { dialect: 'postgres' }
);

// List supported dialects
const dialects = await client.getDialects();

// Health check
const health = await client.health();

await client.stop();

API

SqlGlotClient

Constructor Options

| Option | Type | Default | Description | |--------|------|---------|-------------| | pythonPath | string | 'python3' | Path to Python executable | | serverPath | string | auto-detected | Path to server.py | | startupTimeoutMs | number | 30000 | Max ms to wait for server startup | | requestTimeoutMs | number | 60000 | Max ms per HTTP request |

Methods

• start() — Start the Python microservice
• stop() — Stop the Python microservice
• transpile(sql, options) — Transpile SQL between dialects (batch)
• transpileStatements(sql, options) — Transpile statement-by-statement
• parse(sql, options) — Parse SQL to AST (JSON)
• getDialects() — List all supported dialects
• health() — Server health check

Attribution

This package wraps the excellent sqlglot Python library by Toby Mao and contributors. sqlglot provides a comprehensive SQL parser, transpiler, and optimizer supporting 31 SQL dialects with 8,900+ stars and 7,000+ commits.

License

ISC