TypeScript in Retool: What's Supported and How to Work Around It

If you've tried to use TypeScript in Retool — whether in a script query, a transformer, or a custom component — you've already discovered the hard truth: Retool doesn't natively support TypeScript. You write plain JavaScript, and there's no built-in compiler, no type-checking, and no IntelliSense for your own data models. For teams that rely on typed data models in their main codebase, this gap is genuinely painful.

Why Developers Want TypeScript in Retool

The request isn't about preference — it's about scale. When your Retool app is small, vanilla JavaScript is fine. But as your internal tool grows, you start writing complex transformer logic, chaining multiple query outputs together, and passing data through layers of business logic. At that point, a single misnamed property or unexpected null can silently break everything — and you won't know until a user reports it.

• Data modeling: If your backend already defines TypeScript interfaces for your entities (users, orders, invoices), you want the same shape guarantees when you manipulate that data inside Retool.
• Complex scripts: Multi-step transformations inside a Run Script query are hard to maintain without type hints telling you what each variable actually contains.
• Team collaboration: When multiple developers work on the same Retool app, untyped code becomes a documentation problem. Types are self-documenting.

Does Retool Support TypeScript Natively?

As of now, Retool does not natively compile or execute TypeScript. All JavaScript written in Run Script queries, transformers, and event handlers runs as plain JS in the browser. The Retool team has acknowledged this as a filed feature request, but there is no public release date. If native TypeScript support matters to your team, upvoting the community thread is still the best way to signal demand.

Workarounds to Add Type Safety to Retool Today

While you wait for native support, there are practical strategies that give you meaningful type safety without leaving Retool entirely.

Option 1: Use JSDoc Annotations in Script Queries

JSDoc is the closest thing to TypeScript you can use inside Retool right now. You can annotate your variables and functions with type hints that most modern editors (VS Code, etc.) will understand if you develop your logic externally first.

• Write your complex transformer logic in a .js file locally with JSDoc comments like /** @type {string} */
• Use /** @param {Object} user */ /** @param {string} user.email */ to document expected shapes
• Copy the validated, documented code into your Retool Run Script or transformer

It's not a perfect workflow, but it means you catch shape mismatches before they hit Retool, and your script stays readable for other developers.

Option 2: Pre-compile TypeScript Externally

For teams with a build pipeline, this is the most robust option:

• Write your transformation or business logic in a .ts file in your local repo
• Compile it to JavaScript using tsc or a bundler like esbuild
• Paste the compiled output into a Retool Run Script query or Custom Component

This gives you full TypeScript safety during development. The compiled output is plain JavaScript, which Retool runs without issue. The downside is that edits require going back to your local file, recompiling, and re-pasting — but for stable, complex logic, that tradeoff is often worth it.

Option 3: Move Heavy Logic Out of Retool

If type safety is mission-critical for a particular piece of logic, consider moving it out of Retool entirely. You can expose it as a REST endpoint — built in TypeScript using Node.js, Deno, or any typed language — and call it from a REST API query in Retool. This keeps your typed business logic in a codebase you fully control, and Retool simply becomes the UI layer that calls it.

• Use a lightweight framework like Hono, Express, or Fastify with TypeScript
• Deploy to a serverless platform (Vercel, AWS Lambda, Cloudflare Workers)
• Call it from Retool with a Resource query pointed at your endpoint

What to Do Right Now

Until Retool ships native TypeScript support, here's the priority order for most teams:

• Small apps or simple logic: Write plain JavaScript, add JSDoc comments for the most critical functions, and don't over-engineer it.
• Growing apps with complex transformers: Adopt the external pre-compile workflow. Write in TypeScript locally, compile, paste.
• Enterprise apps with strict type requirements: Move critical logic to a typed API layer and call it from Retool. Keep Retool as pure UI.

The bottom line: TypeScript in Retool isn't natively available yet, but you're not powerless. Between JSDoc, external compilation, and API offloading, you can ship well-structured, maintainable Retool apps today — and be ready to adopt native TypeScript support the moment Retool ships it.