Published by Voxgig, which makes one of the two tools compared here. Facts checked against the first-party sources linked below. Corrections go to info@voxgig.com. The scope and method for every page in this section are published.
@hey-api/openapi-ts is an MIT-licensed OpenAPI to TypeScript generator with millions of weekly npm downloads, used by Vercel, PayPal and others. It is TypeScript only, on purpose.
Its architecture is a plugin pipeline. You choose what gets generated: types alone, or types plus an SDK, plus Zod schemas, plus TanStack Query hooks, plus whatever else the twenty or so plugins cover. Clients are available for fetch, axios, Angular, Next and Nuxt.
It is funded by sponsorship, with a Hey API Platform in beta. Pricing for the platform has not been announced, and the project says there will always be a free plan. The generator itself is free and open source.
Capabilities Hey API has that Voxgig does not, in enough detail to evaluate them.
Nothing else in this comparison lets you choose the output at this resolution. Generate only types for a project that already has a client. Add a fetch client for one that does not. Add Zod validators where you take untrusted input, and TanStack Query hooks where you render it. Every other tool here, Voxgig included, generates a library shaped the way the generator thinks a library should be shaped.
This is the standout, and it is the clearest example of what specialising in one language buys you. For a React application talking to your API, generated query and mutation hooks with correct query keys per operation remove an entire hand-written layer that otherwise rots quietly every time the API changes. No multi-language generator will ever ship this, because the concept does not exist in Go, and that is exactly the point.
Runtime validation and static types from one source, in the shape the TypeScript ecosystem already uses, rather than a validation approach invented by the generator. Speakeasy does this too, in its own SDKs. Hey API gives it to you as a plugin you can point anywhere.
One language means the output can follow that language's conventions exactly instead of the shape that survives translation into seven of them. A multi-language generator compromises somewhere by construction: Voxgig's TypeScript is written by a generator that also has to emit Go.
No partial ticks and no asterisks. If a tool has a feature, the table says it has it. Where a row would need a paragraph to be true, it is a paragraph somewhere else on this page instead of a row here.
| Hey API | Voxgig | |
|---|---|---|
| Licence | MIT | MIT |
| Cost | Free. Platform in beta, unpriced | Free |
| Language targets | TypeScript | 22 bundled language targets, more from packages |
| Frontend integration | TanStack Query hooks, Angular, Next, Nuxt clients | None. The SDK is framework neutral |
| Runtime validation | Zod, as a plugin | Not generated. Types only |
| Cross-cutting behaviour | Per plugin and per client | 18 generated features, same options in every target |
| MCP server, CLI, REPL | No | Yes |
| Output shape | Whatever you enable, plugin by plugin | A complete SDK, features opt-in at construction |
Corrections go to info@voxgig.com or an issue. A correction changes the page and moves its checked date; corrections from Hey API's own team carry the most weight.
First-party sources for the claims on this page. Where they disagree with it, they are the authority.
The generator is MIT and open, and the catalog holds 600+ generated SDKs readable without installing anything.