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.
Anthropic announced on 18 May 2026 that it had acquired Stainless and would wind down all hosted Stainless products, including the SDK generator. New signups, projects and SDKs stopped the same day. Stainless says customers keep the SDKs generated to date and full rights to modify and extend them, and points existing customers at a transition page.
Stainless was a commercial SDK generation service. Its output is the most widely read generated code in the industry: the official OpenAI, Anthropic and Cloudflare client libraries, Meta's Llama Stack, Groq, Cerebras, LangChain and several hundred other providers. Most people who have used a modern AI API in Python or TypeScript have used a Stainless-generated SDK without knowing it.
The targets were TypeScript, Python, Go, Java, Kotlin, Ruby, C#, PHP and Terraform. Generated SDKs were licensed Apache 2.0 to the customer.
The design idea that made it work was a configuration layer sitting between the OpenAPI description and the output. The spec said what the API was. A separate Stainless config said what the library should feel like: resource naming, method names, pagination style, model names, which endpoints were promoted and which were hidden.
What that buys you is the ability to fix an SDK without touching the API description, and to keep the library's shape stable when the spec churns. It is the single most copied idea in this field. Voxgig's semantic model is a different answer to the same problem: rather than a config that adjusts the output, the model is a type-safe description of entities and operations that every surface is generated from.
Capabilities Stainless has that Voxgig does not, in enough detail to evaluate them.
Read the openai or anthropic Python and TypeScript libraries. They read as though a careful person wrote them, and they are generated. Streaming, typed errors, request IDs, automatic pagination, retries with idempotency, per-language conventions honoured rather than approximated. Those repositories are public, and they are the most detailed available reference for what generated output can look like.
Keeping library shape out of the API description is the right instinct, and it is why Stainless output looks designed rather than transcribed. It also makes the config an artefact that has to be maintained and understood, and it was proprietary. Both halves are relevant when evaluating any successor.
Stainless did not stop at SDKs. Its plans counted SDKs, documentation sites and Model Context Protocol servers as the same kind of thing, all generated from one API description and one config, and it led its own marketing on the MCP output rather than treating it as an add-on. That is the same bet Voxgig makes with its six surfaces, made independently, and it is the part of the product most worth copying: an MCP server hand-written beside a generated SDK drifts on the next release, and one generated from the same source cannot.
Standardised streaming, cursor and page-based auto-pagination, typed error hierarchies, and retry-with-idempotency across every language target, at a point when most of this field had none of them. A large part of what customers now expect from any SDK generator, Voxgig included, was normalised here first.
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.
| Stainless | Voxgig | |
|---|---|---|
| Status | Hosted products winding down since 18 May 2026. No new projects | Actively developed |
| Licence | Generator proprietary. Generated SDKs Apache 2.0 to the customer | Generator MIT. Generated SDKs are yours |
| Language targets | 9, including Terraform | 22 bundled language targets, more from packages |
| MCP server | Yes, while it was sold | Yes |
| Where the shape was decided | A proprietary config layer over the spec | A type-safe semantic model, in your repo |
| Where generation ran | The vendor's platform | Your machine |
| Regeneration after the vendor leaves | Not available | Runs from your repo with no account |
Corrections go to info@voxgig.com or an issue. A correction changes the page and moves its checked date; corrections from Stainless'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.