Four independent hosted OpenAPI-to-SDK vendors have exited in twenty months. Konfig shut down entirely in December 2024. Postman acquired liblab in November 2025 and Fern in January 2026. Anthropic acquired Stainless in May 2026 and is winding down its hosted product. Each deal got its own coverage at the time; nobody had put all four dates, sources, and outcomes in one table. That's what this post is. Disclosure: we build Sourced, one of the vendor-neutral hosted options still standing — read the rest with that in mind.
Four exits, in order
Konfig, December 2024. Founder Dylan Huang closed the company and open-sourced the code "exactly as it was when we shut down," in a post dated November 25, 2024. The konfig-dev/konfig GitHub repository description now reads "SDK & API Docs Generator. Sunset as of December 2024," and its last commit is from that December. The repo isn't archived, but nothing has touched it since — no bug fixes, no spec-format updates, no security patches.
liblab, November 14, 2025. Postman announced the acquisition the same day liblab published its own post. Founder Sagiv Ofek wrote that "nothing is changing for you today" and that existing users "can continue to use the platform exactly as you do now." The longer-term plan, per that same post, is integration: SDK generation moving into Postman's platform rather than staying a separate product indefinitely. As of September 2026, liblab.com is still live as a standalone product with six SDK languages and an active CLI — it has not shut down, but its identity as a separate tool has an unannounced expiration date.
Fern, January 8, 2026. Postman announced this acquisition on its own blog: "Today, I'm excited to share that Postman has acquired Fern... The entire Fern team is joining Postman to continue building Fern. The product, brand, and roadmap will stay the same, and existing customers won't see any changes." That's a different shape of exit than liblab's — no stated integration plan, at least not yet, and Fern's own pricing page still shows an active Free-forever tier, an Enterprise tier, and a working "Get started" signup flow as of this writing. Fern is Postman-owned now, but nothing about its product surface has visibly changed.
Stainless, May 15, 2026. Stainless announced it was joining Anthropic and that, starting that day, "new signups, projects, and SDKs will not be available." The company said it's winding down its hosted SDK generator and Docs Platform. Customers keep the SDK code already generated, and eligible customers can use a source-available CLI for local, self-hosted generation. The announcement doesn't give a fixed date for when the wind-down completes — only that new activity stopped immediately.
The table
| Date | Company | Outcome | Primary source |
|---|---|---|---|
| Dec 2024 | Konfig | Shut down entirely; code open-sourced, unmaintained since | github.com/konfig-dev/konfig |
| Nov 14, 2025 | liblab | Acquired by Postman; live standalone today, integration planned | liblab.com/blog/liblab-joins-postman |
| Jan 8, 2026 | Fern | Acquired by Postman; product, brand, roadmap stated unchanged | blog.postman.com/postman-acquires-fern |
| May 15, 2026 | Stainless | Acquired by Anthropic; hosted product winding down, new signups closed same day | stainless.com/blog/stainless-is-joining-anthropic |
What each exit meant for customers
The four outcomes aren't the same shape, and treating them as interchangeable would flatten a real distinction. Konfig's customers lost an actively maintained product outright — the code still runs, but it's frozen. liblab and Fern customers didn't lose anything on the day of their acquisitions; both companies say the product kept running as-is, and both still do as of September 2026. The difference between those two is what happens next: liblab's founder explicitly framed integration into Postman as the plan, while Fern's announcement makes no such statement either way. Stainless customers are the only group in this table who lost the ability to start anything new the same day the news broke — existing SDKs and docs kept working, but the door closed on new projects immediately, which is a sharper cutoff than either Postman acquisition produced.
What's left in the market
As of September 2026, the vendor-neutral hosted options have narrowed to two: APIMatic, which has been in this space the longest and prices per SDK language, and Sourced, which is what we build — OpenAPI to hosted docs plus TypeScript and Python SDK previews in one pass, free to try. Both are still independent; neither has been acquired.
Two more categories sit outside the acquisition story entirely because there's no company to acquire. OpenAPI Generator is community-maintained with 50+ generators across 40+ languages, and Kiota is Microsoft's open-source generator, both covered in more depth in our Kiota vs OpenAPI Generator comparison. Two smaller, newer open-source projects fill a narrower gap: stainful reads an existing stainless.yml and generates an idiomatic Python SDK locally with no hosted service, aimed at teams who don't want to migrate their config; oagen, from WorkOS, is a framework for building custom SDK generators from an OpenAPI spec rather than a turnkey generator itself.
And then there's Postman's own SDK-generation lineup, which is now two products under one owner: liblab and Fern, running separately today with different long-term signals about how much they'll stay that way.
| Category | Options | Ownership |
|---|---|---|
| Vendor-neutral hosted | APIMatic, Sourced | Independent |
| Postman-owned | liblab, Fern | Postman |
| Open source, general-purpose | OpenAPI Generator, Kiota | Community / Microsoft |
| Open source, narrow-purpose | stainful, oagen | Independent maintainers |
| Wound down | Konfig, Stainless (hosted product) | Anthropic (Stainless) |
Why this keeps happening
None of these four companies gave a stated reason that generalizes across all four — Konfig's founder cited the usual startup-economics pressures in a solo post-mortem, Postman's two acquisitions were framed around building a unified API-lifecycle platform, and Anthropic's framing centered on Stainless's SDK-generation expertise fitting Anthropic's own roadmap. What's observable without guessing at motive is the pattern itself: hosted SDK generation is a narrow, infrastructure-heavy product category with a customer base that's valuable to the platforms already selling adjacent tools (API management, in Postman's case) or adjacent infrastructure (models and agent tooling, in Anthropic's case). Four exits in twenty months is enough to call that a trend, not enough to say where it stops.
Honest scope: when this consolidation doesn't matter to you
If you're on liblab or Fern today and your team hasn't hit a limitation the product doesn't solve, there's no immediate reason to move — both are functioning products, and "acquired" isn't the same as "shut down." If you're comfortable running your own CI and templates, OpenAPI Generator or Kiota sidestep this whole story, since neither has a company behind it to be acquired. This table is a market-structure observation, not a countdown — the only company in it with a same-day cutoff is Stainless, and that cutoff already happened in May.
FAQ
Is this list of four exits complete?
It covers the vendor-neutral hosted SDK-generation and API-docs companies with confirmed acquisition or shutdown announcements as of September 2026. It doesn't include every company that does adjacent work (API management platforms, general dev-tool consolidation), which is a broader story than this table.
Did Fern shut down or stop taking new customers?
No. As of this writing, Fern's pricing page shows an active Free tier and a working signup flow. Postman's announcement states the product, brand, and roadmap stay the same — that's different from Stainless, where new signups stopped the day of the announcement.
Is liblab shutting down?
No. It's a live, standalone product as of September 2026, acquired by Postman in November 2025. Its founder has stated the long-term plan is integration into Postman's platform, but no shutdown or migration deadline has been announced.
What happens to SDKs already generated by Konfig or Stainless?
In both cases, customers keep the code that was already generated. Neither vendor can regenerate, patch, or support it going forward — Konfig's repository is frozen, and Stainless's hosted generator no longer accepts new projects.
Are Sourced and APIMatic the only vendor-neutral hosted options left?
Among companies with the scale and track record to appear in this specific consolidation story, yes, as of September 2026. Smaller or newer entrants may exist; this table tracks confirmed acquisitions and shutdowns, not the full competitive field.
Why does "vendor-neutral" matter here?
It means the company generating your SDK doesn't also own the API platform or model provider your SDK might end up serving. That's not inherently better or worse — it's a different incentive structure, and whether it matters depends on how much you weigh a generator's independence from adjacent products it could someday prioritize.
Try it yourself
Sourced is one of the last two independent, vendor-neutral hosted options standing (see the table above) — and the shortest path from an OpenAPI spec to live docs and SDK previews, at four steps versus six or seven for the acquired alternatives (see the counted-steps walkthrough). Create hosted docs from your repo or start free with a direct OpenAPI upload — no credit card, unlimited previews.