Stainless's free tier, verified against stainless.com/pricing as of September 2026, gives you up to 5 "generators" (any mix of SDK, docs site, or MCP server), 5 seats, and specs up to 25 endpoints, with 100 CI preview builds a month at a 25/day rate limit. It excludes a custom docs domain, AI markdown rendering, custom JS/CSS, password protection, and removing the "powered by Stainless" mark. Most teams outgrow it the moment they need a real docs domain or cross 25 endpoints.
One update this post can't skip: as of September 2026, none of the limits below apply to a new user, because Stainless isn't accepting new users. Per Stainless's own announcement, Stainless is joining Anthropic, and new signups, projects, and SDKs stopped the day that post went live — the company says it's winding down its hosted SDK generator and Docs Platform. WorkOS's coverage states plainly that the hosted SDK generator is going away. The breakdown below is a historical reference for existing account holders; if you have a live Stainless project, the migration guide covers what to do with what you already own.
What's actually in the free plan
Pulled directly from the pricing page's free-tier breakdown:
- Generators: up to 5. A generator is any single SDK, docs site, or MCP server — they all draw from the same pool of 5.
- Seats: 5.
- SDK features included: private SDKs (early access, free during early access at any size), webhooks, streaming, async support, auth, headers, testing with unit tests, and custom code — though custom code is capped to a limited number of files.
- Support: email only.
- API size: specs up to 25 endpoints are included at no charge.
- Preview builds: 100 per month, with a 25-per-day rate limit.
- Docs, excluded on free: custom domain, AI markdown rendering, custom JS/CSS, the complete component library, Git as source of truth, AI chat, password-protected docs, and removing the "powered by Stainless" footer.
- Miscellaneous, excluded on free: GitHub member sync.
Where teams actually hit the ceiling
The 25-endpoint cap. Most production APIs pass 25 endpoints well before they're ready to ship an SDK. Once you cross that line, you're either trimming your spec or moving to a paid tier — and Stainless's public pricing page doesn't list exact dollar amounts for the tiers above Free, so budget a sales conversation before you commit.
Generators shared across SDK, docs, and MCP. If you want a TypeScript SDK, a Python SDK, a docs site, and an MCP server, that's already 4 of your 5 generators — with no room left to experiment with a second docs environment or a staging MCP server.
No custom domain on docs. For a lot of teams, "can we put docs at docs.ourcompany.com" is the first real requirement, and it's not available on the free plan.
Preview build rate limit. 25 builds a day sounds like a lot until a CI pipeline runs on every commit across a few active branches — at that point the daily cap, not the monthly one, is what you'll notice first.
Stainless free tier vs. Sourced free tier
| Stainless Free | Sourced Free | |
|---|---|---|
| Cost | $0 | $0, no credit card |
| Units included | Up to 5 generators (SDK, docs, or MCP, shared pool) | Unlimited SDK + docs previews, up to 2 hosted noindex docs review sites and one hosted MCP server |
| Endpoint cap | ≤25 endpoints | Not endpoint-capped for previews |
| Custom domain | No | Not on free (ships with paid plans) |
| Seats | 5 | 1 API project on free |
| Support | — | |
| What's gated | Custom domain, AI markdown, custom JS/CSS, password protection, branding removal | Production publishing (npm/PyPI/custom domain), team seats beyond the free project |
Sourced's free tier doesn't count SDK and docs previews against a shared unit pool — you can regenerate both as many times as you want while you're evaluating. What's gated on Sourced is publishing: getting a live SDK onto npm or PyPI, or moving docs to a custom domain, requires a paid plan (Launch at $99/month per API project, Scale at $349/month), the same way Stainless gates its docs-domain and branding features on paid plans. Neither company gives away production publishing for free — that's a fair comparison, not a gotcha.
Honest scope
If your spec is genuinely under 25 endpoints and you only need one SDK plus a docs site with the Stainless-branded footer, the free tier might carry you a surprisingly long way if you already have an account (new signups are closed as of September 2026 — see above) — don't pay for a paid plan you don't need yet. And if you're already deep into a Stainless workflow with stainless.yml conventions your team relies on, staying and paying for the next tier is often less disruptive than a full migration. Free-tier limits are a reason to evaluate alternatives, not an automatic reason to switch.
Try before you commit to either
Create hosted docs from your GitHub repo and compare the generated docs and SDK previews against what you're getting from Stainless's free tier today. Run your spec through the OpenAPI validator first if you're not sure it's clean enough to generate against. When you're ready to move, start free — no credit card required.
FAQ
Does Stainless's free tier include a custom docs domain?
No. As of September 2026, custom domain, AI markdown rendering, custom JS/CSS, password-protected docs, and removing the "powered by Stainless" mark are all excluded from the free plan per stainless.com/pricing.
How many endpoints can I use on the Stainless free tier?
Up to 25 endpoints are included at no charge. Specs larger than that move you into paid-tier territory, though exact overage pricing isn't published on the static pricing page.
What counts as one "generator" on Stainless?
Any single SDK, docs site, or MCP server. The free plan includes up to 5 generators total, shared across whatever combination you deploy.
Is there a daily limit on Stainless preview builds?
Yes. The free plan includes 100 preview builds per month with a 25-per-day rate limit.
Does Sourced's free tier cap the number of SDK previews I can generate?
No. Sourced's free tier includes unlimited SDK and docs previews plus up to 2 hosted noindex docs review sites and one hosted MCP server. What requires a paid plan is publishing to npm, PyPI, or a custom docs domain.
Should I switch off Stainless's free tier just because of the 25-endpoint cap?
Not automatically. If everything else about the workflow fits, paying for the next Stainless tier may be simpler than migrating. Switch when the limit combines with something else you need — a custom domain, more generators, or a compatibility report Stainless doesn't offer.