Stainless prices around a single unit called a "generator" — any one SDK, docs site, or MCP server. The Free plan includes up to 5 generators, 5 seats, and specs up to 25 endpoints, with full numbers published at stainless.com/pricing. Above Free, Stainless names Starter, Pro, and Enterprise tiers on the same page, but as of September 2026 the page does not display specific dollar amounts, per-seat costs, or per-generator overage pricing for those tiers in its static content — you'll need a live quote to get exact numbers.
Worth knowing before you read the generator-unit breakdown below: as of September 2026, this pricing model is closed to new customers. Per Stainless's own announcement, Stainless is joining Anthropic, and the company says new signups, projects, and SDKs stopped the day that post published, as part of winding down its hosted SDK generator. WorkOS's coverage of the move puts it directly: the hosted SDK generator is going away. Everything below remains accurate as a record of how Stainless priced itself and useful if you're an existing customer planning a move — see the migration guide for what transfers.
The one concept that explains the whole model: the generator
Everything in Stainless pricing traces back to "a generator is any single SDK, docs site, or MCP server." That's the billable unit. It means:
- A TypeScript SDK and a Python SDK are 2 generators, not 1.
- A docs site is its own generator, separate from any SDK.
- An MCP server is also its own generator.
- They all draw from the same pool, whatever your plan's generator limit is.
Once you internalize that, the rest of the pricing page reads as "how many generators do you get, and what features come attached to your docs generator specifically."
What's confirmed on the Free plan
- $0. Up to 5 generators, 5 seats.
- API size: specs up to 25 endpoints included.
- Preview builds: 100/month, 25/day rate limit.
- SDK features included: private SDKs (free during early access), webhooks, streaming, async support, auth, headers, testing, unit tests, and limited custom code.
- Support: email.
- Docs features excluded: custom domain, AI markdown rendering, custom JS/CSS, the full component library, Git as source of truth, AI chat, password protection, and removing the "powered by Stainless" mark.
- Also excluded: GitHub member sync.
What's named but not priced in public: Starter, Pro, Enterprise
Stainless's pricing page references tiers above Free — commonly discussed as Starter, Pro/Growth, and Enterprise — but as of September 2026 the static page content does not surface a dollar figure, per-seat rate, or per-generator overage cost for any of them. Some third-party writeups quote specific numbers for these tiers, but they disagree with each other, which is itself a signal that the real figures are quote-based or change based on plan negotiation rather than fixed and public. The reliable path is: request current pricing directly from Stainless rather than trusting a secondhand number, including this post.
What we can say with confidence about the shape of paid tiers, based on what's visible on the page:
- Overage billing applies when your endpoint count exceeds your plan's included limit.
- Enterprise unlocks things like SOC2 reports on request and purchase-order/invoicing billing.
- There's a documented free-tier path for qualifying non-commercial open-source (FOSS) projects.
A pricing model decoder: questions to ask before you buy
| Question | Why it matters |
|---|---|
| How many generators does this tier include? | Determines how many SDKs + docs sites + MCP servers you can run before overage. |
| What happens above the endpoint limit? | Overage billing applies past the plan's included endpoint count — get the rate in writing. |
| Is the docs generator separate from the SDK generators? | Yes — budget it as its own unit, not a freebie attached to an SDK. |
| Does this seat count include reviewers, or only editors? | Seat definitions vary by vendor; confirm before assuming headcount fits. |
| Is custom domain included at this tier, or the next one up? | Confirmed excluded on Free; check explicitly for Starter/Pro. |
How Sourced's pricing compares in structure
Sourced publishes its paid-tier numbers directly: Launch is $99/month per API project (two live SDKs, production docs hosting, repo and registry readiness, sitemap plus llms.txt, up to 3 team members) and Scale is $349/month per API project (five live SDKs, up to 3 custom docs domains, 10 team members, priority support). Enterprise is custom annual pricing with private workers, SSO, audit log, and SLA. Extra live SDKs beyond a tier's included amount are $99/month each after publishing. The free tier — unlimited previews plus up to 2 hosted noindex docs review sites and one hosted MCP server, no credit card — has no generator-pool concept; previews aren't metered the way Stainless's free generators are.
The structural difference isn't "cheaper" or "more expensive" in the abstract — it's that Sourced's paid numbers are on the page, and Stainless's aren't (as of September 2026). If getting an exact number without a sales call matters to your evaluation timeline, that's worth weighing on its own.
Honest scope
If your team already has Stainless's paid tier and it's working, this post isn't a reason to switch — pricing opacity above Free is common in this category (Redocly and ReadMe also gate their higher tiers behind sales conversations for enterprise features), and it doesn't mean the product is bad value. Use this as a checklist for the sales call, not a verdict.
See the numbers instead of asking for them
Create hosted docs from your GitHub repo and see Sourced's free tier limits firsthand, or check the MCP server generator if an MCP server is one of the "generators" you're trying to price out. Full paid pricing is on the page — no call required. Start free.
FAQ
What is a "generator" in Stainless pricing?
Any single SDK, docs site, or MCP server. It's the billable unit the Free plan's "up to 5 generators" limit refers to, per stainless.com/pricing.
Does Stainless publish exact prices for its paid tiers?
Not in the static pricing page content as of September 2026. The Free tier's numbers ($0, 5 generators, 25 endpoints, etc.) are published; Starter, Pro, and Enterprise dollar amounts are not shown in the page's visible content.
Is Stainless free for open-source projects?
The pricing page references a free path for qualifying non-commercial open-source (FOSS) projects, separate from the standard Free plan.
How does Stainless bill for endpoints above the plan limit?
Overage billing applies once your OpenAPI spec's endpoint count exceeds the limit set by your plan, per the pricing page. Specific overage rates aren't published for paid tiers.
Is a docs site billed the same as an SDK on Stainless?
Yes, structurally — a docs site, a TypeScript SDK, and an MCP server are each counted as one "generator" against the same pool.
What does Sourced charge for a comparable setup?
Sourced's Launch plan is $99/month per API project (two live SDKs, production docs hosting) and Scale is $349/month (five live SDKs, up to 3 custom docs domains). The free tier includes unlimited previews and up to 2 hosted noindex docs review sites and one hosted MCP server with no credit card required.