Freedom251 › API Generation Software
Stainless
What Stainless is
Stainless creates SDKs, API documentation, and MCP servers from an OpenAPI specification. Its SDKs cover TypeScript, Python, Go, Java, Kotlin, Ruby, Terraform, C#, and PHP, with rich types, automatic pagination, and retries. The Docs Platform, built on Astro, keeps REST API, SDK, and narrative documentation in sync with an API. It includes hybrid AI search, Markdown copying, AI-tool integration, and light and dark modes. Stainless also generates code-mode MCP servers, allowing agents to use SDKs and documentation instead of working from many endpoint schemas; Claude Code and Cursor are named as compatible tools. The Free plan costs nothing and includes up to five generators, five seats, 25 endpoints, 100 preview builds per month, and a rate limit of 25 per day. It includes email support. Users need a GitHub account for authentication and access to generated staging repositories. Generation cannot be hosted on-premise, though generated SDKs can be kept in a private GitHub repository.
Who it suits
Stainless suits teams generating and maintaining SDKs and API documentation from OpenAPI specifications, or making those resources available to agents through MCP. The Free plan may suit projects within its generator, seat, endpoint, and build limits.
What it does well
- Generates SDKs from OpenAPI specifications.
- SDKs include types, pagination, and retries.
- Documentation stays in sync with the API.
- Free plan includes email support.
What to know first
- Free plan is limited to five generators and five seats.
- Requires a GitHub account.
- Code generation cannot be hosted on-premise.
- Exceeding Free Plan terms triggers a 30-day paid-plan trial.
Limits
The Free plan allows up to five generators, five seats and 25 endpoints, with 100 preview builds per month and a rate limit of 25 per day. Exceeding Free Plan terms triggers automatic enrollment in a 30-day free trial of a paid plan.
Plans
| Plan | Billed and limits | Price |
|---|---|---|
| Free | Up to 5 generators · 5 seats · ≤25 endpoints incl. · 100 preview builds/mo free · rate limit 25/day | Free |
As stainless.com lists them, read 4 Oct 2026. The maker's own page has the final word.
Getting started
- Visit the Stainless website.
- Use a GitHub account for authentication and access to generated staging repositories.
- Start with the Free plan, which includes up to five generators and five seats.
- Provide an OpenAPI specification to generate SDKs, documentation or MCP servers.
- Use the CLI, project scaffolding or schema-to-code generation as needed.
- If you exceed Free Plan terms, the account is automatically enrolled in a 30-day free trial of a paid plan.
Verdict
Stainless brings SDK generation, API documentation, and code-mode MCP servers together around OpenAPI. Check the Free plan limits and automatic trial enrollment, and note the on-premise hosting restriction.
Questions
What does Stainless generate?
It generates SDKs, documentation and MCP servers from an OpenAPI specification.
What is included in the Free plan?
The plan costs nothing and includes up to five generators, five seats, 25 endpoints, 100 preview builds per month and a rate limit of 25 per day. Email support is listed.
Which SDK languages are listed?
The SDK product lists TypeScript, Python, Go, Java, Kotlin, Ruby, Terraform, C# and PHP.
Do I need a GitHub account?
Yes. Stainless requires a GitHub account for authentication and access to generated staging repositories.
Can Stainless be hosted on-premise?
Code generation cannot be hosted on-premise. Generated SDKs can be hosted in a private GitHub repository.
What happens if I exceed the Free Plan terms?
Users are automatically enrolled in a 30-day free trial of a paid plan.
Facts from Stainless's own pages
- Company status
- Stainless says it is joining Anthropic. · stainless.com, 4 Oct 2026
- Docs features
- The Docs Platform advertises AI-powered hybrid search, Markdown copying, AI-tool integration, and light and dark modes. · stainless.com, 4 Oct 2026
- Docs integrations
- Stainless lists ReadMe, Mintlify, Redocly, bump.sh, GitBook, and Docusaurus as documentation providers that support its SDK code snippets. · stainless.com, 4 Oct 2026
- Docs platform
- The Docs Platform keeps REST API, SDK, and narrative documentation in sync with the API and is built on Astro. · stainless.com, 4 Oct 2026
- Hosting limit
- Stainless says its code generation cannot be hosted on-premise, though generated SDKs can be hosted in a private GitHub repository. · stainless.com, 4 Oct 2026
- MCP clients
- The MCP product page names Claude Code and Cursor as tools where agents can use its generated MCP servers. · stainless.com, 4 Oct 2026
- MCP servers
- Stainless generates code-mode MCP servers from OpenAPI specs so agents can use SDKs and documentation instead of many endpoint schemas. · stainless.com, 4 Oct 2026
- SDK features
- Generated SDKs include rich types, auto-pagination, and retries out of the box. · stainless.com, 4 Oct 2026
- SDK languages
- Its SDK product lists TypeScript, Python, Go, Java, Kotlin, Ruby, Terraform, C#, and PHP. · stainless.com, 4 Oct 2026
- Security
- Stainless says Business and Enterprise customers can request its SOC 2 compliance report. · stainless.com, 4 Oct 2026
- Source control
- Stainless requires users to have a GitHub account for authentication and access to generated staging repositories. · stainless.com, 4 Oct 2026
- Support
- The pricing page lists email support for the Free plan. · stainless.com, 4 Oct 2026
- Trial
- When users exceed the Free Plan terms, they are automatically enrolled in a 30-day free trial of a paid plan. · stainless.com, 4 Oct 2026
- What it does
- Stainless generates SDKs, documentation, and MCP servers from an OpenAPI specification. · stainless.com, 4 Oct 2026
Where Stainless stands on Freedom251
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