What is Stainless used for?

Stainless generates typed client SDKs, documentation and MCP servers from an OpenAPI spec for API companies. It is a good fit for publishing official SDKs for an API and exposing an API to AI agents through MCP.

Yes. Stainless has a free plan. A free plan covers up to 5 generators. Starter, Pro and Enterprise plans exist but their prices are not shown on the page; exceeding the free plan starts a 30-day trial of a paid plan.

Is Stainless open source?

No. Stainless is proprietary (closed-source) software and can't be self-hosted. Open-source alternatives to Stainless include OpenAPI Generator and Cortex Docs.

What are some alternatives to Stainless?

Stainless competes with Speakeasy and APIMatic. For open-source options, see Enlisted's ranked list of open-source Stainless alternatives.

Stainless: features, pricing and alternatives

About Stainless

Stainless is a commercial service that produces developer-facing interfaces from an API's OpenAPI specification. It generates idiomatic client SDKs, documentation that follows API changes and MCP servers, so API owners can offer consistent libraries without maintaining each language by hand.

Supported targets shown on the site include TypeScript, Python, Go, Java, Kotlin, Ruby, Terraform, C# and PHP. The vendor's pitch is that good agent experience depends on good developer experience, so SDKs, documentation and MCP servers are all derived from the same spec. The homepage also announces that Stainless is joining Anthropic. Stainless is proprietary and vendor-hosted, with a CLI quickstart, documentation, account sign-up, sales contact and a pricing page.

Key features

Idiomatic SDK generation from OpenAPI
Support for many programming languages
Terraform provider output
Documentation that tracks API changes
MCP servers derived from the spec
Quickstart through a command line tool

Good fit for

→Publishing official SDKs for an API
→Exposing an API to AI agents through MCP

Tags: sdk-generation; openapi; mcp; api-platform; code-generation; developer-experience; saas

Stainless: questions and answers

What is Stainless used for?: Stainless generates typed client SDKs, documentation and MCP servers from an OpenAPI spec for API companies. It is a good fit for publishing official SDKs for an API and exposing an API to AI agents through MCP.
Is Stainless free?: Yes. Stainless has a free plan. A free plan covers up to 5 generators. Starter, Pro and Enterprise plans exist but their prices are not shown on the page; exceeding the free plan starts a 30-day trial of a paid plan.
Is Stainless open source?: No. Stainless is proprietary (closed-source) software and can't be self-hosted. Open-source alternatives to Stainless include OpenAPI Generator and Cortex Docs.
What are some alternatives to Stainless?: Stainless competes with Speakeasy and APIMatic. For open-source options, see Enlisted's ranked list of open-source Stainless alternatives.