Scalar

Scalar turns one OpenAPI document into the pieces an API product needs: hosted docs, client SDKs and an MCP server. It is built for teams whose users are increasingly developers and their coding agents.

Scalar reads your OpenAPI file and publishes API reference docs on your own domain, with pages also available as Markdown for tools that read them. It generates typed client libraries from the same file, so SDK updates follow your API releases. It can also host an MCP server that exposes the operations you choose to AI assistants.

• Hosted API docs with Markdown pages and llms.txt
• Typed SDKs for TypeScript, Python, Go and more
• Hosted MCP server generated from your OpenAPI file
• Call counts, errors and latency per tool and client
• Custom domain, theme and access groups for partners

API companies and platform teams that publish public or partner APIs. It also fits developer relations teams who want customers' coding agents to call the API correctly the first time.

The core is open source under the MIT license and has eight framework integrations. Hosted features such as the docs domain, OAuth and rate limits for the MCP server are part of the hosted service. SDKs are published to standard package registries, including npm and PyPI, with changelogs.