What it does
Scalar is a hosted API interface platform spanning API documentation, generated SDKs, an API registry, and MCP connectivity. Teams can publish OpenAPI and AsyncAPI references, write Markdown or MDX documentation, synchronize content with Git, and generate type-safe client libraries from an API description. Its free hosted plan includes a small number of APIs and one SDK. Scalar also offers a separately shipped, open-source API Client; the platform entry here focuses on its hosted docs, registry, SDK, and MCP workflow.
Turn an API description into several developer-facing interfaces
Scalar's platform connects an OpenAPI file to an interactive API reference, generated SDKs, hosted documentation, registry workflows, and MCP tools. The API References documentation shows a small HTML setup: load the Scalar API Reference package and initialize it with the API document URL. For teams using the hosted platform, the product page adds Markdown and MDX guides, two-way Git sync, SDK publishing, and an API registry.
The Free plan includes hosted OpenAPI docs, a built-in API client, up to three APIs, one SDK for a spec of up to 25 endpoints, and one editor seat. Pro is listed at $150 per month and Business at $600 per month; higher plans raise API and endpoint limits and add team controls. The separate desktop API Client is described in pricing as open-source MIT software and is available for web, macOS, Linux, and Windows. Those client attributes do not make the entire hosted platform open source.
The product is most useful when the API description is already a reliable source of truth and the team wants documentation, SDKs, and agent-facing interfaces to stay aligned. Its free hosted tier is deliberately bounded by API count, endpoint count, and editor seats.
Strengths
- A single OpenAPI or AsyncAPI description can feed interactive references, documentation, SDK generation, registry workflows, and MCP integration.
- The free hosted plan includes up to three APIs, one SDK up to 25 endpoints, and an API client without a credit card.
- The standalone API Client is documented as open-source MIT software with web, macOS, Linux, and Windows builds.
Watch out for
- Free hosted usage is limited by API count, SDK endpoint size, and a single editor seat.
- Paid hosted plans begin at $150 per month; additional SDKs and higher-volume use may add substantial plan cost.
Best for
- API teams maintaining OpenAPI-based references and guides alongside SDKs and Git-synced docs.
- Developers who want to publish a small number of APIs on a free hosted plan before scaling documentation and SDK limits.
- Organizations that want API descriptions exposed to both human developers and MCP-compatible agent tools.
Sources
- Scalar — API Documentation, SDKs, API Client & Registry (Oct 25, 2026)
- Getting Started | Scalar API References (Oct 25, 2026)
- Scalar Pricing — Free & Paid Plans for API Docs & SDKs (Oct 25, 2026)