Infrastructure for APIs in the age of agents.

From an agent's first read of your docs to its millionth production call, Scalar is the layer in between: hosted, observed, and kept in sync from one OpenAPI document.

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Docs

First, an agent has to understand your product.

Agents read docs the way developers do, except they want Markdown, not a rendered page. Scalar serves both from one source, so agents get your API right the first time.

  • Every page in Markdown, plus llms.txt and a Docs MCP endpoint.
  • Your domain, your theme, and access groups for partner portals.
  • An open source core with 15.7k GitHub stars and eight framework integrations.
SDKs

Then a developer's agent builds on it.

Your customers' coding agents write the integration now. Scalar generates typed SDKs from your OpenAPI document, one pull request per release, so an agent's code compiles the first time.

  • TypeScript, Python, Go, Java, Kotlin, and Ruby, plus a CLI.
  • Published to npm, PyPI, Go modules, Maven Central, and RubyGems, with changelogs.
  • Upload your stainless.yml as is and existing call sites keep working.
MCPs

Then users' agents act on it directly — no code at all.

Someone asks Claude or ChatGPT for something, and the agent calls your API itself. Scalar turns your OpenAPI document into that MCP server, which is not yours to run.

  • One line connects any remote MCP client to the operations you choose.
  • Any API fits in a fixed tool set, about 0.2% of context.
  • Hosted on your own subdomain with OAuth, rate limits, and nothing to deploy.
  • Call counts, errors, and latency per tool and client, with arguments never stored.

We run the infrastructure. You run your API.

An MCP server is a production service. It must stay up, authenticate callers, absorb agent traffic, and track a protocol that changes every few months. Scalar runs yours at mcp.yourcompany.com and goes where MCP goes. You keep shipping your API.

Without Scalar

Vibe code APIs, Docs, MCP, & SDKs

With Scalar

or just use one prompt with Scalar

Set up Scalar for this repo with the Scalar MCP server (https://mcp.scalar.com/) and the Scalar CLI (npx -y @scalar/cli@latest).

Find my OpenAPI file and the brand site for , check what my team already has so nothing is duplicated, and confirm with me once. Then:

  1. Publish the API to the Scalar Registry.
  2. Create one SDK with create_an_sdk (it builds itself, never call build_an_sdk).
  3. Host an MCP server for the API with create_an_mcp_server, pointed at the Registry entry.
  4. Scaffold scalar-docs/ with intro, quickstart and authentication guides from the spec, a custom --scalar-* CSS theme from my brand (siteConfig.theme), and a config (schema https://registry.scalar.com/@scalar/schemas/config) whose API reference route points at the Registry entry by namespace and slug, not a local file, so the SDK samples show.
  5. Create the docs project and project publish it.

Report the links. Never delete anything.

Docs SDKs MCPs

Make your API ready for the agents that are already looking for it.

Start with your OpenAPI document. Docs, SDKs, and a hosted MCP server all follow from it.

Community → GitHub → Support →
API Docs Preview API Docs Preview
API Docs
Write beautiful documentation with Markdown, MDX, OpenAPI, AsyncAPI, and two-way Git sync.
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SDKs Preview SDKs Preview
SDKs
Bring your OpenAPI document and get type-safe client libraries for TypeScript, Python and more.
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API Registry Preview API Registry Preview
API Registry
Managing & versioning OpenAPI Documents with a deep Git integration.
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MCP & Agent Preview MCP & Agent Preview
MCP & Agent
OpenAPI-backed MCP servers and SDKs that connect your APIs to LLMs with just-in-time tools and delegated authentication.
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