Product docs stay on /replace/readme-com (Docusaurus). This page is an OpenAPI reference.

A client workspace stays on /replace/postman (Hoppscotch). This page is a public reference.

Scalar is MIT. Swagger UI is Apache-2.0. You pay hosting. Template users never pay c17.

Stacks / Backend

Easy

Scalar / Swagger UI

OpenAPI you host. Scalar is MIT; Swagger UI is Apache-2.0 — SwaggerHub or Stoplight without the hosted design seat.

The problem

SwaggerHub and Stoplight are hosted OpenAPI design desks. You wanted a reference you serve from a spec you keep. Scalar is MIT (scalar/scalar; last push 25 Oct 2026) — an API client and OpenAPI references. Swagger UI is Apache-2.0 (swagger-api/swagger-ui; last push 24 Oct 2026). This is not SwaggerHub's every org, style-guide, or contract SKU, and not Stoplight's every design-library SKU. Product docs stay on /replace/readme-com (Docusaurus). An API client workspace stays on /replace/postman (Hoppscotch).

Replaces

SwaggerHub / Stoplight

Replace SwaggerHub Replace Stoplight See all best open-source API documentation tools

Estimated SaaS saved

$1,200

per year, small team, before lock-in

Start on Railway

Hoppscotch if this is an API client workspace, not a public reference

Sponsor this stack Tip jar

Placeholder: Scalar or Swagger UI in front of an OpenAPI file. Bind HTTP to 0.0.0.0:$PORT. No one-click template in this repo yet — Start on Railway. Product docs stay on /stacks/docusaurus-docs. A client workspace stays on /stacks/hoppscotch-api.

The stack

Scalar
MIT OpenAPI references and client — the published SwaggerHub / Stoplight path
Catalog entry →
Swagger UI
Apache-2.0 OpenAPI renderer
Catalog entry →

Cost table

You stop paying	Typical / year	Self-host instead
SwaggerHub / Stoplight (small team)	$1,200	Scalar or Swagger UI + the spec

Agent setup prompt

Replace SwaggerHub or Stoplight with Scalar (preferred) or Swagger UI.

- Official docs. Point the UI at one OpenAPI file. Confirm one operation renders. Do not claim SwaggerHub orgs, style guides, or Stoplight design libraries.
- Product docs stay on /stacks/docusaurus-docs. A client workspace stays on /stacks/hoppscotch-api.
- Write AGENT_PROMPT.md.

Also as markdown: /stacks/scalar-api-docs.md

FAQ

Scalar or Swagger UI?: Scalar if you want the published SwaggerHub path (references plus a client). Swagger UI if you want that Apache renderer.
Is this ReadMe?: Product docs stay on /replace/readme-com (Docusaurus). This page is an OpenAPI reference.
Is this Postman?: A client workspace stays on /replace/postman (Hoppscotch). This page is a public reference.
Are these free?: Scalar is MIT. Swagger UI is Apache-2.0. You pay hosting. Template users never pay c17.