The spec is not the docs.
Swagger UI is an open-source OpenAPI viewer and tester. It ships 3.2.0 support in v5.32.4 as of April 15, 2026 and does what it says on the tin. If you want a rendered spec with a request tester, use it. Sourcey is a different shape: static documentation built from OpenAPI, Markdown, Doxygen XML, and MCP manifests, in one site.
Side by side.
Both tools are free and open source. They read the same OpenAPI spec and build different things out of it.
| Swagger UI | Sourcey | |
|---|---|---|
| OpenAPI reference | Yes | Yes |
| Markdown guides | No | Yes |
| Doxygen / MCP input | No | Yes |
| Output model | Browser JS app | Static HTML |
| Zero JS runtime | No | Yes |
| Interactive request tester | Yes | No |
| Plugin / customization API | Yes | Config + themes |
| Client-side search | Filter box | Built-in |
| npm packages | swagger-ui, -dist, -react | sourcey |
| License | Open source | AGPL-3.0 (CLI) |
| Pricing | Free | Free |
Where the two actually differ.
Swagger UI renders specs; that is not documentation.
Swagger UI's product page describes the tool as a way to "visualize and interact with" an OpenAPI spec. Microsoft's OpenAPI guidance calls it a UI for local ad-hoc testing against generated OpenAPI documents. Both descriptions are accurate. Neither is documentation. Documentation is onboarding guides, authentication walkthroughs, conceptual pages, tutorials, changelog context, and cross-references across multiple input types. Swagger UI handles none of that, because that was never the product.
swagger.io/tools/swagger-ui; learn.microsoft.com/aspnet/core/fundamentals/openapi/using-openapi-documents.
It is a browser app, not a build artifact.
The official repository ships three JavaScript packages: swagger-ui, swagger-ui-dist, and swagger-ui-react. They render the spec in the browser at request time. That is the shape of the product and it is fine. Sourcey takes a different route: compile at build time, emit static HTML, ship no JavaScript in the default output.
github.com/swagger-api/swagger-ui. Swagger UI is fully customizable through its Configuration API, Plugin system, and custom layouts (swagger.io/docs/open-source-tools/swagger-ui); the difference here is about where the rendering happens, not whether the tool can be extended.
"Try it out" is useful, and browser-limited.
Swagger UI's request tester is the project's best feature. Its own Limitations documentation is straightforward about the edges: browsers refuse to let JavaScript set certain headers, and cookie parameters cannot be controlled from in-browser code. Microsoft's ASP.NET Core OpenAPI guidance recommends exposing OpenAPI UIs in development environments rather than production, on information-disclosure grounds. The tester is a development-time tool. Sourcey does not ship one. If you want in-browser testing, Swagger UI is still the right answer for that surface.
swagger.io/docs/open-source-tools/swagger-ui/usage/limitations; Microsoft Learn ASP.NET Core OpenAPI guidance. Swagger UI is actively maintained and tracking the OpenAPI spec; the 5.32 line added OpenAPI 3.2.0 support and v5.32.4 was current on GitHub as of April 15, 2026.
Same spec. Different site.
Keep the OpenAPI file you already hand to Swagger UI. Sourcey reads OpenAPI 3.0, 3.1, and Swagger 2.0. If you still want interactive request testing, nothing stops you from running Swagger UI alongside Sourcey for that one surface.
Init
Creates sourcey.config.ts and detects any OpenAPI spec in the project.
npx sourcey initPoint at the same spec
Exactly the YAML or JSON you already hand to Swagger UI.
import { defineConfig } from "sourcey";
export default defineConfig({
name: "Your API",
navigation: {
tabs: [
{
tab: "API Reference",
slug: "api",
openapi: "./openapi.yaml",
},
],
},
});Add guides around the reference
Markdown with frontmatter. Swagger UI has no surface for multi-page narrative, onboarding, authentication walkthroughs, or changelog context; this is where Sourcey does the work.
---
title: Getting Started
---
## Authentication
:::note
All requests need an API key in the `Authorization` header.
:::
```bash
curl -H "Authorization: Bearer $KEY" https://api.example.com/v1/ping
```Build and deploy
Static HTML output. Keep a Swagger UI deployment on /try if you still want the request tester; link it from the docs.
$ npx sourcey build
Sourcey — building documentation site
Pages: 24
Output: dist
Time: 1.3sCommon questions.
Is Swagger UI abandoned?
No. The 5.32 line added OpenAPI 3.2.0 support and v5.32.4 was current on GitHub as of April 15, 2026. The tool is maintained and does its job.
Does Sourcey replace Swagger UI's request tester?
No. Sourcey outputs static HTML; an in-browser tester needs a JavaScript runtime. Keep a Swagger UI page for testing, or build a dedicated hydrated playground. Either approach runs alongside Sourcey docs without conflict.
Can I run Swagger UI and Sourcey together?
Yes. Sourcey for the public docs, Swagger UI on /try for the interactive tester, probably against staging. Microsoft's OpenAPI guidance recommends exposing OpenAPI UIs in development rather than production; that split matches this shape.
Is Swagger UI customizable?
Yes. The official docs cover the Configuration API, a Plugin system, and custom layouts. The real difference with Sourcey is scope. Swagger UI renders a spec; Sourcey builds a multi-source documentation site and compiles it to static HTML at build time.
What does Sourcey do that Swagger UI does not?
Markdown guides alongside the OpenAPI reference. Doxygen and MCP input in the same site. Client-side search across pages and operations. A build-time output you deploy as static HTML. Multi-tab navigation across different content types.
What does Swagger UI do that Sourcey does not?
In-browser interactive request testing from the rendered spec. That is Swagger UI's headline feature; Sourcey does not try to replace it.
Own your docs.
Open source. Self-host it, fork it, ship it on your own infrastructure. No account required.
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