Over the past few years, API documentation has evolved from a simple afterthought into a strategic asset for companies building developer-facing products. Great docs are no longer just about listing endpoints — they are about guiding developers, reducing time-to-value, and creating a seamless experience that reflects a product’s maturity.
One company leading the way in this space is Fern. Backed by Y Combinator and having raised $9M in Series A funding from Bessemer Venture Partners, Fern helps teams build documentation experiences akin to Stripe-level quality. Their customers — like Webflow and ElevenLabs — benefit from branded, interactive, and user-friendly documentation portals that accelerate developer adoption. With features like “Ask AI”, orientation flows, and seamless onboarding, Fern proves how API documentation can dramatically improve Developer Experience (DX) — and even become a competitive moat.
But what if we go one step further — not just making API docs beautiful and interactive, but also deeply integrating them into the development process itself?
That’s where Zylo-docs comes in.
Zylo-docs is built for developers who want real-time documentation that evolves with their code. Unlike many other services that require a CLI to be installed and used in parallel with code, Zylo-docs can be added as a simple dependency:
pip install zylo-docs
This means API documentation becomes a lightweight extension of your development environment — not a separate tool to maintain. For FastAPI users, it offers deep integration, allowing auto-synchronization of OpenAPI specs directly from your backend code, without having to worry about external syncing or duplication.
On top of that, Zylo-docs provides a headless UI-based local web editor, where you can preview your spec in real-time. You can see your changes immediately, and even use Zylo-AI to improve and rewrite your OpenAPI specs in a more user-friendly, organized, and interactive manner. Once finalized, your docs can be published and shared in just a few seconds.
Ultimately, Zylo-docs is not just an API docs generator — it’s a developer-native documentation platform. It empowers teams to keep their specs up-to-date, improve collaboration, and deliver docs that actually help developers build faster.
If Fern is setting the bar for external API presentation, Zylo-docs is redefining how docs should work at the code level — all while staying lightweight, real-time, and developer-first.