# Consolidate your API tech stack One platform for Docs, SDKs, and CLIs. Replace three vendor contracts with a single source of truth, used by ElevenLabs, Adobe, and Deepgram. Shipping docs and SDKs with Fern: ElevenLabs, Adobe (Frame.io), Deepgram, Webflow, AssemblyAI, LaunchDarkly. ## Three contracts become one Most API teams pay for a docs platform, an SDK generator, and a reference portal, then spend engineering time keeping them in sync. Fern is one platform that ships all three from the same spec. - **Docs platform.** Replace Mintlify, ReadMe, GitBook, or Redocly. Versioned docs with API reference, guides, search, and AI chat built in. - **SDK generator.** Replace Stainless, Speakeasy, or OpenAPI Generator. 9+ languages from one spec, with publishing to npm, PyPI, and Maven automated in CI. - **Reference and playground.** Replace Scalar, Swagger UI, or hand-rolled portals. Interactive reference and an API playground from the same spec that drives your SDKs. ## Why teams consolidate on Fern - **One spec, every surface.** Docs, SDKs, reference, and playground all generate from the same OpenAPI source. No drift between code snippets and client libraries, ever. - **Ship in one PR, not three.** A spec change opens a PR with updated docs, SDKs, and reference together. One review, one release, zero coordination meetings. - **9+ SDK languages, multi-protocol.** TypeScript, Python, Go, Java, C#, PHP, Ruby, Swift, and Rust, generated from the same spec. REST, WebSockets, and gRPC out of the box. - **Agent-ready docs out of the box.** Auto-generated llms.txt, clean Markdown endpoints, an MCP server, and Ask Fern. Coding agents get accurate context for free. ## What Square's engineering team says > We evaluated several SDK generators and Fern stood out for its clean, language-native, and thoughtfully architected code. The Fern team partnered with us every step of the way including OpenAPI improvements, alpha releases and launch announcements. > > — John Fellman, Head of Engineering, Developer Platform, Square ## See it in production Each of these teams used to run multiple API tooling vendors. Today they ship from one Fern pipeline. - **ElevenLabs** (Docs + SDKs). Consolidated docs and SDKs onto Fern so every audio model launch ships with reference and clients on day one. - **Frame.io (Adobe)** (Docs + SDKs). Replaced two vendors with Fern and ships its developer docs and TypeScript and Python SDKs from one pipeline. - **Deepgram** (Docs + SDKs). Unified REST and WebSocket docs plus TypeScript and Python SDKs on Fern, cutting doc PR turnaround from 30 to 60 minutes down to 5. - **Cohere** (Docs + SDKs). Publishes docs and generates SDKs in four languages from Fern, replacing the clients it used to maintain by hand. - **AssemblyAI** (Docs + SDKs). Publishes its speech-to-text docs and generates SDKs from Fern, keeping reference and clients aligned across languages. - **Webflow** (Docs + SDKs). Ships its Data API docs and its TypeScript and Python SDKs from Fern, so reference and clients track the API together. ## What you get back - **One source of truth.** Docs, SDKs, and reference generate from the same spec, so a breaking change can't make it to production with stale clients or docs. - **Faster, fewer releases.** Ship the API, docs, and SDKs in one PR. Cut the manual coordination tax between platform, docs, and DX teams. - **One contract, one vendor.** Stop renewing three SaaS contracts. One procurement cycle, one security review, one SOC 2 Type II vendor across the API surface. ## Common questions from teams consolidating **Do we have to adopt every product on day one?** No. Most teams start with one surface (usually Docs or SDKs) and consolidate the rest over the next one to two quarters. Pricing and onboarding scale with what you turn on. **What happens to our existing docs site or SDK packages?** Existing URLs and npm/PyPI/Maven coordinates are preserved. We mirror your current docs information architecture and SDK surface so consumers stay backward-compatible. **Can we use Fern for just docs, or just SDKs?** Yes. The platform is modular. Many customers start with Docs and add SDKs later, or vice versa. Consolidation is a path, not a prerequisite. **What spec formats and protocols does Fern support?** OpenAPI 3.1 and AsyncAPI as first-class inputs, plus gRPC and the native Fern Definition. Multiple specs merge into one SDK natively. Discriminated unions, SSE, and streaming all get typed helpers across REST, WebSockets, and gRPC. **How does Fern keep docs and SDKs in sync?** Code snippets in your reference docs are generated from the same spec that drives your SDKs. When the spec changes, snippets and clients update together. **How long does migration take?** Most teams cut over docs in 1 to 2 weeks and SDKs in 2 to 4 weeks per language family. A Fern engineer embeds with your team through the cutover. **Can we self-host?** Yes. On-premise and self-hosted deployment for regulated industries. SOC 2 Type II, 99.9% uptime SLA. **Are the generators open source?** Yes. Every SDK generator is Apache-2.0 licensed on GitHub. Fork, audit, or self-host the entire pipeline. **What does ongoing support look like?** You get dedicated SDK engineers on committed hours, a shared Slack channel, and first-line triage on your public SDK repo's GitHub Issues. ## Get started - Book a demo: - Read the full comparison: