October 2026 Summaries

Fern Docs has shifted all documentation sites to prebuilt static pages, rendering content at publishing time and delivering completed pages from the edge while retaining features such as search, Ask Fern, and login. Across customer sites including Cash App, Persona, ID.me, Sigma, and Twelve Labs, mobile Lighthouse scores increased substantially, often reaching 98–100, while first contentful paint improved to roughly 1.3–1.7 seconds and total blocking time fell sharply. The redesign removes duplicated page data, reduces page sizes by two to four times, limits JavaScript to interactive components, and serves assets from customers’ own domains rather than a shared Fern domain. Local development previews are also faster and use less memory, while publishing now deploys a fully built site without cache-clearing delays or post-publication warm-up periods. Security has been strengthened through strict content security policies that permit only scripts included in each published page, and subdomain-based sites can gain further response-time improvements through a DNS update.

A Fern benchmark comparing AI-agent integrations with Square’s payments API found that agents using Square’s TypeScript SDK, generated by Fern, produced more reliable implementations than those using raw HTTP requests against the OpenAPI specification. Across tasks involving customer search, pagination, order creation, and payment processing, raw HTTP implementations often lacked rate-limit retry handling, used invalid endpoints or parameters, and failed under simulated 429 responses, while SDK implementations benefited from built-in retries, typed request fields, pagination helpers, and centralized authentication. The reported results showed Sonnet 4.6 completed all six SDK runs successfully versus none of its raw HTTP runs under rate limits, while Haiku 4.5 also had fewer crashes, shorter scripts, and substantially lower bug-fixing token use with the SDK. The post argues that standardized SDKs reduce support burden, inconsistent client behavior, and risks from custom retry logic, while allowing API providers to distribute updates and monitor SDK versions; it promotes generating multi-language SDKs from OpenAPI specifications with Fern.