Changelog

Ask Fern can now mask personally identifiable information (emails, phone numbers, SSNs, credit card numbers) in a user's question. When enabled via the mask-pii: true config flag, structured PII is redacted in the browser and never sent to Fern.

Image handling is now automatically optimized and lazy-loaded, reducing initial page load time and improving Core Web Vitals scores. Search indexing is up to 40% faster, and the table component gains sortable columns, sticky headers, and improved mobile responsiveness.

Enhanced DDoS protection and rate limiting have been added to all Fern Docs instances. Features include adaptive rate limits that adjust based on traffic patterns, IP-based filtering for malicious ranges, stricter request validation, and real-time monitoring with automated alerts. Cloud-hosted documentation receives these protections automatically; self-hosted deployments require an update.

Ask Fern now supports 15+ languages for chat and document indexing with automatic language detection and per-language model optimization. API Explorer loads 40% faster with optimized payload handling and caching, and webhook reference pages now include request/response examples and custom event type support.

Site-wide default and per-page changelog layout can be set to either a searchable timeline of condensed cards or a stacked full-entry view preserving code formatting and copy buttons.

Redirects are now validated against available locales, and locale-specific slugs can be configured per page. Search analytics gained query context, result interaction tracking, and performance metrics by locale.

Changelog pages now render as a compact, date-grouped timeline with a search bar that syncs to the shareable ?q= URL parameter. Entries with multiple releases can tag each heading independently using the ChangelogTags component; tags are clickable and link to the filtered timeline.

Local library docs generation

Local library docs generation

Removed llms-full.txt

Removed llms-full.txt

fern-docs agent skill

fern-docs agent skill

Scope search by product or version

Scope search by product or version

Markdown rendering for API components

Markdown rendering for API components

CLI link checker

CLI link checker

Custom robots.txt