Changelog

4.89.0

(feat): fern generate now accepts multiple --api flags. Previously, running fern generate --api api1 --api api2 failed because yargs collapsed the values into a single comma-joined string that was then looked up as a workspace name. --api is now declared as an array option, so each --api <name> value is parsed individually and the command generates for the union of the specified API workspaces (de-duplicated).

4.88.0

(feat): fern generate now accepts multiple --group flags. Passing e.g. fern generate --group typescript --group java --group python generates for all of the listed groups instead of failing with 'typescript,java,python' is not a valid group or alias. Each value is resolved independently (including aliases) and the union is generated.

4.87.1

(fix): Gracefully handle “Self-referencing circular pointer” errors from OpenAPI specs. Instead of failing the entire publish, the CLI now logs a warning with the offending file path and circular $ref breadcrumbs, then continues processing without full reference resolution.

4.87.0

(feat): Add new docs.yml metadata fields for controlling dynamically generated OG images: og:dynamic:text-color, og:dynamic:background-color, og:dynamic:logo-color (dark | light), and five visibility toggle flags (og:dynamic:show-logo, og:dynamic:show-section, og:dynamic:show-description, og:dynamic:show-url, og:dynamic:show-gradient). Also fixes a pre-existing gap where og:dynamic and og:background-image were missing from the Zod MetadataConfig schema, causing fern check to reject them.

(fix): Populate apiNameToId in fern docs dev so MDX widgets that resolve APIs by user-facing name (e.g. <MergeSupportedFieldsByIntegrationWidget apiName="hris_v2" ... />) work in local preview. Previously the preview server hardcoded this mapping to {}, causing such widgets to throw MergeWidgetResolutionError and render the affected pages as 500 Internal Server Error.

(chore): Emit non-fatal warnings during fern check / fern docs dev when docs.yml metadata settings silently conflict. Covered cases:

• og:dynamic: true combined with og:image or twitter:image (the static images only apply to the homepage once dynamic generation is enabled).
• og:dynamic:* sub-settings or og:background-image set without og:dynamic: true (they are ignored).
• og:dynamic:logo-color set with og:dynamic:show-logo: false (no effect).
• og:image:width / og:image:height set without og:image.
• og:dynamic:text-color equal to og:dynamic:background-color (text is invisible).

4.86.2

(fix): Gate the consolidation of top-level OpenAPI servers into a single multi-URL environment behind a new setting, multi-server-strategy, with values environment-per-server (default) and urls-per-environment. Previously (since 4.71.4) any spec where endpoint-level servers: overrides referenced top-level x-fern-server-name values would collapse all top-level servers into one environment, silently removing named environment constants (e.g. Environment.AGENT) from generated SDKs. The old pre-4.71.4 behavior of emitting one environment per top-level server is now restored by default; customers who want the Box-style “one logical environment with multiple named base URLs” behavior can opt in by setting multi-server-strategy: urls-per-environment under api.specs[].settings.

(fix): Fix WebSocket base URLs silently overwriting HTTP base URLs when both share the same x-fern-server-name (OpenAPI + AsyncAPI) inside a consolidated environment. Colliding WebSocket URLs are now suffixed with their protocol (e.g. Agent_wss) so both the HTTP and WSS URLs remain addressable. Only applies when multi-server-strategy: urls-per-environment is set.

4.86.1

(chore): When an OpenAPI endpoint has multiple request and response examples that cannot be paired by matching summary fields, the CLI now emits a warning explaining which response example had no match and how to fix it, rather than silently producing an extra example with an empty request body.

4.86.0

(feat): Allow theme.product-switcher: tabs in docs.yml. When set, the product switcher renders as a row of tabs in the docs header on desktop, with a dropdown fallback on mobile.

4.85.2

(chore): Surface descriptive Fiddle error messages (e.g. GithubAppNotInstalled) in the CLI instead of the generic “Failed to create job. Please try again or contact support@buildwithfern.com” fallback. The _other visitor callback receives core.Fetcher.Error directly ({ reason, statusCode, body }), but extractErrorMessage was looking one level too deep under .content, so the descriptive message was never extracted.

4.85.1

(fix): Fix x-fern-discriminated: true to correctly keep specific schemas as discriminated unions when prefer-undiscriminated-unions-with-literals is enabled.

4.85.0

(fix): Fix shell completion triggering upgrade notices and slow network calls. Suppress upgrade messages and skip version redirection when the shell invokes --get-yargs-completions so that TAB completions are fast and side-effect-free.

(feat): Add shell completion support to CLI v2 with content-aware completions for --group, --api, and --instance flags. The completion reads fern.yml to suggest valid values when the user presses TAB.

4.84.2

(fix): Fix wire test infrastructure to correctly handle array query parameters in WireMock stubs and test verification across all generators with wire test support.

4.84.1

(fix): Fix [object Object] being logged (and recorded in the automation summary) when a generator fails during fern automations generate. The automation-mode catch in the remote workspace runner now propagates TaskAbortSignal instead of stringifying it, and pulls the real failure message off the task context for the run summary. Also makes InteractiveTaskContextImpl.finish() idempotent so the duplicate Failed. line is gone.

4.84.0

(feat): Add --skip-if-no-diff flag to fern generate that skips opening a PR / pushing when the generated output has no diff from the base branch. The existing no-diff skip behavior is decoupled from automationMode and now gated behind its own skipIfNoDiff config. fern automations generate continues to skip no-diff PRs by default.