> For clean Markdown content of this page, append .md to this URL. For the complete documentation index, see https://buildwithfern.com/learn/llms.txt. ## 4.21.1 **`(chore):`** Bump bundled @fern-api/generator-cli to 0.10.1. Auto-versioned MAJOR/MINOR bumps no longer produce a version-only `changelog.md` block when the AI analysis returns an empty changelog entry; the PR description, version bump reason, or commit message body is used instead. ## 4.21.0 **`(feat):`** Generated root clients (sync and async) now implement `AutoCloseable`. `close()` shuts down the underlying `OkHttpClient`'s dispatcher executor and evicts its connection pool, but only when the SDK created that `OkHttpClient` itself — a client supplied via `Builder.httpClient(...)` is left running, since the caller owns its lifecycle. This lets short-lived applications (e.g. CLIs, or code that finishes after using WebSockets) release the client's background threads instead of relying on JVM shutdown.