# December 19, 2025

## 3.39.0

**`(feat):`** Add opt-in `pydantic_config.positional_single_property_constructors` to allow `Wrapper("value")`
for single-required-field models (excluding discriminator literals). Note: can break if the model
later adds required fields; kwargs are more stable.

## 3.29.1

**`(chore):`** Make version optional when fetching dynamic IR from SDK uploads. If no version is explicitly specified in the api snippets config, the CLI will not send a version and the API will use the latest available version.

## 3.29.0

**`(feat):`** Add `fern docs preview delete <url>` command to delete preview deployments. This allows users to clean up preview sites that were generated with `fern generate --docs --preview`.

**`(feat):`** Add `fern docs preview list` command to list all preview deployments with pagination support via `--limit` and `--page` options.

## 3.28.0

**`(feat):`** Refactor `fern check` output with improved formatting and severity labels. Violations are now displayed in a hierarchical format grouped by `[sdk]` and `[docs]`, with `[error]` (red) and `[warning]` (yellow) labels for each violation. When multiple APIs exist, violations are further grouped by API name. Additional UX improvements include: blue-colored paths, cyan `[sdk]` and magenta `[docs]` headers for visual distinction, warnings displayed before errors, blank lines between violations for readability, and inline issue display when path is empty.

## 3.27.3

**`(chore):`** Updates dynamic snippets to pull from an SDK version, if available and specified in the `api.snippets` configuration.

## 3.27.2

**`(fix):`** Fix example resolution to treat dollar-prefixed strings as literals when they don't match the valid example reference format. Strings like `"$3.00"`, `"$USD"`, or `"$PATH"` are now treated as literal values without requiring escaping. Valid example references (e.g., `$Type.Example` or `$import.Type.Example`) continue to work as expected.

## 3.27.1

**`(fix):`** Fix `fern docs dev` hot reload to properly restart the docs server when files change.