Fern Writer | Fern Documentation

Fern Writer is a Slack-based technical writing agent that keeps your docs aligned as your product evolves. It’s powered by Devin from Cognition. Fern Writer understands Fern components and your writing style, and can be customized via an AGENTS.md file in your docs repository.

How it works

Making a request

In Slack channels where you’ve added Fern Writer, tag @Fern Writer and describe the change you need. Fern Writer only responds when directly tagged. It will react to your message to confirm receipt, then create a pull request and reply with a link.

Fern Writer supports image and file attachments for additional context. When tagged in an existing thread, it reads the full conversation to understand context before responding.

Use case	Sample request
Document a new feature from a pull request	`@Fern Writer document the new rate limiting feature added in PR #123`
Add new content to existing pages	`@Fern Writer add a section about webhook retry behavior to the webhooks guide`
Reorganize and consolidate content	`@Fern Writer merge the authentication and authorization pages, and add a redirect from the old auth page`
Fix errors and improve clarity	`@Fern Writer fix the broken code example in the quickstart and update the package version to v2.1.0`

Video example

Reviewing and merging

Request changes by commenting in the Slack thread. Once the PR meets your requirements, merge it like any other pull request.

Pull request attribution

Each pull request includes a Requested by field in the description, attributing the change to the person or team that initiated the request. Commits are signed and attributed to fern-support, ensuring that automated changes are clearly distinguishable from manual contributions in your repository’s history.

Setup

Fern Writer only supports GitHub. GitLab and other Git providers aren’t supported.

To start using Fern Writer, add it to your Slack workspace (you must be a Slack admin) and invite it to channels where your team discusses documentation.

Get your unique install link

Get a unique Slack installation link for your organization. Provide:

Your Fern token
The GitHub repository containing your documentation in owner/repo format (e.g., acme/docs). The Fern GitHub App must be installed in the repository.

You can alternatively use this cURL request:

$ curl -G https://fai.buildwithfern.com/scribe/slack/get-install \
>      -H "Authorization: Bearer <YOUR_FERN_TOKEN>" \
>      --data-urlencode github_repo=<OWNER/REPO>

Follow the URL returned in the response.

Add to your workspace

You’ll be redirected to Slack to authorize Fern Writer. Select the workspace where you want to add Fern Writer and click Allow.

Add to channels

Once installed, add Fern Writer to Slack channels where your team discusses documentation.

Privacy and data handling

Fern Writer doesn’t store your Slack messages directly. When you tag @Fern Writer or reference a message or thread, the content is stored in a session to generate the documentation pull request. Session data isn’t retained after the task completes.

Neither Fern nor Devin uses your data to train AI models. Fern explicitly configures its Devin integration to opt out of any data collection for model training. Your channel messages, code, and documentation content are never used for training purposes. See Devin’s documentation on Slack integration security for additional details.