Publishing to npm | Fern Documentation

Publish your public-facing Fern TypeScript SDK to the npm registry. After following the steps on this page, you’ll have a versioned package published on npm.

This page assumes that you have:

An initialized fern folder. See Set up the fern folder.
A GitHub repository for your TypeScript SDK. See Project structure.
A TypeScript generator group in generators.yml. See TypeScript Quickstart.

Configure SDK package settings

You’ll need to update your generators.yml file to configure the package name, output location, and client naming for npm publishing. Your generators.yml should live in your source repository (or on your local machine), not the repository that contains your TypeScript SDK code.

Configure `output` location

In the group for your TypeScript SDK, change the output location from local-file-system (the default) to npm to indicate that Fern should publish your package directly to the npm registry:

generators.yml

1 groups: 
2   ts-sdk: # Group name for your TypeScript SDK
3     generators:
4       - name: fernapi/fern-typescript-sdk
5         version: 2.5.0
6         output:
7           location: npm

Add a unique package name

Your package name must be unique in the npm repository, otherwise publishing your SDK to npm will fail.

generators.yml

1 groups: 
2   ts-sdk:
3     generators:
4       - name: fernapi/fern-typescript-sdk
5         version: 2.5.0
6         output:
7           location: npm
8           package-name: your-package-name

Configure `namespaceExport`

The namespaceExport option controls the name of the generated client. This is the name customers use to import your SDK (import { your-client-name } from 'your-package-name';).

generators.yml

1 groups: 
2   ts-sdk:
3     generators:
4       - name: fernapi/fern-typescript-sdk
5         version: 2.5.0
6         output:
7           location: npm
8           package-name: your-package-name
9         config:
10           namespaceExport: YourClientName # must be PascalCase

Generate an npm token

Log into npm

Log into npm or create a new account.

Navigate to Access Tokens

Click on your profile picture.
Select Edit Profile.
Select Access Tokens.

Generate Token

Click on Generate New Token, then choose the appropriate token type.

For more information on access tokens and which type to choose, see npm’s About access tokens documentation.

Option 1: Classic Token

Select Classic Token
Name your token and select Automation as the token type.
Click Generate Token.

Save your new token – it won’t be displayed after you leave the page.

Option 2: Granular Access Token

Select Granular Access Token.
Name your token.
Set an expiration.
Configure your token’s access to packages and scopes.
Configure your token’s access to organizations. In order to fill this out, you must have at least one organization already configured in npm. See Creating an organization for more information.
Optionally fill out additional permissions according to your organization’s requirements.
Click Generate Token.

Save your new token – it won’t be displayed after you leave the page.

Configure npm publication

Add repository location

Add the path to the GitHub repository containing your TypeScript SDK:

generators.yml

1 groups: 
2 	ts-sdk:
3 	generators:
4 		- name: fernapi/fern-typescript-sdk
5 		version: 2.5.0
6 		output:
7 			location: npm
8 			package-name: your-package-name
9 		config:
10 			namespaceExport: YourClientName
11 		github: 
12 			repository: your-org/company-typescript

Configure npm authentication token

Add token: ${NPM_TOKEN} to generators.yml to tell Fern to use the NPM_TOKEN environment variable for authentication when publishing to the npm registry.

generators.yml

1 groups: 
2   ts-sdk:
3 	generators:
4 	  - name: fernapi/fern-typescript-sdk
5 		version: 2.5.0
6 		output:
7 		  location: npm
8 		  package-name: name-of-your-package
9 		  token: ${NPM_TOKEN}
10 		config:
11 		  namespaceExport: YourClientName
12 		github: 
13 		  repository: your-org/your-repository

Choose your publishing mode

Optionally set the mode to control how Fern handles SDK publishing:

mode: release (default): Fern generates code, commits to main, and tags a release automatically
mode: pull-request: Fern generates code and creates a PR for you to review before release
mode: push: Fern generates code and pushes to a branch you specify for you to review before release

You can also configure other settings, like the reviewers or license. Refer to the full github (generators.yml) reference for more information.

generators.yml

1 groups: 
2   ts-sdk:
3 	generators:
4 	  - name: fernapi/fern-typescript-sdk
5 		version: 2.5.0
6 		output:
7 		  location: npm
8 		  package-name: name-of-your-package
9 		  token: ${NPM_TOKEN}
10 		config:
11 		  namespaceExport: YourClientName
12 		github: 
13 		  repository: your-org/your-repository
14 		  mode: push
15 		  branch: your-branch-name # Required for mode: push

Publish your SDK

Decide how you want to publish your SDK to npm. You can use GitHub workflows for automated releases or publish directly via the CLI.

Release via a GitHub workflow

Set up a release workflow via GitHub Actions so you can trigger new SDK releases directly from your source repository.

Set up authentication

Open your source repository in GitHub. Click on the Settings tab. Then, under the Security section, open Secrets and variables > Actions.

You can also use the url https://github.com/<your-repo>/settings/secrets/actions.

Add secret for your npm Token

Select New repository secret.
Name your secret NPM_TOKEN.
Add the corresponding token you generated above.
Click Add secret.

Add secret for your Fern Token

Select New repository secret.
Name your secret FERN_TOKEN.
Add your Fern token. If you don’t already have one, generate one by running fern token. By default, the fern_token is generated for the organization listed in fern.config.json.
Click Add secret.

Set up a new workflow

Set up a CI workflow that you can manually trigger from the GitHub UI. In your repository, navigate to Actions. Select New workflow, then Set up workflow yourself. Add a workflow that’s similar to this:

.github/workflows/publish.yml

1 name: Publish TypeScript SDK
2 
3 on:
4   workflow_dispatch:
5     inputs:
6       version:
7         description: "The version of the TypeScript SDK that you would like to release"
8         required: true
9         type: string
10 
11 jobs:
12   release:
13     runs-on: ubuntu-latest
14     steps:
15       - name: Checkout repo
16         uses: actions/checkout@v4
17 
18       - name: Install Fern CLI
19         run: npm install -g fern-api
20 
21       - name: Release TypeScript SDK
22         env:
23           FERN_TOKEN: ${{ secrets.FERN_TOKEN }}
24           NPM_TOKEN: ${{ secrets.NPM_TOKEN }}
25         run: |
26           fern generate --group ts-sdk --version ${{ inputs.version }} --log-level debug

You can alternatively configure your workflow to execute on: [push]. See Vapi’s npm publishing GitHub Action for an example.

Regenerate and release your SDK

Navigate to the Actions tab, select the workflow you just created, specify a version number, and click Run workflow. This regenerates your SDK.

The rest of the release process depends on your chosen mode:

Release mode (default): If you didn’t specify a mode or set mode: release, no further action is required. Fern automatically tags the new release with your specified version number and initiates the publishing workflow in your SDK repository.
Pull request or push mode: If you set mode: pull-request or mode: push, Fern creates a pull request or pushes to a branch respectively. Review and merge the PR (pull-request) or branch (push), then tag a new release to initiate the publishing workflow in your SDK repository.

Once the workflow completes, you can view your new release by logging into npm and navigating to Packages.

Release via CLI and environment variables

Set npm environment variable

Set the NPM_TOKEN environment variable on your local machine:

$ export NPM_TOKEN=your-actual-npm-token

Regenerate and release your SDK

Regenerate your SDK, specifying the version:

$ fern generate --group ts-sdk --version <version>

The rest of the release process depends on your chosen mode:

Release mode (default): If you didn’t specify a mode or set mode: release, no further action is required. Fern automatically tags the new release with your specified version number and initiates the publishing workflow in your SDK repository.
Pull request or push mode: If you set mode: pull-request or mode: push, Fern creates a pull request or pushes to a branch respectively. Review and merge the PR (pull-request) or branch (push), then tag a new release to initiate the publishing workflow in your SDK repository.

Once the workflow completes, you can view your new release by logging into npm and navigating to Packages.

Configure SDK package settings

Configure output location

Add a unique package name

Configure namespaceExport

Generate an npm token

Log into npm

Navigate to Access Tokens

Generate Token

Option 1: Classic Token

Option 2: Granular Access Token

Configure npm publication

Add repository location

Configure npm authentication token

Choose your publishing mode

Publish your SDK

Release via a GitHub workflow

Set up authentication

Add secret for your npm Token

Add secret for your Fern Token

Set up a new workflow

Regenerate and release your SDK

Release via CLI and environment variables

Set npm environment variable

Regenerate and release your SDK

Configure `output` location

Configure `namespaceExport`