Set up changesets in a GitHub repository

Install changeset-bot on your repository

Install @changesets/cli

yarn add --dev @changesets/cli

Initialize changesets

yarn changeset init

Add a release script

// package.json
{
  "scripts": {
    "release": "yarn build && changeset publish"
  }
}

Generate an npm token

Add an NPM_TOKEN secret for your repository

Create .github/workflows/release.yml

(Optional) Add snapshot releases to your CI workflow

# .github/workflows/ci.yml
name: CI
on:
  push:
    branches-ignore:
      - $default-branch
jobs:
  ci:
    name: CI
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repo
        uses: actions/checkout@master
        with:
          # This makes Actions fetch all Git history so that Changesets
          # can generate changelogs with the correct commits.
          fetch-depth: 0

      # If you use a version of Node other than 12, change it here.
      - name: Set up Node.js 12.x
        uses: actions/setup-node@master
        with:
          node-version: 12.x

      # If you use npm instead of yarn, change this to `npm install`.
      - name: Install dependencies
        run: yarn

      # Change this to customize your build command.
      - name: Build
        run: yarn build

      # Change this to customize your test command.
      - name: Test
        run: yarn test

      - name: Create .npmrc
        run: |
          cat << EOF > "$HOME/.npmrc"
            //registry.npmjs.org/:_authToken=$NPM_TOKEN
          EOF
        env:
          NPM_TOKEN: ${{ secrets.NPM_TOKEN }}

      - name: Release snapshot
        run: |
          npx changeset version --snapshot
          npx changeset publish --tag canary
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

      - name: Post published version to GitHub checks
        run: |
          name=$(jq -r .name package.json)
          version=$(jq -r .version package.json)
          npx action-status --context=$name --state=success --description=$version --url="https://unpkg.com/$name@$version/"
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}