Publish and Pick a Hermes Release

July 7, 2026 · View on GitHub

Important

Only Meta release crew should publish Hermes releases. If you are a community releaser that is picking a Hermes pick request, ping a Meta release crew member to publish the Hermes release.

Note

Publishing the Hermes tags is a manual, Meta-only flow — follow the steps below. The rn-release-automator CLI does not publish Hermes itself, but its cut-branch command guides you through the React-Native-side steps: it opens this guide at the right moment, then prompts for the new Hermes tag(s) and runs the bump-hermes-version.js script + commit + push for you (Step 4). prepare-release also flags any Hermes-related pick requests as 🔴 so they aren't picked automatically.

Prerequisites: You'll need access to the Hermes repo. You can give yourself permission via the Meta Internal OSS dashboard.

See the guide you need, based on the React native release you are running:

For React Native >= 0.87

Starting from React Native 0.83, we need to have one tag for HermesV1.

We decoupled the build of Hermes from the React Native repository and we can now consume Hermes binaries that are produced in the Hermes repository

Step 1: Cherry-pick

Important

If you cutting a release candidate, skip this step

  1. Checkout the 250829098.0.0-stable branch.
  2. Pick the relevant commits onto that branch. The pick requests should be from static_h and no other branch on Hermes.
  3. Push the picks to the remote branch.

Step 2: Build Hermes and Publish Tag

Navigate to the RN Build Hermes and run the workflow once. This workflow:

  • builds the Hermes artifacts;
  • publishes them on maven;
  • publishes the hermes-compiler to NPM;
  • publish the tag on GitHub

The tag will be created as last step, and we need to wait for the whole process to end before React Native can start the Release.

Important

If you are releasing a patch for Hermes V1 for the latest version of React Native, you also have to bump the patch number hermes-compiler/package.json file from the 250829098.0.0-stable

  1. Set the branch to the Hermes V1 release branch: 250829098.0.0-stable
  2. Set the release type as Release

Step 3: Bump the Hermes version on the React Native release branch

Using the newly generated Hermes tag run the following script on the React Native release branch:

# Replace <the_hermes_tag> with the tag that will look like 'hermes-2022-07-20-RNv0.70.0-bc97c5399e0789c0a323f8e1431986e207a9e8ba'
./packages/react-native/scripts/hermes/bump-hermes-version.js -s <the_hermes_v1_tag>

An example of the invocation is:

./packages/react-native/scripts/hermes/bump-hermes-version.js -s hermes-v250829098.0.2

Note

The script also support the -v parameter to specify the Hermes V1 version. When not passed, the script will check the latest version of hermes published on NPM and will prompt for confirmation.

Add and commit the extra files that got created at:

  • packages/react-native/sdks/.hermesV1version and updated at:
  • packages/react-native/sdks/hermes-engine/version.properties
  • packages/react-native/package.json

Now you can continue with the rest of your React Native release.

git add packages/react-native/sdks/.hermesvesion packages/react-native/sdks/.hermesv1vesion packages/react-native/sdks/hermes-engine/version.properties
git commit -m "Bump hermes version"

Step 4: Bump version on Hermes v1 release branch

The 250829098.0.0-stable should always track the next version that we are going to release.

After the build started and the tag is generated, bump the hermes-compiler versions on those branches:

From the 250829098.0.0-stable branch

  1. Open the npm/hermes-compiler/package.json file
  2. Bump the patch number by 1
  3. Commit and push.

Step 5: [Only for Branch Cut] Bump hermes versions on React Native main branch

  1. Go to the react-native repository
  2. Update the packages/react-native/sdks/hermes-engine/versions.properties file by bumping the HERMES_V1_VERSION_NAME This is an example PR.

For React Native 0.83 <= X < 0.87

Starting from React Native 0.83, we need to have two tags for Hermes:

  • A tag for the (legacy) Hermes
  • A tag for HermesV1

We decoupled the build of Hermes from the React Native repository and we can now consume Hermes binaries that are produced in the Hermes repository

Step 1: Check-out or create the (Legacy) Hermes release branch

If you are cutting a release candidate

Create a Hermes release branch of the form release-v0.<hermes-minor> from latest main.

Make sure your branch is pushed to the remote.

# Run this in the Hermes repo:
git checkout main
git pull origin main
git checkout -b release-v0.14
git push origin HEAD

Step 2: Cherry-pick

For (Legacy) Hermes

Important

If you cutting a release candidate, skip this step

  1. Pick the relevant commits onto that branch. The pick requests should be from main and no other branch on Hermes.
  2. Push the picks to the remote branch.

For HermesV1

Important

If you cutting a release candidate, skip this step

  1. Checkout the 250829098.0.0-stable branch.
  2. Pick the relevant commits onto that branch. The pick requests should be from static_h and no other branch on Hermes.
  3. Push the picks to the remote branch.

Step 3: Build Hermes and Publish Tag

Navigate to the RN Build Hermes and run the workflow twice. This workflow:

  • builds the Hermes artifacts;
  • publishes them on maven;
  • publishes the hermes-compiler to NPM;
  • publish the tag on GitHub

The tag will be created as last step, and we need to wait for the whole process to end before React Native can start the Release.

Important

If you are releasing a patch for legacy Hermes, you also have to bump the patch number hermes-compiler/package.json file from the release-v0.XX branch. If you are releasing a patch for Hermes V1 for the latest version of React Native, you also have to bump the patch number hermes-compiler/package.json file from the 250829098.0.0-stable

For (Legacy) Hermes

  1. Set the branch to the release branch (e.g.: release-v0.14)
  2. Set the release type as Release

For Hermes V1

  1. Set the branch to the Hermes V1 release branch: 250829098.0.0-stable
  2. Set the release type as Release

Step 4: Bump the Hermes version on the React Native release branch

Using the newly generated Hermes tag run the following script on the React Native release branch:

# Replace <the_hermes_tag> with the tag that will look like 'hermes-2022-07-20-RNv0.70.0-bc97c5399e0789c0a323f8e1431986e207a9e8ba'
./packages/react-native/scripts/hermes/bump-hermes-version.js -t <the_hermes_tag> -s <the_hermes_v1_tag>

An example of the invocation is:

./packages/react-native/scripts/hermes/bump-hermes-version.js -t hermes-v0.14.0 -s hermes-v250829098.0.2

Note

The script also support the -h parameter to specify the legacy Hermes version and the -v parameter to specify the Hermes V1 version. When not passed, the script will check the latest version of hermes published on NPM and will prompt for confirmation.

Add and commit the extra files that got created at:

  • packages/react-native/sdks/.hermesversion
  • packages/react-native/sdks/.hermesV1version and updated at:
  • packages/react-native/sdks/hermes-engine/version.properties
  • packages/react-native/package.json

Now you can continue with the rest of your React Native release.

git add packages/react-native/sdks/.hermesvesion packages/react-native/sdks/.hermesv1vesion packages/react-native/sdks/hermes-engine/version.properties
git commit -m "Bump hermes version"

Step 5: Bump version on main and Hermes v1 release branch

The main branch and the 250829098.0.0-stable should always track the next version that we are going to release.

After the build started and the tag is generated, bump the hermes-compiler versions on those branches:

For Legacy Hermes

From the main branch:

  1. Create a separate branch <username>/bump-hermes-compiler-to-0.X.0 (replace <username> and X with your gh username and the next minor version of Hermes)
  2. Open the npm/hermes-compiler/package.json file
  3. Bump the minor number by 1
  4. Commit and push.
  5. Open a PR on the Hermes repository
  6. Import and land it.

For Hermes V1

From the 250829098.0.0-stable branch

  1. Open the npm/hermes-compiler/package.json file
  2. Bump the patch number by 1
  3. Commit and push.

Step 6: [Only for Branch Cut] Bump hermes versions on React Native main branch

  1. Go to the react-native repository
  2. Update the packages/react-native/sdks/hermes-engine/versions.properties file by bumping the HERMES_V1_VERSION_NAME This is an example PR.