How do I get the links to the internal distribution builds with expo/expo-github-action?

I am building internal distribution builds for a React Native Expo app via GitHub actions and EAS Build. The workflow is triggered on push using expo/expo-github-action@v7. Once the build is finished, the action logs 2 URLs (and 2 QR codes) where the .apk and .ipa can be downloaded:

I want to get those links programmatically so I can use them in the next step to notify my Slack channel, for example.

I've looked in the documentation, but it's very generic. Can anyone help?

I fixed this the "hard way" because expo-github-action does not have any outputs.

First, I needed to get the build output as JSON. I did so with the --json switch:

eas build --profile preview --platform all --non-interactive --json

Second, I stored the result in a variable like so:

build_json=$(eas build --profile preview --platform all --non-interactive --json)

Next, I parsed the JSON and extracted the links out of it:

android_link=$(echo $build_json | jq -r '.[] | select(.platform=="ANDROID") | .artifacts.applicationArchiveUrl')
ios_link=$(echo $build_json | jq -r '.[] | select(.platform=="IOS") | .artifacts.applicationArchiveUrl')

Finally, I've assigned the variables to outputs:

EOF=$(dd if=/dev/urandom bs=15 count=1 status=none | base64)
echo "build_json<<$EOF" >> $GITHUB_OUTPUT
echo "$build_json" >> $GITHUB_OUTPUT
echo "$EOF" >> $GITHUB_OUTPUT
echo "android_link=$android_link" >> $GITHUB_OUTPUT
echo "ios_link=$ios_link" >> $GITHUB_OUTPUT

Note that the system that GitHub Actions uses to create outputs is brittle and does not work well with apices or newlines, so in the case of build_json, the only safe alternative is to use a random separator instead of the <name>=<variable> syntax.

I could then use the outputs with steps.<step id>.outputs.android_link, etc.

The overall solution looks like this:

build_json=$(eas build --profile preview --platform all --non-interactive --json)
android_link=$(echo $build_json | jq -r '.[] | select(.platform=="ANDROID") | .artifacts.applicationArchiveUrl')
ios_link=$(echo $build_json | jq -r '.[] | select(.platform=="IOS") | .artifacts.applicationArchiveUrl')
EOF=$(dd if=/dev/urandom bs=15 count=1 status=none | base64)
echo "build_json<<$EOF" >> $GITHUB_OUTPUT
echo "$build_json" >> $GITHUB_OUTPUT
echo "$EOF" >> $GITHUB_OUTPUT
echo "android_link=$android_link" >> $GITHUB_OUTPUT
echo "ios_link=$ios_link" >> $GITHUB_OUTPUT

Hopefully it will help the next person save day of investigation or so!