Migrate from Fastlane

GPC replaces fastlane supply (and parts of fastlane deliver) for Google Play operations. This guide maps Fastlane commands, environment variables, and CI configurations to their GPC equivalents.

Why Migrate?

	GPC	Fastlane supply
API coverage	187 endpoints	~20 endpoints
Runtime	Node.js or standalone binary	Ruby + Bundler + 150+ gems
Reviews and Vitals	Yes	No
Subscriptions and IAP	Yes	No
JSON output	Structured, TTY-aware	Partial
Cold start	<500ms	2-3s
Rollout control	halt/resume/complete	Upload with rollout only
CI quality gates	Exit code 6 on threshold breach	Not available
Dry-run	`--dry-run` on all write commands	Not available

Command Mapping

Uploads and Releases

Fastlane	GPC	Notes
`fastlane supply --aab app.aab`	`gpc releases upload app.aab`	Defaults to internal track
`fastlane supply --aab app.aab --track beta`	`gpc releases upload app.aab --track beta`	Same track names
`fastlane supply --aab app.aab --track production --rollout 0.1`	`gpc releases upload app.aab --track production --rollout 10`	GPC uses percentage (10), not decimal (0.1)
`fastlane supply --apk app.apk`	`gpc releases upload app.apk`	APK also supported
`fastlane supply --aab app.aab --mapping mapping.txt`	`gpc releases upload app.aab --mapping mapping.txt`	Same behavior

Metadata and Listings

Fastlane	GPC	Notes
`fastlane supply --skip_upload_aab`	`gpc listings push --dir metadata/`	Push metadata only
`fastlane supply --skip_upload_aab --skip_upload_metadata --skip_upload_images`	`gpc releases upload app.aab`	Upload binary only
`fastlane supply init`	`gpc listings pull --dir metadata/`	Download all metadata to local
`fastlane supply --metadata_path ./metadata`	`gpc listings push --dir ./metadata`	Same concept

Screenshots and Images

Fastlane	GPC	Notes
`fastlane supply --skip_upload_aab --skip_upload_metadata`	`gpc listings images upload --lang en-US --type phoneScreenshots ./screens/*.png`	Upload screenshots
N/A	`gpc listings images list --lang en-US --type phoneScreenshots`	List existing images
N/A	`gpc listings images delete --lang en-US --type phoneScreenshots --id <id>`	Delete specific image

Rollout Management

Fastlane	GPC	Notes
`fastlane supply --track production --rollout 0.5`	`gpc releases rollout increase --track production --to 50`	Percentage vs decimal
`fastlane supply --track_promote_to production --track beta`	`gpc releases promote --from beta --to production`	Clearer flag names
N/A	`gpc releases rollout halt --track production`	No Fastlane equivalent
N/A	`gpc releases rollout resume --track production`	No Fastlane equivalent
N/A	`gpc releases rollout complete --track production`	No Fastlane equivalent

Commands Only in GPC

GPC Command	Description
`gpc vitals crashes`	Crash rate and clusters
`gpc vitals anr`	ANR rate
`gpc vitals crashes --threshold 2.0`	CI quality gate (exit code 6)
`gpc reviews list --stars 1-2`	Filter and list reviews
`gpc reviews reply <id> "Thanks"`	Reply to reviews
`gpc subscriptions list`	Manage subscriptions
`gpc iap list`	Manage in-app products
`gpc purchases get <token>`	Verify purchases
`gpc reports download financial`	Download financial reports
`gpc users invite <email>`	Manage developer account users
`gpc testers add <email>`	Manage beta testers

Environment Variables

Fastlane	GPC	Format
`SUPPLY_JSON_KEY`	`GPC_SERVICE_ACCOUNT`	File path or JSON string
`SUPPLY_JSON_KEY_DATA`	`GPC_SERVICE_ACCOUNT`	GPC accepts both file path and inline JSON in the same variable
`SUPPLY_PACKAGE_NAME`	`GPC_APP`	Package name
N/A	`GPC_DEVELOPER_ID`	Required for user management (Fastlane does not support this)

Rollout Values: Decimal vs Percentage

This is the most common gotcha when migrating. Fastlane uses decimal fractions (0.0-1.0), GPC uses percentages (0-100).

Fastlane	GPC	Meaning
`--rollout 0.01`	`--rollout 1`	1% of users
`--rollout 0.05`	`--rollout 5`	5% of users
`--rollout 0.1`	`--rollout 10`	10% of users
`--rollout 0.5`	`--rollout 50`	50% of users
`--rollout 1.0`	`--rollout 100` or omit	100% of users

Metadata Directory Format

GPC supports the Fastlane metadata directory structure. If you already have a metadata/ or fastlane/metadata/android/ directory, it works with gpc listings push.

Fastlane Format (supported by GPC)

metadata/
├── en-US/
│   ├── title.txt
│   ├── short_description.txt
│   ├── full_description.txt
│   ├── changelogs/
│   │   └── 42.txt              # Version code
│   └── images/
│       ├── phoneScreenshots/
│       │   ├── 1.png
│       │   └── 2.png
│       ├── icon.png
│       └── featureGraphic.png
├── ja-JP/
│   ├── title.txt
│   ├── short_description.txt
│   └── full_description.txt

GPC Commands with Fastlane Directory

bash

# Download current listings to Fastlane-compatible directory
gpc listings pull --dir metadata/

# Push local metadata to Play Console
gpc listings push --dir metadata/

# Preview changes without applying (dry-run)
gpc listings push --dir metadata/ --dry-run

# Push release notes from changelogs directory
gpc releases notes set --track beta --file metadata/en-US/changelogs/

CI Migration: GitHub Actions

Before (Fastlane)

yaml

# .github/workflows/release.yml (Fastlane)
name: Release
on:
  push:
    tags: ["v*"]

jobs:
  release:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - uses: ruby/setup-ruby@v1
        with:
          ruby-version: 3.2
          bundler-cache: true

      - uses: actions/setup-java@v4
        with:
          distribution: temurin
          java-version: 17

      - name: Build
        run: ./gradlew bundleRelease

      - name: Deploy to Play Store
        env:
          SUPPLY_JSON_KEY_DATA: ${{ secrets.PLAY_STORE_KEY }}
          SUPPLY_PACKAGE_NAME: com.example.myapp
        run: |
          bundle exec fastlane supply \
            --aab app/build/outputs/bundle/release/app-release.aab \
            --track internal

After (GPC)

yaml

# .github/workflows/release.yml (GPC)
name: Release
on:
  push:
    tags: ["v*"]

jobs:
  release:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - uses: actions/setup-java@v4
        with:
          distribution: temurin
          java-version: 17

      - name: Build
        run: ./gradlew bundleRelease

      - uses: actions/setup-node@v4
        with:
          node-version: 20

      - name: Deploy to Play Store
        env:
          GPC_SERVICE_ACCOUNT: ${{ secrets.GPC_SERVICE_ACCOUNT }}
          GPC_APP: com.example.myapp
        run: |
          npm install -g @gpc-cli/cli
          gpc releases upload \
            app/build/outputs/bundle/release/app-release.aab \
            --track internal \
            --json

Key differences:

No Ruby/Bundler setup required
Node.js setup instead (or use standalone binary for zero dependencies)
Environment variables renamed (SUPPLY_JSON_KEY to GPC_SERVICE_ACCOUNT)
--json flag for machine-readable output
No Gemfile or Fastfile needed

CI Migration: GitLab CI

Before (Fastlane)

yaml

release:
  image: ruby:3.2
  stage: deploy
  before_script:
    - gem install fastlane
  script:
    - |
      fastlane supply \
        --aab build/app-release.aab \
        --track internal \
        --json_key_data "$SUPPLY_JSON_KEY_DATA"
  only:
    - tags

After (GPC)

yaml

release:
  image: node:20
  stage: deploy
  before_script:
    - npm install -g @gpc-cli/cli
  script:
    - gpc releases upload build/app-release.aab --track internal --json
  variables:
    GPC_SERVICE_ACCOUNT: $GPC_SERVICE_ACCOUNT
    GPC_APP: com.example.myapp
  only:
    - tags

Fastfile to Shell Script

If you have a complex Fastfile, translate each lane to a shell script or CI step.

Fastfile

ruby

lane :deploy do
  gradle(task: "bundleRelease")
  supply(
    aab: "app/build/outputs/bundle/release/app-release.aab",
    track: "internal",
    skip_upload_metadata: true,
    skip_upload_images: true,
    skip_upload_screenshots: true,
  )
end

lane :promote_to_beta do
  supply(
    track: "internal",
    track_promote_to: "beta",
    skip_upload_metadata: true,
    skip_upload_images: true,
    skip_upload_screenshots: true,
  )
end

lane :metadata do
  supply(
    skip_upload_aab: true,
    skip_upload_apk: true,
    metadata_path: "./metadata",
  )
end

GPC Equivalent

bash

#!/bin/bash
# deploy.sh — replaces Fastfile lanes
set -euo pipefail

deploy() {
  ./gradlew bundleRelease
  gpc releases upload \
    app/build/outputs/bundle/release/app-release.aab \
    --track internal \
    --json
}

promote_to_beta() {
  gpc releases promote --from internal --to beta --json
}

metadata() {
  gpc listings push --dir ./metadata --json
}

# Run the requested lane
"${1:-deploy}"

Step-by-Step Migration

Install GPC -- npm install -g gpc or use the standalone binary
Set up auth -- gpc auth login --service-account key.json
Test with dry-run -- gpc listings push --dir metadata/ --dry-run
Update CI secrets -- Replace SUPPLY_JSON_KEY with GPC_SERVICE_ACCOUNT
Update CI workflow -- Replace Fastlane commands with GPC equivalents
Verify -- Run gpc doctor to confirm everything is connected
Remove Fastlane -- Delete Gemfile, fastlane/ directory (optional, can coexist during transition)

Migrate from Fastlane ​

Why Migrate? ​

Command Mapping ​

Uploads and Releases ​

Metadata and Listings ​

Screenshots and Images ​

Rollout Management ​

Commands Only in GPC ​

Environment Variables ​

Rollout Values: Decimal vs Percentage ​

Metadata Directory Format ​

Fastlane Format (supported by GPC) ​

GPC Commands with Fastlane Directory ​

CI Migration: GitHub Actions ​

Before (Fastlane) ​

After (GPC) ​

CI Migration: GitLab CI ​

Before (Fastlane) ​

After (GPC) ​

Fastfile to Shell Script ​

Fastfile ​

GPC Equivalent ​

Step-by-Step Migration ​

Migrate from Fastlane

Why Migrate?

Command Mapping

Uploads and Releases

Metadata and Listings

Screenshots and Images

Rollout Management

Commands Only in GPC

Environment Variables

Rollout Values: Decimal vs Percentage

Metadata Directory Format

Fastlane Format (supported by GPC)

GPC Commands with Fastlane Directory

CI Migration: GitHub Actions

Before (Fastlane)

After (GPC)

CI Migration: GitLab CI

Before (Fastlane)

After (GPC)

Fastfile to Shell Script

Fastfile

GPC Equivalent

Step-by-Step Migration