iOS TestFlight with fastlane

Wire one-command TestFlight releases into a native iOS project using fastlane. The result: fastlane beta (or an optional pnpm ios:testflight alias) archives a Release build, computes the next build number, signs, exports an IPA, and uploads it to TestFlight — no manual Xcode archiving and no Apple ID / 2FA prompts.

This skill targets a single app, TestFlight only (not App Store review submission, not CI). It assumes an XcodeGen-based project by default but works for a committed .xcodeproj by deleting one line.

Artifacts to copy

Three concrete, working files live in references/ — copy them and change the marked constants rather than writing from scratch:

• references/Fastfile → apps/ios/fastlane/Fastfile. Two lanes: beta

(build + upload) and upload (push an existing IPA). All the hard-won logic and gotcha comments are inline.

• references/Appfile → apps/ios/fastlane/Appfile. App id + team id.
• references/env.testflight.local.example → <repo-root>/.env.testflight.local

(gitignored). Holds the secrets.

references/setup-and-gotchas.md is the full guide — read it before running a release. Load it for App Store Connect API-key creation, signing requirements, the versioning model, multi-target plist handling, and the gotcha rationale.

Workflow

1. Install fastlane via Homebrew, not gem install — macOS system Ruby is

too old: brew install fastlane.

1. Create an App Store Connect API key (Users and Access → Integrations →

App Store Connect API, "App Manager" role). Capture the Key ID, Issuer ID, and the one-time .p8 download. Details in references/setup-and-gotchas.md.

1. Copy the three artifacts above into place. apps/ios/ is an example

layout; if the iOS project lives elsewhere, adjust the IOSDIR/ROOTDIR .. depth at the top of the Fastfile so they resolve to the iOS project dir and the repo root (where .env.testflight.local lives).

1. Set the constants in the Fastfile: SCHEME, BUNDLEID, TEAMID, and

PLISTS — list one Info.plist per shipping target (app + every embedded extension). Match Appfile to the same bundle id / team id.

1. Keep or delete the xcodegen generate line — keep for XcodeGen projects,

delete when the .xcodeproj is committed.

1. Fill .env.testflight.local — required: ASCAPIKEY_ID,

ASCAPIISSUERID, ASCAPIKEYPATH, ASCAPPLEID; optional: TESTFLIGHTSIGNINGAUTHMODE (defaults to the appleid path when unset). Add the file to .gitignore.

1. Dry-run, then release: fastlane beta skip_upload:true archives and

exports an IPA without publishing; once that succeeds, run fastlane beta.

Key facts the agent must not get wrong

• Build numbering is automatic. The lane stamps

max(latest TestFlight, local plists) + 1 into every listed plist. Never hand-edit CFBundleVersion; do bump CFBundleShortVersionString (marketing version) by hand, and keep it identical across all target plists or the lane aborts.

• ASCAPPLEID is the numeric app id, not an email. This is the most common

first-run failure.

• Signing uses automatic signing + -allowProvisioningUpdates; the Mac needs

an Apple Distribution certificate (true if it has archived to the App Store from Xcode before).

• export_method is "app-store" (legacy alias), and signing xcargs must

be passed to both the archive and export steps — both encoded in the Fastfile, explained in references/setup-and-gotchas.md.

Portability

Keep the skill project-agnostic. The bundle ids, team id, and apps/ios/... paths in the artifacts are examples — every release-specific value belongs in the copied Fastfile or the gitignored env file, never hardcoded as a requirement.

Reference files

• references/setup-and-gotchas.md — prerequisites, ASC API key, signing,

versioning model, multi-target plists, gotcha rationale, adaptation checklist.

• references/Fastfile — the working lanes to copy.
• references/Appfile — app id + team id.
• references/env.testflight.local.example — secrets template.