Patch Demo

A fake Expo storefront for demoing Codemagic Patch OTA updates. Tap Add to cart and checkout fails. Publish a JS fix via Patch, install the update prompt, and the button works.

Prerequisites

• Local Codemagic Patch server already running (see the codemagic-patch repo)
• Xcode Command Line Tools on your Mac
• cmpatch CLI from the Patch monorepo

Verify Patch is reachable:

curl -fsS http://localhost:3000/health

Patch configuration

This app targets the local dev stack defaults:

Setting	Value
App	demo-app
Deployment	staging
Deployment key	dev_local_deployment_key
API URL	http://localhost:3000
Download base	http://localhost:9100/codemagic-patch
API token	cm_pat_local-dev-token-change-me-00000001

codemagic-patch.config.json is already initialized for this project.

One-time CLI login

cmpatch stores credentials locally after you sign in once. You do not need to pass a token on every release.

cmpatch login \
  --server-url http://127.0.0.1:3000 \
  --token cm_pat_local-dev-token-change-me-00000001 \
  --non-interactive

Credentials are saved to ~/.codemagic-patch/credentials.json. After that, cmpatch release-react works without export CODEMAGIC_PATCH_TOKEN=....

If you still see auth errors, check the server URL matches what you logged into (http://127.0.0.1:3000, not the dashboard port 5173).

Local builds

CocoaPods is installed. Because the repo path contains a space (cloned repos), local iOS builds use a symlink and a small patch script.

One-time setup

ln -sfn "/Users/zachgoldie/cloned repos/patch-demo-app" ~/patch-demo-app
cd ~/patch-demo-app
npm run demo:setup:ios

demo:setup:ios runs expo prebuild, patches Xcode scripts for the spaced path, and runs pod install.

Build and run on simulator

cd ~/patch-demo-app
npm run demo:ios -- --device "iPhone 17 Pro"

Always build from ~/patch-demo-app (the symlink), not the spaced path directly.

After changing native config in app.json, re-run npm run demo:setup:ios before building again.

localhost in the Patch URLs works because the simulator runs on your Mac, where Patch is listening.

Demo toggles

At the top of App.tsx:

Toggle	What it does
CHECKOUT_BROKEN	Intentional checkout bug. Flip to false and publish an OTA to demo the fix.
CHECK_CONDITION	When to look for updates: "on-launch", "on-resume", or "both".
INSTALL_CONFIRMATION	true shows Later / Install Now; false installs with no confirm UI (sync()).
INSTALL_MODE	How the install is staged (ON_NEXT_RESTART, IMMEDIATE, etc.).

Demo recording script

1. Broken baseline

Ensure CHECKOUT_BROKEN is true at the top of App.tsx, then build and install a Release simulator build (npm run demo:ios).

Open the app and tap Add to cart. You should see a payment failure (intentional bug).

2. Publish the OTA fix

Flip the toggle locally:

// App.tsx
const CHECKOUT_BROKEN = false;

Publish to your local Patch server (from the project root):

cd ~/patch-demo-app
npm run publish:ota

Or call cmpatch release-react directly. Signed releases need a private key at patch-signing/patch-private-key.pem (gitignored). A cmpatch-private.pem symlink at the project root points at it so dashboard-generated commands that use the default path also work.

3. Install the update

With the app still on the simulator, background it (Cmd+Shift+H) and return to foreground, or kill and relaunch.

An Update Available alert appears. Tap Install Now. The app reloads.

Tap Add to cart again. Checkout succeeds.

Project structure

App.tsx                       Screen, demo toggles, Patch update flow
scripts/publish-ota.mjs       Publishes a normal release to local Patch
codemagic-patch.config.json   cmpatch project context

Important notes

• Expo Go will not work. Patch requires a custom native build.
• Do not use Metro dev mode for the demo. Build Release so the app boots from the embedded JS bundle. That is the bundle an OTA update replaces.
• Keep expo.version at 1.0.0 so OTA releases match the native binary version.