Continuing Codex work on iPhone or iPad

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Goal and the iPhone's role

The iPhone sends requests and displays results; the connected host provides source files, terminal, dependencies and signed-in websites. Installing ChatGPT on the phone does not install Codex CLI or synchronize computer folders into Files. Read the mobile overview and Remote host setup to distinguish connection, task and execution.

Before starting: prepare the host and account

Update ChatGPT desktop on your Mac or Windows computer, use the same account/workspace as the iPhone and confirm Codex access. Extract the Small Steps pack, copy expected into codex-iphone-lab and retain the original. Check the five source files on the host before pairing. Use this fictional practice project rather than private production work.

Install or update the official ChatGPT app from App Store, verifying OpenAI as publisher. Complete SSO, MFA or passkey requirements before Remote setup. Organization access may need administrator enablement and rollout can vary. If Remote is absent, record app version and workspace; switching Safari or reinstalling CLI does not establish feature access.

This lesson uses iPhone as the example. On iPad, first confirm that Remote is actually available in your ChatGPT app and that you can select a host before following the same file-reading exercise. The official page describes iOS access without guaranteeing a separate iPad layout. Do not infer iPad button positions from iPhone screens or treat this lesson as evidence of an iPad test.

Add your own identification file on the host

Create remote-check.txt in codex-iphone-lab, replacing 01 below with your own marker. Inspect any existing file; do not overwrite another task's file. This sixth file supplements the five website files. Use a unique marker per copy, never an account, password or pairing code. Privately note the marker and full path; omit the marker from the later prompt.

IOS-PRACTICE-01

Step 1: scan into Remote with Camera

On the host, open Settings → Connections → Control this Mac or PC, select Set up or Add and complete verification to display the pairing QR code. In iPhone Camera's Photo mode, frame the entire code and tap the detected link; Control Center's code scanner is another route. Do not upload a photo of the code to a chatbot. The link should open official ChatGPT setup.

If scanning fails, fit the whole code in frame, reduce glare and use photo/scanner mode. If only Safari opens, verify the installed official app and intended login, then restart setup from the host. Keep pairing URLs, QR codes, authentication codes and account details out of public troubleshooting posts and teaching screenshots.

Confirm account, workspace and host in the phone setup. Success should show the host in Remote and let you select codex-iphone-lab and open a Codex task. A login-complete page alone is insufficient. If the listed machine is wrong, revisit the intended host's pairing setup. Diagram 1 is the iPhone entry, 2 the selected host and 3 the verifiable project result.

Step 2: send a precise file-read request

Paste the following into the host project's task composer in Remote. Check that keyboard autocorrection has not altered filenames or function names. This is a prompt, not a terminal command for iPhone. Send once, observe the response and record identifying task information so you can return after switching apps.

Read this Small Steps project without changing files. Confirm the working directory and inspect app.js and core.mjs. Identify the localStorage key, the field that records completion, and the function that rejects blank task titles. Cite the file for each answer. If a file is unavailable, report that instead of guessing.

Expect mokaair-codex-todo-v1 from app.js, completed and addTask's blank-title check from core.mjs, and the actual working directory. Generic todo-app advice is insufficient; ask which file was inspected. For a wrong directory, stop and select the correct host/project. A plausible explanation alone does not prove the connection reached your files.

Read a marker unique to this copy

Read remote-check.txt from this task's project now.
Quote its exact content and report the absolute file path and the tool used to read it.
Do not edit files or infer the marker from earlier messages.
If the file is missing or cannot be read, report that limitation.

Compare the reply with the marker and path in your host-side note and with the tool read record. The host's displayed name and this file marker are different facts. To check freshness, wait for the task to finish, change and save only the marker on the host, then send the same read request without supplying the new value. A stale value, missing tool evidence or mismatched path remains unverified; check saved state, host and copy first.

Step 3: follow up, review approvals and inspect progress

In the same project, explain what happens when I add Read and Build, complete Read, and choose Completed. Then explain an empty task title. Separate code you inspected, tests actually run, and checks still pending. Do not edit or clear stored data.

With only Read and Build initially present, expect Completed to show only Read and blank titles to be rejected. Account for any other stored tasks; this read-only request leaves them unchanged. Separate inspected code, executed tests and pending UI checks. Verify the predicted behavior in the computer's local preview.

If an approval appears, inspect the operation, directory and scope against your request. This read-only exercise does not need new external accounts, website publication or deletion. Review long commands on the host if the phone view is insufficient. If no approval appears, inspect the original Remote task's state instead of repeatedly creating new tasks.

Step 4: leave and return to the same task

After the read-only response finishes, switch to another iPhone app, then return through ChatGPT → Remote to the same host/task. Inspect the last response and current state, then ask for a fresh current-directory read. Old visible text does not prove the host is online now. A new successful read verifies present access.

Notifications signal completion or attention; they do not validate results. Open the task even without a notification. If the host sleeps, disconnects or closes the app, restore it and inspect whether the previous request finished. For later writable tasks, avoid resending create/submit actions merely because the phone disconnected. This read-only exercise teaches recovery first.

Completion checks and common misunderstandings

A host's localhost URL entered in iPhone Safari points to the phone, not the computer. Review host-provided results or screenshots in Remote and use the computer for local preview; public preview/deployment is a separate step. Manage access through host setup, and check task cancellation separately. Signing out does not automatically delete pairings.

Finish by asking for host/directory, inspected content, unrun tests and next steps, excluding account details and codes. Compare that handoff on the computer so future phone progress checks distinguish completed work. Continue to cross-device work and context handoff, or use the Android lesson for equivalent verification on another phone.

On the host, remove only the remote-check.txt created in this exercise. Keep the five website files and never delete or overwrite pre-existing files. The marker and code requests are read-only. Record pairing or product operations you did not perform as untested.

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Three numbered stages: identify the starting point, perform the exercise, and verify the result. Original illustration, not a product screenshot.

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