Run a Practical Development Task with Codex Mobile

Remote development is easier to control when implementation is divided into investigation, planning, implementation, verification, and review gates. This guide uses a small example: adding an RSS link to a profile page.

Define Completion Criteria

- Add an RSS link without changing the existing design
- Reuse the existing link component
- Update both locales when the site has paired content
- Pass the relevant test or verification command
- Do not deploy, upgrade dependencies, or format unrelated files

Phase 1: Investigate without Changing Files

I want to add an RSS link to the profile page.
Do not change files yet. Investigate and report:
1. Target page and link component
2. Existing external-link pattern
3. Locale synchronization needs
4. Minimum verification commands
5. Risks
List the files used as evidence.

Check that the reported files stay within the request. Ask for justification if Codex proposes a broad UI rewrite or a new dependency.

Check: Target files, conventions, and verification are clear, and no diff exists yet.

Phase 2: Lock the Plan

Create a file-by-file implementation plan from the investigation.
Preserve the existing UI and routing. Add no dependency.
Do not implement yet.

Review whether the plan:

• Uses the minimum number of files
• Reuses an existing component
• Keeps locale changes paired
• Selects verification that matches the change
• Excludes unapproved builds and deployment

Phase 3: Implement a Small Diff

The plan is approved. Implement only the RSS link.
Preserve existing uncommitted work and do not touch unrelated files.
After implementation, report changed files and stop.

Review the changed-file list before the content. Ask why any lockfile, configuration, or generated file changed.

Check: The diff is limited to planned files and contains no broad deletion or replacement.

Phase 4: Run Focused Verification

Run the minimum safe verification defined by this repository for this change.
If a production build, deployment, or external write is required, do not run it. Report why it is needed.

The report should distinguish completed and skipped checks.

Completed:
- content validation: passed
- link check: passed

Not run:
- production build: explicit approval required

Phase 5: Review the Diff

Review the final diff and report:
- Evidence that requirements are met
- Summary by changed file
- Test results
- Unverified items
- Remaining security, accessibility, and i18n risks
Do not commit, push, or open a PR.

Ask for large diffs one file at a time. Do not allow critical conditions or link targets to be omitted from the review.

Redirect Work Safely

Change direction. Add the link to the profile body, not the header.
Remove only the header change. Preserve all other pre-existing changes.

A vague instruction such as “undo it” can remove user work. Name the exact change to remove and the changes to preserve.

Handle Failures

Situation	Instruction
Test failure	Reproduce and report whether the new diff caused it before fixing
Missing permission	Explain the permission and purpose, then wait for approval
Ambiguous requirement	Present options and tradeoffs without implementing
Existing user changes	Preserve them and separate the task diff in the report
Host disconnect	Reconnect and re-check the thread, branch, and git status

Summary

Process gates compensate for a small screen. Investigation, planning, implementation, verification, and review keep scope and quality visible while working remotely.

Next, Update a Personal Blog Every Day applies the full sequence to article creation.

See the references for the external specifications and background sources used on this page.[1][2]

References

1. OpenAI, Codex documentation
2. OpenAI, OpenAI API documentation