AI coding agents can move a project forward while leaving you unsure how the result works. A feature runs, the tests pass, and the explanation sounds plausible. Yet you cannot say where the new behavior starts or what else it affects. That gap makes the next request harder to judge.
To keep up with code your AI coding agent writes, make understanding part of each change. Whether you use Claude Code, Codex, or Cursor on a Mac, work in small increments, inspect the actual diff, and trace the behavior before moving on. You need a repeatable reading routine that fits between tasks.
Give each task a boundary you can explain
Before asking for implementation, describe the observable behavior you want. State what should change, what should stay the same, and how you will recognize success. A request to reject an empty form submission gives you something specific to verify. A request to improve the form leaves many decisions open.
Ask the agent to identify the likely areas of change before editing. Treat that list as a hypothesis: if the implementation spreads elsewhere, ask what made the extra work necessary. An unexpected dependency or configuration change deserves attention while the task is still small.
Ask for intent and evidence
A useful instruction is: Explain the intended behavior, the main design choice, and the checks you will run. After editing, summarize what changed and identify anything you could not verify.
Keep that explanation beside the diff. It gives you questions to investigate; the code and checks determine whether the answers hold.
Read one stable increment at a time
Ask the agent to finish a coherent piece of behavior and pause. Reviewing a moving working tree makes it difficult to know whether the code you just read still matches what will be kept. If another task is already running, agree on a stopping point before beginning the review.
Start with git status --short to see the current state. Distinguish changes that existed before the task from those made during it. Shared working trees can contain your own unfinished edits, so avoid assuming every modified file belongs to the agent’s request.
Use small commits as checkpoints after review and relevant checks. A useful checkpoint contains one explainable change and a message describing its purpose. If the project uses branches, keep the branch focused on the same objective. Unrelated cleanup can be a separate task, with its own explanation and review.
Build a map from the changed files
Before reading individual lines, inspect the file list and change summary. git diff --name-status shows which tracked files changed in the unstaged diff. git diff --stat gives a rough sense of where the work is concentrated. Neither command lists untracked files, so keep the status output in view.
Group the files by responsibility: entry points, behavior, stored data, configuration, and tests. You are building a reading order. If a task changes a validation rule, find the rule, its caller, and the tests that describe the expected result.
Investigate files that do not fit that map. A dependency update might be necessary, but it should have a reason. A deleted test might signal changed requirements, or it might remove the only check for an existing behavior. Ask which explanation the diff supports.
Follow one behavior through the code
Pick a concrete input and follow it from the entry point to the result. Open definitions when a changed line calls unfamiliar code. Find references when a function’s contract changes, because callers outside the diff may rely on its previous behavior. Search for the same concept elsewhere to see how the project already handles it.
Do this for a normal case and a relevant failure case. For a form change, consider both a valid submission and missing input. Check where validation occurs, how failure reaches the interface, and whether anything is saved before rejection.
Turn uncertainty into a precise question
Instead of asking the agent to explain everything, ask what a particular caller assumes, where an error is handled, or why state changes before a check. Request the definition or reference that supports its answer, then inspect it yourself.
Write a short behavior note in your own words. If you cannot describe the input, the decision, and the effect, you have found the next part to read.
Close the loop with checks and a checkpoint
Choose checks from the behavior you traced. Run the relevant existing tests, then use the project’s normal build or static checks where the change calls for them. For interface work, exercise the interaction yourself. A successful command answers a bounded question; record what it covered and what it did not.
Read changed tests too. Confirm that their assertions would fail if the intended behavior were absent. A test that repeats a result calculated by the implementation can agree with the same mistake. Pay particular attention when the agent changes expected values or removes assertions.
Before the next task, inspect the final diff again. Fixes made after review create new material to understand. Check untracked files explicitly: a new helper or test may be essential even though it never appeared in the ordinary diff. Keep the checkpoint only when you can explain its purpose and its evidence.
An optional Mac workflow for reading changes
Yenpo is a native Mac app for reading and reviewing code changes in local Git repositories. It shows line diffs by commit, branch comparisons against main from the common ancestor or directly, and uncommitted local changes, including untracked files. Local language servers support jumping to definitions and finding references; full-text search is also available. Language servers are not bundled with the app.
There is no integration with Claude Code, Codex, Cursor, or GitHub. You open the local repository to read its changes. AI Reader is optional and uses your own AI provider. It shows which files it reads and what it searches for, with clickable file-and-line references. It is read-only by default. Allow Edits applies only to the next message you send to AI Reader, after which it returns to read-only mode.
No Yenpo account and no telemetry. It only connects to your own AI provider, an optional daily update check, and downloads you start yourself.
It is Freeware for macOS 14+, on Apple silicon and Intel. These reading tools can support the routine above; understanding and accepting the change remain your responsibility.
Know when you are ready for the next task
Before continuing, explain the change without copying the agent’s summary. Name the behavior, the affected callers, the checks you ran, and any open question. If an important answer is missing, pause and resolve it or reduce the scope. Keeping up becomes manageable when each task ends with a small piece of code you can confidently explain.