Aider AI pair programmer: how to review diffs when the agent edits files in bulk

Published 2026-04-26 · 5 min read

Aider works differently from every other AI coding tool in one important way: it shows you the complete diff before applying anything, then asks a single question. You type y to apply all the changes to all the files, or n to reject everything and start over. There is no “approve this file but not that one” mode in the default workflow. One decision, all changes.

That design is clean and explicit in theory. In practice it creates a review problem that is harder than it looks: you are reviewing potentially hundreds of lines of diff in a monospace terminal, under the implicit pressure that “no” means rebuilding your prompt from scratch and losing everything Aider just produced. The combination of bulk review, terminal rendering, and re-prompt cost creates three specific attention traps that don’t appear in IDE-based tools like Cline or Windsurf.

Why Aider’s review model is different

With a tool like Cline, you approve each tool call individually — granular, GUI-rendered, with the file diff shown in your editor’s built-in diff viewer. With Claude Code, you see a response in a panel and the edits land in your editor where you can inspect them before accepting. With Aider, the diff appears in the terminal, scrolls past as Aider generates it, and then sits there waiting for your y/n.

The terminal presentation matters. A GUI diff viewer gives you syntax highlighting, side-by-side comparison, collapsible sections, and navigation shortcuts. A terminal diff is a wall of + and - lines in a monospace font with no affordances for navigation beyond scrolling up. For a 30-line diff, this is fine. For a 400-line diff across 8 files, the cognitive load of reviewing it in a terminal is significantly higher than reviewing the same diff in a proper viewer — and Aider gives you no option to open it elsewhere before deciding.

The three Aider attention traps

1. Terminal diff exhaustion

When Aider generates a large diff, most developers do the same thing: they scan the first file carefully, check the second, skim the third, and by file four they are reading the first line of each hunk and scrolling past the rest. The shape of the diff looks right, the direction feels correct, so they type y.

This is not laziness — it is a rational response to cognitive load. Reading a 400-line terminal diff with full attention takes several minutes and requires holding context across file boundaries in working memory. The brain optimizes by reducing coverage as fatigue increases. The result is that the beginning of the diff gets reviewed and the end does not. But Aider’s speculative changes — the ones where the model went further than you intended — tend to appear at the end, not the beginning. The parts you stop reading are exactly the parts most likely to need catching.

2. The re-prompt tax

Typing n rejects the entire diff. Nothing is applied. You have to re-phrase your prompt, and Aider will re-generate the changes from scratch — which may produce a different set of edits that doesn’t capture what was correct in the first attempt.

This asymmetry matters. The cost of y is accepting a change that might need fixing. The cost of n is losing the work and re-prompting, with no guarantee the next response is better. Over a long Aider session this asymmetry nudges you toward acceptance bias: when you feel uncertain about part of the diff, you are more likely to type y and plan to fix it later than to type n and re-explain your intent. “Fix it later” is how vibe coding debt accumulates — not from one bad decision, but from fifty small ones where the friction of the right answer was slightly higher than the friction of the wrong one.

3. Context window drift

Aider maintains a running conversation. As the conversation grows — across a long session or a complex refactor with many turns — earlier constraints and architectural decisions move further from the active context window. You might have told Aider in turn 3 to “never change the public API surface” or “keep this file under 200 lines.” By turn 12, that constraint may be summarized or absent from what the model is working with.

The symptom is subtle: Aider’s diffs start to look correct locally but drift from your earlier intent globally. Each individual change is defensible. The accumulated set of changes is not what you would have designed. And because you’re reviewing each diff in isolation rather than against the original constraint, you don’t catch the drift until you look at the full git diff and realize the codebase is different in ways you didn’t intend.

What actually helps

Scroll to the bottom first

Before reading a diff from the top, scroll to the last hunk and read it. Then read the second-to-last. Then go back to the beginning and read forward.

This reverses the natural scanning pattern that leaves the end of the diff unreviewed. The speculative changes — the ones where Aider went further than your prompt implied — tend to be at the end of the diff, after the more obvious and correct changes at the top. Reading the end first means you catch the overreach before your working memory is already loaded with the beginning.

It also gives you a rough “scope check” before investing in a line-by-line read: if the last hunk is touching files you didn’t intend to change, you can type n immediately without scrolling through the correct parts of the diff first.

Keep tasks to one file at a time

The review problem scales with the size of the diff. A diff that touches one file is reviewable in a terminal. A diff that touches eight files is not — not with the same quality of review.

Instead of prompting Aider to “refactor the authentication flow,” prompt it to “refactor auth.ts only — don’t touch any other files.” Then apply, commit, and start the next turn for the next file. This produces more turns and more commits, but each diff is small enough to review with actual attention rather than exhaustion-driven scanning. The pause between turns also gives you a moment to re-evaluate the plan before committing to the next step.

Aider’s --auto-commits=false flag is useful here: it prevents Aider from committing after each accepted diff, so you can run git diff in your normal diff viewer to review the accumulated changes before staging anything. This separates the Aider approval step (which happens in the terminal) from the real review step (which happens in your editor or diff tool).

Re-state the constraint before each turn

Context window drift is invisible until it causes a problem. The cheapest defense is to add a one-sentence constraint reminder at the start of each prompt: “Reminder: don’t touch the public API. Now, [actual task].”

This feels redundant after you’ve said it three times. It is still correct. Re-stating a constraint puts it in the active context window for that turn, regardless of how long the conversation has run or how many times the model has summarized earlier messages. It takes three seconds to write and costs nothing. Missing the constraint costs a full re-prompt or a manual fix.

The same principle applies to pre-framing your review: before Aider generates the diff, state what “wrong” looks like. “This should touch auth.ts only. If I see changes in user.ts, reject immediately.” Written down before the diff appears, this gives you a specific check to apply rather than a general sense of “does this look right?”

The compounding cost of bulk acceptance

Aider is a powerful tool precisely because it can edit multiple files in a single turn and auto-commit the result. That power is also where the risk concentrates. Each y you type without a full review is a small under-investment in the quality gate that Aider is designed around. In a single session, the cost of each under-reviewed diff is small. Across 20 sessions, the accumulated drift from bulk acceptance is what produces a codebase that feels right at the component level but wrong at the system level — where each function is locally correct but the interfaces between them reflect the agent’s assumptions, not yours.

Scroll to the bottom first. Keep tasks to one file. Re-state constraints. These are not Aider-specific best practices so much as defenses against the specific way that terminal-based bulk review degrades under realistic conditions. Aider is fastest when you review fastest — but reviewing fast is only safe when you’ve set up the conditions that make fast review accurate.

Use the Aider wait for a real cognitive reset.

ZenCode detects AI generation pauses and shows a 10-second breathing overlay in your editor. The reset before you read the diff is the same reset that keeps the review accurate. Works in VS Code. Free.

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