Cursor Composer layers in agentic coding

Cursor Composer output stays reviewable when every layer around it leaves a receipt the next layer can check. Composer is the agent pane in Cursor, Anysphere's AI code editor, that drafts and applies multi-file changes in one loop. The loop is the easy part. The layers around it decide whether the work survives review.

Here is the failure I keep seeing. The diff reads confident, the summary reads calm, and the reviewer who has to merge it cannot reconstruct a single decision underneath. Confidence is a writing style. Review needs evidence. When the decision trail stays in chat, the merge becomes a guess.

The fix is not a smarter model. It is a habit: each layer writes down what the next layer needs.

Give every layer a receipt

Think of an agent run as a stack of layers: the prompt, the rules file, the hooks, the review. Each layer has gaps. Incidents happen when the gaps line up, and an unwritten decision trail lines them up by default.

So you close the gaps with four small artifacts, one per common failure.

A decision stub fixes review theater. Your CI is green and reviewers still ask "why this approach?" with no written answer. Force three lines in the PR template: constraints considered, rejected alternatives, verification proof. Now the debate is about explicit tradeoffs instead of vibes.

A scope ledger fixes scope fog. Cursor .mdc rule language sounds precise until two reviewers argue about what it meant. Put a five-line ledger in the parent chat: goal, allowed paths, forbidden paths, verification command, merge owner. Review becomes checking the ledger against the diff.

A CLAUDE.md supremacy clause fixes permission creep. On shared laptops, Claude Code bash approvals turn into muscle memory. State at the top of CLAUDE.md which hooks win, which folders need human eyes, and where temporary overrides live. Sessions stop inventing policy mid-run.

A replay sandwich fixes replay gaps. Teams on Codex CLI merge green runs whose transcripts never reached review. Have AGENTS.md require an intent line, the command transcript, and a diff summary before the PR opens. Review gets reproducible without standing behind someone's terminal.

Paste this delegation snapshot

Drop a rule like this into your repo so the boundaries live in a file, not in someone's head. Adapt the globs to your layout.

---
description: Delegation boundary snapshot (adapt globs to your repo)
globs:
  - "**/*"
alwaysApply: false
---

- Cursor: keep scopes explicit in `.mdc`; forbid undeclared MCP domains.
- Claude Code: cite `CLAUDE.md` precedence before expanding bash scope.
- Codex: ensure `AGENTS.md` carries replay-friendly verification notes for CLI runs.

This belongs in your workflow before the change ever reaches review: the handoff has to survive without the original operator in the room.

Run the merge gate

A layered workflow is working when these four answers come from files, not from memory. Read the gate before you approve.

If any answer needs a chat transcript or a person's memory, that layer has a gap. None of this replaces architecture judgement. Agents speed up execution, not ownership.

Common questions

How do we keep Cursor Composer output reviewable? Give every layer a receipt: a five-line scope ledger in the chat, a decision stub in the PR, precedence rules in the repo, and a verification command whose output is pasted or linked. A reviewer should trace the intent without replaying the session. If they cannot, the trail is still living in chat.

What is a decision stub in a PR? A decision stub is three forced lines in the PR template: constraints considered, rejected alternatives, and verification proof. It exists because green CI answers what changed but never why this approach. The stub moves that debate from vibes to explicit tradeoffs a reviewer can check in seconds.

Why does agent output sound confident but fail review? Because confidence is a writing style and review needs evidence. Composer output reads calm whether or not the decision trail exists. When the trail stays in chat, the gaps in prompt, rules, and review line up, and the merge becomes a guess about work nobody wrote down.

Where do these receipts actually live? In files your team already reads: the PR description, the .mdc rule, CLAUDE.md, and AGENTS.md. The point is to keep the boundary out of chat memory, which no reviewer can audit later. A file can be diffed, blamed, and pointed at during review.

Start with one layer

Pick the failure that bites your team most often, write its receipt into a file this week, and check it at your next merge. If your Composer workflow ships faster than your review can explain it, our agentic coding training walks a team through all four layers on your own repo.

Further reading

• Cursor docs: Agent
• Claude Code docs: getting started
• OpenAI Developers: Codex quickstart
• Model Context Protocol specification
• Google Search Central: helpful, people-first content
• Google Search Central: generative AI content guidance
• OpenAI Skills repository