who changes it
The agent rewrites its own code with no second set of eyes.
A reviewer finds flaws; a separate editor patches them.
Self-correction shouldn't mean an agent quietly rewriting itself in production with no oversight. Agent Studio coordinates a builder, reviewer, and editor in a loop bounded by runtime, child-call, spend, and iteration limits. Evaluation runs again after a pushed patch, while findings, mutations, source hashes, deployment references, and residual risks remain visible in the Studio record.
review · fix · re-verify — bounded · recorded
The pitch for self-improving agents is seductive and the reality is often scary: an agent that edits its own code on a loop, with no second reader, no bound on how long it runs, and no record of what it changed. When it works you don't know why; when it breaks you can't tell what it did. Autonomy without verification isn't improvement — it's an agent drifting, and drift in code that holds production grants is exactly the thing you don't want unattended.
Agent Studio's coordinator doesn't stop at the first draft. A reviewer specialist reads the generated code and names findings; an editor can make a targeted patch; evaluation runs again; and the loop stops at acceptance or its configured limits. The Studio report records the evidence, while public publishing stays explicit after private review.
After Agent Studio builds the first cut, a reviewer specialist inspects the generated code the way a senior engineer would — flagging missing input validation, unhandled errors, over-broad grants, and tool calls that reach further than the task needs. It is a real read of the code, not a confidence score.
Each finding is handed to an editor specialist that makes the fix — adds the validation, narrows the grant, closes the error path — and hands the patch back for re-verification. The agent improves by having a second agent correct it, not by silently rewriting itself.
After each fix the build's smoke tests run again. A patch that makes the code cleaner but breaks a call path is caught in the same loop that produced it, so 'self-healing' never means 'quietly shipped something that no longer works.'
The loop is capped — a spend budget and a maximum number of review passes. It converges or it stops and hands you what it has. There is no open-ended agent burning tokens to rewrite itself forever; improvement runs inside a box you set.
The reviewer can flag grants broader than the task requires, and the editor can narrow the declared audience, TTL, tools, or resources in response. The finding and resulting source change stay visible in the Studio evidence rather than being treated as an automatic security guarantee.
Studio stores iteration results, reviewer findings, mutation status, source hashes, deployment references, tests, and residual risks in its run report and event records. Specialist agent invocations can have their own signed run receipts, but the patch diff and publish decision are separate records.
The agent rewrites its own code with no second set of eyes.
A reviewer finds flaws; a separate editor patches them.
Open-ended — it iterates until it decides it's done.
Capped by a spend budget and a maximum number of review passes.
A rewrite ships on the model's say-so.
Smoke tests re-run after every fix before the pass counts.
Self-modification tends to accrete grants and standing access.
Reviewer tightens grants — scope shrinks as the agent improves.
Changes happen silently; you find out when something breaks.
Findings, mutations, source hashes, tests, and residual risks stay in the Studio run record.
It means a bounded build→review→improve→re-verify loop. Agent Studio builds a private agent, evaluates it, asks a reviewer specialist to inspect the source, and can ask an editor specialist for a targeted patch. The loop stops when acceptance passes or a configured budget, child-call limit, runtime limit, or iteration cap is reached. Studio keeps the generated agent private; publishing it remains an explicit step after review.
The coordinator enforces bounded runtime, child-call, spend, and iteration settings, and records why the run stopped. Evaluation runs again after a pushed patch, with unresolved failures and reviewer findings carried into the final report. Studio can deploy the generated agent privately during the loop, but a request to publish it publicly remains an explicit next step after private review.
A blind retry loop re-rolls the whole generation and hopes. a2a's loop is diagnostic: the reviewer reads the code and names specific flaws — missing input validation, an unhandled error path, a grant broader than the task needs — and the editor makes a targeted patch for each. Because the findings and patches are explicit and recorded, you can read what was wrong and how it was fixed, rather than trusting that a green test means the code is sound.
It should not grow silently. The reviewer can identify an over-broad grant and the editor can make a targeted source change to narrow it. Whether a specific iteration changes authority depends on the findings and patch; the Studio report preserves the review, mutation status, source hashes, and residual risks for inspection.
Yes. The Studio report and progress events expose the iterations, test results, review summary and finding hashes, mutation status, source head, deployment references, and residual risks. Those are control-plane records, not fields in an Ed25519 ExecutionReceipt. Executed specialist or agent runs may have their own signed receipts, and public publishing remains an explicit action after the generated agent is reviewed privately.
All guides live in the guides index.
Agent Studio coordinates builder, reviewer, and editor specialists inside bounded runtime, child-call, spend, and iteration limits. It records tests, findings, mutations, source hashes, deployment references, and residual risks, keeps generated agents private by default, and leaves public publishing as an explicit next step.