Perch makes a recurring requirement directly runnable against one edited method. The rule stays beside the code, so the next agent can check the same behavior instead of relying on the previous conversation.
Check a saved rule on the current method
This is the same requirement and command used in the captured refund example:
- name: refund-once
where: checkout.py
each: method
ensure: Refunded orders cannot be refunded again.
The deliberately broken method calls the payment provider without checking the order status:
def refund(order, payment):
payment.refund(order.total)
order.status = "refunded"
return order
Run the focused check from the repository root:
perch check checkout.py::refund --rules refund-once --json
In the September 20, 2026 capture, the unguarded refund was flagged at 80% confidence and exited 3. Adding if order.status == "refunded": return order before the payment call made the check pass and exit 0. The capture uses refund.py; use checkout.py when adapting the public order-service source at commit 4af67af.
Save the rule with the code, then use the same command to check the next agent edit. Add regression tests for concurrency and payment-provider idempotency in the application.
Compare the review workflow
| Workflow | Perch | Qodo |
|---|---|---|
| Rule authoring | name, where, and a plain-English ensure |
Compliance objectives with success/failure criteria |
| Focused check | Choose a method and named rule in a CLI command | Documented compliance checks evaluate PR changes |
| Adoption | Add a requirement check beside existing tests | Use Qodo’s review, compliance, and improvement workflow |
Make each correction a reusable method check
Perch turns a correction such as “refunded orders cannot be refunded again” into a named requirement beside the code. Give it a selector, write the requirement in English, and run it against the edited method. The next agent session and CI can use that same rule and command.
How Qodo handles review
Qodo documents custom compliance objectives, repository configuration, and code improvement suggestions. Its compliance workflow uses objectives and success or failure criteria; Qodo also offers developer tools beyond pull request comments.
Add Perch to your agent workflow
Follow the Perch quick start, then save the requirement with the code. Install the skill for the coding agent you use:
perch setup claude-code
# Or: perch setup codex
# Or: perch setup cursor
The Perch skill instructs the agent to check the named rule after each relevant edit, inspect the finding, repair the code, and recheck. Keep the rule and regression test beside the application so the next session can use the same requirement.
With your base reference fetched, add perch scan --since origin/main --filter type=lint beside your tests in CI. CI setup explains the changed-code scan. Gated findings exit 3; exits 1 and 2 mean the check did not complete.
Compare cost and result limits
Perch charges 10¢ per 1,000 rule checks, with cached checks free. The pricing comparison estimates about 50¢ for a mid-sized pull request with about 150 methods read, including surrounding code. Usage follows the selected questions and their code context.
Unchanged requests reuse cached answers for free; fresh model judgments can vary. Perch’s CLI is MIT licensed. Model analysis sends relevant source to the configured service.
Competitor documentation reviewed October 14, 2026. All comparisons · Perch rule syntax