Code Review GuideTools & workflows

AI code review head-to-head library

CodeRabbit vs Propel

Propel places custom coding standards on Pro, while Starter excludes custom rules. CodeRabbit also distinguishes built-in checks from custom pre-merge checks by plan. Teams buying review for their own standards should compare the qualifying tiers rather than the lowest advertised subscription.

Code Review Guide · Reviewed October 14, 2026 · Published by Perch / Verglas LLC

CodeRabbit and Propel at a glance

Documented review inputs, requirements and licensing
DecisionCodeRabbitPropel
Review scopePull requests, local changes, and agent-loop review.Context-aware PR review with plan-specific PR allowances.
Local review inputCLI and IDE review committed and uncommitted changes.PR integration; a local CLI was not verified.
Custom requirementsGuideline files and natural-language pre-merge checks; custom-check allowances depend on plan.Custom coding standards are on Pro; Starter excludes custom rules.
License and serviceCommercial review service.Commercial review platform.
Official referencesCodeRabbit sourcesPropel sources

Check the plan required for custom coding standards

Write the required standard before the trial and confirm it can be configured on the quoted tier. Record PR allowances and developer subscriptions for that configuration.

CodeRabbit billing

Essentials: $24/user/month billed annually, or $30 monthly. Public-repository reviews are free.

Essentials annual subscription floor; 1 repository and 5 included reviews/developer/hour. Eligible extra reviews cost 25¢ per reviewed file. Built-in checks are included; custom pre-merge checks start on Team.

CodeRabbit plan sources and workload assumptions

Propel billing

Starter: $24/developer/month billed annually. Pro: $64 annually.

Pro annual subscription floor selected for custom coding standards, up to 500 developers and 10,000 PRs. Starter has a lower price and 1,000 PR allowance.

Propel plan sources and workload assumptions

Subscription amounts are plan floors or quoted allowances. Repeated reviews, selected effort, provider charges and exclusions can change the bill. Equal review counts do not establish equal analysis scope.

A third option for the agent’s next edit

When Perch is the better choice

Perch is a stronger fit when saving a custom English requirement is the central task. Project, file and method rules use the same workflow without a separate custom-rule plan tier.

For an agent that repeatedly removes tenant authorization from a database update, save the requirement as a named Perch rule:

- name: tenant-scoped-update
  where: "orders.py"
  ensure: >-
    The cancellation UPDATE must constrain tenant_id to actor.tenant_id
    before changing the order. An id-only or owner-only update breaks
    this requirement.

This requirement comes from the FastAPI tenant-authorization recipe, which includes the implementation, deliberate regression and captured Perch checks. The same named check can run against the working file after the next agent edit. Perch working-file checks support selecting rules directly; rule selectors cover project, file and method scope.

Install, configure the agent, check and repair

npm install -g @lakeday/perch
perch login
perch setup claude-code
# Or choose: perch setup codex
# Or choose: perch setup cursor

Use the setup command for your coding agent. Download the focused pack without replacing existing files:

curl -fL 'https://reporules.fyi/fastapi/tenant-cancellation/rule-pack.zip' -o tenant-rule.zip
unzip -n tenant-rule.zip
perch check orders.py --rules tenant-scoped-update --json
# Repair the reported finding after the agent edit.
perch check orders.py --rules tenant-scoped-update --json

Keep your existing root perch.yaml. The ZIP adds its focused rule under .perch/rules/; unzip -n preserves existing files. Review and adapt the selector and application path before running it in your repository. Run the saved check after an edit, repair any finding, and repeat the identical check alongside application regression tests.

Download the tenant-authorization rule pack · Inspect pack contents and agent task

Pay for fresh checks, reuse unchanged answers

Perch charges 10¢ per 1,000 fresh rule checks, with no developer seat fees. Cached unchanged checks are free. About 50¢ per mid-sized PR is a rounded estimate for approximately 150 methods read at the captured September–October 2026 density of 34 questions per method; the unrounded example is 51¢. A single named-rule check is a different scope. Team workload calculations show the assumptions.

The Perch CLI is MIT licensed; hosted analysis is paid and relevant source is sent to the configured model service. Fresh model judgments can vary. Unchanged requests can reuse cached results.

Test the same requirement before choosing

  1. Use one authorized public change with a known regression and a clean control. Pin the base and reviewed code, and keep the documented requirement available to both tools.
  2. Record each tool’s configuration, reviewed files, review effort, findings and false positives. Record cost and elapsed time from the actual run.
  3. Repair the regression and repeat the relevant review. For Perch, preserve existing configuration, run the saved rule after the edit, and repeat the same check after repairing a finding.

This article compares documented product workflows and terms. The public evaluation materials include captured Perch requirement checks; authenticated CodeRabbit and Greptile runs remain unscored. They do not establish a measured accuracy ranking between these tools.

Reviewed October 14, 2026. Unverified features are marked as unverified rather than treated as absent. Current terms and actual trial results should determine a purchase.

CodeRabbit documentation

Propel documentation

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