Codex reviews changes.
Hyrax judges the system.
Codex can review a pull request and then take a follow-up task, which makes it useful for closing small gaps quickly. Hyrax evaluates whether work fits the system it lands in, and proves it by running the project test suite before the pull request opens.
- Hyrax audits roughly 400 of its own repositories.
- Free plan: full access, up to 100 PR reviews a month, a $30 starter credit, and $10/month ongoing.
Verified end to end, with no Codex code review handoff
What changes when Hyrax runs above the tools.
The codebase, not the diff
Codex code review sees the change in front of it. Hyrax audits the whole repository, so problems that no single pull request touches still surface.
Verified before it arrives
Every change runs the project baseline tests, build and lint, and passes a second reviewer agent, before the pull request exists.
Context that compounds
The map of the codebase lives in the repository and strengthens with every merge, so the next decision starts from everything learned before it.
How Hyrax and Codex code review make decisions.
| Decision criteria | Codex code review | Hyrax |
|---|---|---|
| Unit of work | The pull request, reviewed by a delegated run. | The whole repository, audited continuously across six domains. |
| Codebase context | Reads the repository at review time, guided by AGENTS.md. | A durable map committed to the repository as HYRAX.md and .hyrax/discovery, so it strengthens as the codebase changes. |
| Output type | Review issues, and a follow-up task when asked. | Verified pull requests, plus issues ranked by severity and effort. |
| Verification | Can run tests inside its sandbox during the run. | Baseline tests, build, lint and a second reviewer agent run against the project itself before a pull request opens. |
| Human control | The team reviews the diff and merges. | A human approves and merges every pull request. Hyrax never merges on its own. |
| Delivery surface | GitHub, ChatGPT and the CLI. | GitHub pull requests, with issues and posture in the Hyrax console. |
| Pricing model | ChatGPT plans from $20 per month, or API usage. | Free plan with a $30 starter credit and $10/month ongoing. Paid is $30 per user per month and each paid user gets $30/month of credits. |
Read how Codex code review describes itself: openai.com/codex(opens in a new tab)
Comments on a diff, or a verified pull request.
- 01A pull request opens and Codex code review reads the diff.
- 02Codex code review returns comments, summaries and suggested changes.
- 03The team interprets the feedback, makes the edits, and merges.
- 01Maps the codebase and keeps the map in the repository
- 02Applies architectural judgment across six domains
- 03Opens a verified pull request that a human merges
GitHub-native. Human-controlled. Verified before merge. No training on customer code.
From install to the first verified pull request.
Install the GitHub App
Grant read access to the repositories in scope. No card is required to start.
Hyrax maps the repository
Discovery writes HYRAX.md and .hyrax/discovery into the repository, so humans and AI tools read the same context.
Review the first pull request
Approved upgrades arrive as verified pull requests. A human merges every one.
Both tools solve real problems.
Choose Codex code review if
The team already uses Codex for tasks and wants review in the same place. Keeping one tool for both is a fair reason to choose it.
Choose Hyrax if
Deciding what deserves attention matters more than reviewing what arrived. Hyrax audits six domains across the repository and verifies every change against the project itself.
ChatGPT subscription or API usage.
Free plan with a $30 starter credit and $10/month ongoing. Paid is $30 per user per month, and each paid user gets $30/month of credits.
Questions about Codex code review and Hyrax.
Does Hyrax work alongside Codex code review?
Yes, and most teams run both. Codex code review keeps doing its job. Hyrax works at the level of the whole codebase, decides what is worth changing, and delivers verified pull requests. Nothing about the Codex code review setup has to change.
What does Hyrax change in the repository?
Discovery writes HYRAX.md and a .hyrax/discovery directory, which document the architecture, conventions and risk areas of the codebase. Everything else arrives as a normal pull request on its own branch. Hyrax has no write access to the default branch.
How does pricing work?
The free plan includes full access, a $30 starter credit and $10/month of credits ongoing, with no card required. The paid plan is $30 per user per month, and each paid user gets $30/month of credits. Pull request reviews are included on every plan.
What happens after signup?
Installing the GitHub App and granting access to a repository takes a few minutes. Hyrax maps the codebase, then runs the first audit and returns issues ranked by severity and effort. The first verified pull requests follow once an audit is approved.