Codex executes tasks.
Hyrax judges the system.
OpenAI Codex takes a delegated task, works it in a sandbox and returns a branch or pull request, which is an efficient way to clear scoped work. Hyrax determines whether that work fits the system, and proves it by running the project test suite before a 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 handoff
What changes when Hyrax runs above the tools.
Judgment above the agents
Codex executes the task it is given. Hyrax decides what is worth doing and whether the result fits the system it lands in.
Verified before review
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 make decisions.
| Decision criteria | Codex | Hyrax |
|---|---|---|
| Unit of work | The delegated task, run in a sandbox. | The whole repository, audited continuously across six domains. |
| Codebase context | Reads the repository at task 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 | A branch or pull request per task. | Verified pull requests, plus issues ranked by severity and effort. |
| Verification | Runs tests inside the sandbox when the setup provides them. | Baseline tests, build, lint and a second reviewer agent run against the project itself before a pull request opens. |
| Human control | The developer reviews the diff and merges. | A human approves and merges every pull request. Hyrax never merges on its own. |
| Delivery surface | ChatGPT, the CLI, the IDE and GitHub. | GitHub pull requests, with issues and posture in the Hyrax console. |
| Pricing model | Included in 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 describes itself: openai.com/codex(opens in a new tab)
Comments on a diff, or a verified pull request.
- 01A developer assigns Codex a task.
- 02Codex writes code for that task and stops when the task is done.
- 03The team decides whether the change fits the wider system, then 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 if
There is scoped work to delegate and the team already lives in the OpenAI ecosystem. Codex is a practical way to clear that queue.
Choose Hyrax if
Somebody still has to decide what is worth building and whether it fits. Hyrax audits the codebase across six domains and verifies each change against the project itself.
Included in ChatGPT plans, or API usage per task.
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 and Hyrax.
Does Hyrax work alongside Codex?
Yes, and most teams run both. Codex 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 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.