Skip to main content

Codex alternative for AI-native engineering teams

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.

13verification steps per fix
6audit domains
$0to start, credits included
hyrax/fix-session-timeout
Merge-ready

[Hyrax] Refresh session token before expiry

hyrax-bot wants to merge · +24 −6

13 / 13 checks passed
Baseline test written
Type check
Unit + integration tests
Post-fix audit clean
CI pipeline confirmed
8 more, including isolated worktree, diff size guard and reviewer agent
Verified end to end, with no Codex handoff

Why teams switch

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 fix 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 improves with every merge, so the next decision starts from everything learned before it.

Comparison

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 improves as the codebase changes.
Output type
A branch or pull request per task.
Verified pull requests, plus findings 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 findings 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)

Start freeGitHub-native. Human-controlled. Verified before merge.

Workflow

Comments on a diff, or a verified pull request.

Codex
  1. 01A developer assigns Codex a task.
  2. 02Codex writes code for that task and stops when the task is done.
  3. 03The team decides whether the change fits the wider system, then merges.
Hyrax
  1. 01Maps the codebase and keeps the map in the repository
  2. 02Applies architectural judgment across six domains
  3. 03Opens a verified pull request that a human merges
GitHub-native
Human approval before merge
Verified pull requests
No training on customer code

Getting started

From install to the first verified pull request.

01

Install the GitHub App

Grant read access to the repositories in scope. No card is required to start.

02

Hyrax maps the repository

Discovery writes HYRAX.md and .hyrax/discovery into the repository, so humans and AI tools read the same context.

03

Review the first pull request

Approved improvements arrive as verified pull requests. A human merges every one.

The honest verdict

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 fix against the project itself.

Codex pricingFrom $20/mo

Included in ChatGPT plans, or API usage per task.

Hyrax pricing$0 to start

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.

FAQ

Questions about Codex and Hyrax.

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.

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.

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.

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 findings ranked by severity and effort. The first verified pull requests follow once an audit is approved.

Build what you're proud to ship.

GitHub-native. Human-controlled. Verified before merge.