Delegating test work, not judgement
A lot of test work is well-defined but time-consuming: add coverage for this module, fix this flaky test, migrate these specs. It's the kind of task you could hand to a capable engineer with clear instructions, which is what Codex is designed for.
The result depends on the instructions and the environment. We make sure the agent can install dependencies, run your suite and follow your conventions, and that every result arrives as a pull request a human reviews.
What we set up
Agent instructions
AGENTS.md files describing commands, structure and test rules.
Task environments
Setup scripts so the agent can build the app and run tests in its sandbox.
Task templates
Reusable briefs for coverage gaps, flaky fixes and refactors.
Review checklist
What reviewers check before merging agent-written tests.
CLI workflows
Codex CLI for local, interactive test writing alongside your engineers.
Metrics
Merge rate, rework and coverage gained per task, to see what's working.
How we keep it reliable
- Well-scoped tasks only: One module, one flaky test or one migration batch per task.
- Proof in the pull request: Each pull request shows the tests passing, including repeated runs for flakes.
- Your standards, written down: Naming, fixtures and assertion style live in the repo, not in someone's head.
- No secrets in sandboxes: Test environments use test data and scoped credentials only.
- Humans merge: Agents propose; your engineers decide.
Good first use cases
- Unit and API coverage gaps: Modules with little or no coverage, handled in parallel.
- Quarantined flaky tests: Work through the quarantine list with fixes proven by repeat runs.
- Framework upgrades: Version bumps and API changes applied across the suite.
- Test refactors: Remove duplication and hard waits without changing behaviour.
Where it fits
Codex-assisted testing works best alongside a solid QA automation framework and a CI pipeline it can run. We can set up both and train your team on writing good agent tasks. See our QA automation, API testing and performance testing services.