Flaky tests block your whole team.
Stop them at the pull request.
The test layer of Mergify's CI platform. Test Engine reruns tests on every pull request and stops a flaky test before it reaches your default branch. The flaky tests already in your suite get ranked by impact and quarantined, so they stop blocking merges.
It plugs into the test frameworks you already use, on any CI.
Used by the platform teams that ship fast and keep CI green
"Mergify gave us a merge queue that behaves predictably under heavy load. Reliability is everything, and Mergify made stability a solved problem."
Rushin Shah, Sr. Manager DevInfra
"The merge queue is a huge value from Mergify: it keeps our main stable and allows us to merge quickly with confidence."
Minh Tran, Platform Engineer
"You get the benefits of Mergify immediately. There is no competitor doing stuff like this."
Florian Berchtold, Software Engineer
"Since adopting Mergify, our code quality has skyrocketed. We've drastically reduced post-deployment bugs."
Bálint Bartha, Senior Platform Engineer
"We transitioned from manual chaos to over 20 safe deploys per day. Mergify is becoming a critical part of our delivery function."
Chris Irving, Engineering Manager
"We basically turned GitHub into an autonomous system. Mergify runs the entire choreography for us."
Fabien Marty, Senior Staff Software Engineer
"With dozens of engineers and long-running CI jobs, Mergify turned what used to be a daily bottleneck into a background process. Our teams focus on hardware, not merge logistics."
Ben Holtzman, Senior Design Enablement Engineer
"Before Mergify, we spent too much time manually coordinating merges. Now everything flows automatically."
Nicolas Beaussart-Hatchuel, Senior Staff Software Engineer
"Mergify was the best fit. It saved a couple of hours per engineer per month and resolved our bottleneck with the merge queue."
Tomas Nekolny, Engineering Manager
"The support on Slack is really good, reactive and transparent. We have other partners where problems feel less transparent. With Mergify, it's fluid."
Clément Danjou, VP Blockchain
One flaky test. A full day wasted.
Flaky tests don't just fail. They cascade. Here's what a single unreliable test does to your team every day.
Most teams have 10, 20, or 40 of these tests. Nobody tracks them. Nobody owns them. The cost compounds silently until CI results mean nothing.
The fix
Three pillars of test reliability
Test Engine stops new flaky tests at the pull request, and handles the ones already on your default branch: it ranks them by impact and quarantines them until someone fixes them.
Other tools find a flaky test after it has merged. Test Engine catches it on the pull request, before it reaches your default branch.
Pillar 1
Prevention
Catch flaky tests at PR time, before they merge to main. Test Engine reruns your tests on every pull request and flags the ones producing inconsistent results. The author gets a PR comment telling them exactly which test is unreliable and since when.
No more merging a "green" PR only to discover the test was flaky all along.
Pillar 2
Detection
Detection finds the unhealthy tests already in your codebase and ranks them by impact, so the ones costing you the most get fixed first. Every test in your suite gets a confidence score based on its pass/fail history on the default branch. Health statuses (Healthy, Flaky, Broken) make it obvious which tests need attention and which are safe to trust.
No more guessing whether a failure is real or just noise.
Pillar 3
Quarantine
When a test is confirmed flaky, Test Engine quarantines it. The test still runs in CI, but its result no longer blocks merges or marks the pipeline as failed. When the test stabilizes, quarantine lifts automatically.
No manual triage. The system handles it.
Without these three pillars, flaky tests win
Most teams underestimate how much flaky tests cost them until the problem is measurable.
Developer trust breaks down
When tests fail randomly, engineers stop trusting CI. They re-run, skip, or ignore results. Quality slips.
Merge queues grind to a halt
One flaky test blocks a batch of PRs. The whole queue retries. Multiply that across a day and you lose hours of engineering time.
Debugging is a time sink
Is the test broken or flaky? Engineers waste hours answering a question the tool should answer for them.
The backlog grows silently
Without tracking, flaky tests accumulate. By the time it is painful, there are dozens to triage and no data to prioritize them.
We had 40 known-flaky tests and no system to deal with them. Engineers just re-ran the suite and hoped. Test Engine quarantined the worst offenders on day one, and within a month we actually fixed most of them because we could finally see which ones mattered.
Lucas Meier
Staff Software Engineer at Norde
Want to see Test Engine on your test suite?
Works with any test framework. Native plugins for zero-config setup, or upload JUnit XML from any runner.
Works with any CI platform
Test Engine works at the test framework level, not the CI platform level. GitHub Actions, Jenkins, CircleCI, Buildkite, or anything else. If your tests produce results, Test Engine can read them.
Works with any test framework
Native plugins available for select frameworks, with more shipping regularly. Any framework that outputs JUnit XML is supported.
Don't see yours? Tell us and we'll probably build it.
Bring your own agent
Your AI agent doesn't know which tests are flaky. Now it can.
AI coding tools write code and debug failures, but they waste time investigating tests that were already known-flaky. The Mergify CLI gives any agent access to your test health data. No integration needed. Just a CLI call.
$ mergify ci flaky-tests --repo myorg/myapp
Found 7 quarantined tests in myorg/myapp:
test_payment_webhook flaky quarantined 3d ago
test_email_delivery flaky quarantined 1w ago
test_rate_limiter_edge_case flaky quarantined 2d ago
Your AI agent can now skip these when debugging CI failures.
One CLI call. Any agent.
Cursor, Claude Code, GitHub Copilot, Windsurf, Codex, or your own custom agent. If it can run a shell command, it can query your test health data.
Stop debugging noise
When CI fails, your agent checks which tests are quarantined and skips them. It only investigates failures that are actually new.
No plugins, no setup
The CLI outputs structured data any tool can parse. Add it to your agent's instructions and it just works.
Integrating Mergify transformed our development process. It gives us full control over merges and schedules. It streamlined our workflow, helped catch issues early, and improved team efficiency and software reliability.
Sean Davis
Senior CI/CD Engineer at Ava Solutions
Real teams, real results
Engineering teams we helped merge faster, safer, and cheaper
Stop letting flaky tests slow your team down
2k+ organizations use Mergify to merge 75k+ pull requests a month without breaking main.