Formerly Test Insights
Flaky tests block your whole team.
Stop them at the pull request.
Test Engine is the test layer of Mergify's CI platform, and it plugs into the test frameworks you already use. It catches flaky tests on the pull request before they merge, and quarantines the ones already in your suite so they stop blocking merges.
Used by the platform teams that ship fast and keep CI green
"Two-step CI completely transformed how we handle long hardware tests. Instead of burning hours on repeated runs, we validate once and merge with confidence."
Rushin Shah, Sr. Manager DevInfra · Cerebras
"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 · Apex Fintech Solutions
"You get the benefits of Mergify immediately. There is no competitor doing stuff like this."
Florian Berchtold, Software Engineer · Luminar
"The merge queue is a time-saver! Contributors no longer have to carry the mental load of monitoring their PRs!"
Johan Lorenzo, Staff Release Engineer · Mozilla
"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 · Jane
"Our merge queue is like a safety net. Every PR that lands has been tested, approved, and verified under the exact same conditions."
Fabien Marty, Senior Staff Software Engineer · Botify
"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 · AheadComputing
"Before Mergify, we spent too much time manually coordinating merges. Now everything flows automatically."
Nicolas Beaussart-Hatchuel, Senior Staff Software Engineer · PayFit
"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 · Productboard
"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 · Zama
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.
Plugs into your test suite
Native in every test framework
Test Engine runs inside the test framework you already use, whatever CI sits underneath.
Results upload from inside the run and quarantine applies there too, so a quarantined failure never touches your exit code. GitHub Actions, Buildkite and Jenkins each have a setup guide.
Don't see your framework? Tell us and we'll probably build it.
The fix
What Test Engine does with every test run
Prevention stops new flaky tests at the pull request. Detection ranks the ones already on your default branch by how much they hurt, and Quarantine keeps their failures out of your merges while 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 on the pull request, before they merge to main. Test Engine reruns the tests a pull request adds or changes, on the same commit, and flags every one that flips between pass and fail. Each new test shows up as healthy, flaky or broken before anyone clicks merge.
Reruns stay inside a CI budget you set, and run through a native plugin such as pytest-mergify or rspec-mergify. No more merging a "green" PR only to discover the test was flaky all along.
Pillar 2
Detection
Detection finds the unhealthy tests already on your default branch and ranks them by impact, the share of their runs that failed, so the ones costing you the most get fixed first. Every test sits under Healthy, Flaky or Broken. With a plugin installed, Test Engine can rerun a suspect test on the default branch to confirm the verdict instead of waiting for its next failure.
A test that passes for a week after its last failure goes back to healthy on its own. No more guessing whether a failure is real or just noise.
Pillar 3
Quarantine
Quarantine is a state a test is in. A quarantined test keeps running and reporting, but its failures stop blocking merges or failing the pipeline, on every branch. Turn on auto-quarantine and Test Engine puts a flaky test there by itself once enough runs back the verdict (broken tests too, if you opt in). One red run among thousands of green ones never quarantines anything.
Every move in or out of quarantine, yours or Test Engine's, lands in the event log and can post to Slack. No more @skip with a TODO nobody reads.
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
Part of the CI platform
Your tests and your merge queue finally talk
A standalone flaky-test tool can tell you a test is unreliable. Test Engine sits next to Merge Queue and CI Insights, so what it knows about a test changes what the queue does with it.
A known flake can't kick a PR out of the queue
Quarantine applies on every branch, the merge queue's included. When a quarantined test fails during a queue run, the pipeline still passes, so the pull request keeps its place instead of getting dequeued.
One CI connection for jobs and tests
Test Engine runs on the same CI integration as CI Insights. Connect GitHub Actions, Buildkite or Jenkins once, and both read from it.
Without a test layer, your CI pays the bill
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.
Want to see Test Engine on your test suite?
Native in pytest, Jest, RSpec, Vitest, Playwright, Go and every other major test framework.
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 tests quarantines list --repository myorg/myapp
tests/payments/test_webhook.py::test_payment_webhook
branch: *
recovered: no
tests/email/test_delivery.py::test_email_delivery
branch: *
recovered: no
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
Pass --json and 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
Your tests already run. Make them count.
Mergify merges more than half a million pull requests a month without breaking main.