Regression Testing for AI Agents

TestStack

Your agent completed the task yesterday. Did it still work after the last prompt change? TestStack runs it against real, isolated environments — including the internal tools and legacy UIs that will never have a clean API — and tells you the moment it breaks, before your users do.

no spam, just a note when there’s something to try.

teststack — checkout-agent

$ teststack run --plan checkout-agent

✓ add_item_to_cart

✓ apply_promo_code

✗ complete_checkout — regression detected

agent stalled on new 2FA step (added in last deploy)

3 passed · 1 failed · re-running failed run…

75%

of orgs call agentic AI testing pivotal to their 2026 strategy. Only 16% have actually shipped it.

30%

of travel bookings are projected to run through AI agents by 2030 — IDC.

Why TestStack?

Built on the same isolated execution model teams already trust for QA automation — repointed at validating AI agents instead of scripted tests.

Real Isolated Execution

Every run gets its own sandboxed browser and container — no shared state, no flaky cross-contamination between tests.

Catch Regressions Automatically

Track pass rate over time and re-run failed runs automatically. Know the moment a prompt or model change breaks something that used to work.

Works Where There’s No API

Test agents against real UIs — internal tools, legacy portals, anything your agent has to click through because there’s nothing to call instead.

Resource-Safe at Scale

Quota-aware browser allocation means your test suite never oversubscribes shared infrastructure, even running many agents in parallel.

CI/CD Native

Trigger from GitHub Actions, GitLab CI, or your existing pipeline. Fail the build the moment an agent regresses.

Full Run Visibility

Every run captures a complete trace — what the agent saw, what it did, and exactly where it went wrong.