How does it plug into our platform?

One API call when a build finishes. Everything runs through the REST API at https://qa.replay.io/api/v1 , documented by an OpenAPI spec: create a project for the app, let Replay QA explore and test it, then pull structured bugs, root causes and fix prompts back into your agent's loop and mark them resolved.

Will testing slow down delivery for our users?

It doesn't have to. You choose where the gate sits: before publish, before share, or asynchronously after the first preview, so testing and fixing happen in the background before delivery.

Do we need to write or maintain tests?

No. Generated apps have nobody to write tests for them. Replay QA explores each app, discovers the user journeys, and writes and runs its own Playwright tests.

Our users' apps have no traffic yet. Does that matter?

No. Replay QA generates its own sessions from a URL, so it works on apps nobody has used yet. That's also why tools that depend on real user sessions don't fit generated apps.

Can it test apps that aren't publicly reachable?

Yes. A reverse proxy lets Replay QA test localhost or private-network apps without exposing them, and one project can target several environments, such as dev, staging and production.

Security Scan can run as an extra pass for broken access control, IDOR and cross-tenant data exposure, the vulnerability classes AI-written apps tend to ship with. It needs ownership verification, which a platform can automate for the apps it hosts.

How is it priced at platform volume?

Replay QA is designed for high volume, and platforms get usage-based or committed-volume pricing. Schedule a call and we'll size it to your build volume.

Can we use the results to improve our agent?

Yes. Every report is structured: kind, severity, root cause and fix. Across thousands of builds that becomes a dataset of exactly where your agent fails, which shows you what to change in its prompts, tools and evals.

Replay QA for App Builder Platforms

The autonomous QA layer for app‑building platforms.

Insert Replay QA into your builder harness for runtime visibility of the apps your platform builds.

Talk to us Try Replay QA

Replay QA is an autonomous testing agent for the apps your platform builds.

Your platform sends it an app with one API call. Replay QA tests it like a real user would and sends back what's broken, why, and how to fix it. There's no test suite to write and no QA team to hire.

Works alongside built-in testing

How is this different than the browser-testing in your platform?

Built-in browser testing shows your agent what a user would see. Replay QA records what the app actually did, so it can explain why something broke and prove that the fix works.

Built-in agent browser testing

What it captures: Screenshots or a video of the session, plus whatever surfaces in the console and network logs
When something fails: The symptom: what the screen showed and the error that surfaced
The fix: The same agent that wrote the code guesses at a fix from the symptom
Bugs that don't reproduce: Race conditions, stale state and timing bugs often pass on the next run and slip through

Replay QA

What it captures: A deterministic recording of the whole runtime: every function call, state change, network request and render
When something fails: The root cause, traced back through the recording to the code responsible
The fix: A suggested fix with the evidence attached, ready for your build loop
Bugs that don't reproduce: Captured on the run where they happen, and replayed exactly as they occurred

Keep your built-in testing. It's a fast check while the agent builds. Replay QA runs alongside it as the independent check that explains failures and verifies fixes.

Catch issues that static code review can't see.

Built upon our core time-travel debugging infrastructure, Replay QA explores each generated app, writes and runs its own tests, and catches failures before your users do.

Broken functionality and reliability

Oversized API responses returning 502
onboarding sending invalid URLs
older PR-run links returning “not found”
repeated login redirects

Performance

Smaller API payloads
database indexes
parallel database reads
cached repeated requests
smaller initial JavaScript bundles
appropriately sized images

Visual/accessibility polish

Layout shifts
low-contrast labels
overflowing sidebar text
mismatched button heights
font-loading shifts

Error handling and usability

Retry controls instead of falsely saying a run was deleted
checkout confirmation
clearer progress and permission messages
a not-found page for nonexistent routes

Security and hardening

Credential redaction
restricting project data returned to viewers
authentication gates
CSP and response headers
removing unused third-party scripts

Examples of real agent-ready bug reports with evidence.

Every Replay QA bug report is prepared with coding agents in mind: a detailed root cause analysis, a suggested fix, a deterministic runtime recording, and all the context needed to do the job.

Pre-launch

Build the highest quality app for your customers.

An app builder with built-in runtime visibility will build better apps.

One API call: Send the app when a build finishes. Structured bugs come back to your agent.
No test suite: Generated apps have nobody to write tests, so Replay QA discovers the user journeys and writes and runs its own tests.
No traffic needed: It generates its own sessions from a URL, so it works on apps nobody has used yet.
You choose the gate: Before publish, before share, or asynchronously after first preview.
Security Scan: An optional extra pass for broken access control and cross-tenant data exposure: the vulnerability classes AI-written apps ship with.
Built for volume: Designed for high volume, with usage-based pricing for platforms.

Post-launch

Continuous improvement for your customers' apps.

Building the app is one thing. Maintaining it over time is another. With our Self-healing API, you can offer your customers an always-on way to turn user signals into ready-to-ship fixes and improvements.

1
User sessions on your site/appReal users click through the live app.
2
Fullstory detects frustration signalsFullstory's Subtext snippet watches each session and flags when something goes wrong.
3
Replay QA generates bug reportsReproduces the problem, finds the root cause from the recording, and files an agent-ready bug report.
4
Builder fixes and lands changesYour build loop fixes the bug, Replay QA verifies the fix, and the change ships automatically.

↺ Always on: the next sessions run on the improved app.

Detect: Fullstory's Subtext JS snippet runs in your customer's app, watches real user sessions, and flags when something goes wrong.
Diagnose: Replay QA reproduces the problem, finds the root cause from the recording, and files a bug with a severity, the recording evidence and a bug ID.
Fix: Your Build Loop picks up the bug and opens a pull request that explains why, what changed and the tradeoffs, linked back to the bug.
Verify: Replay QA signs in to the PR preview, explores the changed surface for anything new it broke, then replays the journey that found the bug to prove the fix holds.
Ship: Once the fix is verified, your harness merges it and ships the improvement to your customer's app automatically. Fixes that don't pass go back to Your Build Loop for another attempt.

Customer Spotlight

Replay QA enabled a first-party QA experience for Audos' platform for entrepreneur/builders.

Audos wants to help everyday entrepreneurs build one million $1M companies in the next ten years. It aims to be the best place to build not just a product, but a business: each entrepreneur gets a landing page, a V0 of their app, marketing, analytics, a brand, and a community of other founders. Otto, Audos's flagship agent, works alongside each one as their AI co-founder.

At that volume, no team can hand-test what gets built. Audos integrated Replay QA's REST API directly into its platform to create a first-party QA experience: every app an entrepreneur builds on Audos is explored, tested and root-caused by Replay QA, and the bugs flow back into Audos's build loop to be fixed before launch. Entrepreneurs get the highest-quality version of their business without ever writing a test.

“It was clear there was an attention to detail that we needed to help the people who don't know what a console log is.”

Andres Zubillaga, Founding team, Audos (answering why they chose to partner with Replay QA)

What engineers are saying

“Of all the technologies I've seen this year, Replay QA makes me the most excited. … This is a product I would insist on having before writing a single line of code.”

Dave Monk

QA Engineer (ex Apple, Microsoft)

“Before Replay, we spent somewhere between 1–2 hours per day per dev in this reproducibility purgatory.”

Mark Probst

VP Engineering, Glide

“Replay.io is galaxy brain tooling. Real gamechanger.”

Dan Abramov

React Maintainer

See the proof yourself.

Drop this prompt into your coding agent, along with one or more URLs to web apps generated by your app builder, and see what Replay QA uncovers.

Use Replay QA (https://qa.replay.io) to test the web apps listed below. They were generated by our app builder.

Drive everything through the REST API at https://qa.replay.io/api/v1. Read the OpenAPI spec at /api/v1/openapi.json first; it documents the full workflow. Authenticate with my API token ("Authorization: Bearer lqa_..."), asking me for it if needed.

Your job:
1. Create one QA project per app URL below. Give it the target_url and a short note on what the app is for.
2. Let QA run. Poll each project's status and don't kick off explorations or test runs yourself; QA drives those.
3. When the runs finish, read the full root-caused report for each open bug.
4. Summarize the results for me: bugs per app, grouped by kind (broken functionality, performance, visual/accessibility, error handling, security), with the root cause and suggested fix for each. Don't change any code.

App URLs:
- [paste one or more URLs here]

Needs a Replay QA API token. Free to start at qa.replay.io, no credit card.

Frequently asked questions

Keep it. The question is whether the agent that wrote the code should be the only one checking it. Replay QA is an independent second opinion, and where a visual pass stops at the symptom, it hands your agent a root cause from a deterministic runtime recording. Run both on the same builds and compare.

Ready to talk?

Schedule a call to get the ball rolling.

Book a call with Thomas Daly

Head of Product, Replay

Schedule a call