On this page
If you want a Keploy alternative that verifies what a change did in the web app itself (the screen, the requests it sent, the state, the console), Reticle is built for that. If you want API and integration regression tests recorded from real traffic, with mocked dependencies, Keploy is the stronger choice, and it is open source too.
What Keploy does
Keploy says it "builds a Digital Twin of your production behavior: real API traffic, mocks, and dependencies, so every AI- or human-written change is verified in CI before it ships. Open source, zero code changes" (keploy.io).
It captures incoming requests and outgoing dependency calls (databases, queues, APIs) with eBPF, turns them into tests and mocks, and replays them against new builds to catch regressions. It also generates unit tests with AI. It is Apache-2.0 with about 18,700 GitHub stars (GitHub, 2026-10-25) and was releasing as recently as 2026-10-24.
Pricing is public: open source free, a free Playground, Pro at $19 per user a month plus usage, Enterprise custom (pricing, checked 2026-10-25).
What Reticle does
Reticle checks an AI coding agent's change from inside the running web app and returns a verdict with evidence. It reads the network calls, the application state and the console, and on React and Svelte it names the file:line to fix.
Your agent calls it through MCP while it works. Flows are saved and replay deterministically, with no model in the loop. It also drives sites you do not own, reading network, console and DOM there. The SDK is open source (Apache-2.0); the hosted platform runs the same checks on previews and pull requests.
Keploy vs Reticle at a glance
| Keploy | Reticle | |
|---|---|---|
| Layer | Server and API (eBPF capture) | Web app, in the page |
| Records | Incoming requests and dependency calls | Flows driven in the browser, with outcomes |
| Replays against | New builds, with dependencies mocked | Your running app, deterministically |
| Drives a browser or reads UI state | No | Yes: DOM, app state, console |
| Languages | Language-agnostic via eBPF | JavaScript web apps: React, Next.js, Vue, Svelte, Angular |
| Points to the fix | The API diff | The failing request or state, and file:line on React and Svelte |
| Open source | Yes, Apache-2.0 | SDK Apache-2.0; server FSL-1.1 |
| Pricing | Free OSS; Pro $19/user/month | Start free, no card; open-source SDK free |
Where Keploy is the better choice
- The risk is in the backend. Keploy records real traffic and dependency calls and replays them with mocks, which catches API and integration regressions Reticle does not look for.
- Your services are not JavaScript. eBPF capture works regardless of language.
- You want no code changes at all. Keploy captures traffic without touching your code.
- You want a large open-source community. Keploy's repo is one of the most-starred in this space.
Where Reticle is the better choice
- The bug is in the web app. A button that fires a request twice, a store that disagrees with the total on screen, an error logged to the console while the page looks fine. Those live in the browser, which Keploy does not drive.
- You need to know what the user would see. Reticle checks the DOM and app state together with the network, so "the API returned the right thing but the page shows the wrong thing" fails.
- The coding agent should check its own frontend change. Reticle runs in the agent's loop over MCP and names the source line on React and Svelte.
- Re-runs are deterministic. Eight replays of a saved flow gave one verdict; re-verifying four flows costs about 480 tokens.
On 88 seeded bugs, Reticle caught 85 with no false alarms (benchmark scorecard).
Can you use both?
Yes, and this pair fits well. Keploy guards the API and integration layer with recorded traffic. Reticle guards the web app on top of it, reading what the page, the state and the requests did after each step. One agent-written change can break either layer.
For the broader case, read what AI verification is. Related pages: the Meticulous alternative, which also records and replays, and all alternatives.
Try Reticle in five minutes
Paste one line to your coding agent, and it installs and wires the SDK in your app:
Follow https://raw.githubusercontent.com/reticlehq/reticle/main/SKILL.md
Or run npx @reticlehq/core init yourself. The README has the details.
FAQ
What is the best alternative to Keploy?
The best alternative to Keploy depends on the layer you need to cover. For the web app itself, with a coding agent verifying changes in the browser, Reticle fits. For API contract or integration tests, compare other record-and-replay or contract-testing tools. Keploy itself remains a strong open-source choice for backends.
Does Keploy test the frontend?
No, Keploy works at the server and API layer: it records incoming requests and dependency calls and replays them against new builds. It does not drive a browser or read UI state. Reticle covers that layer, reading the DOM, application state, network and console inside the running web app.
How is Reticle different from Keploy?
Reticle is different from Keploy in the layer it checks. Keploy records and replays API traffic on the backend with mocked dependencies. Reticle drives the web app, reads what the page, application state, requests and console did after each step, and names the source line on React and Svelte.
Is Keploy open source?
Yes, Keploy is open source under the Apache-2.0 licence, with about 18,700 GitHub stars as of October 2026, and offers a paid Pro plan from $19 per user a month. Reticle's in-app SDK is also Apache-2.0, and its server is source-available under FSL-1.1.
Why Reticle
Your agent says it works. Reticle checks.
- Checks each change inside the running app: network, state and console, not a screenshot.
- Returns a pass or fail with the evidence and the file:line to fix.
- Open-source SDK on your machine, or the platform on every preview and PR.
No credit card required.