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If you want a Datadog Synthetics alternative that checks an agent's change before it merges, from inside the running app, Reticle is built for that. If you want production journey monitoring tied to your traces and logs, Datadog Synthetics is the right tool, and Reticle is not a production monitor.
What Datadog Synthetics does
Datadog Synthetic Monitoring runs codeless recorded browser tests, API, multistep and network path tests from managed or private locations, on schedules and in CI, correlated with APM, RUM and logs. Its line: "Catch broken journeys before your customers do" (datadoghq.com).
Bits Testing, an AI agent, "explores your application to map its most critical user journeys" and generates test suites (docs). The Datadog MCP server has a synthetics toolset for agents such as Claude Code, Cursor and Codex (MCP docs).
Pricing is public: browser testing from $12 per thousand test runs a month billed annually, API testing from $5 per 10,000 runs (pricing, checked 2026-10-25). It is not open source.
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 it drives are saved and replay deterministically, with no model in the loop. It also drives sites you don't own, reading network, console and DOM there; app state and file:line need its SDK in your build. The SDK is open source (Apache-2.0); the hosted platform runs the same checks on previews and pull requests.
Datadog Synthetics vs Reticle at a glance
| Datadog Synthetics | Reticle | |
|---|---|---|
| When it runs | On schedules and in CI, mostly against deployed environments | While the agent works, in CI, and on previews |
| What it checks | Black-box journeys, correlated with APM, RUM and logs | Network, app state, console and DOM after each step |
| Test creation | Recorder, prompt, or Bits Testing exploration | Flows your agent (or you) drive, saved and replayed |
| Agent integration | Datadog MCP server synthetics toolset | MCP tools the agent calls while it works |
| Points to the fix | Failure classification and backend correlation | The failing request or state, and file:line on React and Svelte |
| Open source | No | SDK Apache-2.0; server FSL-1.1 |
| Pricing | From $12 per 1,000 browser runs | Start free, no card; open-source SDK free |
Where Datadog Synthetics is the better choice
- You already run Datadog. Synthetic failures sit next to the traces, logs and infrastructure that explain them.
- You need production journey monitoring. Managed global locations, schedules and alerts are the point of the product. Reticle does not watch production.
- You want journeys discovered for you. Bits Testing explores the app and generates suites without code.
- You are a large org with an existing Datadog contract. Procurement and governance are already done.
Where Reticle is the better choice
- You want to stop the bug before deploy. Reticle checks each change while the agent works, so a broken flow never reaches the environment a monitor watches.
- The failure is inside the page. Store state that disagrees with the screen, a request fired twice, a silent console error. Reticle reads those from inside the app.
- You want the fix location. The verdict names the failing request or state and, on React and Svelte, the source line, so the agent edits the right file.
- You want predictable re-run cost. Saved flows replay with no model in the loop: a four-flow suite re-verifies in about 480 tokens, and replays do not flake.
On 88 seeded bugs, Reticle caught 85 with no false alarms; two of the other three are traps a correct tool must not flag, and one is a genuine miss. The method is in the benchmark scorecard.
Can you use both?
Yes. Reticle checks changes before they merge; Datadog Synthetics watches journeys after they deploy and ties failures to the backend. They catch the same kind of bug at different moments.
See AI verification for the pre-merge argument, and the Checkly alternative page for another monitoring tool.
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 Datadog Synthetics?
The best alternative to Datadog Synthetics depends on the job. For production synthetic monitoring, look at Checkly, Grafana Synthetic Monitoring, New Relic or Dynatrace. For checking an agent's change before it merges, inside the running app through network, state and console, Reticle fits. Monitoring and pre-merge checks complement each other.
Is Reticle a replacement for synthetic monitoring?
No, Reticle is not a replacement for synthetic monitoring. It has no scheduled runs from global locations, no alerting and no APM correlation. It verifies changes before they ship, while a coding agent works, in CI and on previews. Keep a monitoring tool for production and use Reticle earlier in the loop.
How is Reticle different from Datadog Bits Testing?
Reticle is different from Datadog Bits Testing in where it looks. Bits Testing explores a deployed app from outside and generates journey tests. Reticle runs inside the app before merge, reads requests, state and console after each step, and names the source line to fix, so the coding agent can repair the change itself.
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.