Checksum alternative: agents that use your app

Checksum is sales-led: its docs describe a demo, scoping and a time-boxed proof of value before anything runs, and its homepage gives a pricing basis but no prices. It also asks for a test environment URL, logins for each role and read-only access to your front-end repository. People look elsewhere when they want to try agents on a link today, when they want public prices, or when they want agents that play different users instead of writing tests.

• Checksum: an end-to-end agent writes Playwright tests and an API agent covers endpoints, delivered as pull requests to a repository you own.
• Mimiq: no suite to keep. Agents try a task as different users, about 5 to 15 minutes for 5 agents.
• Checksum: pricing based on the number of workflows maintained, no figures published, and a demo and proof of value to start.
• Mimiq: first test free, then a $9 Starter (120 credits that never expire) or monthly plans from $19.
• Both: an MCP server for coding agents, and a way to run on every change.

Checksum describes AI agents that generate, run and heal tests in the background, as a testing layer for coding agents. An End-to-End Agent creates Playwright tests and heals them when they break, and an API Agent covers endpoints. Its FAQ says the tests are real code that lives in your repository: when a selector or flow changes, it detects the failure, fixes the test and opens a pull request for your review. Its docs say Checksum never writes to your code repository; generated and healed tests arrive as pull requests in a separate tests repository, which your team reviews and merges like other code.

To decide what to test, detection reads your front-end repository when one is connected, or explores the running app, and looks for key journeys, business flows and error cases. You can add flows by hand or record a walkthrough with a Chrome extension, and a Deep mode adds an interview phase. Its homepage says production errors feed new tests and that it plugs into your CI to run on every commit. Its MCP server lets Claude Code, Cursor and VS Code trigger generation, healing and runs in its cloud, with results coming back as a pull request. Its Results as a Service offering adds a human engineer who verifies results.

Getting started is a conversation, not a sign-up: a demo, scoping of product areas and success criteria, then a time-boxed proof of value. Checksum asks for a test environment URL, logins for each role, any IP allowlisting, confirmation that bot protection will not block automated browsers, and read-only access to your front-end repository on GitHub, GitLab, Azure DevOps or Bitbucket. Its homepage says pricing is based on the number of workflows maintained, with no per-seat fees and no per-run charges, and shows no figures. Its site and docs describe web and API testing and do not mention native mobile apps.

Mimiq sends AI agents to use your web app. You paste a link and give a task in plain words, such as "Sign up and start using it". Each agent opens the app in its own real browser, plays a person with a reason to be there, and works toward the task for up to 40 steps. The report shows what broke (errors on screen, buttons that do nothing, forms that reject good input, dead ends), what the browser caught on the site (JavaScript errors, requests that failed or answered 4xx or 5xx, and requests slower than 3 seconds, ranked by how many agents hit each), and where each agent got stuck or gave up and why, in its own words, with the step and a screenshot. The problems are ranked, with suggested fixes.

You can run it by pasting a link in the app, from a coding agent through the MCP server at mcp.mimiqai.com (Claude Code, Cursor, Codex, VS Code and Windsurf), or on every preview deploy with the GitHub Action github.com/victorgulchenko/mimiq-preview-check, which works with Vercel, Netlify and Cloudflare Pages previews, leaves one pull request comment and can fail the check. Agents get a working inbox for verification codes. With paid credits they can also sign in with a test account and open protected previews, using a Vercel bypass secret or basic auth. Teams can also build the agents from their own customers with a CSV import.

Mimiq does not write or export test scripts, does not test native mobile apps, and does not predict how many real people will finish. Every agent is simulated, agents choose their own paths so two runs can differ, and a run is not exhaustive. Agents cannot pay with real cards, and a CAPTCHA can stop them.

Checksum is a managed suite. Its agents work out what to test, write the tests as code, run them on every commit and fix them when the app changes, and you review the pull requests. You end up owning Playwright tests that cover known flows and the API, which is the strength of a suite: the same checks on every change, including API checks that Mimiq does not run at all.

Mimiq keeps no suite. Each run is a fresh set of agents, each playing a person with a reason to be there, and the report is about their experience: the errors and slow requests the browser caught, where one gave up and why in its own words, and wording that sent a newcomer the wrong way. A saved test checks the outcome it names; it does not tell you that a newcomer would not understand a step.

Neither is exhaustive. Checksum's tests cover the flows it detected. Mimiq runs vary, because agents choose their own paths, and Mimiq does not export a script you could rerun.

Choose Checksum when you want API tests as well as browser tests, when you want the tests as Playwright code in your own repository, when you want a vendor to keep them healthy and a human engineer to verify results, or when you want checks to run on every commit.

Choose Mimiq when you have a link or a preview and no suite yet, when you want a first read in minutes without a call, when you want public prices, or when you want agents built from your own customers on a staging build.

Mimiq pricing is public: the first test is free with a free account (Google sign-in, no card), and the account includes 50 credits. An agent uses 5 credits, so 5 agents use 25. After that it is a $9 Starter (120 credits that never expire) or monthly plans from $19. Mimiq is not a regression suite. If the same checks must run the same way on every release, Checksum or a scripted suite is the right tool.