MCP server · Coding
tailtest for Cline
by avansaber
Lets Cline write and run tests for your code, then sort failures into real bugs, setup issues, or bad tests.
tailtest is a helper for Cline, the coding assistant that lives inside your editor. It watches when Cline changes a file and then writes tests for that change, runs them, and tells you what went wrong. It is handy if you use Cline to build things and want a safety net that checks the work.
What is an MCP server? The 30-second version
On its own, Cline can chat and edit files, but it does not know how to test your project in a structured way. An MCP server is a small helper program that gives Cline a new skill. This one connects Cline to tailtest, a testing tool, so Cline can ask it to plan tests, run them, and explain failures. You do not install anything separate; the helper runs quietly behind the scenes when Cline needs it.
What this MCP server does
You ask Cline to test a file, or you turn on auto mode so it happens after every edit. Cline calls the tailtest helper, which looks at your project to figure out the language and test runner. The helper writes test scenarios, runs them, and reads the results. Then it sorts each failure into one of three buckets: a real bug in your code, a problem with your setup, or a mistake in the test itself. You get that summary right in the Cline chat.
Click to zoomWhat you can do with it
- Write tests for a file you just edited
- Run those tests automatically
- Tell you which failures are real bugs
- Flag failures caused by your environment
- Point out tests that are wrong, not your code
- Run a tougher adversarial pass to try to break your code
- Set how many test scenarios to generate
Try asking your AI
- “Set up tailtest in this project”
- “Test the file I just edited”
- “Run an adversarial pass on src/utils.py”
- “Why did my last test run fail?”
What it gives back to you
You get a short report in the Cline chat. It lists the test scenarios it created, which ones passed, and which failed. Each failure is labelled as a real bug, an environment problem, or a test bug, so you know what to fix first.
Before you start
What you need
- Cline installed in your editor (VS Code, Cursor, JetBrains, and others)
- Python installed on your computer
- Your project open in the editor
Good to know
It can write new files and run commands in your project, so review what it does before approving, especially in auto mode.
Install it with your AI
Add tailtest for Cline to your AI, no technical skills needed
You don't install anything by hand. You copy one prompt, paste it into an AI that can work on your computer, and it checks, installs and connects the server for you, asking you when it needs something.
Sign in to get the install prompt
Members get a ready-made prompt that lets the Claude desktop app check tailtest for Cline, install it and connect it for them, step by step. You don't need any technical skills: you copy, paste and answer a few questions. Your connected AI can also find and install any of the 4,066 MCP servers here for you.
Who it's for
Developers and technical teams who use Cline to write code and want automatic tests without setting them up by hand.
