# Tailtest

> tailtest auto-generates and runs tests for every file your AI agent edits in Claude Code. R1-R15 rule layer + adversarial test mode (V13).

- **Type:** MCP server
- **Install:** `agentstack add mcp-avansaber-tailtest`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [avansaber](https://agentstack.voostack.com/s/avansaber)
- **Installs:** 0
- **Category:** [AI & ML](https://agentstack.voostack.com/c/ai-and-ml)
- **Latest version:** 0.1.0
- **License:** MIT
- **Upstream author:** [avansaber](https://github.com/avansaber)
- **Source:** https://github.com/avansaber/tailtest
- **Website:** https://tailtest.com

## Install

```sh
agentstack add mcp-avansaber-tailtest
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# tailtest -- AI software testing for Claude Code

[](https://opensource.org/licenses/MIT)
[](https://github.com/avansaber/tailtest)
[](https://github.com/avansaber/tailtest/releases/latest)
[](https://tailtest.com/platform/agent-edits/)

> You build. Claude builds. tailtest makes sure it works.

**tailtest** is the open-source AI software testing layer for [Claude Code](https://www.anthropic.com/claude-code). It runs inside the build loop: every time Claude edits a file, tailtest queues the file, generates production-shaped scenarios using the R1-R15 rule layer, runs them with your existing test runner (pytest, jest, go test, etc.), and surfaces failures back to Claude within the same turn. Hook-based. Deterministic. No prompting required.

Open source (MIT), no telemetry, no SaaS account. Includes adversarial mode (R15) that biases scenario generation toward 8 breakage categories -- the mode we've used to find 16 real bugs across 47 open-source Python repositories.

**[Read more on tailtest.com](https://www.tailtest.com/) · [Platform overview](https://www.tailtest.com/platform/) · [Agent-edit testing deep dive](https://www.tailtest.com/platform/agent-edits/) · [Full docs](https://www.tailtest.com/docs/)**

---

## Install

```bash
claude plugin marketplace add avansaber/tailtest
claude plugin install tailtest@avansaber-tailtest
```

Restart Claude Code after install. No other setup required.

## Update

```bash
claude plugin marketplace update avansaber-tailtest
claude plugin update tailtest@avansaber-tailtest
```

## Uninstall

```bash
claude plugin remove tailtest@avansaber-tailtest
```

---

## How it works

After any Claude-written file lands in your project:

1. tailtest generates scenarios that describe real business behavior -- not function signatures
2. It runs them using your existing test runner (pytest, vitest, jest, go test, and more)
3. Pass: `tailtest: N scenarios -- all passed.` Fail: one line surfaced, "want me to fix this?"

---

## Supported languages

Python, TypeScript, JavaScript, Go, Ruby, PHP, Java, Kotlin, C#, Rust

Runners are auto-detected from `pyproject.toml`, `package.json`, `go.mod`, `build.gradle.kts`, `*.csproj`, `*.sln`, and other standard manifests.

---

## Quick config

Create `.tailtest/config.json` in your project root to control depth:

```json
{ "depth": "standard" }
```

Options: `simple` (2-3 scenarios), `standard` (5-8, default), `thorough` (10-15).

See [tailtest.com/docs/config](https://tailtest.com/docs/config) for all options.

---

## Other tailtest variants

Same R1-R15 rule layer, same adversarial test mode, different host integration. **This repo is the Claude Code variant.**

- **[tailtest](https://github.com/avansaber/tailtest)** -- Claude Code plugin (hook-driven; this repo)
- **[tailtest-cursor](https://github.com/avansaber/tailtest-cursor)** -- Cursor plugin (hook-driven)
- **[tailtest-codex](https://github.com/avansaber/tailtest-codex)** -- Codex CLI plugin (hook-driven)
- **[tailtest-cline](https://github.com/avansaber/tailtest-cline)** -- Cline plugin (MCP-driven; reaches 8+ editors via Cline's host coverage)

See [tailtest.com/demo/claude-code](https://tailtest.com/demo/claude-code) for a live walkthrough of this variant, or [tailtest.com/comparison](https://tailtest.com/comparison) for a feature matrix across all four.

---

## License

MIT

## Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

- **Author:** [avansaber](https://github.com/avansaber)
- **Source:** [avansaber/tailtest](https://github.com/avansaber/tailtest)
- **License:** MIT
- **Homepage:** https://tailtest.com

Install and usage instructions live in the source repository linked above.

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/mcp-avansaber-tailtest
- Seller: https://agentstack.voostack.com/s/avansaber
- Browse the marketplace: https://agentstack.voostack.com/browse

---
Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.