What is tarn?
tarn is a MCP server by NazarKalytiuk that aPI testing tool with YAML tests and structured JSON failures agents can act on: run, validate, inspect, rerun failed tests and get fix plans. It is listed under Developer tools and has 5 GitHub stars.
| Type | Mcp server |
|---|---|
| Author | NazarKalytiuk |
| Repository | NazarKalytiuk/tarn |
| Popularity | 5 GitHub stars |
| Category | Developer tools |
| Security | Low risk (84/100) |
| Rank | #2,170 of 4,418 MCP servers; #493 in Developer tools |
| License | MIT |
| Last commit | 2026-06-04 |
| Runs | Locally |
| Language | Rust |
| Platforms | macOS, Windows, Linux |
Is tarn safe to install?
tarn scores 84/100 on the MCPMods security check: Low risk. Things to review: can take actions such as send, write or deploy. It passed 4 of 6 checks.
MCP server results come from listing signals: who publishes it, where your data goes and what it can do. The code itself is not scanned yet.
| Check | Result |
|---|---|
| Community-built server | Note |
| Runs on your machine only | Pass |
| No credentials mentioned | Pass |
| Can take actions such as send, write or deploy | Review |
| No code execution | Pass |
| Source on GitHub | Pass |
How do I install tarn?
- Find the launch command. The README says how the server starts (npx, uvx, docker or a remote URL) and which API keys it needs.
https://github.com/NazarKalytiuk/tarn
- Add it to Claude Code. Replace the part after -- with the command from the README. Remote servers use --transport http with a URL.
claude mcp add tarn -- <command from README> claude mcp add --transport http tarn <server-url>
- Check it connected. This lists your MCP servers and their status.
claude mcp list
Or ask Claude to set it up
Paste this into Claude Code and it installs tarn for you:
Add the "tarn" MCP server from https://github.com/NazarKalytiuk/tarn to Claude Code. Read its README for the launch command and any API keys I need, run claude mcp add, then check that it connects.