Mantis

Name: Mantis
Author: perzianhq

by perzianhqversion 0.1.13i★ –iRuns on your computer

Registry nameio.github.perzianhq/mantis

Install

Overview

Description from the maker (original English)

The web as short, numbered text for AI agents: a lean browser interface over Playwright.

PopNx MCP’s three pillars

These three are never merged into one score: opinions, measurements and popularity are different things.

User voiceiNo reviews yetReviews open together with accounts in a later step
Our basic checksi1 of 1 passedChecked from public information; code not scanned yet
UsageiNot measured yet★ –

What you can do with it

We have not written a plain-language summary for this one yet. Below are the facts we read from the registry.

Connection: Runs on your computer
Transport: stdio
Category: Web & browsers

Install

Pick the AI app you use, then copy the settings.

Before you install

Basic checks: 1 of 1 passed
Runs on your computer with your user’s permissions (files, network, apps).
The registry lists no key to fill in.

You need

npmNode.js installed (for the npx command)

Which app do you use?

ClaudeClaude CodeCursorVS CodeChatGPT

Pick your app above. We remember it, so next time the button says “Install in …”.

Open Claude Desktop → Settings → Developer → Edit Config, and paste this into claude_desktop_config.json

{
  "mcpServers": {
    "mantis": {
      "command": "npx",
      "args": [
        "-y",
        "mantis-browser"
      ]
    }
  }
}

Run this in your terminal

claude mcp add mantis -- npx -y mantis-browser

Open in Cursor

Or copy the settings yourself

Paste into .cursor/mcp.json in your project, or ~/.cursor/mcp.json

{
  "mcpServers": {
    "mantis": {
      "command": "npx",
      "args": [
        "-y",
        "mantis-browser"
      ]
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

Open in VS Code

Or copy the settings yourself

Paste into .vscode/mcp.json in your project

{
  "servers": {
    "mantis": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "mantis-browser"
      ]
    }
  }
}

Your browser asks to open the app, then the app shows the settings and asks you to confirm. Key values are left empty for you to fill in.

This one runs on your computer, and ChatGPT can only connect to servers on the internet. Pick another app.

Your choice stays on this device in a cookie; no account needed.

These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.

What it can do

Runs on your computer; the tool list appears in your AI app after you install it.

Basic checksi

We check information anyone can see; we have not read the code. Checks that do not apply are left out of the count. · Checked Nov 7, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account perzianhq, which owns the repo
… Not checked yet
Still maintained
We have not read this repo from GitHub yet
… Not checked yet
Has a licence
We have not read this repo from GitHub yet
– Not applicable
Endpoint responds
This one runs on your computer; there is no internet endpoint
– Not applicable
Sign-in with OAuth
Runs on your computer and uses local settings instead
… Not checked yet
No hidden instructions in tool descriptions
Runs on your computer; we can only read tool lists from internet endpoints

Compared with others in Web & browsersi

More stars than 0% of the other 881 servers in this category
Published to the registry more recently than 95% of the other 881 servers in this category
Basic checks equal to or better than 100% of the other 881 servers in this category

Compared with every active server in this category in the registry. Stars count only when the publisher owns the repo.

Common questions

Is Mantis safe?

It passed 1 of 1 applicable basic checks. We have not read the code. Before adding a key or token, see what access the server asks for and use a key with only the permissions you need.

What keys or codes does it need?

The registry does not list a required key, though some servers ask you to sign in on first use.

Does it run on my computer or in the cloud?

It runs on your computer. Your AI app starts it when needed, and data does not pass through the maker’s servers (unless it calls an online service itself).

Is it still maintained?

The GitHub repo last changed –, and the latest version (0.1.13) reached the registry 2 days ago.

Which apps can use it?

Apps that support MCP, such as Claude Desktop, Claude Code, Cursor and VS Code. You also need Node.js on your computer.

What can I use instead?

In the same category: Browser Use, Chrome DevTools MCP, MCP Server Browser

Alternatives

Servers in the same category from other makers, sorted by stars.

Reading a card:★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi

Browser Use

by browser-use

Lets AI do web tasks for you, such as filling forms, searching and extracting data, in the maker’s cloud browsers or on your computer.

Computer or cloud★ 120,087MITUpdated 17 days ago

Install

Chrome DevTools MCP

by ChromeDevTools

Lets AI use Chrome’s developer tools to inspect pages, find what makes them slow and spot errors. Made by the Chrome DevTools team.

Runs on your computer★ 54,821Apache-2.0Updated 16 days ago

Install

MCP Server Browser

by bytedance

MCP server for browser use access

Runs on your computer★ 39,550Apache-2.0Updated 14 months ago

Install

README from the maker

Open the README

Copied from the maker’s repo as written. PopNx MCP has not reviewed or endorsed it. HTML, images and scripts are removed. Links lead off this site.

Lets AI agents browse the web as short, numbered text instead of screenshots.

perzian.dev/mantis · by Perzian

It works with Claude Code, Codex, Cursor or your own agent as an MCP server. Install in two commands.

npx -y -p mantis-browser mantis install

claude mcp add mantis -- npx -y -p mantis-browser mantis-mcp npx -y -p mantis-browser mantis read https://example.com # try it without an agent

Windows, Linux servers and other agents: SETUP.

*One real task (Luna, each tool’s median run of 5 by input tokens, replayed): about half the time, over 3.5x fewer input tokens, less than half the calls. Across all 5 runs: 3-5x fewer tokens, about half the time, 11-12 calls vs 21-29. This is a selected example from 16 long tasks; medians across all 16 are in Results. Full video.*

Security and threat model: SECURITY.md.

How it works

What the agent sees

Results

Mantis vs the accessibility tree (Playwright MCP) on public sites, gpt-6-luna and claude-haiku-5-5. Every cell is a per-run median; time is end-to-end wall time per run:

*0.1.13: headline numbers are 0.1.9's; later builds checked on Dickens (Luna, Haiku), the capability-v1 local set and the visual-live-v1 real-site set.*

Long tasks (correct: 14 keyed tasks, 42 runs per cell; medians: all 16 tasks, 48 runs per cell; both approaches run in the same session):

	Luna Mantis	Luna tree	Haiku Mantis	Haiku tree
Correct	35/42	34/42	40/42	40/42
Input tokens (median)	244k	345k	268k	506k
Tool calls (median)	17	24	19	30
Time (median)	42s	66s	54s	85s

Short tasks (30 tasks, 90 runs per cell; tree and screenshot columns are the earlier 20261026 run):

	Luna Mantis	Luna tree	Luna screenshot	Haiku Mantis	Haiku tree	Haiku screenshot
Correct	88/90	86/90	90/90	90/90	88/90	88/90
Input tokens (median)	64k	99k	104k	38k	88k	33k
Tool calls (median)	3	4	7	3	5	6
Time (median)	16s	31s	35s	19s	30s	23s

Versus the accessibility tree:

Long tasks: accuracy within one run, 29-47% fewer input tokens, 29-37% fewer calls, about a third less time.
Short tasks: accuracy equal or better, 35-57% fewer input tokens.

Versus screenshots:

Luna: screenshots score 2 runs higher but use more tokens and time.
Haiku: screenshots use fewer tokens.

Caveats:

Short-task times compare a newer Mantis build with the earlier tree and screenshot run, so treat that time gap as indicative.
Scores come from deterministic answer keys on the final page state. Two long iframe/tab tasks can't be keyed and are left out of the long-task counts.
Method and full caveats: bench/RESULTS.md.

Use your own Chrome

Optional. Mantis can drive your real Chrome (your tabs, your sign-ins) instead of launching a fresh browser:

Run npx -y -p mantis-browser mantis chrome. It starts Chrome on 127.0.0.1:9222 with a dedicated profile.
Add MANTIS_CDP_URL=http://127.0.0.1:9222 to the env of the Mantis MCP config.
Sign in to your sites once in that profile; sign-ins persist there.
Mantis then acts on your real tabs, so act carefully. Without the variable nothing changes.

Limitations

No canvas input: canvas, WebGL, maps and drawing apps are described only as canvas, with no coordinate click or draw tool.
Login and bot walls need ask_human, which needs a display.
Benchmarked only on read, navigate and form-fill tasks on public sites, with two models. The screenshot baseline is this project's own tool, and a few tasks were swapped after results (disclosed).
Page content is untrusted data; see SECURITY.md.
Small v0.1.x beta.

Learn more

How it works in detail
Claude skill: teaches Claude how to read Mantis output
Install, configuration and tool reference
Re-running the benchmarks

License

MIT

Mantis

Overview

PopNx MCP’s three pillars

What you can do with it

Install

Before you install

What it can do

Basic checksi

Maker matches the repo

Still maintained

Has a licence

Endpoint responds

Sign-in with OAuth

No hidden instructions in tool descriptions

Compared with others in Web & browsersi

Common questions

Alternatives

Browser Use

Chrome DevTools MCP

MCP Server Browser

README from the maker

How it works

What the agent sees

Results

Use your own Chrome

Limitations

Learn more

License