Snapstack Server

Name: Snapstack Server
Author: bgaze

by bgazeversion 1.2.3i★ –iRuns on your computer

Registry nameio.github.bgaze/snapstack-server

Install

Overview

Description from the maker (original English)

Local always-on server for SnapStack: browser capture intake + MCP over 127.0.0.1.

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": {
    "snapstack": {
      "command": "npx",
      "args": [
        "-y",
        "snapstack-server",
        "mcp"
      ]
    }
  }
}

Run this in your terminal

claude mcp add snapstack -- npx -y snapstack-server mcp

Open in Cursor

Or copy the settings yourself

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

{
  "mcpServers": {
    "snapstack": {
      "command": "npx",
      "args": [
        "-y",
        "snapstack-server",
        "mcp"
      ]
    }
  }
}

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": {
    "snapstack": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "snapstack-server",
        "mcp"
      ]
    }
  }
}

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 6, 2026

✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account bgaze, 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 876 servers in this category
Published to the registry more recently than 15% of the other 876 servers in this category
Basic checks equal to or better than 100% of the other 876 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 Snapstack Server 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 (1.2.3) reached the registry 5 months 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 16 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 15 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.

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The SnapStack server is a single always-on Node process: it receives browser captures from the extension, stacks them on disk, and serves them to any MCP-capable LLM client over Streamable HTTP. It listens only on 127.0.0.1 — nothing ever leaves your machine.

New here? The full install + usage guide lives in the extension README:

[snapstack-extension](https://github.com/bgaze/snapstack-extension). This page is the technical reference.

Architecture

One always-on process serves both the extension (capture) and your MCP client, decoupled by a folder on disk.

[MV3 extension]  --POST /push (bytes) ┐

▼ [SnapStack server - 127.0.0.1:4123] ├─ writes → stack on disk └─ MCP /mcp (HTTP) ← MCP client

Capture — the extension encodes the shot as WebP (PNG fallback), downscales it, and POSTs it here.
Stack — one image file (.webp/.png) plus a twin .json (url, title, timestamp, dimensions) per capture, named NN : a stable two-digit number (assigned in capture order, restarts at 01 when the stack empties) plus a timestamp, under ~/.snapstack/.
Retrieval — get_screenshots returns a JSON manifest (number, absolute path, dimensions, metadata — *no image bytes*); the client reads only the files it needs, by path. Deletion is a separate, explicit clear_screenshots step. Retrieval never deletes.

Requirements

Node.js ≥ 18 (tested on Node 20). No git needed at runtime.
An MCP-capable LLM client speaking the HTTP (Streamable HTTP) or stdio transport.
The [snapstack-extension](https://github.com/bgaze/snapstack-extension) loaded in your browser.

Install & run

On Windows, use an Administrator terminal, otherwise the global npm install and the scheduled-task registration

may get rejected.

The server ships on npm and installation is straightforward on macOS, Linux and Windows:

Install globally: npm i -g snapstack-server
Enable background service: snapstack enable

SnapStack auto-starts on login, restarts on crash, and updates itself on each launch. To check its status or if an update is available, simply run snapstack in your terminal.

Available commands:

snapstack                            # status report: service + server health, update check

snapstack start | stop | restart # control the running service (this session) snapstack update # update the CLI (npm i -g) + restart the server on the latest snapstack run # run the daemon in the foreground (no auto-start)

The daemon self-updates on each (re)start/login; the global CLI (the snapstack command) does not. Run snapstack update to bring both to the latest in one go.

The full end-to-end walkthrough (idiomatic install paths, MCP client registration, the extension) is in the [extension README](https://github.com/bgaze/snapstack-extension).

MCP

SnapStack speaks two MCP transports over the same on-disk stack — pick whichever your client supports:

// HTTP (server already running) — register http://127.0.0.1:4123/mcp; copy deploy/mcp.json

{ "type": "http", "url": "http://127.0.0.1:4123/mcp" }

// stdio (the client spawns the process)

{ "command": "npx", "args": ["-y", "-p", "snapstack-server", "snapstack", "mcp"] }

The HTTP /mcp endpoint is stateless (a fresh server + transport per request); the stdio front-end (snapstack mcp) is spawned on demand and reads the same ~/.snapstack stack. Capture intake (/push) always stays in the running server, independent of either MCP front-end.

Exposed tools

Tool	Description
`get_screenshots`	Lists pending captures as a JSON manifest (stable number, absolute path, dimensions, metadata) — no image bytes, no deletion. Pass `numbers` (e.g. `[1,3]`) to list only those.
`clear_screenshots`	Deletes captures. Pass `numbers` to delete specific ones; omit to clear the whole stack. Numbering restarts at `01` once empty.
`count_screenshots`	Number of pending captures, without retrieving them.

get_screenshots and count_screenshots are read-only; only clear_screenshots is destructive.

Configuration

Environment variables (infrastructure)

Variable	Default	Purpose
`SNAPSTACK_DIR`	`~/.snapstack`	Stack folder.
`SNAPSTACK_PORT`	`4123`	Listening port (always on `127.0.0.1`).

Capture policy (shared across your browsers)

The encoding/capture settings are owned by the server and stored in ~/.snapstack/config.json, so a single edit applies to every browser running the extension. They are edited from the extension's options page — not an environment variable — and fetched by the extension before each capture.

Key	Default	Meaning
`format`	`webp`	Image format: `webp`, `png` or `jpg`.
`quality`	`0.85`	Lossy quality (`0`–`1`; the extension UI shows it as a percentage).
`maxWidth`	`1568`	Downscale captures wider than this to this width in px (`0` = no resize).
`maxSlices`	`50`	Full-page capture: hard cap on stitched slices.

Two endpoints back it: GET /config returns the effective policy; POST /config validates and replaces it (host- + CORS-guarded like every capture route). The file is a non-image, so a stack clear never touches it; deleting it just restores the defaults above.

Troubleshooting

Capture server not started message in the extension: run snapstack start (or snapstack run in the foreground), or check the auto-start with snapstack. Test: curl http://127.0.0.1:4123/health.
Port already in use (`EADDRINUSE`): set SNAPSTACK_PORT to another value.
`snapstack: command not found` after switching Node version (nvm, fnm, volta, Laravel Herd, nvm-windows): npm i -g drops the snapstack command in the global bin of the Node version that was active at install time only, so switching versions hides it. This is how npm globals work, not a SnapStack bug — the background service is unaffected and keeps capturing; only the CLI command disappears. Fix: re-run npm i -g snapstack-server under the current Node version (or switch back to the one used at install).
The client doesn't see the tools: the server must run before the MCP client starts; check the config (type: "http", correct URL). Direct test: curl http://127.0.0.1:4123/count.
Inspect the stack: ls ~/.snapstack (image files + human-readable .json).

Support

A question or an idea? → GitHub Discussions
Found a bug? → open an issue

License

MIT — see LICENSE.

Snapstack Server

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

Architecture

Requirements

Install & run

MCP

Exposed tools

Configuration

Environment variables (infrastructure)

Capture policy (shared across your browsers)

Troubleshooting

Support

License