REA
Reverse engineer anything from your terminal or agent with one CLI and MCP server.
Runs on your computer
Spawner
What it does
Preview environments on your self-hosted Spawner server: a copy of your app for each git branch
- Connects Runs on your computer
- Account or key Needs SPAWNER_TOKEN
- Category Developer tools
Install
Pick the AI app you use, then copy the settings.
Passed 3/3 checks · Runs on your computer
First: which AI do you use?
Pick your app and the steps appear below.
Works with Claude, with some setup first
You need a Spawner key (create it on the maker’s site) · Install Node.js on your computer first (one time) · Only the Claude desktop app (Windows or Mac), not the web or phone
Install Node.js
One time only; it works for every server that needs Node.js
Sign up and create a Spawner key
Open the maker’s site, sign up and create an API key for the next step. Check the maker’s site for pricing and free plans.
Open the Claude desktop app’s settings file
SettingsDeveloperEdit Config
Paste these settings and save the file
Checking the commands · copy buttons appear once they pass
Paste the key only into the app’s field, never into a chat or to anyone
Quit Claude and open it again
Try it
Use Spawner and tell me what you can do for me, then show me one thing✓ If Claude says it is using Spawner or shows a Spawner tool in the answer, you are connected
Menu names checked against Anthropic’s help page on Nov 11, 2026 · your screen may differ slightly by app version
ChatGPT cannot connect Spawner yet
Spawner runs on your computer, but ChatGPT can only connect servers that run on the web
What you can do instead
A · Use an app that can connect Spawner
- You need a Spawner key (create it on the maker’s site) · Install Node.js on your computer first (one time) · Only the Claude desktop app (Windows or Mac), not the web or phone
- You need a Spawner key (create it on the maker’s site) · Install Node.js on your computer first (one time)
- You need a Spawner key (create it on the maker’s site) · Install Node.js on your computer first (one time)
- You need a Spawner key (create it on the maker’s site) · Install Node.js on your computer first (one time)
B · Others in Developer tools that work with ChatGPT
Picked from the most used in the same category, only ones that connect by address with no key
- Sentry✓ ChatGPT
- Compiler Explorer✓ ChatGPT
- GitDiagram✓ ChatGPT
Works with Claude Code, with some setup first
You need a Spawner key (create it on the maker’s site) · Install Node.js on your computer first (one time)
Install Node.js
One time only; it works for every server that needs Node.js
Sign up and create a Spawner key
Open the maker’s site, sign up and create an API key for the next step. Check the maker’s site for pricing and free plans.
Open Terminal
Mac: press Command+Space and type Terminal · Windows: open PowerShell
Paste this command and press Enter
Checking the commands · copy buttons appear once they pass
Replace “your-value” with your key before pressing Enter
Paste the key only into the app’s field, never into a chat or to anyone
Type /mcp in Claude Code
You should see Spawner listed as connected
Try it
Use Spawner and tell me what you can do for me, then show me one thing✓ If Claude Code says it is using Spawner or shows a Spawner tool in the answer, you are connected
Menu names checked against Anthropic’s help page on Nov 11, 2026 · your screen may differ slightly by app version
Works with Cursor, with some setup first
You need a Spawner key (create it on the maker’s site) · Install Node.js on your computer first (one time)
Install Node.js
One time only; it works for every server that needs Node.js
Sign up and create a Spawner key
Open the maker’s site, sign up and create an API key for the next step. Check the maker’s site for pricing and free plans.
Click this button to open Cursor
Checking the commands · copy buttons appear once they pass
Fill in your key
In the Spawner settings, SPAWNER_URL, SPAWNER_TOKEN is empty; add your key and save
Paste the key only into the app’s field, never into a chat or to anyone
Open the AI chat in Cursor in Agent mode
Try it
Use Spawner and tell me what you can do for me, then show me one thing✓ If Cursor says it is using Spawner or shows a Spawner tool in the answer, you are connected
Menu names checked against Cursor’s help page on Nov 11, 2026 · your screen may differ slightly by app version
Works with VS Code, with some setup first
You need a Spawner key (create it on the maker’s site) · Install Node.js on your computer first (one time)
Install Node.js
One time only; it works for every server that needs Node.js
Sign up and create a Spawner key
Open the maker’s site, sign up and create an API key for the next step. Check the maker’s site for pricing and free plans.
Click this button to open VS Code
Checking the commands · copy buttons appear once they pass
Fill in your key
In the Spawner settings, SPAWNER_URL, SPAWNER_TOKEN is empty; add your key and save
Paste the key only into the app’s field, never into a chat or to anyone
Open the AI chat in VS Code in Agent mode
Try it
Use Spawner and tell me what you can do for me, then show me one thing✓ If VS Code says it is using Spawner or shows a Spawner tool in the answer, you are connected
Menu names checked against VS Code’s help page on Nov 11, 2026 · your screen may differ slightly by app version
For developers: Terminal commands and JSON settings
Installed on your computer
Claude Code
Checking the commands · copy buttons appear once they pass
Claude Desktop (claude_desktop_config.json)
Checking the commands · copy buttons appear once they pass
Cursor (~/.cursor/mcp.json)
Checking the commands · copy buttons appear once they pass
VS Code (mcp.json)
Checking the commands · copy buttons appear once they pass
Values you fill in
SPAWNER_URLenvAddress of your Spawner server's dashboard, such as https://spawner.preview.example.com. Without it, the server of spawner loginSPAWNER_TOKENsecret envPersonal API token (spn_...), from spawner token create or the dashboard. Without it, the token of spawner login
These settings are generated from the maker’s registry entry. If the README says otherwise, follow the README.
At a glance
- Downloads per weeki
- 70/wk
- Connection
- Runs on your computer
- Latest versioni
- 2.2.1
- Categoryi
- Developer tools
- Published to registryi
- Oct 11, 2026
- Code last changedi
- Oct 31, 2026
- Maker
- Flosk6
- Packages
npm: spawner-cli- Website
- spawner.run
- Registry status
- Active
Which apps can use it
Based on how this server connects and on each app’s own docs, checked Nov 10, 2026.
Run on your computer in
ClaudeGooseLM StudioMsty StudioCherry StudioCursorVS Code + GitHub CopilotVisual StudioWindsurf (Devin Desktop)ZedKiroClineContinueJetBrains AI AssistantClaude CodeCodex CLIGemini CLIOpenCodenodecodeWarpLibreChatRaycast
Related guides
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 13, 2026
- ✓ Pass
Maker matches the repo
The registry name was verified with the GitHub account Flosk6, which owns the repo
- ✓ Pass
Still maintained
Code last changed 13 days ago
- ✓ Pass
Has a licence
Uses Apache-2.0
- – 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
Discussion
Ask, share a tip or report that it does not work. Sorted by what people marked helpful.
No posts yet. Be the first to ask or share.
Posts here are written by users, not the PopNx team.
User reviews
No reviews yet
Compared with others in Developer toolsi
- More stars than 0% of the other 5824 servers in this category
- Published to the registry more recently than 49% of the other 5824 servers in this category
- Basic checks equal to or better than 100% of the other 5824 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 Spawner safe?
It passed 3 of 3 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?
You need to fill in: SPAWNER_TOKEN
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 13 days ago, and the latest version (2.2.1) reached the registry 33 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.
Others in the same category
Servers in the same category from other makers, sorted by stars.
Reading a card:↓ Downloads per weeki★ GitHub starsiThree pillars: reviews · checks · usageiUpdated = latest version published to the registryi
Serena MCP: the IDE for your agent
A powerful toolkit for coding, providing semantic retrieval and editing capabilities.
Runs on your computer
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.
spawner-cli
The command line and MCP server of Spawner. Spawner is an open source, self-hosted preview environment manager: a copy of your app for each git branch, on your own server, with its own URLs, database and logs, for teams and their coding agents.
With spawner, developers and coding agents create, update and delete environments from a worktree, uncommitted changes included, run commands in them and read their logs.
Install
npm install -g spawner-cliIt needs Node.js 20 or later, and a Spawner server: install one with a single command. Every server also serves the CLI of its own version at /api/v1/cli/spawner.
Log in
spawner login https://spawner.preview.example.comType the code it shows in the dashboard and approve the login: the CLI stores a personal token. In CI or a container, SPAWNER_URL and SPAWNER_TOKEN replace the login.
Commands
# write .spawner/, and offer to add the instructions for coding agentsspawner init
the environment of the current branch, from this worktree
spawner up --wait
run a command in a service
spawner exec feat-login db -- psql -U app -c "select * from users"
only the error lines, stack traces kept whole
spawner logs feat-login api --errors
a link for someone without an account
spawner share feat-login
spawner down feat-login
Before the first spawner up of a project, an admin adds the project in the dashboard (Projects, New project). The other commands: status, ls, stats, capacity, url, shell, stop, start, sleep, wake, extend, token, whoami and logout.
Commands print JSON with --json and exit with stable codes: 4 when the environment failed, 6 when the quota or the server's capacity is reached, 7 when .spawner/ was refused.
MCP server
spawner mcp is an MCP server on stdio, with the login and the rights of the CLI. In Claude Code:
claude mcp add spawner -- spawner mcpIn a project's .mcp.json, or Cursor's .cursor/mcp.json:
{"mcpServers": { "spawner": { "command": "spawner", "args": ["mcp"] } } }
It has nine tools: spawner_up, spawner_status, spawner_list, spawner_logs, spawner_exec, spawner_stats, spawner_url, spawner_share and spawner_down. spawner_exec and spawner_down are marked destructive: whether a client asks before running them depends on the client and its permission settings.
Documentation
- The CLI and the MCP server: every command, JSON outputs, exit codes
- Coding agents: Claude Code, Codex, Cursor, and the instructions
spawner initadds - Quick start: from a fresh server to the first environment
Source: github.com/Flosk6/Spawner. License: Apache-2.0.