Magic MCP vs Localhost MCP
A side-by-side look at the Magic MCP and Localhost MCP MCP servers: transport, auth, tools, quality signals, and the config to install either one in Claude, Cursor, Windsurf or VS Code.
Verdict: choose Magic MCP for developer tools work as a local process; choose Localhost MCP for developer tools as a local process. You can also run both side by side in one mcpServers block.
Which MCP server should you choose?
Choose Magic MCP when
- You need dedicated capabilities in the Developer Tools domain.
- You prefer a local stdio subprocess transport.
- Its auth model fits you: API key required.
- You have the keys it needs:
TWENTY_FIRST_API_KEY, API_KEY_21ST.
Choose Localhost MCP when
- You need dedicated capabilities in the Developer Tools domain.
- You prefer a local stdio subprocess transport.
- Its auth model fits you: No auth required.
- You want tools like
list_dev_servers, port_info, kill_server.
Feature & specification comparison
Rows where the two servers differ are marked.
| Spec | ||
|---|---|---|
| Category | Developer Tools | Developer Tools |
| Quality signal | 53/100 · Good | 59/100 · Good |
| Install command | Confirmed | Confirmed |
| Transport | Local subprocess (stdio) | Local subprocess (stdio) |
| Auth | API key required | No auth required |
| Pricing | Paid service | Free |
| Required env vars | TWENTY_FIRST_API_KEYAPI_KEY_21ST | None listed |
| Verified owner | Community listing | Community listing |
| GitHub stars | 6,089 | 4 |
| Directory activity | 16 views 1 installs 0 upvotes | 3 views 0 installs 0 upvotes |
| Tools | Not listed | 5 |
| Full listing | View Magic MCP | View Localhost MCP |
Tools & capabilities
Magic MCP tools
No tool names declared yet. Check the project README from the listing page.
Localhost MCP tools 5
list_dev_serversRead-only. Lists every local development server (next, vite, nuxt, remix, astro, rails, django, flask, express, deno, bun, etc.) currently LISTENING on a TCP port. For each: port, pid, process name, command line, working directory, project name, detected framework, uptime, memory (MB), CPU %, and owning user. Uses `lsof` on macOS/Linux and `netstat` on Windows; on Windows the cwd/framework fields are limited. Takes no arguments. Returns `{ count, servers[] }`.port_infoRead-only. Inspects a single TCP port and reports the dev server holding it (same fields as `list_dev_servers`). If nothing is listening, or the listener is not a recognised dev process, returns `{ port, status: "free" }`. Useful for answering "what's on :3000?" before starting or killing something.kill_serverTerminates a local dev server by `pid` or `port`. DESTRUCTIVE. Safe by default: with no `confirm`, this is a DRY RUN — it reports what it would kill and changes nothing. Pass `confirm: true` to actually terminate: sends SIGTERM, waits up to 5s, then escalates to SIGKILL (or SIGKILL immediately if `force: true`). Refuses PIDs below 1000 and processes that don't look like dev servers. Provide exactly one of `pid` or `port`. Returns what was (or would be) killed and the signal used.find_zombiesRead-only. Flags dev servers that look abandoned — all three of: uptime > 6h AND CPU < 1% AND memory > 100MB. By default it excludes known always-on noise (VS Code server, language servers, other MCP servers, postgres/redis, sidekiq, etc.); set `include_excluded: true` to also list those. Each candidate comes with the reasons it matched. This tool never kills anything — pass results to `kill_server`. Returns `{ count, candidates[] }`.port_conflictRead-only. Diagnoses an `EADDRINUSE` situation: given a port, returns the dev server currently blocking it plus 5 free alternative ports nearby. Use it when a `listen EADDRINUSE` error fires and you want both the culprit and a port to switch to.
Ready-to-paste client configs
Paste either block (or both) into your client config, e.g. claude_desktop_config.json or ~/.cursor/mcp.json. We only show a config when the install command is confirmed.
Magic MCP
{
"mcpServers": {
"21st-dev-magic-mcp": {
"command": "npx",
"args": [
"-y",
"@21st-dev/cli@latest"
],
"env": {
"TWENTY_FIRST_API_KEY": "YOUR_TWENTY_FIRST_API_KEY_HERE",
"API_KEY_21ST": "YOUR_API_KEY_21ST_HERE"
}
}
}
}
Localhost MCP
{
"mcpServers": {
"hasanjahidul-localhost-mcp": {
"command": "npx",
"args": [
"-y",
"localhost-mcp"
]
}
}
}
Frequently asked questions
Magic MCP is categorized under Developer Tools and uses a local stdio subprocess. Localhost MCP belongs to Developer Tools and uses a local stdio subprocess. Pick Magic MCP for developer tools work and Localhost MCP for developer tools.
Copy the mcpServers block from the config section on this page into your client's config (for example claude_desktop_config.json or ~/.cursor/mcp.json), then fully restart the client.
Magic MCP is listed as a paid service. Auth: api key required. Localhost MCP is listed as free. Auth: no auth required. If a server needs environment variables such as API keys, define them under the env key in your client's MCP config.
Yes. MCP clients support multiple servers: add 21st-dev-magic-mcp and hasanjahidul-localhost-mcp as separate keys in the same mcpServers object, and your assistant will call tools from either one.
On AllMCPs, Magic MCP has a quality signal of 53/100 (Good) with 16 views, 1 installs and 6,089 GitHub stars. Localhost MCP has 59/100 (Good) with 3 views, 0 installs and 4 GitHub stars.