MCPanel

A lightweight desktop app for managing local MCP (Model Context Protocol) servers: "Postman for MCP." No Electron, no bundled runtime, ~7 MB binary.

MCP servers are the small stdio programs that give AI clients access to tools. Today you babysit them with raw terminals, hand-edited JSON configs, and zero visibility. MCPanel gives you a control panel instead.

Features

• Import from the clients you already use. MCPanel reads the MCP servers already configured in Claude Desktop, Claude Code, Cursor, VS Code, and Windsurf, and offers them for import — no retyping. Credential-looking environment variables are moved straight from those plaintext config files into your OS keyring on the way in.
• Service-style toggles. Flip a server on and MCPanel spawns the process and completes the MCP initialize handshake before showing it as running. "Running" means it's genuinely ready for tool calls, not just "the process exists."
• Live log streaming, flood-proof. stdout/stderr of every server, line by line, ANSI escapes stripped. Oversized lines are capped at 64 KiB and bursts beyond the buffer are counted and reported as dropped, so a misbehaving server logging thousands of lines per second can't freeze the UI.
• Tools browser. Pick a running server and its tools are listed; pick a tool and its inputSchema becomes a form — strings, numbers, booleans, enums as the right controls, anything richer as a JSON field — with strict typing on the way out ("12abc" is not a number, 1.5 is not an integer, an empty optional is omitted rather than sent as ""). Call it and read the result as text, not as an envelope. This is the "Postman" part.
• Raw JSON-RPC editor. One tab over: a CodeMirror editor to hand-craft any request and inspect the exact response. Every tool call lands in the shared history as the JSON-RPC it amounted to, and open in editor hands a tool's request over for tweaking.
• No orphaned processes. Servers are spawned into Unix process groups with PDEATHSIG (Linux) or Windows Job Objects with kill-on-close. If MCPanel exits or crashes, the servers it started die with it.
• Sane secrets handling. API keys live in the OS credential manager (Keychain / Windows Credential Manager / Secret Service), never in plaintext config. They're resolved only at spawn time and never appear in logs or events.

Install

Grab the latest build from Releases.

Heads up: builds are currently unsigned. Your OS will complain the first time. This is expected for a young open-source project; code signing certificates are on the roadmap.

macOS (Apple Silicon & Intel)

Download the .dmg. Gatekeeper will likely claim the app is "damaged and can't be opened." It isn't; that's macOS's message for unsigned downloads. Either:

• Right-click the app → Open → Open in the dialog, or

• remove the download quarantine attribute:

  xattr -d com.apple.quarantine /Applications/MCPanel.app
  

Windows

Download the .msi or .exe installer. SmartScreen will warn on first run: click More info → Run anyway.

Linux

Download the .deb, .rpm, or .AppImage. The AppImage needs no install: chmod +x and run. The deb/rpm packages pull in the WebKitGTK runtime automatically.

Quickstart

1. Launch MCPanel and click Import… — if you already run MCP servers in another client, they're listed and ready to bring over. Otherwise click Add server.
2. Enter the command and args, e.g. npx with args -y @modelcontextprotocol/server-filesystem /tmp.
3. Add env vars if the server needs them; mark API keys as secret and they go straight to the OS keyring.
4. Flip the toggle. Watch the status walk Starting → Initializing → Running while logs stream in below.
5. In the workbench, pick a tool from the list, fill in its inputs, and click call. Switch to Raw JSON-RPC when you want to hand-craft the request yourself.

That's it: you now have a supervised MCP server with live logs and a request console.

Build from source

Linux prerequisites:

sudo apt install libwebkit2gtk-4.1-dev build-essential libxdo-dev libssl-dev \
  libayatana-appindicator3-dev librsvg2-dev

Then (Rust stable ≥ 1.95 and Node 20+ required):

npm ci && npm run build        # required once before any cargo command:
                               # the Tauri build embeds dist/ at compile time
npm run tauri dev              # dev app: vite on :1420 + the Rust backend

Tests and checks:

cargo test   --locked --manifest-path src-tauri/Cargo.toml
cargo clippy --locked --manifest-path src-tauri/Cargo.toml --all-targets -- -D warnings
npm test && npm run lint && npm run typecheck

Security model

The UI talks to the backend over a local HTTP gateway. In short:

• The gateway binds 127.0.0.1 on an ephemeral port, never an external interface.
• Every request needs a random 32-byte bearer token, generated fresh per launch, held in memory only, and compared in constant time.
• The Host header is validated against the bound address to block DNS-rebinding attacks.
• CORS is pinned to the app's own webview origins, so browsers can't script against the gateway.
• Secrets are resolved from the OS keyring just-in-time at process spawn; they are never written to config, events, or logs.

Found a vulnerability? See SECURITY.md and please report privately.

Importing from other clients

Import… scans the standard config locations for Claude Desktop, Claude Code
(~/.claude.json), Cursor, VS Code, and Windsurf. If yours lives somewhere else
— a project-local .mcp.json, say — paste its path into the dialog.

• Only stdio servers can be imported. Entries with a url or an http/sse
  transport are listed with the reason they were skipped rather than silently
  dropped; see the limitation below.
• Credentials go to the keyring, not to MCPanel's config. Environment
  variables whose names look like credentials (*_TOKEN, *_API_KEY,
  *_SECRET, *_PASSWORD, …) are written to the OS credential manager and
  stored here only as a marker. Their values are read from the source file
  backend-side and never reach the UI.
• Nothing is overwritten. A name that's already taken is imported as
  name (2), and the dialog says so before and after. Imported servers are
  never armed to auto-start.
• Your original config is untouched. Import only reads.

Known limitations

• Import covers stdio servers only. Remote (http/sse) MCP servers in a
  client's config are reported as skipped, because MCPanel itself speaks stdio
  only — remote transport support is on the roadmap.
• On Unix, if MCPanel itself is SIGKILLed, a reparented grandchild process can survive (PDEATHSIG covers direct children only). Normal exits and crashes are fully covered.
• Windows graceful shutdown is compile-verified but untested on real hardware and likely degrades to grace-then-terminate. Windows testers wanted: if you can try it on a real box, open an issue with what you find.

Contributing

See CONTRIBUTING.md for setup, test commands, and PR conventions. Scoped changes, one concern per PR.

License

MIT © Oussema Taleb