JanusMCP
About
Local, open-source multi-account MCP broker — one endpoint, every account. Add credentials once and switch identity without reconnecting, from any LLM client.
Details
- Author
- bayway
- GitHub stars
- 6
- Downloads
- 233
- Categories
- Other
Jump to
- Multi‑account, one endpoint: N identities, no reconnecting.
- Identity scoping: per‑call, per‑session (Mcp‑Session‑Id), or global.
- Dual transport: stdio + Streamable HTTP in one process.
- Secure vault: OS keychain with encrypted‑file fallback.
- OAuth loopback: PKCE login with auto‑refresh, stored as oauth:<name>.
- Context‑safe: only the active account’s tools are exposed.
Setting up with Highlight
This MCP is not yet compatible with Highlight’s one-click setup. However, you can still use it with Highlight by following these steps:
- Download and install Highlight from highlightai.com/download
- Navigate to the plugins tab and select "Add Custom Plugin"
-
Configure the plugin with the settings below
Plugin Name
JanusMCPCommand (node, npx, python, etc.)Please refer to the README for specific instructions on how to obtain API keys or other required environment variables.
- Enable "Start Automatically" if you want the plugin to start when Highlight launches
From the repository
Install via npm (npx @bayway/janusmcp serve), Homebrew, Scoop, Docker, or build from source. Configure accounts and secrets in config.json and the OS keychain, then run janusmcp serve for stdio or set JANUS_TRANSPORT=http for HTTP. From any connected LLM client use the control tools janus_list_accounts, janus_use_account, and janus_whoami to switch identities; terminal commands like janusmcp tools and janusmcp call provide code‑execution mode.
Claude Desktop / Cursor
Paste into your MCP client config file to install this server.
{
"mcpServers": {
"janusmcp": {
"janusmcp": {
"command": "npx",
"args": [
"@bayway/janusmcp",
"serve",
"#",
"npm",
"(works",
"inside",
"MCP/npx",
"setups)"
]
}
}
}
}McpServers
{
"janusmcp": {
"command": "npx",
"args": [
"@bayway/janusmcp",
"serve",
"#",
"npm",
"(works",
"inside",
"MCP/npx",
"setups)"
]
}
}JanusMCP
One MCP endpoint, every account.
Add your credentials once, switch identity without reconnecting — from any LLM.
<br/>
<sub>One-click buttons require the npm package to be published. See <a href="RELEASING.md">RELEASING.md</a>.</sub>
</div>
The problem
If you work with more than one company, you use the same MCP server (Supabase, GitHub,
Slack…) with different identities — a different account, email and token per client.
Today most LLM clients hold one account at a time per connector: to switch client you
disconnect, reconnect, and redo the OAuth login. Every time.
The MCP protocol has no notion of "account": one session = one identity = one set of
credentials. JanusMCP fills that gap.
What it does
JanusMCP is a local broker that sits between your LLM client and the real MCP servers:
- Add N accounts once for the same service and keep them all available.
- Switch identity without reconnecting — no re-login, no fiddling with config.
- Works with any LLM client — it just speaks standard MCP (stdio + Streamable HTTP).
- Runs locally — your machine, your keychain, your control.
- Keeps the context clean — it exposes only the active account's tools, not N×tools.
┌─────────────────────────────┐ ┌─ Supabase (Client A)
LLM client ─MCP─▶│ JanusMCP broker │─▶ ├─ Supabase (Client B)
(Claude/GPT/ │ active-account · vault · │ ├─ GitHub (Client A)
Gemini/…) │ per-session scoping │ └─ …
└─────────────────────────────┘
You drive it with three control tools that appear in any client:
janus_list_accounts, janus_use_account, janus_whoami.
Install
Once released, install via your favorite channel (all published automatically on each
tag — see RELEASING.md):
npx @bayway/janusmcp serve # npm (works inside MCP/npx setups)
brew install bayway/janusmcp/janusmcp # Homebrew (macOS/Linux)
scoop install janusmcp # Windows
docker run --rm -p 7332:7332 ghcr.io/bayway/janusmcp:latest
…or download a prebuilt binary from Releases.
Build from source (60-second quickstart)
git clone https://github.com/bayway/janusmcp
cd janusmcp/go
make build # produces ./bin/janusmcp
cp config.example.json config.json # edit with your accounts
./bin/janusmcp serve # stdio, for Claude Desktop/Code
Two Supabase clients, PATs kept in your OS keychain (never in the config):
./bin/janusmcp vault set supabase_client_a # paste the PAT
./bin/janusmcp vault set supabase_client_b
// config.json
{
"bindingMode": "session",
"accounts": [
{ "id": "client_a", "service": "supabase", "command": "npx",
"args": ["-y", "@supabase/mcp-server-supabase@latest", "--read-only", "--project-ref=REF_A"],
"env": { "SUPABASE_ACCESS_TOKEN": "vault:supabase_client_a" } },
{ "id": "client_b", "service": "supabase", "command": "npx",
"args": ["-y", "@supabase/mcp-server-supabase@latest", "--read-only", "--project-ref=REF_B"],
"env": { "SUPABASE_ACCESS_TOKEN": "vault:supabase_client_b" } }
]
}
Add it to Claude Desktop:
{ "mcpServers": { "janusmcp": {
"command": "/abs/path/janusmcp/go/bin/janusmcp", "args": ["serve"],
"env": { "JANUS_CONFIG": "/abs/path/janusmcp/go/config.json" } } } }
For ChatGPT / Gemini / Cursor / Copilot, run HTTP and point them at the URL:
```bash
JANUS_TRANSPORT=http JANUS_HTTP_PORT=7332 ./bin/janusmcp serve
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