Privacy
This page is the privacy policy of arcane-mcp, the same text as PRIVACY.md in the repository, which the Claude Desktop extension links to.
arcane-mcp is an open-source Model Context Protocol server that runs on your own machine or server and connects an MCP client (Claude Desktop, an IDE, an agent) to an Arcane server you choose. It is published by José M. Requena Plens and distributed as release binaries, container images and a Claude Desktop extension built from this repository.
This policy applies to every way of running it, including the Claude Desktop extension (.mcpb).
What it collects
Section titled “What it collects”Nothing. arcane-mcp has no telemetry, analytics, crash reporting or update check, and no account, server or service of its own: neither the author nor anyone else receives data from it.
Where data goes
Section titled “Where data goes”Data moves only between three parties, all chosen and run by you:
- Your MCP client sends tool calls (an action and its arguments) to arcane-mcp and receives the results, over standard input and output or, if you start it in HTTP mode, over Streamable HTTP on the address you configure.
- arcane-mcp turns each call into requests to your Arcane server’s API (HTTP and WebSocket) and returns Arcane’s answers to the client. It contacts no other host.
- Your Arcane server (
ARCANE_URL) does the work and may, on your instruction, reach other systems itself (registries, Git repositories, Docker hosts and agents). Those connections are Arcane’s, governed by Arcane’s configuration and the policies of whatever it connects to.
What the results contain (container names, logs, environment variables, Compose files, and so on) is whatever your Arcane server returns for the actions you run, and it goes to your MCP client. If that client sends conversation content to a model provider, the provider’s privacy policy covers that, not this one.
Credentials
Section titled “Credentials”The Arcane API key (or username and password) is read from the environment, a .env file in the working directory, or, for the Claude Desktop extension, the extension settings, where the field is marked sensitive so that Claude Desktop treats it as a secret. arcane-mcp sends the key only to your Arcane server and never writes it anywhere. In HTTP mode, each client’s own key travels in its requests and is held in memory only while the server instance serving that key lives (it is reclaimed when idle).
What it stores
Section titled “What it stores”Nothing. arcane-mcp writes no files, databases or caches; files Arcane returns (downloads, backups) are passed to the client in the tool result. All state is in memory and ends with the process.
arcane-mcp writes logs to standard error, where your MCP client or container runtime keeps them (Claude Desktop writes them to its MCP log files on your computer). By default each tool call adds one audit record naming the tool, the action, the outcome and the duration; argument values are never logged, and argument names only if you set ARCANE_MCP_AUDIT_LOG_ARG_NAMES=true. In HTTP mode a record identifies a client’s key only by a 12-character SHA-256 fingerprint. ARCANE_MCP_AUDIT_LOG=false turns the audit records off, and ARCANE_MCP_LOG_LEVEL sets how much else is logged.
Third parties
Section titled “Third parties”None are involved by arcane-mcp itself. Downloading it involves the host you download from (GitHub Releases, GitHub Container Registry, Docker Hub), under that host’s own privacy policy.
Changes and contact
Section titled “Changes and contact”Changes to this policy are made in this file, and its history is the repository’s commit log. Questions and requests: open an issue at https://github.com/jmrplens/arcane-mcp/issues or write to jmrplens@gmail.com.