Deus Witness runs on your own machine — the client starts it, so there is no endpoint to ping. 3 260 installs a week from pypi. Last commit 25 Oct 2026.
Checks every MCP tool call of your agent with an independent witness and gives signed receipts.
What the code does
We read the source, 40 min ago · rules 995398eba69f
What this server is able to do. For an MCP server this is often the job itself — a terminal server runs commands because that is what it is for. Listed so you know what you are plugging in, not as an accusation.
mod = __import__(modname, fromlist=["x"])
miss = [f for f in COLLATERAL_FILES if not os.path.isfile(os.path.join(d, f))]
e = dict(os.environ if env is None else env)
Found in continuous integration, deployment or infrastructure files, or in a neighbouring package of the same monorepo. None of this is installed when you add the server: it describes how the project is built and released. We list it because a leaked key in a build pipeline is still a real problem, but it is not something this server does on your machine.
out = subprocess.run([FORGE, "resign", hexs, SEED_C, muts], capture_output=True, text=True, check=True).stdout
"policy_hex": "a661767164772d6f72672d706f6c6963792d302e3163766572016470726576f66572756c6573a566706f6c696379a2616b0164726f6c65656f776e6572676365696c696e67a2616b0164726f6c65656f776e6572676d616e646174658068617070726f76616c806a7265766f636174696f6ea2616b0164726f6c6563616e79676d656d…
Is this your server and something here is wrong? Tell us — corrections are free and do not require a plan.
This code can reach further than it looks
We found places where it runs commands, builds paths or queries from values it is given. None of that is a flaw by itself — it becomes one when the code changes, and code changes quietly between releases. We re-read it on every one.
Connect this server
This server runs on your own machine — install it with the package manager and the client starts it for you. Package name taken from the official registry entry.
claude mcp add witness -e 'DEUS_WITNESS_KEY=<DEUS_WITNESS_KEY>' -- uvx deus-witness{
"mcpServers": {
"witness": {
"command": "uvx",
"args": [
"deus-witness"
],
"env": {
"DEUS_WITNESS_KEY": "<DEUS_WITNESS_KEY>"
}
}
}
}[mcp_servers.witness]
command = "uvx"
args = ["deus-witness"]
env = { DEUS_WITNESS_KEY = "<DEUS_WITNESS_KEY>" }{
"mcpServers": {
"witness": {
"command": "uvx",
"args": [
"deus-witness"
],
"env": {
"DEUS_WITNESS_KEY": "<DEUS_WITNESS_KEY>"
}
}
}
}{
"servers": {
"witness": {
"type": "stdio",
"command": "uvx",
"args": [
"deus-witness"
],
"env": {
"DEUS_WITNESS_KEY": "<DEUS_WITNESS_KEY>"
}
}
}
}Put your own value in place of
<DEUS_WITNESS_KEY> (Agent key (dwk_...) created in your Deus Witness account).
The author’s registry entry marks it as required.
Optional settings from the registry entry, left out of the block above:
DEUS_WITNESS_URL (Witness service URL).
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Deus Witness — questions
Answers built from our own checks of this server.