prompt-protection runs on your own machine — the client starts it, so there is no endpoint to ping. 575 installs a week from npm. Last commit 15 Sep 2026.
Scan prompts, tool definitions and model output for injection, and guard agent tool calls.
What the code does
We read the source, 19 h ago · rules 3dff92dd89df
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.
subprocess.run(["node", str(HERE / "normalize.mjs"), "--strings", str(inp), str(outp)], check=True)
'/wH//Pv9/AEABf8IAQAAAQEA/wMCAAD//woD/f8BAPz3Af8AAgD5/wAABAECAgD//wIAAAEAAAD+AAAA+gPp/wADAAD7AP/3AAD//P38/gD//wEE/wAA/vwUAQMD/wD0AAD+CAAABv4C+/8AAAIEAP//A/3/AvwAAAQBAQH8AAAB9AIEAAAAAADkAvP/AAQJAv8AAQH+/v//AQECAf3/+v8A/AABAAYDAAABAQEB/wH6/v/+/wH+AAMA/QH+/v8AAP8C+gEAAAMAAfQA/AAAA…
pattern: /(read|open|output|return|show|cat|print)\s+.{0,20}(\/etc\/passwd|\/etc\/shadow|\/etc\/hosts|\.env|secrets?\.json|credentials?\.json|config\.json|id_rsa)/,
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 prompt-protection -- npx -y prompt-protection{
"mcpServers": {
"prompt-protection": {
"args": [
"-y",
"prompt-protection"
],
"command": "npx"
}
}
}[mcp_servers.prompt-protection]
command = "npx"
args = ["-y", "prompt-protection"]{
"mcpServers": {
"prompt-protection": {
"args": [
"-y",
"prompt-protection"
],
"command": "npx"
}
}
}{
"mcpServers": {
"prompt-protection": {
"args": [
"-y",
"prompt-protection"
],
"command": "npx"
}
}
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prompt-protection — questions
Answers built from our own checks of this server.