EffectFence runs on your own machine — the client starts it, so there is no endpoint to ping. 48 installs a week from npm. Last commit 8 Sep 2026.
Stops agents double-firing side effects: 1,000 racing duplicates, exactly one execution.
What the code does
We read the source, 4 d ago · rules ccca72095570
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.
const child = spawn(binary, process.argv.slice(2), { stdio: "inherit" });
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 effectfence -- npx -y effectfence{
"mcpServers": {
"effectfence": {
"args": [
"-y",
"effectfence"
],
"command": "npx"
}
}
}[mcp_servers.effectfence]
command = "npx"
args = ["-y", "effectfence"]{
"mcpServers": {
"effectfence": {
"args": [
"-y",
"effectfence"
],
"command": "npx"
}
}
}{
"mcpServers": {
"effectfence": {
"args": [
"-y",
"effectfence"
],
"command": "npx"
}
}
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EffectFence — questions
Answers built from our own checks of this server.