Langfuse runs on your own machine — the client starts it, so there is no endpoint to ping. 191 installs a week from npm. Last commit 30 Aug 2026.
MCP server for Langfuse LLM observability — trace and observation analysis.
What the code does
We read the source, 22 h 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.
этот файл ставится пользователю, но в репозитории его нет
const initProcess = spawn(this.claudeCodePath, args, {
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 langfuse -e 'LANGFUSE_SECRET_KEY=<LANGFUSE_SECRET_KEY>' -e 'LANGFUSE_PUBLIC_KEY=<LANGFUSE_PUBLIC_KEY>' -- npx -y langfuse-observability-mcp-server{
"mcpServers": {
"langfuse": {
"command": "npx",
"args": [
"-y",
"langfuse-observability-mcp-server"
],
"env": {
"LANGFUSE_PUBLIC_KEY": "<LANGFUSE_PUBLIC_KEY>",
"LANGFUSE_SECRET_KEY": "<LANGFUSE_SECRET_KEY>"
}
}
}
}[mcp_servers.langfuse]
command = "npx"
args = ["-y", "langfuse-observability-mcp-server"]
env = { LANGFUSE_SECRET_KEY = "<LANGFUSE_SECRET_KEY>", LANGFUSE_PUBLIC_KEY = "<LANGFUSE_PUBLIC_KEY>" }{
"mcpServers": {
"langfuse": {
"command": "npx",
"args": [
"-y",
"langfuse-observability-mcp-server"
],
"env": {
"LANGFUSE_PUBLIC_KEY": "<LANGFUSE_PUBLIC_KEY>",
"LANGFUSE_SECRET_KEY": "<LANGFUSE_SECRET_KEY>"
}
}
}
}{
"servers": {
"langfuse": {
"type": "stdio",
"command": "npx",
"args": [
"-y",
"langfuse-observability-mcp-server"
],
"env": {
"LANGFUSE_PUBLIC_KEY": "<LANGFUSE_PUBLIC_KEY>",
"LANGFUSE_SECRET_KEY": "<LANGFUSE_SECRET_KEY>"
}
}
}
}Put your own values in place of
<LANGFUSE_SECRET_KEY> (Langfuse secret key for authentication), <LANGFUSE_PUBLIC_KEY> (Langfuse public key for authentication).
The author’s registry entry marks them as required.
Optional settings from the registry entry, left out of the block above:
LANGFUSE_BASE_URL (Langfuse API base URL).
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Langfuse — questions
Answers built from our own checks of this server.