Spanlens MCP Server

by spanlensio.github.spanlens/mcp-serverv0.3.0

Read-only access to Spanlens LLM observability: request logs, costs, agent traces, anomalies, model savings and per-user analytics.

13Node.jsstdioofficial registry

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Active11d ago

Install Spanlens MCP server

claude mcp add spanlens -e SPANLENS_API_KEY='<spanlens-api-key>' -- npx -y @spanlens/mcp-server

{
  "mcpServers": {
    "spanlens": {
      "command": "npx",
      "args": [
        "-y",
        "@spanlens/mcp-server"
      ],
      "env": {
        "SPANLENS_API_KEY": "<spanlens-api-key>"
      }
    }
  }
}

Add to ~/.cursor/mcp.json (global) or .cursor/mcp.json (project).

{
  "mcpServers": {
    "spanlens": {
      "command": "npx",
      "args": [
        "-y",
        "@spanlens/mcp-server"
      ],
      "env": {
        "SPANLENS_API_KEY": "<spanlens-api-key>"
      }
    }
  }
}

Settings → Developer → Edit Config (claude_desktop_config.json), then restart.

{
  "servers": {
    "spanlens": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@spanlens/mcp-server"
      ],
      "env": {
        "SPANLENS_API_KEY": "<spanlens-api-key>"
      }
    }
  }
}

Add to .vscode/mcp.json in your workspace.

{
  "mcpServers": {
    "spanlens": {
      "command": "npx",
      "args": [
        "-y",
        "@spanlens/mcp-server"
      ],
      "env": {
        "SPANLENS_API_KEY": "<spanlens-api-key>"
      }
    }
  }
}

Add to ~/.codeium/windsurf/mcp_config.json.

Configuration

Variable	Required	Secret	Description
SPANLENS_API_KEY	yes	yes	Spanlens API key. Must be a scope=public key (sl_live_pub_) issued from the Public Keys card at https://spanlens.io/projects — the server refuses to start with a full-access sl_live_ key.
SPANLENS_BASE_URL	—	—	Override the API endpoint for self-hosted Spanlens. Default: https://api.spanlens.io

Freshness

Active — last maintenance signal 11d ago. The newest of the signals below sets the band.

Last commit (default branch)
2026-09-28 · 11d ago · GitHub
Latest release
no data · GitHub
Package published
no data · npm/PyPI
Registry entry updated
2026-09-28 · 11d ago · official registry · v0.3.0

FAQ

›How do I install the Spanlens MCP server in Claude Code?

Run: claude mcp add spanlens -e SPANLENS_API_KEY='<spanlens-api-key>' -- npx -y @spanlens/mcp-server. For Cursor, VS Code, Claude Desktop and Windsurf, use the install tabs above.

›Does Spanlens require an API key?

Yes. It expects SPANLENS_API_KEY, of which 1 is a secret.

›Can I use Spanlens as a remote (hosted) MCP server?

No hosted endpoint is published; it runs locally over stdio.

›Is Spanlens in the official MCP registry?

Yes, as io.github.spanlens/mcp-server.