Add JSON API endpoint, CLI tool, and MCP server

- Add /api/finger and /api/finger/<username> JSON endpoints
- Remove hardcoded default credentials from config.py; require BASIC_AUTH_USERS env var
- Add cli/finger.py: query and plan-upload CLI using the JSON API
- Add mcp/server.py: FastMCP server exposing finger_user and upload_plan tools
- All credentials and base URL are read from environment variables

mcp/server.py

@@ -0,0 +1,85 @@
+#!/usr/bin/env python3
+"""MCP server for finger-web.
+
+Exposes finger query and plan-upload operations as Claude tools.
+
+Environment variables:
+  FINGER_WEB_URL   Base URL of the finger-web instance (default: http://localhost:5000)
+  FINGER_USER      Username for authenticated endpoints
+  FINGER_PASS      Password for authenticated endpoints
+"""
+
+import os
+
+import requests
+from mcp.server.fastmcp import FastMCP
+
+BASE_URL = os.environ.get("FINGER_WEB_URL", "http://localhost:5000").rstrip("/")
+
+mcp = FastMCP("finger")
+
+
+def _auth():
+    user = os.environ.get("FINGER_USER", "")
+    passwd = os.environ.get("FINGER_PASS", "")
+    return (user, passwd) if user and passwd else None
+
+
+@mcp.tool()
+def finger_user(username: str = "") -> str:
+    """Query finger information for a user via finger-web.
+
+    Pass a bare username (e.g. 'pete') or a user@host address
+    (e.g. '[email protected]').  Leave username empty to list currently
+    logged-in users.
+    """
+    if username and not all(c.isalnum() or c in ".-_@" for c in username):
+        return f"Invalid username: {username!r}"
+
+    url = f"{BASE_URL}/api/finger/{username}" if username else f"{BASE_URL}/api/finger"
+    try:
+        resp = requests.get(url, timeout=10)
+        resp.raise_for_status()
+        data = resp.json()
+        if data.get("status") == "success":
+            return data.get("result", "No information available.").strip()
+        return data.get("error", "Unknown error.")
+    except requests.exceptions.ConnectionError:
+        return f"Cannot connect to {BASE_URL}"
+    except Exception as e:
+        return f"Error: {e}"
+
+
+@mcp.tool()
+def upload_plan(filename: str, content: str) -> str:
+    """Upload or update a finger plan file via finger-web.
+
+    filename  The plan filename (typically your username, e.g. 'pete').
+    content   Plain-text content to publish as your .plan.
+
+    Requires FINGER_USER and FINGER_PASS environment variables to be set.
+    """
+    auth = _auth()
+    if not auth:
+        return "Set FINGER_USER and FINGER_PASS environment variables to authenticate."
+
+    try:
+        resp = requests.post(
+            f"{BASE_URL}/api/upload",
+            files={"file": (filename, content.encode(), "text/plain")},
+            auth=auth,
+            timeout=30,
+        )
+        resp.raise_for_status()
+        data = resp.json()
+        return data.get("message", "Upload successful.")
+    except requests.exceptions.ConnectionError:
+        return f"Cannot connect to {BASE_URL}"
+    except requests.exceptions.HTTPError as e:
+        return f"HTTP error: {e}"
+    except Exception as e:
+        return f"Error: {e}"
+
+
+if __name__ == "__main__":
+    mcp.run()