@site-spy/mcp-server

@site-spy/mcp-server

Let an AI agent watch web pages for you. This MCP server connects your assistant to Site Spy: it can start monitoring a URL, tell you what changed between two points in time, and fetch or search the web on demand. Full docs at docs.sitespy.app.

Install

Get an API key from Settings → API. Every plan, including the free one, can read and write — you are bounded by watch count and daily requests, not by which tools you may call.

If your client has a CLI, this is the whole setup:

# Claude Code
claude mcp add site-spy --env SITE_SPY_API_KEY=your-key -- npx -y @site-spy/mcp-server

# Codex CLI
codex mcp add site-spy --env SITE_SPY_API_KEY=your-key -- npx -y @site-spy/mcp-server

# Gemini CLI  (the -- matters: without it, -y is parsed as a gemini flag)
gemini mcp add -s user -e SITE_SPY_API_KEY=your-key site-spy npx -- -y @site-spy/mcp-server

# OpenClaw
openclaw mcp add site-spy --command npx --arg -y --arg @site-spy/mcp-server \
  --env SITE_SPY_API_KEY=your-key

# VS Code
code --add-mcp '{"name":"site-spy","command":"npx","args":["-y","@site-spy/mcp-server"],"env":{"SITE_SPY_API_KEY":"your-key"}}'

Otherwise add this to your client's config file:

{
  "mcpServers": {
    "site-spy": {
      "command": "npx",
      "args": ["-y", "@site-spy/mcp-server"],
      "env": {
        "SITE_SPY_API_KEY": "your-key"
      }
    }
  }
}

Restart the client afterwards; the tools appear on their own.

[mcp_servers.site-spy]
command = "npx"
args = ["-y", "@site-spy/mcp-server"]

[mcp_servers.site-spy.env]
SITE_SPY_API_KEY = "your-key"

{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "site-spy": {
      "type": "local",
      "command": ["npx", "-y", "@site-spy/mcp-server"],
      "enabled": true,
      "environment": { "SITE_SPY_API_KEY": "your-key" }
    }
  }
}

{
  "mcp": {
    "servers": {
      "site-spy": {
        "command": "npx",
        "args": ["-y", "@site-spy/mcp-server"],
        "env": { "SITE_SPY_API_KEY": "your-key" },
        "enabled": true
      }
    }
  }
}

{
  "inputs": [
    {
      "type": "promptString",
      "id": "site-spy-key",
      "description": "Site Spy API key",
      "password": true
    }
  ],
  "servers": {
    "site-spy": {
      "type": "stdio",
      "command": "npx",
      "args": ["-y", "@site-spy/mcp-server"],
      "env": { "SITE_SPY_API_KEY": "${input:site-spy-key}" }
    }
  }
}

{
  "context_servers": {
    "site-spy": {
      "command": "npx",
      "args": ["-y", "@site-spy/mcp-server"],
      "env": { "SITE_SPY_API_KEY": "your-key" }
    }
  }
}

If you skip SITE_SPY_API_KEY, the agent asks you to authenticate interactively — but that key lives in memory only and is gone when the server restarts.

Tools

Read tools are annotated readOnlyHint, so most clients stop asking permission for them.

get_snapshot and get_diff cap output at 20,000 characters; pass max_chars for more.

Once a token exists, feed URLs are https://sitespy.app/api/rss?token={token} for everything and …/api/rss/watch/{uuid}?token={token} for one watch.

Environment variables

Self-hosting: the backend fetch_url endpoint can be restricted with FETCH_URL_API_ENABLED, FETCH_URL_REQUIRE_MASTER_ADMIN, or FETCH_URL_ALLOWED_API_KEYS.

Troubleshooting

• "API key is invalid or expired" — the key was revoked or regenerated. Copy a fresh one from Settings → API. The server itself is fine; there is no need to work around it.
• Tools never appear — restart the client after editing its config, and check npx runs (Node.js 20.19+).
• "Watch limit reached" — you are at your plan's cap. Delete one or upgrade.
• "Rate limit reached" — the day's write allowance is spent; the error says how long to wait. Reads do not count against it.
• fetch_url keeps timing out — pass fetch_backend explicitly. html_requests is fast and right for static pages; html_webdriver renders JavaScript; flaresolverr is for Cloudflare. auto tries all three and gives up at 30s. On failure the response carries attempts[] and cascade_summary showing what was tried.

Try it

• "Monitor https://example.com/pricing and tell me when the price changes"
• "What changed on my watches this week?"
• "Search for the current Postgres release notes and fetch the top result"