kestrel
Watch any URL for changes: baseline, then check for a diff. Free, no signup/key.
Should I use this
Quality & Safety
Based on automated analysis of tool definitions and protocol compliance.
Context Cost
This is the approximate number of tokens consumed each time the server's tools are loaded into a model's context. Higher counts reduce the attention available for other tasks.
Install
One-Click Install
Add this to your `claude_desktop_config.json` file:
{
"mcpServers": {
"kestrel": {
"url": "https://kestrel.perch-app.workers.dev/mcp"
}
}
}Remote endpoints
https://kestrel.perch-app.workers.dev/mcpstreamable-httpWhat it can do
Tool inventory
Tools (4)
🟡create_watch(url, label, token)
Start monitoring a web page (or JSON/text URL) for changes. Captures a baseline snapshot now. Returns a watch_id and a token — save the token; it's how you check and manage your watches later. Pass an existing token to add more watches under the same account.
Input Schema
{
"type": "object",
"properties": {
"url": {
"type": "string",
"description": "Absolute http(s) URL to monitor, e.g. https://example.com/pricing"
},
"label": {
"type": "string",
"description": "Optional human label for this watch."
},
"token": {
"type": "string",
"description": "Optional. Your existing Kestrel token to group this watch with others. Omit to get a new token."
}
},
"required": [
"url"
]
}🟢check_watch(watch_id, token)
Re-fetch a watched page and report whether it changed since the last check, with a short list of added/removed content lines. Updates the baseline to the new content. Call this every time you want the latest status (e.g. each run/heartbeat).
Input Schema
{
"type": "object",
"properties": {
"watch_id": {
"type": "string"
},
"token": {
"type": "string",
"description": "The token returned by create_watch."
}
},
"required": [
"watch_id",
"token"
]
}🟢list_watches(token)
List all watches under your token, with per-watch check/change counts.
Input Schema
{
"type": "object",
"properties": {
"token": {
"type": "string"
}
},
"required": [
"token"
]
}🔴delete_watch(watch_id, token)
Stop monitoring a page and delete the watch.
Input Schema
{
"type": "object",
"properties": {
"watch_id": {
"type": "string"
},
"token": {
"type": "string"
}
},
"required": [
"watch_id",
"token"
]
}Community
Evidence