MCP server

Castle MCP by usefulapi

io.usefulapi/castle

Checked 25 Oct 2026, 20:29 UTC · Connected to it and listed its tools

Investigate security events and manage the allow/deny lists an analyst acts on.

Website Source

At a glance

Type

MCP server

Publisher

usefulapi.io (verified by the MCP Registry)

Status

Working at last check

Tools

14

Token cost

About 2,753 tokens per request

Sets up in

Claude Code, Claude Desktop, Codex, Gemini CLI, Cursor, VS Code, Antigravity, ChatGPT, OpenAI API, Grok

Last checked

25 Oct 2026, 20:29 UTC

Connect it to your agent

Add to CursorAdd to VS CodeVS Code Insiders

Opens the app, which shows the server and asks you to confirm. For other apps, copy the setup below.

Claude Code

claude mcp add --transport http castle https://castle.usefulapi.io/mcp

Claude Desktop

Settings → Connectors → Add custom connector, and paste the URL.

Codex (config.toml)

[mcp_servers.castle]
url = "https://castle.usefulapi.io/mcp"

Gemini CLI

{"mcpServers":{"castle":{"httpUrl":"https://castle.usefulapi.io/mcp"}}}

Cursor

{"mcpServers":{"castle":{"url":"https://castle.usefulapi.io/mcp"}}}

VS Code

{"servers":{"castle":{"type":"http","url":"https://castle.usefulapi.io/mcp"}}}

Antigravity

agy mcp add castle https://castle.usefulapi.io/mcp

ChatGPT

Settings → Apps & Connectors → Advanced settings: turn on Developer mode, then Create a connector and paste the URL. Which plans can do this varies.

OpenAI API (Responses tools)

{"type":"mcp","server_label":"castle","server_url":"https://castle.usefulapi.io/mcp","require_approval":"always"}

Grok (xAI API tools)

{"type":"mcp","server_label":"castle","server_url":"https://castle.usefulapi.io/mcp"}

Tools

• castle_archive_list_item ~134 tokens
  Archive a list entry so it stops matching. Reversible with castle_unarchive_list_item. Castle: DELETE /v1/lists/{list_id}/items/{id}/archive.
• castle_count_list_items ~165 tokens
  Count the entries in one list, with the same optional filters as the search. Read-only despite being a POST. Castle: POST /v1/lists/{list_id}/items/count.
• castle_create_list ~222 tokens
  Create a new allow or deny list. primary_field is the event field its entries match on, e.g. ip or user.email. Castle: POST /v1/lists.
• castle_create_list_item ~312 tokens
  Add an entry to a list — for example block an IP or an email. This changes live policy behaviour. Castle: POST /v1/lists/{list_id}/items.
• castle_get_events_schema ~92 tokens
  List the event fields you can filter and group on, with their types. Read this first — the other query tools need real field names. Castle: GET /v1/events/schema.
• castle_get_list ~94 tokens
  Fetch a single list with its primary and secondary field definitions. Castle: GET /v1/lists/{id}.
• castle_get_list_item ~128 tokens
  Fetch a single list entry — its value, who added it, the comment and its archive time. Castle: GET /v1/lists/{list_id}/items/{id}.
• castle_group_events ~379 tokens
  Aggregate matching events by one or more fields — the fast way to see which IPs, devices or countries dominate a spike. Read-only despite being a POST. Castle: POST /v1/events/group.
• castle_search_events ~408 tokens
  Query the security event stream — logins, registrations, transactions and their risk verdicts. Read-only despite being a POST: Castle takes the query in the body. Castle: POST /v1/events/query.
• castle_search_list_items ~225 tokens
  Search the entries of one list — the blocked IPs, emails or device ids it holds. Read-only despite being a POST. Castle: POST /v1/lists/{list_id}/items/query.
• castle_search_lists ~190 tokens
  Find the allow/deny lists defined in the environment. Read-only despite being a POST. Castle: POST /v1/lists/query.
• castle_unarchive_list_item ~127 tokens
  Restore a previously archived list entry so it matches again. Castle: PUT /v1/lists/{list_id}/items/{id}/unarchive.
• castle_update_list ~141 tokens
  Rename a list or change its colour or description. Castle: PUT /v1/lists/{id}.
• castle_update_list_item ~136 tokens
  Change the comment on a list entry. Castle: PUT /v1/lists/{list_id}/items/{id}.

Browse

• Email

Related MCP servers

• Socialloop
  SocialLoop: AI-native event platform — sell tickets, manage guests, run affiliates & promo codes.
• Wall-Event Circumvention Sentinel
  Sequence sentinel: wall events + channel-switch scoring; HALT, hold, signed receipt.
• Thecastlemap Castles
  Castles, fortresses, palaces and ruins worldwide: search, nearby, fame ranking, statistics. CC0.
• BorealHost
  Agent-native web hosting — deploy sites, manage DNS, register domains, scale infrastructure
• RotaCloud MCP by usefulapi
  Read RotaCloud shifts, attendance, leave, availability and payroll; create shifts and handle leave.
• Laravel Forge MCP by usefulapi
  Manage Laravel Forge servers, sites, and deployments from your AI assistant.
• Eventbrite MCP by usefulapi
  Manage Eventbrite events, ticket classes, venues and discounts; read attendees, orders and reports.
• OneUptime
  Manage incidents, alerts, monitors, status pages, on-call and telemetry in OneUptime.

Badge for your README

[![AptLynx](https://aptlynx.net/badge/io.usefulapi/castle.svg)](https://aptlynx.net/servers/io.usefulapi/castle)

Listing text is written by the maker; AptLynx lists tools and does not vouch for them. Find another tool · Browse by topic · For agents