# createOneCalendarEventParticipant

A write tool on the Twenty MCP Server MCP server.

Agent View of the PolicyLayer registry record for `createOneCalendarEventParticipant`. HTML page: https://policylayer.com/tools/jdu278-twenty-mcp-server/createonecalendareventparticipant

## Facts

- Tool: `createOneCalendarEventParticipant`
- Server: Twenty MCP Server (`jdu278/twenty-mcp-server`) — https://policylayer.com/tools/jdu278-twenty-mcp-server.md
- Homepage: https://github.com/Jdu278/twenty-mcp-server
- Risk category: Write (Medium risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "createOneCalendarEventParticipant",
    "arguments": {}
  }
}
```

## Why createOneCalendarEventParticipant is rated Medium

This tool creates a calendar event participant entry, which is a reversible modification of CRM data. It does not execute arbitrary code, delete data, or involve financial transactions. The severity is medium because the blast radius involves adding participants to calendar events in a CRM system, which could affect scheduling and organizational workflows but can be easily undone by removing the participant.

From the tool's own definition: "Tool name contains 'createOne' which indicates creation of a new entity; description states 'Create One calendarEventParticipant'; sibling tools follow the pattern of create operations (createManyAttachments, createManyCompanies, etc.)"

## Use case

AI agents use createOneCalendarEventParticipant to create or update resources in Twenty MCP Server, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Twenty MCP Server environment.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Twenty MCP Server:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "createOneCalendarEventParticipant": {
      "limits": [
        {
          "counter": "createonecalendareventparticipant_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Twenty MCP Server (218)

- `deleteOneAttachment` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneattachment.md
- `deleteOneBlocklist` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneblocklist.md
- `deleteOneCalendarChannel` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonecalendarchannel.md
- `deleteOneCalendarChannelEventAssociation` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonecalendarchanneleventassociation.md
- `deleteOneCalendarEvent` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonecalendarevent.md
- `deleteOneCalendarEventParticipant` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonecalendareventparticipant.md
- `deleteOneCompany` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonecompany.md
- `deleteOneConnectedAccount` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneconnectedaccount.md
- `deleteOneFavorite` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonefavorite.md
- `deleteOneFavoriteFolder` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonefavoritefolder.md
- `deleteOneMessage` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonemessage.md
- `deleteOneMessageChannel` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonemessagechannel.md
- `deleteOneMessageChannelMessageAssociation` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonemessagechannelmessageassociation.md
- `deleteOneMessageFolder` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonemessagefolder.md
- `deleteOneMessageParticipant` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonemessageparticipant.md
- `deleteOneMessageThread` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonemessagethread.md
- `deleteOneNote` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonenote.md
- `deleteOneNoteTarget` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonenotetarget.md
- `deleteOneOpportunity` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneopportunity.md
- `deleteOnePerson` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneperson.md
- `deleteOneTask` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonetask.md
- `deleteOneTaskTarget` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonetasktarget.md
- `deleteOneTimelineActivity` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteonetimelineactivity.md
- `deleteOneView` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneview.md
- `deleteOneViewField` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneviewfield.md
- `deleteOneViewFilter` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneviewfilter.md
- `deleteOneWorkflow` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneworkflow.md
- `deleteOneWorkflowAutomatedTrigger` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneworkflowautomatedtrigger.md
- `deleteOneWorkflowRun` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneworkflowrun.md
- `deleteOneWorkflowVersion` — Destructive — https://policylayer.com/tools/jdu278-twenty-mcp-server/deleteoneworkflowversion.md
- …and 188 more: https://policylayer.com/tools/jdu278-twenty-mcp-server.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=jdu278-twenty-mcp-server · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/jdu278-twenty-mcp-server