# updateUserFamilyWithId

Updates a family with a given Id. OR Adds a user to an existing family. The family Id must be specified.

Agent View of the PolicyLayer registry record for `updateUserFamilyWithId`. HTML page: https://policylayer.com/tools/io-fusionauth-mcp-api/updateuserfamilywithid

## Facts

- Tool: `updateUserFamilyWithId`
- Server: Fusionauth (`@fusionauth/mcp-api`) — https://policylayer.com/tools/io-fusionauth-mcp-api.md
- Install: `npx -y @fusionauth/mcp-api`
- Homepage: https://github.com/FusionAuth/fusionauth-mcp-api
- 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": "updateUserFamilyWithId",
    "arguments": {}
  }
}
```

## Why updateUserFamilyWithId is rated Medium

This tool modifies user family relationships and data, which are reversible write operations. It does not delete data (ruling out Destructive), does not execute arbitrary code (ruling out Execute), and does not move money (ruling out Financial).

From the tool's own definition: "Tool name contains 'update' and 'Add'; description states 'Updates a family' and 'Adds a user to an existing family'. These are reversible modification operations."

## Use case

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

## Recommended policy (PolicyLayer)

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

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

## Other tools on Fusionauth (313)

- `deleteAPIKeyWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteapikeywithid.md
- `deleteApplicationRoleWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteapplicationrolewithid.md
- `deleteApplicationWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteapplicationwithid.md
- `deleteConnectorWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteconnectorwithid.md
- `deleteConsentWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteconsentwithid.md
- `deleteEmailTemplateWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteemailtemplatewithid.md
- `deleteEntityGrantWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteentitygrantwithid.md
- `deleteEntityTypePermissionWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteentitytypepermissionwithid.md
- `deleteEntityTypeWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteentitytypewithid.md
- `deleteEntityWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteentitywithid.md
- `deleteFormFieldWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteformfieldwithid.md
- `deleteFormWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteformwithid.md
- `deleteGroupMembersWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletegroupmemberswithid.md
- `deleteGroupWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletegroupwithid.md
- `deleteIdentityProviderWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteidentityproviderwithid.md
- `deleteIPAccessControlListWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteipaccesscontrollistwithid.md
- `deleteJwtRefresh` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletejwtrefresh.md
- `deleteKeyWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletekeywithid.md
- `deleteLambdaWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletelambdawithid.md
- `deleteMessageTemplateWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletemessagetemplatewithid.md
- `deleteMessengerWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletemessengerwithid.md
- `deleteOAuthScopeWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteoauthscopewithid.md
- `deleteTenantWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletetenantwithid.md
- `deleteThemeWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deletethemewithid.md
- `deleteUserActionReasonWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteuseractionreasonwithid.md
- `deleteUserActionWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteuseractionwithid.md
- `deleteUserBulk` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteuserbulk.md
- `deleteUserLinkWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteuserlinkwithid.md
- `deleteUserRegistrationWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteuserregistrationwithid.md
- `deleteUserTwoFactorWithId` — Destructive — https://policylayer.com/tools/io-fusionauth-mcp-api/deleteusertwofactorwithid.md
- …and 283 more: https://policylayer.com/tools/io-fusionauth-mcp-api.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`

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