updateRegistrationWithId

Updates the registration for the user with the given Id and the application defined in the request.

SERVERFusionauth SOURCE@fusionauth/mcp-api

Medium RISK CLASS

Category Write

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-fusionauth-mcp-api/updateregistrationwithid.md

WHAT IT DOES

What updateRegistrationWithId does on Fusionauth

AI agents use updateRegistrationWithId 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.

RISK

Why updateRegistrationWithId is rated Medium

This tool modifies user registration information, which is a Write action (creates or modifies data reversibly). While not destructive, unauthorized updates to user registrations could have significant impact on user access and authentication state across applications, warranting high severity.

From the tool's definition Tool name 'updateRegistrationWithId' and description 'Updates the registration for the user' indicate modification of user registration data, which is a reversible write operation.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs updateRegistrationWithId safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Fusionauth, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For updateRegistrationWithId, this is the rule to start with:

updateRegistrationWithId Rate-limited

updateRegistrationWithId stays usable, but capped: an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "updateRegistrationWithId": {
      "limits": [
        {
          "counter": "updateregistrationwithid_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Fusionauth, apply this rule, and every updateRegistrationWithId call is checked against it from then on.

FAQ

Questions about updateRegistrationWithId

What does the updateRegistrationWithId tool do? +

Updates the registration for the user with the given Id and the application defined in the request. It is categorised as a Write tool in the Fusionauth MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on updateRegistrationWithId? +

Register the Fusionauth MCP server in PolicyLayer and add a rule for updateRegistrationWithId: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Fusionauth. Nothing to install.

What risk level is updateRegistrationWithId? +

updateRegistrationWithId is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit updateRegistrationWithId? +

Yes. Add a rate_limit block to the updateRegistrationWithId rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block updateRegistrationWithId completely? +

Set action: deny in the PolicyLayer policy for updateRegistrationWithId. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides updateRegistrationWithId? +

updateRegistrationWithId is provided by the Fusionauth MCP server (@fusionauth/mcp-api). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

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