createApplicationRoleWithId
Creates a new role for an application. You must specify the Id of the application you are creating the role for. You can optionally specify an Id for the role inside the ApplicationRole object itself, if not provided one will be generated.
This record as markdown: /tools/io-fusionauth-mcp-api/createapplicationrolewithid.md
What createApplicationRoleWithId does on Fusionauth
AI agents use createApplicationRoleWithId 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.
Why createApplicationRoleWithId is rated Medium
This tool creates a new application role, which is a reversible write operation (the role can be deleted later). It modifies application configuration by adding a new role but does not execute arbitrary code, delete data, or move money. The moderate severity reflects that creating unauthorized roles could grant unintended permissions to users, but the impact is confined to role management within a single application.
From the tool's definition Tool description explicitly states 'Creates a new role for an application', indicating irreversible creation of a new resource.
Attacks that exploit this kind of access
The rule that runs createApplicationRoleWithId 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 createApplicationRoleWithId, this is the rule to start with:
createApplicationRoleWithId 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.
The button opens the PolicyLayer dashboard: create your workspace, connect Fusionauth, apply this rule, and every createApplicationRoleWithId call is checked against it from then on.
Questions about createApplicationRoleWithId
Creates a new role for an application. You must specify the Id of the application you are creating the role for. You can optionally specify an Id for the role inside the ApplicationRole object itself, if not provided one will be generated. 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.
Register the Fusionauth MCP server in PolicyLayer and add a rule for createApplicationRoleWithId: 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.
createApplicationRoleWithId is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the createApplicationRoleWithId 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.
Set action: deny in the PolicyLayer policy for createApplicationRoleWithId. 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.
createApplicationRoleWithId 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.
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