retrieveJwtPublicKey

SERVERFusionauth SOURCE@fusionauth/mcp-api

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

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

WHAT IT DOES

What retrieveJwtPublicKey does on Fusionauth

AI agents call retrieveJwtPublicKey to retrieve information from Fusionauth without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why retrieveJwtPublicKey is rated Low

This tool retrieves public cryptographic keys used for JWT verification. Public keys are non-sensitive (by definition, they are publicly distributed), and the operation has no side effects—it only reads and returns existing configuration data.

From the tool's definition Tool name 'retrieveJwtPublicKey' and description 'Retrieves the Public Key' indicate a query/fetch operation that returns cryptographic key material for JWT verification without modifying any data.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs retrieveJwtPublicKey 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 retrieveJwtPublicKey, this is the rule to start with:

retrieveJwtPublicKey Allowed

retrieveJwtPublicKey is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "retrieveJwtPublicKey": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

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

FAQ

Questions about retrieveJwtPublicKey

What does the retrieveJwtPublicKey tool do? +

Retrieves the Public Key configured for verifying the JSON Web Tokens (JWT) issued by the Login API by the Application Id. OR Retrieves the Public Key configured for verifying JSON Web Tokens (JWT) by the key Id (kid). It is categorised as a Read tool in the Fusionauth MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on retrieveJwtPublicKey? +

Register the Fusionauth MCP server in PolicyLayer and add a rule for retrieveJwtPublicKey: 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 retrieveJwtPublicKey? +

retrieveJwtPublicKey is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit retrieveJwtPublicKey? +

Yes. Add a rate_limit block to the retrieveJwtPublicKey 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 retrieveJwtPublicKey completely? +

Set action: deny in the PolicyLayer policy for retrieveJwtPublicKey. 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 retrieveJwtPublicKey? +

retrieveJwtPublicKey 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

More on Fusionauth, and thousands of servers like it.

This server

All 314 Fusionauth tools →

Across the catalogue

The MCP Attack Database →

Guides

Roll out MCP under one policy →Data exfiltration →MCP token cost →