GET /api/hub/pubkey — verify hub-signed payloads.
AI agents call kya_hub_pubkey to retrieve information from UMBRAXON/kya Hub without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves a public key for the purpose of verifying signatures on hub-signed payloads. It performs cryptographic verification (a read-only operation) without creating, modifying, deleting, or executing any code. The low severity reflects minimal blast radius: misuse would yield false verification results but cannot corrupt data, move funds, or trigger destructive actions.
From the tool's definition Tool description states 'GET /api/hub/pubkey — verify hub-signed payloads.' GET is a read operation; verification of cryptographic signatures is a lookup/validation action with no side effects.
Attacks that exploit this kind of access
GET /api/hub/pubkey — verify hub-signed payloads. It is categorised as a Read tool in the UMBRAXON/kya Hub MCP Server, which means it retrieves data without modifying state.
Register the UMBRAXON/kya Hub MCP server in PolicyLayer and add a rule for kya_hub_pubkey: 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 UMBRAXON/kya Hub. Nothing to install.
kya_hub_pubkey is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the kya_hub_pubkey 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 kya_hub_pubkey. 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.
kya_hub_pubkey is provided by the UMBRAXON/kya Hub MCP server (umbraxon/kya-hub). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
Teams ship this data inside their own products. See what a licence covers →