Fetch the UGF login nonce for a wallet address. Agent signs this nonce externally then calls ugf_authenticate.
AI agents call ugf_get_nonce to retrieve information from Universal Gas Framework MCP Server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool performs a simple query/retrieval of a nonce value. It has no destructive, financial, or code execution capabilities. The nonce itself is a public value used for authentication flow. While the nonce will be signed and used for authentication, the fetch operation itself is purely informational.
From the tool's definition Tool description states 'Fetch the UGF login nonce for a wallet address.' The verb 'Fetch' and the action of retrieving a nonce are data retrieval operations with no side effects.
Attacks that exploit this kind of access
Fetch the UGF login nonce for a wallet address. Agent signs this nonce externally then calls ugf_authenticate. It is categorised as a Read tool in the Universal Gas Framework MCP Server MCP Server, which means it retrieves data without modifying state.
Register the Universal Gas Framework MCP Server MCP server in PolicyLayer and add a rule for ugf_get_nonce: 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 Universal Gas Framework MCP Server. Nothing to install.
ugf_get_nonce 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 ugf_get_nonce 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 ugf_get_nonce. 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.
ugf_get_nonce is provided by the Universal Gas Framework MCP Server MCP server (tychiwallet/ugf-mcp). 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.
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