AI agents use mono_transfer to commit financial operations through Monospay — usually the final step of a payment, billing, or trading workflow. A call moves real money.
This tool directly moves money (USDC on Base blockchain) from one agent/account to another. It commits financial obligations and transfers value irreversibly. This is the most severe category (Financial) in the classification hierarchy. The requirement for a private key indicates direct control over fund movement.
From the tool's definition Tool name is 'mono_transfer' and description states 'Send money to another agent. Requires MONO_PRIVATE_KEY.' The server description explicitly contextualizes this as 'Pay per MCP tool call in USDC on Base.' The combination of 'Send money' with cryptocurrency…
Attacks that exploit this kind of access
Send money to another agent. Requires MONO_PRIVATE_KEY. It is categorised as a Financial tool in the Monospay MCP Server, which means it involves financial transactions. Block by default and require explicit approval.
Register the Monospay MCP server in PolicyLayer and add a rule for mono_transfer: 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 Monospay. Nothing to install.
mono_transfer is a Financial tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the mono_transfer 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 mono_transfer. 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.
mono_transfer is provided by the Monospay MCP server (monospay/monospay). 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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