Approve TRC-20 spending allowance. Signs and broadcasts on-chain. Requires TRON_PRIVATE_KEY.
AI agents use approve_trc20 to commit financial operations through MERX - TRON Resource Exchange — usually the final step of a payment, billing, or trading workflow. A call moves real money.
Approving a TRC-20 spending allowance grants a third-party contract the right to transfer tokens from the user's wallet up to the approved amount. This is a financial operation with on-chain consequences — a malicious or mistaken approval can result in complete loss of tokens. It signs and broadcasts a real blockchain transaction, making it irreversible and financially consequential.
From the tool's definition Approve TRC-20 spending allowance. Signs and broadcasts on-chain. Requires TRON_PRIVATE_KEY.
Attacks that exploit this kind of access
Approve TRC-20 spending allowance. Signs and broadcasts on-chain. Requires TRON_PRIVATE_KEY. It is categorised as a Financial tool in the MERX - TRON Resource Exchange MCP Server, which means it involves financial transactions. Block by default and require explicit approval.
Register the MERX - TRON Resource Exchange MCP server in PolicyLayer and add a rule for approve_trc20: 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 MERX - TRON Resource Exchange. Nothing to install.
approve_trc20 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 approve_trc20 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 approve_trc20. 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.
approve_trc20 is provided by the MERX - TRON Resource Exchange MCP server (Hovsteder/merx-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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