Void a transaction. POST /transactions/{transactionId}/void. Only works before settlement; after settlement use refund_transaction instead.
AI agents use void_transaction to commit financial operations through Rebillia MCP Server — usually the final step of a payment, billing, or trading workflow. A call moves real money.
Voiding a transaction cancels a financial transaction before it settles, directly impacting payment flows and revenue. This is a financial operation that reverses a monetary commitment, making it Financial category. The blast radius is critical because misuse could void legitimate customer payments or orders at scale.
From the tool's definition Void a transaction. POST /transactions/{transactionId}/void. Only works before settlement; after settlement use refund_transaction instead.
Attacks that exploit this kind of access
Void a transaction. POST /transactions/{transactionId}/void. Only works before settlement; after settlement use refund_transaction instead. It is categorised as a Financial tool in the Rebillia MCP Server MCP Server, which means it involves financial transactions. Block by default and require explicit approval.
Register the Rebillia MCP Server MCP server in PolicyLayer and add a rule for void_transaction: 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 Rebillia MCP Server. Nothing to install.
void_transaction 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 void_transaction 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 void_transaction. 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.
void_transaction is provided by the Rebillia MCP Server MCP server (rhinosaas/rebillia-mcp-server). 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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