This record as markdown: /tools/ahmeth4n-renef-mcp/renef-exec.md
What renef_exec does on Renef
AI agents invoke renef_exec to trigger actions in Renef. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.
Why renef_exec is rated High
This tool runs arbitrary Lua code inside a target Android process. An AI agent could inject any logic — read/write memory, hook functions, exfiltrate data, crash the process, or perform destructive operations. The blast radius is critical because execution is unbounded and operates inside a live process with potentially elevated (root) privileges given the server context.
From the tool's definition "Executes Lua code in the target process"
Attacks that exploit this kind of access
The rule that runs renef_exec safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Renef, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For renef_exec, this is the rule to start with:
renef_exec stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect Renef, apply this rule, and every renef_exec call is checked against it from then on.
Questions about renef_exec
Executes Lua code in the target process. It is categorised as a Execute tool in the Renef MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Renef MCP server in PolicyLayer and add a rule for renef_exec: 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 Renef. Nothing to install.
renef_exec is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the renef_exec 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 renef_exec. 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.
renef_exec is provided by the Renef MCP server (ahmeth4n/renef-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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