sandbox_exec
Task #48 — run a shell command THROUGH the deny-by-default
This record as markdown: /tools/verimem/sandbox-exec.md
What sandbox_exec does on Verimem
AI agents invoke sandbox_exec to trigger actions in Verimem. 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 sandbox_exec is rated High
This tool executes shell commands, which is the definition of the Execute category. Shell command execution can have wide-ranging side effects depending on the arguments provided (file operations, network calls, process spawning, etc.).
From the tool's definition Tool name 'sandbox_exec' combined with description 'run a shell command' explicitly indicates execution of arbitrary shell commands. The phrase 'THROUGH the deny-by-default' suggests this bypasses or operates within a security sandbox.
Attacks that exploit this kind of access
The rule that runs sandbox_exec safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Verimem, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For sandbox_exec, this is the rule to start with:
sandbox_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 Verimem, apply this rule, and every sandbox_exec call is checked against it from then on.
Questions about sandbox_exec
Task #48 — run a shell command THROUGH the deny-by-default. It is categorised as a Execute tool in the Verimem MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Verimem MCP server in PolicyLayer and add a rule for sandbox_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 Verimem. Nothing to install.
sandbox_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 sandbox_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 sandbox_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.
sandbox_exec is provided by the Verimem MCP server (aureliocpr-ctrl/verimem). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
More on Verimem, and thousands of servers like it.
Across the catalogue