dart_call_function
Execute a Dart function in the ARM64 emulator by address or name, with simplified runtime (mock built-ins, tagged pointers). Pass a sessionId to reuse the cached snapshot; the executor still initialises fresh CPU state per call (register state is never shared across calls).
This record as markdown: /tools/io-github-vmoranv-jshookmcp/dart-call-function.md
What dart_call_function does on Jshookmcp
AI agents invoke dart_call_function to trigger actions in Jshookmcp. 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 dart_call_function is rated High
Executes arbitrary Dart functions in an emulator with direct memory/register manipulation, enabling code execution with unpredictable side effects.
From the tool's definition Execute a Dart function in the ARM64 emulator by address or name
Attacks that exploit this kind of access
The rule that runs dart_call_function safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Jshookmcp, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For dart_call_function, this is the rule to start with:
dart_call_function 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 Jshookmcp, apply this rule, and every dart_call_function call is checked against it from then on.
Questions about dart_call_function
Execute a Dart function in the ARM64 emulator by address or name, with simplified runtime (mock built-ins, tagged pointers). Pass a sessionId to reuse the cached snapshot; the executor still initialises fresh CPU state per call (register state is never shared across calls). It is categorised as a Execute tool in the Jshookmcp MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Jshook MCP server in PolicyLayer and add a rule for dart_call_function: 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 Jshookmcp. Nothing to install.
dart_call_function 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 dart_call_function 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 dart_call_function. 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.
dart_call_function is provided by the Jshook MCP server (@jshookmcp/jshook). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
More on Jshook, and thousands of servers like it.
Across the catalogue