nemu_new_byte_array
Wrap base64 bytes as a JNI jbyteArray handle to pass as an argument into call_jni_export (e.g. the plaintext a signing routine consumes). Returns the handle.
This record as markdown: /tools/io-github-vmoranv-jshookmcp/nemu-new-byte-array.md
What nemu_new_byte_array does on Jshookmcp
AI agents invoke nemu_new_byte_array 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 nemu_new_byte_array is rated High
Creates JNI handles for passing data to native code execution routines, enabling arbitrary native function invocation.
From the tool's definition Wrap base64 bytes as JNI jbyteArray handle to pass into call_jni_export
Attacks that exploit this kind of access
The rule that runs nemu_new_byte_array 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 nemu_new_byte_array, this is the rule to start with:
nemu_new_byte_array 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 nemu_new_byte_array call is checked against it from then on.
Questions about nemu_new_byte_array
Wrap base64 bytes as a JNI jbyteArray handle to pass as an argument into call_jni_export (e.g. the plaintext a signing routine consumes). Returns the handle. 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 nemu_new_byte_array: 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.
nemu_new_byte_array 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 nemu_new_byte_array 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 nemu_new_byte_array. 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.
nemu_new_byte_array 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.
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