memory_assemble
Assemble x64 assembly instructions to machine code bytes (x64dbg inline assembler parity). Uses Keystone assembler via koffi FFI (keystone.dll) if available on Windows, with a built-in fallback opcode table for common instructions (NOP, RET, INT3, PUSH/POP, MOV, XOR, ADD, SUB, INC, DEC). assemble...
This record as markdown: /tools/io-github-vmoranv-jshookmcp/memory-assemble.md
What memory_assemble does on Jshookmcp
AI agents use memory_assemble to create or update resources in Jshookmcp, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Jshookmcp environment.
Why memory_assemble is rated Medium
An AI agent can call memory_assemble faster than any human can review: one bad instruction and it creates or modifies resources in Jshookmcp by the hundred, each call as confident as the last.
Attacks that exploit this kind of access
The rule that runs memory_assemble 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 memory_assemble, this is the rule to start with:
memory_assemble stays usable, but capped: an agent stuck in a loop can't make hundreds of changes 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 memory_assemble call is checked against it from then on.
Questions about memory_assemble
Assemble x64 assembly instructions to machine code bytes (x64dbg inline assembler parity). Uses Keystone assembler via koffi FFI (keystone.dll) if available on Windows, with a built-in fallback opcode table for common instructions (NOP, RET, INT3, PUSH/POP, MOV, XOR, ADD, SUB, INC, DEC). assemble: compile ASM string to hex bytes. assemble_at: assemble + write directly to target process memory at address (destructive, audit trail recorded). Separate multiple instructions with semicolons or newlines. Max 256 instructions, 4096 assembled bytes. It is categorised as a Write tool in the Jshookmcp MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Jshook MCP server in PolicyLayer and add a rule for memory_assemble: 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.
memory_assemble is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the memory_assemble 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 memory_assemble. 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.
memory_assemble 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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