v8_heap_snapshot_capture

SERVERJshookmcp SOURCE@jshookmcp/jshook

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-vmoranv-jshookmcp/v8-heap-snapshot-capture.md

WHAT IT DOES

What v8_heap_snapshot_capture does on Jshookmcp

AI agents call v8_heap_snapshot_capture to retrieve information from Jshookmcp without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why v8_heap_snapshot_capture is rated Low

Captures memory snapshots which may expose sensitive data in heap but performs no destructive action.

From the tool's definition Capture a V8 heap snapshot for offline analysis. The snapshot is persisted to artifacts/heap-snapshots/

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs v8_heap_snapshot_capture 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 v8_heap_snapshot_capture, this is the rule to start with:

v8_heap_snapshot_capture Allowed

v8_heap_snapshot_capture is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "v8_heap_snapshot_capture": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Jshookmcp, apply this rule, and every v8_heap_snapshot_capture call is checked against it from then on.

FAQ

Questions about v8_heap_snapshot_capture

What does the v8_heap_snapshot_capture tool do? +

Capture a V8 heap snapshot for offline analysis. The snapshot is persisted to artifacts/heap-snapshots/ (data + sidecar meta) so it survives a server restart; set persist=false to keep it in-memory only. It is categorised as a Read tool in the Jshookmcp MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on v8_heap_snapshot_capture? +

Register the Jshook MCP server in PolicyLayer and add a rule for v8_heap_snapshot_capture: 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.

What risk level is v8_heap_snapshot_capture? +

v8_heap_snapshot_capture is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit v8_heap_snapshot_capture? +

Yes. Add a rate_limit block to the v8_heap_snapshot_capture 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.

How do I block v8_heap_snapshot_capture completely? +

Set action: deny in the PolicyLayer policy for v8_heap_snapshot_capture. 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.

What MCP server provides v8_heap_snapshot_capture? +

v8_heap_snapshot_capture 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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