hooks_worker-cancel
Cancel a running worker Use when native Bash hooks (via Claude Code\
This record as markdown: /tools/io-github-ruvnet-claude-flow/hooks-worker-cancel.md
What hooks_worker-cancel does on Claude Flow
AI agents call hooks_worker-cancel to permanently remove resources in Claude Flow, typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
Why hooks_worker-cancel is rated Critical
Cancelling a running worker is an irreversible action: any in-progress computation, queued tasks, or partial results are discarded and cannot be recovered. This matches the Destructive category (irreversible termination of an active process). Severity is high because misuse by an AI agent could prematurely kill critical orchestration workers in an enterprise environment, disrupting workflows.
From the tool's definition 'Cancel a running worker' — cancelling an active worker terminates its execution irreversibly, losing in-progress work and state
Attacks that exploit this kind of access
The rule that runs hooks_worker-cancel safely
PolicyLayer is an MCP gateway: it sits between your AI agents and Claude Flow, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For hooks_worker-cancel, this is the rule to start with:
hooks_worker-cancel is removed from the agent's tool list entirely, so the agent never calls it. The rest of the server keeps working.
The button opens the PolicyLayer dashboard: create your workspace, connect Claude Flow, apply this rule, and every hooks_worker-cancel call is checked against it from then on.
Questions about hooks_worker-cancel
Cancel a running worker Use when native Bash hooks (via Claude Code\. It is categorised as a Destructive tool in the Claude Flow MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Claude Flow MCP server in PolicyLayer and add a rule for hooks_worker-cancel: 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 Claude Flow. Nothing to install.
hooks_worker-cancel is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the hooks_worker-cancel 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 hooks_worker-cancel. 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.
hooks_worker-cancel is provided by the Claude Flow MCP server (claude-flow). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
More on Claude Flow, and thousands of servers like it.
Across the catalogue