This record as markdown: /tools/io-github-ruvnet-claude-flow/emit-event.md
What emit-event does on Claude Flow
AI agents invoke emit-event to trigger actions in Claude Flow. 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 emit-event is rated High
Emitting events is a side-effecting operation that triggers execution in one or more subscribers. The actual blast radius depends on what those subscribers do, which could range from benign logging to spawning agents or modifying state. Given the context of an AI orchestration platform with agent swarms, misuse could cascade into significant unintended operations.
From the tool's definition 'Emit an event to subscribers' — triggers an external operation (event dispatch) whose downstream effects depend on what subscribers are registered and what actions they take.
Attacks that exploit this kind of access
The rule that runs emit-event 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 emit-event, this is the rule to start with:
emit-event 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 Claude Flow, apply this rule, and every emit-event call is checked against it from then on.
Questions about emit-event
Emit an event to subscribers. It is categorised as a Execute tool in the Claude Flow MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Claude Flow MCP server in PolicyLayer and add a rule for emit-event: 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.
emit-event 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 emit-event 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 emit-event. 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.
emit-event 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.
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