signal_emit

Emit a signal from a node in the EDITED scene, firing its connected callables now. DESTRUCTIVE (edit-time side effects) — gated by confirmation. Args use the tagged-Variant convention.

SERVERBreakpoint SOURCEbreakpoint-mcp

High RISK CLASS

Category Execute

Parameters 42 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/breakpoint-mcp/signal-emit.md

WHAT IT DOES

What signal_emit does on Breakpoint

AI agents invoke signal_emit to trigger actions in Breakpoint. 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.

Parameter	Type	Required	Description
`args`	array	—	Signal arguments (JSON scalars or __type__-tagged Variants)
`path`	string	Yes	Node path relative to the scene root
`signal`	string	Yes	Signal name
`confirm`	boolean	—	Auto-approve this destructive action (skip the confirmation prompt)

Parameters from the server's own tool schema.

RISK

Why signal_emit is rated High

The tool triggers signal emission which fires connected callables immediately, causing real-time side effects in the edited scene. While the description labels it DESTRUCTIVE, it actually executes code (callables) rather than irreversibly deleting/overwriting data.

From the tool's definition "Emit a signal from a node in the EDITED scene, firing its connected callables now. DESTRUCTIVE (edit-time side effects) — gated by confirmation."

Risk signalsAccepts file system path (path)

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs signal_emit safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Breakpoint, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For signal_emit, this is the rule to start with:

signal_emit Rate-limited

signal_emit 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "signal_emit": {
      "limits": [
        {
          "counter": "signal_emit_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL → Instant setup, no code required.

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

FAQ

Questions about signal_emit

What does the signal_emit tool do? +

Emit a signal from a node in the EDITED scene, firing its connected callables now. DESTRUCTIVE (edit-time side effects) — gated by confirmation. Args use the tagged-Variant convention. It is categorised as a Execute tool in the Breakpoint MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

What parameters does signal_emit accept? +

signal_emit accepts 4 parameters: args, path, signal, confirm. Required: path, signal. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on signal_emit? +

Register the Breakpoint MCP server in PolicyLayer and add a rule for signal_emit: 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 Breakpoint. Nothing to install.

What risk level is signal_emit? +

signal_emit is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit signal_emit? +

Yes. Add a rate_limit block to the signal_emit 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 signal_emit completely? +

Set action: deny in the PolicyLayer policy for signal_emit. 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 signal_emit? +

signal_emit is provided by the Breakpoint MCP server (breakpoint-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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