heartbeat_lease · State Trace MCP: Risk & Policy

WHAT IT DOES

What heartbeat_lease does on State Trace

AI agents use heartbeat_lease to create or update resources in State Trace — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your State Trace environment.

WHY IT NEEDS A POLICY

Why heartbeat_lease needs a policy

The tool modifies the state of a task lease (extending its expiry time), which is a reversible write operation with minimal blast radius — it simply prevents a task from timing out and does not delete, execute code, or involve financial transactions.

From the tool's definition Extend the lease on a claimed task so it does not expire while work is in progress

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

heartbeat_lease Rate-limited

heartbeat_lease 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "heartbeat_lease": {
      "limits": [
        {
          "counter": "heartbeat_lease_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches State Trace, so you can run agents against it safely.

FAQ

Questions about heartbeat_lease

What does the heartbeat_lease tool do? +

Extend the lease on a claimed task so it does not expire while work is in progress. It is categorised as a Write tool in the State Trace MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on heartbeat_lease? +

Register the State Trace MCP server in PolicyLayer and add a rule for heartbeat_lease: 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 State Trace. Nothing to install.

What risk level is heartbeat_lease? +

heartbeat_lease is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit heartbeat_lease? +

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

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

heartbeat_lease is provided by the State Trace MCP server (agent-pattern-labs/state-trace). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.