supersede_memory · OpenMemBrain MCP: Risk & Policy

WHAT IT DOES

What supersede_memory does on OpenMemBrain

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

WHY IT NEEDS A POLICY

Why supersede_memory needs a policy

This is a Write action because it modifies the state of an existing memory object (changing its status from active to superseded) in a reversible manner. It does not retrieve data (Read), execute arbitrary code (Execute), permanently delete records (Destructive), or involve financial impact (Financial).

From the tool's definition Tool description states 'Mark an existing memory as superseded'—a metadata state change operation. The tool modifies memory records reversibly (memories are 'excluded from retrieval but preserved in audit history'), not deleted.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

supersede_memory Rate-limited

supersede_memory 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": {
    "supersede_memory": {
      "limits": [
        {
          "counter": "supersede_memory_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 OpenMemBrain, so you can run agents against it safely.

FAQ

Questions about supersede_memory

What does the supersede_memory tool do? +

Mark an existing memory as superseded. Superseded memories are excluded from retrieval but preserved in audit history. It is categorised as a Write tool in the OpenMemBrain MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on supersede_memory? +

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

What risk level is supersede_memory? +

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

Can I rate-limit supersede_memory? +

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

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

supersede_memory is provided by the OpenMemBrain MCP server (mohamadalhusseinie/openmembrain). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.