memory_ingest_session · Mementos MCP: Risk & Policy

WHAT IT DOES

What memory_ingest_session does on Mementos

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

WHY IT NEEDS A POLICY

Why memory_ingest_session needs a policy

This tool ingests/writes data (session transcript) into the memory system for processing. It creates new records/memories, which is a reversible write operation. It does not delete data, execute code, or involve financial transactions. The severity is medium because an AI agent could ingest incorrect or sensitive data into the memory system, potentially polluting the knowledge base.

From the tool's definition Submit a session transcript for async memory extraction. Returns job_id to track progress.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

memory_ingest_session Rate-limited

memory_ingest_session 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": {
    "memory_ingest_session": {
      "limits": [
        {
          "counter": "memory_ingest_session_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 Mementos, so you can run agents against it safely.

FAQ

Questions about memory_ingest_session

What does the memory_ingest_session tool do? +

Submit a session transcript for async memory extraction. Returns job_id to track progress. It is categorised as a Write tool in the Mementos MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on memory_ingest_session? +

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

What risk level is memory_ingest_session? +

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

Can I rate-limit memory_ingest_session? +

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

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

memory_ingest_session is provided by the Mementos MCP server (@hasna/mementos). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.