remember · Nexus Core MCP: Risk & Policy

WHAT IT DOES

What remember does on Nexus Core

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

WHY IT NEEDS A POLICY

Why remember needs a policy

This is a straightforward data-write operation. It stores or updates a key-value pair in what is likely a personal knowledge base or fact store. The 'Overwrites existing entry' language indicates modification of existing records, which is classic Write behavior. The optional expiration parameter adds time-bound metadata but does not change the core category.

From the tool's definition 'Save a fact under `key`. Overwrites existing entry.' — the tool creates and modifies data (writes facts to storage), with reversible semantics (overwrite, not deletion). No permanent destruction, no external execution, no financial impact.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

remember Rate-limited

remember 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": {
    "remember": {
      "limits": [
        {
          "counter": "remember_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 Nexus Core, so you can run agents against it safely.

FAQ

Questions about remember

What does the remember tool do? +

Save a fact under key. Overwrites existing entry. Optional ISO-8601 expires. It is categorised as a Write tool in the Nexus Core MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on remember? +

Register the Nexus Core MCP server in PolicyLayer and add a rule for remember: 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 Nexus Core. Nothing to install.

What risk level is remember? +

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

Can I rate-limit remember? +

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

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

remember is provided by the Nexus Core MCP server (noumenon-ai/nexus-core). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.