append-to-stream · mem0 MCP Server MCP: Risk & Policy

WHAT IT DOES

What append-to-stream does on mem0 MCP Server

AI agents use append-to-stream to create or update resources in mem0 MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your mem0 MCP Server environment.

WHY IT NEEDS A POLICY

Why append-to-stream needs a policy

The name 'append-to-stream' strongly implies a write operation — adding new content to an existing stream — which is reversible (the stream can be modified or deleted). With no description to confirm, confidence is moderate. Given sibling tools include 'delete-stream' and 'create-memory-stream', this tool likely handles appending memories to an existing stream, placing it in the Write category.

From the tool's definition Tool name 'append-to-stream' suggests adding data to an existing memory stream; description is empty and uninformative.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

append-to-stream Rate-limited

append-to-stream 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": {
    "append-to-stream": {
      "limits": [
        {
          "counter": "append-to-stream_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 mem0 MCP Server, so you can run agents against it safely.

FAQ

Questions about append-to-stream

What does the append-to-stream tool do? +

append-to-stream. It is categorised as a Write tool in the mem0 MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on append-to-stream? +

Register the mem0 MCP Server MCP server in PolicyLayer and add a rule for append-to-stream: 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 mem0 MCP Server. Nothing to install.

What risk level is append-to-stream? +

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

Can I rate-limit append-to-stream? +

Yes. Add a rate_limit block to the append-to-stream 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 append-to-stream completely? +

Set action: deny in the PolicyLayer policy for append-to-stream. 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 append-to-stream? +

append-to-stream is provided by the mem0 MCP Server MCP server (sadiuysal/mem0-mcp-server-ts). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.