Save all memories to the database, overwriting existing ones
AI agents use save-memories to create or update resources in Memory MCP — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Memory MCP environment.
This tool creates or modifies data reversibly—it writes memories to MongoDB, overwriting prior entries. While overwriting occurs, the operation is not irreversible deletion; the old data is replaced, not purged. This fits Write (create/modify reversibly) rather than Destructive.
From the tool's definition Tool description states it 'overwrite[s] existing ones', indicating modification of persisted data via database operations. The tool name 'save-memories' combined with description confirms data persistence and modification capability.
Documented attack patterns abuse exactly the kind of access save-memories gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Memory MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for save-memories:
{
"version": "1",
"default": "deny",
"tools": {
"save-memories": {
"limits": [
{
"counter": "save-memories_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}save-memories 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.
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Save all memories to the database, overwriting existing ones. It is categorised as a Write tool in the Memory MCP MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Memory MCP server in PolicyLayer and add a rule for save-memories: 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 Memory MCP. Nothing to install.
save-memories is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the save-memories 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.
Set action: deny in the PolicyLayer policy for save-memories. 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.
save-memories is provided by the Memory MCP server (jamesanz/memory-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Memory MCP, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
10 Memory MCP tools catalogued and risk-classified — across an index of 43,000+ MCP servers.