Save a new persistent memory. Use to record important patterns, decisions, bug fixes, user preferences, etc.
AI agents use memory_save to create or update resources in Claude Persistent Memory — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Claude Persistent Memory environment.
This tool creates or modifies persistent data that affects Claude's behavior across sessions. It is reversible (memories can presumably be updated or deleted via other tools), so it is Write rather than Destructive.
From the tool's definition Tool name 'memory_save' and description 'Save a new persistent memory' indicate creation and modification of data.
Documented attack patterns abuse exactly the kind of access memory_save gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Claude Persistent Memory, and nothing reaches the server without passing your rules. This is the rule we recommend for memory_save:
{
"version": "1",
"default": "deny",
"tools": {
"memory_save": {
"limits": [
{
"counter": "memory_save_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}memory_save 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 a new persistent memory. Use to record important patterns, decisions, bug fixes, user preferences, etc. It is categorised as a Write tool in the Claude Persistent Memory MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Claude Persistent Memory MCP server in PolicyLayer and add a rule for memory_save: 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 Claude Persistent Memory. Nothing to install.
memory_save 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 memory_save 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 memory_save. 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.
memory_save is provided by the Claude Persistent Memory MCP server (mimi180306/claude-persistent-memory). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Claude Persistent Memory, 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.
4 Claude Persistent Memory tools catalogued and risk-classified — across an index of 43,000+ MCP servers.