Show a memory's change history — the prior versions archived by
AI agents call memory_history to retrieve information from Mem0 Mcp Toggle without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries and displays archived prior versions of a memory, which is a read-only operation that retrieves data with no side effects. It does not create, modify, delete, or execute any operations—it simply presents historical information about how a memory has changed over time.
From the tool's definition Tool name 'memory_history' and description 'Show a memory's change history — the prior versions archived by' indicates retrieval of historical data without modification or deletion.
Attacks that exploit this kind of access
Show a memory's change history — the prior versions archived by. It is categorised as a Read tool in the Mem0 Mcp Toggle MCP Server, which means it retrieves data without modifying state.
Register the Mem0 Mcp Toggle MCP server in PolicyLayer and add a rule for memory_history: 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 Toggle. Nothing to install.
memory_history is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the memory_history 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_history. 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_history is provided by the Mem0 Mcp Toggle MCP server (ost527/mem0-mcp-toggle). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
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