AI agents use touch_memory to create or update resources in Mnemex — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Mnemex environment.
This tool modifies an existing memory's decay/timestamp state by reinforcing it, which is a reversible write operation. It doesn't delete data, execute code, or have financial implications. The blast radius is low since it only resets decay timers on existing memories.
From the tool's definition Reinforce memory to reset decay
Documented attack patterns abuse exactly the kind of access touch_memory gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Mnemex, and nothing reaches the server without passing your rules. This is the rule we recommend for touch_memory:
{
"version": "1",
"default": "deny",
"tools": {
"touch_memory": {
"limits": [
{
"counter": "touch_memory_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}touch_memory 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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Reinforce memory to reset decay. It is categorised as a Write tool in the Mnemex MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Mnemex MCP server in PolicyLayer and add a rule for touch_memory: 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 Mnemex. Nothing to install.
touch_memory 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 touch_memory 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 touch_memory. 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.
touch_memory is provided by the Mnemex MCP server (prefrontal-systems/cortexgraph). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 13 Mnemex tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
13 Mnemex tools catalogued and risk-classified — across an index of 42,500+ MCP servers.