Trigger a pict-rs prune of remote media. Exposes the admin purge endpoint; deletes cached media for federated posts older than N days. Rate-limited: 2/hour.
AI agents call lemmy_media_prune to permanently remove resources in Crow — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
This tool triggers deletion of cached media without a reversible way to recover it. Although the blast radius is somewhat contained (deletion only affects federated post cache older than N days, not primary user data), the irreversibility and admin-level access to purge operations place it in the Destructive category.
From the tool's definition 'deletes cached media for federated posts older than N days' — the tool explicitly performs irreversible deletion of data
Risk signalsAdmin/system-level operation
Documented attack patterns abuse exactly the kind of access lemmy_media_prune gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Crow, and nothing reaches the server without passing your rules. This is the rule we recommend for lemmy_media_prune:
{
"version": "1",
"default": "deny",
"hide": [
"lemmy_media_prune"
]
}lemmy_media_prune disappears from the agent's tool list entirely, and any attempt to call it is denied. The rest of the server keeps working.
Free to start. No card required.
Trigger a pict-rs prune of remote media. Exposes the admin purge endpoint; deletes cached media for federated posts older than N days. Rate-limited: 2/hour. It is categorised as a Destructive tool in the Crow MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the Crow MCP server in PolicyLayer and add a rule for lemmy_media_prune: 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 Crow. Nothing to install.
lemmy_media_prune is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the lemmy_media_prune 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 lemmy_media_prune. 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.
lemmy_media_prune is provided by the Crow MCP server (kh0pper/crow). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Crow, 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.
576 Crow tools catalogued and risk-classified — across an index of 43,000+ MCP servers.