Publish a Hive message. to_urn=null for broadcast.
AI agents invoke hive.message_publish to trigger actions in Mnemos. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.
Publishing a message triggers an external operation (message delivery, potentially to multiple recipients via broadcast) whose effects depend on the arguments (recipient URN, message content). This is an outbound action with side effects beyond simple data storage, making Execute the most appropriate category.
From the tool's definition 'Publish a Hive message' and 'to_urn=null for broadcast' — triggers external message delivery/fanout to agents
Documented attack patterns abuse exactly the kind of access hive.message_publish gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Mnemos, and nothing reaches the server without passing your rules. This is the rule we recommend for hive.message_publish:
{
"version": "1",
"default": "deny",
"tools": {
"hive.message_publish": {
"limits": [
{
"counter": "hive.message_publish_rate",
"window": "minute",
"max": 10,
"scope": "grant"
}
]
}
}
}hive.message_publish stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
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Publish a Hive message. to_urn=null for broadcast. It is categorised as a Execute tool in the Mnemos MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
Register the Mnemos MCP server in PolicyLayer and add a rule for hive.message_publish: 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 Mnemos. Nothing to install.
hive.message_publish is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the hive.message_publish 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 hive.message_publish. 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.
hive.message_publish is provided by the Mnemos MCP server (ncz-os/mnemos). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Mnemos, 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.
15 Mnemos tools catalogued and risk-classified — across an index of 43,000+ MCP servers.