Cross-post a status from one federated bundle to another via the shared transform library. Requires idempotency_key — duplicate keys within 7 days return the cached result. on_publish trigger queues with a 60-second delay + cancel notification (no fake undo-after-publish).
AI agents use crow_crosspost to create or update resources in Crow — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Crow environment.
This tool publishes/creates content by cross-posting a status across federated bundles. It is a Write operation (creates a new post in another bundle). The 60-second delay with cancel notification and idempotency key suggest it is reversible within a short window, but the primary action is content creation. No financial, destructive, or arbitrary code execution is involved.
From the tool's definition Cross-post a status from one federated bundle to another via the shared transform library
Documented attack patterns abuse exactly the kind of access crow_crosspost 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 crow_crosspost:
{
"version": "1",
"default": "deny",
"tools": {
"crow_crosspost": {
"limits": [
{
"counter": "crow_crosspost_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}crow_crosspost 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.
Free to start. No card required.
Cross-post a status from one federated bundle to another via the shared transform library. Requires idempotency_key — duplicate keys within 7 days return the cached result. on_publish trigger queues with a 60-second delay + cancel notification (no fake undo-after-publish). It is categorised as a Write tool in the Crow MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Crow MCP server in PolicyLayer and add a rule for crow_crosspost: 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.
crow_crosspost 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 crow_crosspost 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 crow_crosspost. 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.
crow_crosspost 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.