Upload an image/video and publish it as a status. Uploads via POST /api/v2/media (async processing) then POST /api/v1/statuses. Pass file_path OR file_base64+filename. Rate-limited: 10/hour.
AI agents use mastodon_post_with_media 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 creates and publishes social media content (a status with attached media), which is a reversible write operation. While the content publication could have reputational implications, it is not destructive (can be deleted), not financial, and not code execution.
From the tool's definition The tool 'mastodon_post_with_media' performs POST operations to upload media and publish a status via 'POST /api/v2/media' and 'POST /api/v1/statuses', which creates new content on the Mastodon platform.
Documented attack patterns abuse exactly the kind of access mastodon_post_with_media 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 mastodon_post_with_media:
{
"version": "1",
"default": "deny",
"tools": {
"mastodon_post_with_media": {
"limits": [
{
"counter": "mastodon_post_with_media_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}mastodon_post_with_media 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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Upload an image/video and publish it as a status. Uploads via POST /api/v2/media (async processing) then POST /api/v1/statuses. Pass file_path OR file_base64+filename. Rate-limited: 10/hour. 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 mastodon_post_with_media: 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.
mastodon_post_with_media 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 mastodon_post_with_media 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 mastodon_post_with_media. 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.
mastodon_post_with_media 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.