Save the current diagram to its file (error if no filename set)
AI agents use save to create or update resources in MCP-BPMN Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MCP-BPMN Server environment.
The save operation creates or modifies files on disk, fitting the Write category (creates or modifies data reversibly). Severity is medium because file overwrites could lose previous versions if not version-controlled, but the operation is reversible via undo/restore mechanisms typical in BPMN editors.
From the tool's definition Tool is named 'save' and described as 'Save the current diagram to its file', which persists modified data to disk. This is a write operation that modifies the file system with diagram content.
Documented attack patterns abuse exactly the kind of access save gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and MCP-BPMN Server, and nothing reaches the server without passing your rules. This is the rule we recommend for save:
{
"version": "1",
"default": "deny",
"tools": {
"save": {
"limits": [
{
"counter": "save_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}save 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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Save the current diagram to its file (error if no filename set). It is categorised as a Write tool in the MCP-BPMN Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the MCP-BPMN Server MCP server in PolicyLayer and add a rule for save: 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 MCP-BPMN Server. Nothing to install.
save 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 save 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 save. 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.
save is provided by the MCP-BPMN Server MCP server (oisee/mcp-bpmn). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from MCP-BPMN Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
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41 MCP-BPMN Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.