AI agents use bpmn_connect 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.
This tool creates new connections (sequence flows) between existing BPMN elements, which is a reversible modification of diagram data. While it changes the diagram's structure, the action is not destructive (can be undone by removing the connection) and does not delete or overwrite data.
From the tool's definition The tool 'bpmn_connect' connects two elements with a sequence flow, which modifies the BPMN diagram structure by adding or establishing relationships between diagram elements. This is a creation/modification action on the diagram's graph structure.
Documented attack patterns abuse exactly the kind of access bpmn_connect 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 bpmn_connect:
{
"version": "1",
"default": "deny",
"tools": {
"bpmn_connect": {
"limits": [
{
"counter": "bpmn_connect_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
} bpmn_connect 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.
Connect two elements with a sequence flow. 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 bpmn_connect: 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.
bpmn_connect 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 bpmn_connect 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 bpmn_connect. 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.
bpmn_connect 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.
Free to start. No card required.
41 MCP-BPMN Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.