AI agents use bpmn_add_gateway 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 a new gateway element within a BPMN diagram, which modifies the diagram structure reversibly. It is a Write operation because it adds/creates data (a gateway node) that can be edited or removed. While it manipulates process definitions, there is no execution of actual business processes, no irreversible deletion, and no financial impact.
From the tool's definition Tool name 'bpmn_add_gateway' and description 'Add a gateway (decision point) to the process' indicate creation of a new process element within a BPMN diagram.
Documented attack patterns abuse exactly the kind of access bpmn_add_gateway 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_add_gateway:
{
"version": "1",
"default": "deny",
"tools": {
"bpmn_add_gateway": {
"limits": [
{
"counter": "bpmn_add_gateway_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
} bpmn_add_gateway 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.
Add a gateway (decision point) to the process. 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_add_gateway: 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_add_gateway 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_add_gateway 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_add_gateway. 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_add_gateway 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.