add_membership · Redmine MCP: Risk & Policy | PolicyLayer

WHAT IT DOES

What add_membership does on Redmine

AI agents use add_membership to create or update resources in Redmine — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Redmine environment.

WHY IT NEEDS A POLICY

Why add_membership needs a policy

This tool creates or assigns memberships (user/group to project mappings) with role definitions. While it modifies project access control, the operation is reversible—memberships can be removed. It does not delete data or execute arbitrary code, so it falls under Write rather than Destructive or Execute.

From the tool's definition Tool name 'add_membership' and description 'Add a user or group to a project with specified roles' indicate the tool creates a new membership relationship, which is a reversible data modification.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

add_membership Rate-limited

add_membership 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "add_membership": {
      "limits": [
        {
          "counter": "add_membership_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Redmine, so you can run agents against it safely.

FAQ

Questions about add_membership

What does the add_membership tool do? +

Add a user or group to a project with specified roles. It is categorised as a Write tool in the Redmine MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on add_membership? +

Register the Redmine MCP server in PolicyLayer and add a rule for add_membership: 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 Redmine. Nothing to install.

What risk level is add_membership? +

add_membership is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit add_membership? +

Yes. Add a rate_limit block to the add_membership 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.

How do I block add_membership completely? +

Set action: deny in the PolicyLayer policy for add_membership. 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.

What MCP server provides add_membership? +

add_membership is provided by the Redmine MCP server (yenpu/redmine-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.