oauth_v2_user_access · Slack MCP: Risk & Policy

WHAT IT DOES

What oauth_v2_user_access does on Slack

AI agents use oauth_v2_user_access to create or update resources in Slack — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Slack environment.

WHY IT NEEDS A POLICY

Why oauth_v2_user_access needs a policy

An AI agent can call oauth_v2_user_access faster than any human can review — one bad instruction and it creates or modifies resources in Slack by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

oauth_v2_user_access Rate-limited

oauth_v2_user_access 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": {
    "oauth_v2_user_access": {
      "limits": [
        {
          "counter": "oauth_v2_user_access_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 Slack, so you can run agents against it safely.

FAQ

Questions about oauth_v2_user_access

What does the oauth_v2_user_access tool do? +

oauth_v2_user_access. It is categorised as a Write tool in the Slack MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on oauth_v2_user_access? +

Register the Slack MCP server in PolicyLayer and add a rule for oauth_v2_user_access: 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 Slack. Nothing to install.

What risk level is oauth_v2_user_access? +

oauth_v2_user_access is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit oauth_v2_user_access? +

Yes. Add a rate_limit block to the oauth_v2_user_access 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 oauth_v2_user_access completely? +

Set action: deny in the PolicyLayer policy for oauth_v2_user_access. 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 oauth_v2_user_access? +

oauth_v2_user_access is provided by the Slack MCP server (karbassi/slack-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.