create_oauth_client · Posterly MCP: Risk & Policy

WHAT IT DOES

What create_oauth_client does on Posterly

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

WHY IT NEEDS A POLICY

Why create_oauth_client needs a policy

This tool creates OAuth application credentials and configuration, which is reversible data modification (credentials can be rotated/revoked). The 'WRITE' label in the description confirms this is a creation/modification operation.

From the tool's definition Tool description explicitly states 'Create a public OAuth 2.1 + PKCE developer client' and is marked 'WRITE'. Creates OAuth credentials and configuration artifacts.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

create_oauth_client Rate-limited

create_oauth_client 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": {
    "create_oauth_client": {
      "limits": [
        {
          "counter": "create_oauth_client_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 Posterly, so you can run agents against it safely.

FAQ

Questions about create_oauth_client

What does the create_oauth_client tool do? +

Create a public OAuth 2.1 + PKCE developer client. WRITE: confirm app name, redirect URIs, and scopes with the user before calling. It is categorised as a Write tool in the Posterly MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on create_oauth_client? +

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

What risk level is create_oauth_client? +

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

Can I rate-limit create_oauth_client? +

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

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

create_oauth_client is provided by the Posterly MCP server (posterly-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.