myob_oauth_refresh · MYOB Codex MCP: Risk & Policy

WHAT IT DOES

What myob_oauth_refresh does on MYOB Codex MCP

AI agents invoke myob_oauth_refresh to trigger actions in MYOB Codex MCP. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why myob_oauth_refresh needs a policy

This tool triggers an external OAuth token refresh operation against MYOB's authentication servers. It executes an authentication flow (a network/API call) that produces a new access token, which is an external side effect beyond simple data retrieval. It doesn't read business data, write records, or destroy data — it executes an auth operation.

From the tool's definition Refresh MYOB OAuth access token using the stored refresh token

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

myob_oauth_refresh Rate-limited

myob_oauth_refresh stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "myob_oauth_refresh": {
      "limits": [
        {
          "counter": "myob_oauth_refresh_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about myob_oauth_refresh

What does the myob_oauth_refresh tool do? +

Refresh MYOB OAuth access token using the stored refresh token. It is categorised as a Execute tool in the MYOB Codex MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on myob_oauth_refresh? +

Register the MYOB Codex MCP server in PolicyLayer and add a rule for myob_oauth_refresh: 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 MYOB Codex MCP. Nothing to install.

What risk level is myob_oauth_refresh? +

myob_oauth_refresh is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit myob_oauth_refresh? +

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

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

myob_oauth_refresh is provided by the MYOB Codex MCP server (jaeko44/myob-codex-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.