High Risk →

reauth

Re-run OAuth for an existing Gmail account without removing it. Opens a browser for Google sign-in. Use when the refresh token expires (invalid_grant) or scopes change.

Part of the Mailbox MCP server. Enforce policies on this tool with Intercept, the open-source MCP proxy.

mailbox-mcp Execute

AI agents invoke reauth to trigger processes or run actions in Mailbox. Execute operations can have side effects beyond the immediate call -- triggering builds, sending notifications, or starting workflows. Rate limits and argument validation are essential to prevent runaway execution.

reauth can trigger processes with real-world consequences. An uncontrolled agent might start dozens of builds, send mass notifications, or kick off expensive compute jobs. Intercept enforces rate limits and validates arguments to keep execution within safe bounds.

Execute tools trigger processes. Rate-limit and validate arguments to prevent unintended side effects.

mailbox.yaml
tools:
  reauth:
    rules:
      - action: allow
        rate_limit:
          max: 10
          window: 60
        validate:
          required_args: true

See the full Mailbox policy for all 49 tools.

Tool Name reauth
Category Execute
MCP Server Mailbox MCP Server
Risk Level High

View all 49 tools →

Agents calling execute-class tools like reauth have been implicated in these attack patterns. Read the full case and prevention policy for each:

Browse the full MCP Attack Database →

Other tools in the Execute risk category across the catalogue. The same policy patterns (rate-limit, validate) apply to each.

reauth is one of the high-risk operations in Mailbox. For the full severity-focused view — only the high-risk tools with their recommended policies — see the breakdown for this server, or browse all high-risk tools across every MCP server.

What does the reauth tool do? +

Re-run OAuth for an existing Gmail account without removing it. Opens a browser for Google sign-in. Use when the refresh token expires (invalid_grant) or scopes change.. It is categorised as a Execute tool in the Mailbox MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on reauth? +

Add a rule in your Intercept YAML policy under the tools section for reauth. You can allow, deny, rate-limit, or validate arguments. Then run Intercept as a proxy in front of the Mailbox MCP server.

What risk level is reauth? +

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

Can I rate-limit reauth? +

Yes. Add a rate_limit block to the reauth rule in your Intercept 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 reauth completely? +

Set action: deny in the Intercept policy for reauth. 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 reauth? +

reauth is provided by the Mailbox MCP server (mailbox-mcp). Intercept sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Let agents act without letting them run wild.

Deterministic policy on every MCP tool call. Per-identity grants. Full audit log.

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