startSignup

SERVERStable Baseline SOURCEhttps://api.stablebaseline.io/functions/v1/cloud-serve/mcp

Low RISK CLASS

Category Other

Parameters 30 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-stablebaseline-sb/startsignup.md

WHAT IT DOES

What startSignup does on Stable Baseline

AI agents call startSignup as a supporting operation in Stable Baseline workflows.

Parameter	Type	Required	Description
`intent`	string	—	Reason for the signup. Currently only 'mcp_setup' is supported.
`agent_label`	string	—	Self-identification of the calling agent (e.g. 'Claude Desktop', 'Cursor', 'Custom CLI'). Shown to the user on the confirmation page so they know what they're a
`desired_org_name`	string	—	Optional hint for the org name to suggest if the user has no organisation yet. Ignored for users who already have an org.

Parameters from the server's own tool schema.

RISK

Why startSignup is rated Low

This tool initiates an OAuth-style device authorization flow for user sign-up/login. It doesn't read user data, write application data, execute code, destroy anything, or move money — it purely starts an authentication handshake and returns a URL and code for the user to authorize. The closest category is Other, as it's an identity/auth initiation step.

From the tool's definition Begin an agent-driven sign-up to Stable Baseline. Anonymous-callable. Returns a `verification_url` and a 6-character `user_code` that the agent must show to the user.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs startSignup safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Stable Baseline, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For startSignup, this is the rule to start with:

startSignup Rate-limited

startSignup gets a rate cap, and everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "startSignup": {
      "limits": [
        {
          "counter": "startsignup_rate",
          "window": "minute",
          "max": 60,
          "scope": "grant"
        }
      ]
    }
  }
}

SET A RULE FOR THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Stable Baseline, apply this rule, and every startSignup call is checked against it from then on.

FAQ

Questions about startSignup

What does the startSignup tool do? +

Begin an agent-driven sign-up to Stable Baseline. Anonymous-callable. Returns a verification_url and a 6-character user_code that the agent must show to the user. The user opens the URL in their browser, signs in or signs up if necessary, enters the code, and clicks Authorize. The agent meanwhile polls pollSignupStatus({device_code}) every poll_interval_seconds until the status changes to authorized, at which point it receives an api_key it can use for subsequent MCP calls. The whole flow has a 10-minute TTL. It is categorised as a Other tool in the Stable Baseline MCP Server, which means it performs auxiliary operations.

What parameters does startSignup accept? +

startSignup accepts 3 parameters: intent, agent_label, desired_org_name. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on startSignup? +

Register the Stable Baseline MCP server in PolicyLayer and add a rule for startSignup: 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 Stable Baseline. Nothing to install.

What risk level is startSignup? +

startSignup is a Other tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit startSignup? +

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

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

startSignup is provided by the Stable Baseline MCP server (https://api.stablebaseline.io/functions/v1/cloud-serve/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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