previewSubscriptionChange

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

Critical RISK CLASS

Category Financial

Parameters 32 required

Recommended Approval-gatedsee the rule below

Registry record Grade F, identity unverified Pull the record →

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

WHAT IT DOES

What previewSubscriptionChange does on Stable Baseline

AI agents use previewSubscriptionChange to commit financial operations through Stable Baseline, usually the final step of a payment, billing, or trading workflow. A call moves real money.

Parameter	Type	Required
`target_tier`	string	Yes
`target_seats`	integer	—
`organisation_id`	string	Yes

Parameters from the server's own tool schema.

RISK

Why previewSubscriptionChange is rated Critical

This tool directly involves subscription billing changes, proration calculations, and initiates Stripe Checkout flows. Even though it is a 'preview' step, it produces a confirmation_token used to commit financial transactions (subscription upgrades/downgrades, seat purchases).

From the tool's definition 'Preview a subscription tier or seat change', 'proration and next-invoice math', 'cross-tier upgrades from Free return requires_checkout=true; the apply step creates a hosted Stripe Checkout session', 'upgrade their plan (free→pro), downgrade, add seats,…

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs previewSubscriptionChange 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 previewSubscriptionChange, this is the rule to start with:

previewSubscriptionChange Approval-gated

Any call to previewSubscriptionChange is blocked until a human approves it. The rest of the server keeps working.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "previewSubscriptionChange": {
      "deny_if": [
        {
          "conditions": [],
          "on_deny": "Requires human approval."
        }
      ]
    }
  }
}

GATE THIS TOOL → Instant setup, no code required.

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

FAQ

Questions about previewSubscriptionChange

What does the previewSubscriptionChange tool do? +

Preview a subscription tier or seat change. Returns confirmation_token (10-min TTL) plus proration and next-invoice math. Cross-tier upgrades from Free return requires_checkout=true; the apply step creates a hosted Stripe Checkout session. Rate limit 30/h. Use when the user asks to upgrade their plan (free→pro), downgrade, add seats, increase seats, or change subscription tier — ALWAYS call this preview first, then applySubscriptionChange with the returned token after the user confirms. It is categorised as a Financial tool in the Stable Baseline MCP Server, which means it involves financial transactions. Block by default and require explicit approval.

What parameters does previewSubscriptionChange accept? +

previewSubscriptionChange accepts 3 parameters: target_tier, target_seats, organisation_id. Required: target_tier, organisation_id. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on previewSubscriptionChange? +

Register the Stable Baseline MCP server in PolicyLayer and add a rule for previewSubscriptionChange: 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 previewSubscriptionChange? +

previewSubscriptionChange is a Financial tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit previewSubscriptionChange? +

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

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

previewSubscriptionChange 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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