DOWNGRADE_NOT_IMMEDIATE

A plan without a period cannot start while a period plan is running.

HTTP status	409
Group	Pricing and purchase
Retryable	No — sending it again changes nothing

What happened

You asked to buy a no-period tier (Agent Metered) while a plan with a period is active. The running block cannot be cut short, so the no-period plan has nowhere to start.

What to do

Let the current plan end — turn auto-renew off, or leave it off — and buy the no-period tier after endMs; or keep the period plan and renew it with setAutoRenew(true, months, maxPrice).

The problem document

Every error is application/problem+json (RFC 9457) with the same shape:

{
  "type": "https://docs.co-relayer.com/errors/downgrade-not-immediate",
  "title": "A plan without a period cannot start while a period plan is running.",
  "status": 409,
  "detail": "A sentence about this specific occurrence.",
  "instance": "req_01JB…",
  "code": "DOWNGRADE_NOT_IMMEDIATE",
  "retryable": false,
  "hint": "Let the current plan end — turn auto-renew off, or leave it off — and buy the no-period tier after `endMs`; or keep the period plan and renew it with `setAutoRenew(true, months, maxPrice)`."
}

See the error model for what each member means and how to handle unknown codes.