> ## Documentation Index
> Fetch the complete documentation index at: https://docs.heydollr.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Session Expired or Invalid

> Fix checkout, payout, transfer, or refund session errors before execution.

Execution failed because the `session_id` is missing, expired, or does not match the operation type.

## The problem

[Sessions](/api/sessions) are short-lived intents. If too much time passes between creating a session and calling [executions](/api/executions), the session may no longer be active.

Other causes:

* Using a payout session ID with `executions/collection`
* Wrong `source_id` / `source_type` on checkout session create
* Invoice still `IDLE` (not published)

## How to identify

* 422 errors mentioning session not found or not active
* `session_id` from an old test run or different merchant account

## Solution

<Steps>
  <Step title="Verify source is publishable">
    Invoice/order should be `ACTIVE` — `PUT /v1/invoices/publish/:id` when using document-first flow.
  </Step>

  <Step title="Create a new session">
    `POST /v1/sessions/checkout` (or payout/transfer/refund) immediately before execute.
  </Step>

  <Step title="Execute with a new reference_id">
    New session → new UUID v4 `reference_id` for the execution attempt.
  </Step>
</Steps>

## Related

* [Sessions API concept](/api/sessions)
* [Invoice not publishable](/reference/error-catalog#resource-state-errors)