# Introducing Session ID to StartPaymentSession — Shopify developer changelog
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## Introducing Session ID to StartPaymentSession

As of Payments Apps API version 2024-10, the StartPaymentSession payload for all payment extension types will have one new field: [session_id](https://shopify.dev/docs/apps/build/payments/request-reference#request-body).

This identifier is shared across payment sessions that belong to the same payment group, buyer session, and share payment details. It can be used to power auth rate calculations.

*Published: October 01, 2024*
Tags: API, New
Link: https://shopify.dev/changelog/introducing-session-id-to-startpaymentsession

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