The Core Lightning v26.06 Release Candidate 1 introduces several new features and improvements for both users and developers. Key user-focused updates include the 'graceful' command for preparing the system for shutdown, a new 'sendamount' command for specifying payment amounts, and enhancements to the 'xpay' command, which is set to replace 'pay'. The 'xpay' command now supports additional parameters and updates payment details upon receiving a 'channel_update' error. For developers, new JSON-RPC commands like 'createproof' for BOLT12 payment proof creation and 'decode' for 'lnp' payer proof format are introduced. Additionally, protocol updates include changes in channel closing wait times and message-padding defaults. For more details, refer to the [changelog](https://github.com/ElementsProject/lightning/blob/v26.06rc1/CHANGELOG.md).