BIP Proposal: Stateless PSBT Coordination (Blind Relay)

The recent release of @signing-room/sdk version 1.0.0 marks a significant advancement in the realm of cryptographic operations and coordination logic for signing ceremonies, particularly decoupled from the main Angular client. The new TypeScript SDK is designed to be framework-agnostic, enabling developers to orchestrate ephemeral, end-to-end encrypted PSBT coordination ceremonies programmatically. This flexibility is further enhanced by the SDK's integration with the standard web UI, which ensures that all actions such as room creation, participant joining, and signature uploads are synchronized in real time across the system.

This SDK facilitates not just traditional uses but also innovative applications like headless multisig automation, where AI agents can perform signing ceremonies autonomously, yet under the supervision of a human coordinator who retains the ability to finalize transactions. Such capabilities extend the utility of the SDK, making it suitable for more complex and secure transaction environments.

A detailed developer walkthrough has been provided to help users understand and implement the SDK effectively. The walkthrough includes explanations on the architectural setup of the signing room components and their interactions. It demonstrates initializing rooms, simulating participant joins programmatically, locking rooms, and merging PSBTs dynamically. Additionally, the walkthrough guides developers on how to generate a SHA-256 cryptographic integrity seal client-side, which anchors the room’s event-log to the finalized transaction hex, ensuring data integrity and security.

For those interested in exploring or integrating this SDK, resources are available including the repository hosted on GitHub and the package available on NPM. A video walkthrough is also accessible via YouTube, providing a visual and practical representation of the SDK’s capabilities and usage. Feedback on API ergonomics, the event-driven coordination design, or suggestions for additional features would be greatly appreciated to enhance the tool further.