Implement webhook notifications for certificate lifecycle events

[AnnabelJoe]

Description

Third-party systems (energy management platforms, accounting software) need to be notified of certificate events in real time via webhooks.

Acceptance Criteria

• Webhook registration API (POST /api/webhooks)
• Events: certificate.minted, certificate.transferred, certificate.retired
• HMAC-SHA256 signature on webhook payload
• Retry with exponential backoff on delivery failure
• Webhook delivery log accessible to users

Priority

Medium

Estimated Effort

Large

Dependencies

Background job queue

Labels

enhancement, product

[ScriptedBro]

@ScriptedBro has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Hi, I’m a backend and Web3 developer experienced in event-driven systems, secure webhook infrastructure, and blockchain-integrated APIs. I understand the need for reliable real-time certificate event delivery to third-party platforms. I will implement a secure webhook registration API, support the required certificate lifecycle events, and add HMAC-SHA256 signing for payload verification. I will also build retry handling with exponential backoff, integrate delivery logging for user visibility, and ensure the architecture works cleanly with the background job queue for reliable asynchronous processing.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @ScriptedBro to this issue.

[Dev-Odun-oss]

@Dev-Odun-oss has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

I'd like to work on this issue. I've read through the codebase and I have a clear picture of what needs to be done here. I'll keep the implementation minimal and aligned with the existing patterns in the project.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Dev-Odun-oss to this issue.

[Sammy-Samy]

@Sammy-Samy has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

please assign

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Sammy-Samy to this issue.

[drips-wave]

Congratulations, @Sammy-Samy! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

🧑‍💻 @Sammy-Samy: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

Warning

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

🌊 Happy Wave 🌊