settlement-engine webhook retry doesn't preserve original request headers

[therealjhay]

ProblemcreateWebhookWorker sends only Content-Type + signature; merchant endpoints expecting custom headers (idempotency, auth) lose them across the retry model.

1. No header passthrough.
2. Custom headers not supported.
3. Merchant integrations limited.

Solution

• Support configurable headers per subscription.
• Preserve across attempts.
• Test header delivery.

Acceptance Criteria

• Configured headers delivered.
• Consistent across retries.
• pnpm --filter @bettapay/webhook-delivery build passes.

Note for Contributors: Write a clear PR description. Show a custom-header delivery test.

[Hollujay]

I would like to work on this issue because I will get it done.

[RaymondAbiola]

Hi! I love to work on this issue.

I have experience working with backend webhook systems and API integrations, including request handling, retries, authentication, and idempotency. I can update the webhook delivery flow to support configurable subscription headers and ensure they are preserved consistently across every retry attempt.

I’ll also add a test covering custom-header delivery and verify that the webhook delivery package builds successfully.

Thanks!

[Fury03]

Hi Maintainer, I'd like to take this up.

Proposed approach:

• Configurable headers per subscription: add support for merchants to define custom headers (e.g., idempotency keys, auth tokens, custom signatures) in the subscription configuration. These will be stored alongside existing webhook settings.
• Preservation across retries: modify createWebhookWorker to merge the configured custom headers into every request attempt, including retries. The original Content-Type and signature headers will still be included, but custom headers will be preserved exactly as configured.
• Implementation points:
  • Update the subscription schema/model to store a list of custom headers (key-value pairs).
  • Adjust the webhook delivery package to read and apply these headers on each attempt.
  • Ensure no header duplication or override conflicts between built-in and custom headers.
• Tests: add a test that verifies custom headers are delivered on the initial request and remain unchanged on retries (e.g., using a mock server to capture headers). The build command pnpm --filter @bettapay/webhook-delivery build will pass.
• Docs/comments: document the new feature in the webhook delivery README or comments, including how to configure custom headers.

I have experience with backend webhook systems, retry logic, and API integrations, and I’m confident I can implement this cleanly. Looking forward to your feedback.

[grantfox-oss]

🦊 GrantFox — @RaymondAbiola has been assigned to this issue as part of the Third Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #569)
2. Your PR will be reviewed by the Betta-Pay maintainers

Good luck! Track your progress on GrantFox.

[grantfox-oss]

🎉 This issue has been marked as completed on GrantFox as part of the Third Campaign campaign!

@RaymondAbiola's PR #589 was approved and merged by @therealjhay.

🏆 @RaymondAbiola: You earned 35 FoxPoints for this contribution! Your current tier: Explorer (752 total points). Track your full progress on GrantFox.

👏 Great work, @RaymondAbiola! Keep contributing to Betta-Pay.