Add helper for building the trade webhook POST payload from an indexed trade event

[Chucks1093]

Summary

The webhook delivery layer needs to serialize an indexed trade event into the correct POST payload shape. This serialization should live in a shared helper so it can be tested independently and reused for both buy and sell event types.

Scope

• Add a buildWebhookPayload(event: TradeEvent): WebhookPayload helper
• Output shape: { event_type, creator_id, actor_address, amount, price, fee_paid, timestamp }
• Add unit tests for a buy event and a sell event confirming all fields are mapped correctly

Acceptance Criteria

• Buy event maps to correct event_type: 'buy' payload
• Sell event maps to correct event_type: 'sell' payload
• All payload fields are populated correctly from the input event

ETA: 12 hours

---

Coordinate on Telegram

[ZuLu0890]

I would love to work on this issue

[umohjosephemmanuel-cyber]

Implemented a reusable webhook payload serialization helper to transform indexed trade events into standardized POST request formats, ensuring accurate field mapping for buy and sell transactions through comprehensive unit testing and validation.

[Mhidesav]

i would like to be assigned this issue please

[spiffamani]

I'm a full-stack Software Engineer with 3 years of experience
I'd love to take this on — thanks for considering me

[CollinsKRO]

@CollinsKRO has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Good Day maintainer, pls assign me this issue. I'd love to work on it. Thanks.

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

[Cjay-Cyber-2]

@Cjay-Cyber-2 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

i would like to work on this kindly assign me

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Cjay-Cyber-2 to this issue.

[chinelo002]

@chinelo002 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi, my name is chinelo002, and I am a fullstack and smart contract developer skilled in React, Next.js, JavaScript, TypeScript, Tailwind CSS, and Soroban. For this task, I will:

1. Implement a reusable buildWebhookPayload(event: TradeEvent): WebhookPayload helper that converts indexed trade events into the standardized webhook POST payload structure.
2. Map all required fields (event_type, creator_id, actor_address, amount, price, fee_paid, and timestamp) directly from the source event while supporting both buy and sell trade types.
3. Ensure the helper is integrated as a shared utility so it can be reused consistently across webhook delivery flows for all trade event variants.
4. Add unit tests covering both buy and sell events, verifying correct event_type values and validating that every payload field is populated and serialized accurately.

ETA: 10 hours

ℹ️ Repo Maintainers: To accept this application, review their application or assign @chinelo002 to this issue.

[Maximum-Prosper]

@Maximum-Prosper has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi maintainer.
I'd like to work on this project.
Please kindly assign.

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

[drips-wave]

Congratulations, @chinelo002! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @chinelo002: 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 🌊