Implement robust retry mechanism for failed contract syncs

[wagmiiii]

Repo context. accensa-app is the off-chain half of Accensa — the merchant back-office for x402 sellers on Stellar. Three workspace packages matter: apps/web (Next.js dashboard and the indexer at src/app/api/sync), packages/sdk (@accensa/sdk), and apps/demo-merchant. The Soroban contracts live in accensa-contracts.

🟢 Unblocked. Indexer sync logic can be updated independently of contract state.

Problem

The indexer occasionally misses events due to transient RPC failures. Without a retry mechanism, missed events require a full resync to recover data.

What to build

• In , add exponential backoff logic for RPC calls.
• Store the last successfully processed ledger cursor persistently.
• Implement a fallback polling routine if the primary event stream disconnects.

Acceptance criteria

• RPC failures trigger a retry with exponential backoff.
• Indexer seamlessly recovers from temporary network drops without missing events.
• Logs clearly indicate when retries are occurring.

Contact & Support

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• SUPPORT.md — contribution help, Wave process, and the full list of channels

[Deevhyne1023]

@Deevhyne1023 has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

Hi, I've looked into this issue and have experience implementing retry mechanisms for failed operations, including handling transient contract sync failures with proper backoff and error handling. Confident I can build this robustly and meet the acceptance criteria, happy to start once assigned, thanks!

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Deevhyne1023 to this issue.

[nekwasar]

@nekwasar has applied to work on this issue as part of the Stellar Wave Program's 8th wave.

HELLO org maintainer, kindly assign me this issue please

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

[drips-wave]

Congratulations, @nekwasar! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on August 31, 2026.

🧑‍💻 @nekwasar: 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

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