Implement `SorobanOnchainAdapter` for Live Soroban Transactions

[Cedarich]

Complexity Score: 200

Description

The current OnchainModule uses a MockOnchainAdapter. For Wave 3, we need a production-ready SorobanOnchainAdapter that interacts with the AidEscrow contract on the Stellar Testnet/Mainnet using the Stellar SDK.

Requirements

• Create SorobanOnchainAdapter in app/backend/src/onchain/soroban-onchain.adapter.ts.
• Implement initEscrow, createClaim, and disburse methods.
• Use the Stellar SDK to build, sign, and submit Soroban transactions.
• Handle transaction submission errors and parse XDR for results.
• Ensure the adapter is correctly instantiated in onchain.module.ts when ONCHAIN_ADAPTER=soroban.

Tech Stack

• NestJS, Stellar SDK (@stellar/stellar-sdk), Soroban CLI (for local testing).

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[RUKAYAT-CODER]

@RUKAYAT-CODER has applied to work on this issue as part of the Stellar Wave Program's 3rd wave.

Hi am a full stack developer I will like to work on this task.

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[drips-wave]

Congratulations, @RUKAYAT-CODER! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on March 30, 2026.

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