Soroban Indexer: Implement real transaction & event indexing with Soroban SDK

[grantfox-oss]

Description

Complete the Soroban blockchain indexer by filling in the placeholder methods in soroban.indexer.ts, integrating with the soroban-client SDK, and adding reliable event/transaction processing.

Background

soroban.indexer.ts currently contains stubbed implementations for key indexing behavior. The indexer is expected to:

• fetch and persist blockchain transactions
• stream and store smart contract events
• manage unprocessed events
• update transaction status reliably

Without these implementations, the platform cannot track Soroban blockchain activity or respond to contract events.

Scope

• Implement indexBlock(blockNumber)
• Implement indexContractEvents()
• Add indexTransaction(txHash, type, metadata)
• Add getUnprocessedEvents()
• Add markEventProcessed(eventId)
• Integrate all of the above with soroban-client
• Ensure transaction status is tracked correctly and contract events are streamed/processed

Goals

• Make SorobanIndexer functional and production-ready
• Use real Soroban ledger and event APIs rather than placeholders
• Persist transactions and events into Prisma models
• Provide an event processing workflow for downstream consumers
• Track transaction confirmation status and handle retries/fresh indexing

Requirements

1. indexBlock(blockNumber)

• Fetch ledger/transaction data from Soroban for a given block/ledger sequence
• Use Server methods from soroban-client to load the ledger and its transactions
• Parse each transaction and its effects
• Persist transaction records into prisma.blockchainTransaction
• Handle blocks with multiple transactions, skipped or failed transactions
• Update transaction status using real on-chain confirmation state
• Avoid duplicate writes via upsert or duplicate key handling

2. indexContractEvents()

• Subscribe to or poll Soroban contract events using soroban-client
• Filter events for config.soroban.contractAddress and relevant event names
• Persist events into prisma.contractEvent with metadata and a processed flag
• Support streaming or cursor-based polling so events are not missed
• Handle disconnects and reconnect/retry logic

3. indexTransaction(txHash, type, metadata)

• Create or update a transaction record for an arbitrary transaction hash
• Include:
  • txHash
  • transaction type
  • fromAddress
  • toAddress
  • amount
  • currency
  • contractAddress
  • functionName
  • parameters
  • status based on actual Soroban transaction result
  • blockNumber
  • timestamp
• Use status values like PENDING, CONFIRMED, FAILED
• Track and update transaction status when confirmed on-chain
• Catch Prisma duplicate errors gracefully

4. getUnprocessedEvents()

• Return a batch of contractEvent rows where processed = false
• Limit the result size for worker processing
• Use ordering to process oldest events first
• Support downstream event consumer loop in blockchain.worker.ts

5. markEventProcessed(eventId)

• Update a contract event row to processed = true
• Optionally record processing metadata/timestamp
• Ensure this is idempotent and safe for retry

Integration requirements

• Use soroban-client SDK APIs rather than placeholder comments
• Prefer real Soroban JSON-RPC endpoints from config.soroban.networkUrl
• Keep indexer loop in sync with existing index.ts startup
• Ensure indexLatestTransactions() and indexContractEvents() coordinate properly
• Add error handling and backoff for network or RPC failures
• Make event indexing resilient across restarts

Acceptance criteria

• indexBlock() fetches and indexes transactions from actual Soroban ledgers
• indexContractEvents() pulls or streams contract events and stores them
• indexTransaction() persists real transaction metadata and status
• getUnprocessedEvents() returns unprocessed contract events reliably
• markEventProcessed() marks events as processed after handling
• Transaction records include correct on-chain status and ledger/block info
• The indexer can resume from the last processed ledger or event after restart
• Existing worker flows in blockchain.worker.ts can process events correctly

Notes

• If the current Prisma schema lacks the required fields, update it as needed
• Document any new config values or assumptions in index.ts
• Keep the implementation clean and use a service-oriented style
• Optionally add helper methods for event cursor persistence and transaction polling

[SHEROSE0]

Hello! I have experience in full-stack and blockchain development, and I'd like to take on this issue. I can provide a clean, maintainable solution. Please assign it to me if it's still open.

[Menjay7]

Hi! I came across this issue and would love to work on it. I have experience with similar tasks and I'm confident I can investigate, implement a clean solution, and thoroughly test it before submitting a PR. If the issue is still open, I would appreciate it if you could assign it to me. Thank you!

[naninu123]

Ready to jump on this.

GrantFox contributor with 9 merged PRs across Rust, TypeScript, and CI/CD. Recent: LiquidFlow #114, StellarLend #998.

I'll audit the codebase, identify the exact change needed, and PR it cleanly.

Available immediately.

[grantfox-oss]

🦊 GrantFox — @SHEROSE0 has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #83)
2. Your PR will be reviewed by the aid-linkk maintainers

Good luck! Track your progress on GrantFox.

[GBOYEE]

I'm interested in tackling this! Strong frontend background, clean PR coming shortly.

[GBOYEE]

Hi! I'd like to work on this issue.

I have experience with this stack and can deliver a clean, tested solution. Please assign this to me and I'll submit a PR shortly.

My approach:

• Analyze the root cause
• Implement a fix following existing code patterns
• Add tests and documentation

Thanks!