Implement cross-network transaction audit trail and replay protection

[grantfox-oss]

Transactions and refunds can be retried if a response is lost, but there is no durable cross-network audit trail that distinguishes safe retries from duplicate submissions.

Affected areas: app/backend/src/transactions/transaction.service.ts, app/backend/src/refunds/refunds.service.ts, app/backend/src/audit/audit.service.ts, app/backend/src/transactions/transaction.repository.ts, app/backend/src/common/idempotency/*.

Implementation scope:

• Persist transaction requests with client-provided idempotency key, network, contract call details, and resulting hash.
• Use the audit trail to detect duplicate on-chain submission attempts across retries.
• Add replay protection for stale or replayed client requests.
• Add monitoring for duplicate transaction hash generation.

Acceptance criteria:

• Replayed or retried requests return the original transaction record instead of resubmitting.
• Audit trail exposes whether a transaction was a retry, duplicate, or new submission.
• Tests cover same payload across different networks and repeated retries.

[noevidence1017]

Hello Maintainer. I am a fullstack dev and i've checked through this issue. I would love to resolve this issue as soon. Please assign

[Y33t-dev]

Hello Maintainer , I would love to resolve this issue as I am familiar with it. Please assign

[prissca]

i will love to work on this issue

[Emmy6654]

Hi Team,

I am writing to submit my application to design and implement the cross-network transaction audit trail and replay protection mechanisms. When tracking or executing state changes across fragmented networks, the absence of an immutable audit trail and rigid replay barriers opens the system up to double-spend equivalents, signature reuse vulnerabilities, and visibility blind spots.

I will build a dual-purpose security framework that enforces strict cryptographic uniqueness for cross-network messages while maintaining a clear, searchable telemetry log for debugging and compliance

[grantfox-oss]

🦊 GrantFox — @prissca 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 #28)
2. Your PR will be reviewed by the BlockDash-Studios maintainers

Good luck! Track your progress on GrantFox.

[MaryammAli]

@prissca
what is the update on this issue