Create indexed events idempotency table

[pragmaticAweds]

Repository

This issue belongs in Fundable-Protocol/Backend under indexer/.

Migrated from https://github.com/Fundable-Protocol/stellar_indexer/issues/6.

Context

Every processed event needs deterministic identity storage so retries, restarts, and replays do not duplicate writes.

Scope

• Define indexed event schema
• Add migration with uniqueness constraints
• Store contract ID, ledger number, transaction hash, and event index
• Add indexes for replay/debug queries

Out of Scope

• Unrelated package work
• Docker, CI, or deployment work unless named in scope
• Broad refactors outside the touched package

Acceptance Criteria

• Scope items are complete
• Relevant tests are added or updated
• Documentation is updated when needed
• bun run type-check passes
• bun run test passes
• bun run lint passes
• bun run indexer:type-check passes
• bun run indexer:test passes
• bun run indexer:lint passes

Dependencies

• Add database dependency and migration tooling #20

Suggested Files or Packages

• indexer/common/src/db/
• migration files
• indexer/INDEXER_GUIDELINES.md

[Timothy2025-20]

@Timothy2025-20 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi maintainer, am a software engineer with years of experience and an enthusiast in open source projects. i will like to resolve this issue if assigned to me, Thank you

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Timothy2025-20 to this issue.

[Arome8240]

@Arome8240 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hello, I'm a smart contract and full stack developer, open for contributions. contributed to over 20 project on OnlyDust and Drips , with expertise in Solidity, Cairo, JavaScript, TypeScript, and RUST. I am passionate about building secure and scalable blockchain solutions, and I would love the opportunity to contribute my skills toward solving this issue.

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[Banx17]

@Banx17 has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Good day Team, I would love to work with you on this issue, please kindly assign thanks.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @Banx17 to this issue.

[drips-wave]

Congratulations, @Arome8240! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @Arome8240: 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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