Multi-source ingest (RPC + Horizon fallback)

[Miracle656]

Background

RPC outage shouldn't stop the indexer. Fall back to Horizon when RPC is unhealthy.

What to build

A pluggable source interface with two implementations and a health-check-driven switcher.

Key files

• src/indexer/sources/ (new)

Acceptance criteria

• Auto-fails over on RPC outage
• Documented behavior

Drips Wave · Complexity: Advanced · 200 points

[ALIPHATICHYD]

@ALIPHATICHYD has applied to work on this issue as part of the Stellar Wave Program's 5th wave.

Hi maintainer
I'd love to work on this issue

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

[drips-wave]

Congratulations, @ALIPHATICHYD! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 2, 2026.

🧑‍💻 @ALIPHATICHYD: 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

When opening a PR, please link it to this issue to ensure it gets tracked accurately. Points are awarded when this issue is marked as completed by the maintainer.

🤠 Repo maintainers: Please keep an eye on the contributor's progress and review their work before the due date. You can manage this issue, including adjusting its complexity and points, here.

🌊 Happy Wave 🌊

[drips-wave]

This issue has been completed by @ALIPHATICHYD as part of the Stellar Wave Program's 5th Wave 🥳

😎 @ALIPHATICHYD: You earned 200 Points for completing this issue! After the current Wave ends, you'll be eligible for a percentage of the Wave's reward pool based on the percentage of total points you've earned. Learn more here. You can also Leave a review to share your experience working on this issue.

🧑‍💻 Repo maintainers: How'd the contributor do? Leave a review to share your experience working with them.