Rebar Transaction Checker

🛠️ About the Project

🚀 Inspiration

As Bitcoin adoption grows, so do concerns around censorship and miner preferences. Rebar Shield offers a way to submit Bitcoin transactions directly to private mining pools. But users need a way to verify their transactions actually meet the criteria before submitting.

That’s where Rebar Transaction Checker comes in.

I wanted to build a tool that helps people: • Decode raw Bitcoin transactions, • Verify they contain the proper fee output required by Rebar Shield, • Confirm they meet the required fee rate, • And finally, submit the transaction directly to Rebar Shield (or other private mempools).

🔧 What It Does • Raw transaction decoder with visual breakdown of inputs, outputs, fees, and Rebar compliance. • Validation against Rebar’s official /info endpoint to confirm the output fee is sufficient and correctly structured. • Live mempool view of Rebar Shield and mempool.space feerates. • Submission tool that sends transactions directly to the Rebar endpoint if valid.

🧠 What I Learned • How to work with raw Bitcoin transactions and decode them using public APIs. • The structure and submission process for JSON-RPC transactions to custom endpoints like Rebar. • Better UI/UX practices under time pressure. • CORS, FastAPI + React integration, and deployment with Render.

🏗️ How I Built It • Frontend: React + Tailwind CSS for styling and form input validation. • Backend: FastAPI to bridge between frontend and external APIs like BlockCypher and Rebar. • Deployment: Hosted on Render, with CORS and routing configured. • Tools: GitHub, Devpost, Vite, and a ton of Chrome devtools.

🧱 Challenges • Handling edge cases for transactions with no outputs or malformed formats. • Avoiding incorrect fee calculation assumptions (e.g., implied fee vs explicit output). • Getting CORS working properly with Render deployments. • Designing clean, actionable UI without feature creep.

⸻

🛠️ Built With • React • Tailwind CSS • FastAPI • BlockCypher API • Rebar Shield API • Vite • Render

Built With

• blokc-cypher-api
• fastapi
• react
• rebar-shield-api
• render
• tailwind
• vite