[ANN] raw₿it — Visual Raw Transaction Builder & Script Debugger (open-source)

[rawBit_io]

Hi everyone,

I’d like to share a project I’ve been working for the last year raw₿it — a visual raw transaction builder & script debugger.

https://rawbit.io

Source:https://github.com/rawBit-io/rawbit

It’s an interactive web application that lets you drag-and-drop predefined nodes on a canvas to build real Bitcoin transactions from scratch, with every byte updating live.

How it works:
The tool runs in your browser (calculations via lightweight backend) or fully offline with local install. Connect nodes to generate preimages, signatures, witnesses, TXID/WTXID, and more — no hex editing required. Step through script execution opcode by opcode and watch the stack change in real time.

Key Features: 
- Build transactions visually (P2PKH, multisig, timelocks, SegWit, etc.) 
- See the exact Python code behind every node 
- Change values and instantly update preimages, TXID, weight, fees 
- Multi-tab workspace, undo/redo, dark mode, shareable flows, testnet/mainnet/regtest switch 
- 10 hands-on lessons included (all transactions broadcast to testnet for verification) 


Disclaimer: 
This is an educational tool only — it is not designed or intended for handling real funds. Use it solely for learning and experimentation to avoid any risks.

Feedback, bug reports, and new lesson ideas welcome.

Thanks!

[BattleDog]

This looks really damn cool. I spent a good chunk of my early Bitcoin years hand-rolling raw tx hex in a terminal, copy-pasting into `sendrawtransaction`, then staring at some cryptic "TX decode failed" error because I messed up a single byte, lol.

Something like this would have saved me a lot of late-night swearing and a few sacrificed testnet coins.

A couple of selfish feature wishes from a grumpy old dev: descriptors/miniscript support would make this an amazing teaching tool for modern wallet design, and an easy way to export a PSBT or `bitcoin-cli` command from a flow would bridge the gap between "toy in the browser" and "I know what to type on a real node". Also, anything you can do to make the offline/local mode super obvious and frictionless is huge from an opsec point of view.

Anyway, nice work all 'round.

[rawBit_io]

This looks really damn cool. I spent a good chunk of my early Bitcoin years hand-rolling raw tx hex in a terminal, copy-pasting into `sendrawtransaction`, then staring at some cryptic "TX decode failed" error because I messed up a single byte, lol.

Something like this would have saved me a lot of late-night swearing and a few sacrificed testnet coins.

A couple of selfish feature wishes from a grumpy old dev: descriptors/miniscript support would make this an amazing teaching tool for modern wallet design, and an easy way to export a PSBT or `bitcoin-cli` command from a flow would bridge the gap between "toy in the browser" and "I know what to type on a real node". Also, anything you can do to make the offline/local mode super obvious and frictionless is huge from an opsec point of view.

Anyway, nice work all 'round.

Thank you for such thoughtful response! The idea for this project came from my own struggle with messing up bytes and forgetting the rules for different tx types after some time — that's when I got the idea that a visual tool with an integrated script debugger would be really helpful 

Thanks for the suggestions for new features — I'll look into when I can create nodes and lessons for descriptors/miniscript and PSBT. 

Regarding your suggestion about bitcoin-cli commands, it is already partially there — for example, in Flow Examples > "Intro P2PKH", the node "Final Raw Transaction (ready to broadcast)" shows the comment 'bitcoin-cli -testnet sendrawtransaction <hex>', and the raw tx hex can be copied with the copy button. Actually, at some point I had an RPC node that talked to locally installed Bitcoin Core and could send tx to the network, but I decided against it, so sending should be a really conscious operation. 

Regarding making offline mode super easy — good idea, I'll think about a simple solution, because it can be used locally now but you need to install both the frontend and backend.