rawBit

rawBit is a visual, node-based editor for constructing and understanding Bitcoin transactions. Connect inputs, keys, and scripts on a canvas to build raw transactions visually.

Try it now: rawbit.io | Run locally: See Quick start below

Flow Examples

rawBit ships with 16 hands-on example lessons you can load, tweak, and inspect. They progress from legacy to SegWit and Taproot, but each is standalone — start anywhere.

• Lessons 1–2: P2PKH, P2PK, multisig, and P2SH fundamentals
• Lessons 3–4: Timelocks (nLockTime / nSequence), CLTV/CSV patterns
• Lessons 5–6: OP_RETURN anchors, Spilman payment channel
• Lesson 7: Pre-SegWit malleability (why TXIDs changed)
• Lesson 8: SegWit P2WPKH (BIP143 preimage, witness)
• Lesson 9: SegWit P2WSH (multisig & conditional scripts)
• Lesson 10: Fee savings: wrapped SegWit vs legacy
• Lesson 11: Taproot key-path spend (P2TR, Schnorr)
• Lesson 12: Taproot script-path spend (taptree, control block, tapscript)
• Lesson 13: Taproot script-path multisig (NUMS + OP_CHECKSIGADD)
• Lesson 14: MuSig2 multisig (BIP327, aggregated Schnorr)
• Lesson 15: Trezor signing flow (BIP39/BIP32, RFC6979, hardware signing comparison)
• Lesson 16: Summer of Bitcoin 2026 PoC flow

The lesson transactions were broadcast on testnet3, so you can inspect them on-chain and compare the raw bytes yourself.

Lesson notes: docu/l-sum.md currently covers lessons 1-14; lessons 15-16 are available in the app.

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What rawBit does

• Build and inspect transactions visually: Drag predefined nodes for keys, scripts, serialization, signing, and verification onto a canvas.
• Compare formats side-by-side: P2PKH, P2SH, wrapped SegWit, native SegWit v0, and Taproot v1 flows.
• Watch bytes change live: Tweak nSequence, nLockTime, witness data, and SIGHASH types while sizes, weight, TXID/WTXID, preimages, witnesses, and fees update.
• Debug scripts step by step: Inspect stack diffs after each opcode and see where validation fails.
• Inspect the implementation: Open calculation nodes to view the exact Python function used by the backend.
• Work with larger lessons: Use multi-tab history, templates, clipboard, search, minimap, and the protocol flow map.
• Export reproducible artifacts: Save/load full JSON, compact/LLM snapshots, and optional share links. Imports use collision-safe IDs.
• Target Bitcoin networks where relevant: Address and script nodes support mainnet, testnet, and regtest options where the operation needs a network.

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Who is this for?

Educators, auditors, and protocol-curious developers who want to understand Bitcoin transactions at the byte and script level.

Non-goals

rawBit is not a wallet, broadcaster, or custody tool. Keep real funds out of it.

⚠️ Educational use only. rawBit can assemble mainnet-valid transactions, but you should not broadcast them or handle real funds with this tool. Use testnet or regtest for anything you intend to send.

🌐 Hosted rawBit currently needs to send calculation data to the backend. Users who require "nothing leaves my machine" should use the local install.

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Prerequisites

• Node.js 18+
• npm
• Python 3.12+ with pip (backend depends on the forked python-bitcointx)
• C compiler toolchain + libsecp256k1 headers

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Quick start (local)

git clone https://github.com/rawBit-io/rawbit
cd rawbit

# 1) Frontend
npm install
npm run dev                    # Vite dev server → http://localhost:3041/

# 2) Backend (new terminal)
python3 -m venv .myenv
source .myenv/bin/activate     # Windows: .myenv\Scripts\activate
pip install -r requirements.txt
pip install -r requirements-special.txt
python3 backend/routes.py      # Flask API → http://localhost:5007/

Open http://localhost:3041/. The frontend bundles lesson flows from src/my_tx_flows/ and sends calculations to http://localhost:5007/bulk_calculate. The backend also exposes /flows, /code, and /healthz.

The backend uses a forked python-bitcointx pinned in requirements-special.txt. A virtualenv keeps those bindings isolated.

Optional: environment tweaks

Tracked env files provide defaults for the app and tests. For private local overrides, use shell environment variables or an ignored mode-local file such as .env.development.local; see .env.example for supported keys. Local dev pages force remote API URLs back to http://localhost:5007 unless VITE_ALLOW_REMOTE_API=true.

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Architecture (at a glance)

• Frontend: React + Vite + Tailwind + @xyflow/react. Handles the canvas, tabs, panels, templates, clipboard, protocol flow map, search/minimap, and per-tab undo/redo.
• Backend: Flask + Python (with python-bitcointx). Evaluates calculation nodes, validates scripts/signatures, enforces a sliding computation-time budget, and exposes /bulk_calculate, /flows, /code, and /healthz.
• Share service: Optional Cloudflare Worker in cloudflare/ for share links (POST /share, GET /s/<id>).

See /docu for the deeper tours:

• frontend-architecture.md – provider stack, hooks, canvas/panels/dialogs.
• backend-overview.md – calculation pipeline, budgets, and API surface.

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Testing

# Frontend lint, typecheck & unit/integration
npm run lint
npm run typecheck
npm run test

# E2E (first run only: downloads browsers)
npx playwright install
npm run test:e2e

# Backend tests
source .myenv/bin/activate
python -m pytest backend/tests

# One command for everything (lint + typecheck + frontend + E2E + backend)
python3 run_all_tests.py        # add --e2e-browsers=all for FF/WebKit too

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Contributing

rawBit is a visual lab for Bitcoin transactions. The most useful contributions are flows and lessons that help others understand how things work. For a broader list of possible contribution directions, see docu/contribute.md. Community discussion: Discord.

Flows and lessons

• Lightning Network
• CoinJoin
• PSBT
• Miniscript
• Mining and block construction
• Cross-chain swaps
• Covenant proposals

Keep flows small and focused on one concept.

Code & bugs

Bug reports and fixes are welcome. We keep features minimal—changes should directly improve understanding or teaching of Bitcoin concepts.

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License

• Code: MIT (LICENSE)
• Docs/tutorials: CC BY 4.0 (LICENSE-docs)