1.3 KiB
COLDCARD Website Implementation
This is the code for the NFC Push TX implementation at https://coldcard.com/pushtx.
Overview
We use the APIs of mempool.space and blockstream.info to broadcast the transaction and for retrieving additional transaction details afterwards.
In an edge case where the transaction is already confirmed (e.g. same Push TX URL used twice), the APIs respond with a 400 error. If that happens, we use bitcoinjs-lib to compute the TXID and try to fetch the details anyway.
How to Build
To build, you need Node.js and NPM installed. There's a Makefile target for
installing dependencies and running the build:
make build
This builds two versions:
- Separate JS and CSS files that power https://coldcard.com/pushtx - saved to
build/ - A self-contained HTML where all JS and CSS is inlined, which is useful for easy
self-hosting - saved to
build-single-file/.
Don't Trust, Verify
The SHA256SUMS file includes hashes of all important files in this repo and is
signed with the PGP key 3F4D 2119 6E14 FD39 3835 492D F960 23C5 8E14 72C9 in
SHA256SUMS.asc (detached signature).
To check the signature:
gpg --verify SHA256SUMS.asc
To check the hashes match:
shasum -a 256 -c SHA256SUMS