Moov
Moov Technical Briefing
Published October 14, 2020
Supported by Finix , Routable and The Kauffman Foundation
Overview
Wade Arnold (ex-Banno, Billgo) and Graham McBain present Moov — a thousand-strong open-source community that has shipped 37 low-level libraries covering the protocols that quietly move money through the US financial system: ACH, wires, image cash letter, Metro 2, IRS FIRE, ISO 20022, and ISO 8583. Wade walks through why none of this was open source before, how the libraries have been battle-tested against the full transaction volumes of Bank of America, PayPal, Square, and Visa, and why the community model beats every fintech writing its own parser from scratch (e.g., Square unifying seven different ACH implementations onto Moov). Graham then demos the Moov ACH library as a Docker image — curl a JSON payload in, get a NACHA-compliant ACH file back — and a WebAssembly-powered in-browser ACH parser that converts ACH to JSON without any data leaving your machine.
0:00 Introduction to Moov — open-source payments plumbing
Wade Arnold introduces Moov. After successful exits with Banno (acquired by Jack Henry) and Billgo, Wade started angel-investing in fintechs and saw every founder spend half their funding round building the same low-level plumbing.
1:00 37 open-source libraries covering the entire US payment stack
Moov has open-sourced 37 low-level libraries covering ACH, wire, image cash letter, Metro 2 credit reporting, IRS FIRE, ISO 20022, and ISO 8583 — the protocols that quietly move money through the US financial system.
1:30 Community validation at Bank of America scale
Moov's libraries have been battle-tested against full transaction volumes from Bank of America, PayPal, Square, and Visa — a thousand-strong community contributing fixes for edge cases like FIS using the wrong character return.
3:00 Making financial services less of a black box
Why financial services has historically been opaque — COBOL and RPG on mainframes — and why Moov believes reference implementations plus documentation are worth more than yet-another-proprietary-vendor.
4:00 Production use cases: ML on SWIFT, unifying ACH at Square
Real-world examples — machine-learning models trained on three years of SWIFT transactions via Moov libraries, and Square unifying seven different ACH implementations (collected through acquisitions) onto a single code base.
6:00 Watchman — community-maintained global watchlist
Graham McBain demos Moov's Watchman project: a global sanctions/watchlist service. When one company needed a list that wasn't included, they contributed it back, getting all the other lists as a bonus.
8:30 ACH file formats, character-limited from the punch-card era
A quick tour of the ACH file format — still character-limited, a living artifact of the punch-card era — and why a parser library beats every fintech writing it from scratch.
9:30 ACH library demo: Docker + curl + JSON
Live demo of Moov's ACH library running as a Docker container: POST customer data as JSON, get back a NACHA-compliant ACH file, or parse an existing ACH file into JSON for your web application.
11:30 WebAssembly in-browser ACH parser
A WebAssembly-compiled in-browser ACH parser — paste an ACH file in, get JSON out, without any data leaving your local machine. Same approach available for image cash letter and other projects.
Presented by Wade Arnold and Graham McBain — Moov · website
Topics: Payments, Banking-as-a-Service, Developer Tools
