OFX/QFX Parsing in JavaScript Without the Pain

npm install @gristmill-dev/gristmill — parse bank exports that would break strict XML parsers, get cents-exact transactions back.

If you're building a budgeting app, an importer, or a finance dashboard, bank-file parsing is the swamp at the edge of your map. Gristmill is a zero-dependency TypeScript library that drains it.

What it handles

• OFX v1/v2 SGML headers, unclosed tags, unescaped entities, empty elements
• Timezone-suffixed dates → ISO strings
• Amounts as integer minor units (no float drift)
• Bank and credit-card statement layouts
• CSV dialect sniffing: delimiters, date formats, column mapping
• Deterministic dedup (pending→posted) and a recurring-payment graph with price-drift tracking

Quick start

import { parseOfx, dedupe, detectRecurring } from "@gristmill-dev/gristmill";

const txs = parseOfx(qfxFileContents);
const { kept } = dedupe(txs);
const subs = detectRecurring(kept);

Apache-2.0 licensed, test suite included with real-world malformed fixtures. Need it hosted as an API instead? That's coming — star the repo to hear about it first.

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