What this demo shows — and what the real pipeline adds
Each sample batch is also downloadable as a CSV file to use as the template for your own ERP or spreadsheet export — the header row is the contract.
The demo above implements the fail-fast layer of the Pain001 pipeline: required-field checks, ISO 13616 mod-97 IBAN checksums, ISO 9362 BIC structure, amount and date formats, and control totals (NbOfTxs, CtrlSum) recomputed from the records rather than trusted. Try the "Introduce an error…" menu — each scenario plants exactly one realistic flaw (a flipped IBAN digit, a malformed BIC, a missing column, a European comma-decimal amount, an impossible date) and shows you the row-level finding a bank's gateway would otherwise report days later.
The installed toolchain runs a much deeper gate: JSON Schema validation per record with field-alias normalisation, five scheme rulebooks (SEPA SCT, Instant, SDD Core, B2B, cross-border) with rule-by-rule --explain output, and final validation of the rendered document against the official ISO 20022 XSD before a single byte is written. Ten pain.001 versions and pain.008.001.02 are supported.
pip install pain001
pain001 -t pain.001.001.09 -d payments.csv -o out/ --scheme sepa-sct --dry-run
Step 3 above is not a simulation: it boots a Python runtime in WebAssembly and runs xmlschema against the official pain.001.001.09 schema, served from this site — the same class of XSD gate the CLI applies. What remains CLI-only is the rest of the pipeline: JSON Schema normalisation, the five scheme rulebooks with --explain, and the other ten message definitions.