{ "name": "Check an invoice CSV for duplicate rows — no AI, no API key", "nodes": [ { "id": "6299154a-96f8-53de-af21-6fb2e170e691", "name": "Form: upload an invoice CSV", "type": "n8n-nodes-base.formTrigger", "typeVersion": 2.5, "position": [ 0, 0 ], "parameters": { "path": "check-invoice-csv-duplicates", "formTitle": "Check an invoice CSV for duplicate rows", "formDescription": "Upload a CSV invoice export. You get back the rows that repeat.", "formFields": { "values": [ { "fieldLabel": "Invoice CSV", "fieldType": "file", "requiredField": true } ] }, "responseMode": "responseNode", "options": {} } }, { "id": "5a51cfc6-6a6f-50b9-b111-bcaec04a803f", "name": "Settings", "type": "n8n-nodes-base.set", "typeVersion": 3.4, "position": [ 240, 0 ], "parameters": { "mode": "manual", "includeOtherFields": true, "assignments": { "assignments": [ { "id": "3b1b2ab0-d37f-5f5d-99f3-641610077556", "name": "dateOrder", "value": "dmy", "type": "string" }, { "id": "9e36f107-3bdd-56c6-8901-3458f017a38e", "name": "defaultCurrency", "value": "EUR", "type": "string" } ] }, "options": {} } }, { "id": "8e420768-6db0-5204-8138-bb461f65502c", "name": "Pick the file", "type": "n8n-nodes-base.code", "typeVersion": 2, "position": [ 480, 0 ], "parameters": { "mode": "runOnceForAllItems", "jsCode": "// The form puts the uploaded file in a binary field named after the form field.\n// Take the first file whatever it is called, and hand it on as \"data\".\nconst item = $input.first() || {};\nconst keys = Object.keys(item.binary || {});\nif (!keys.length) {\n throw new Error('No file arrived. Submit the form again and attach a CSV.');\n}\nconst file = item.binary[keys[0]];\nreturn [{\n json: { file_name: file.fileName || 'invoices.csv', mime_type: file.mimeType || '' },\n binary: { data: file },\n}];" } }, { "id": "61c98e93-1d2f-54cb-a449-84692089157e", "name": "CSV to text", "type": "n8n-nodes-base.extractFromFile", "typeVersion": 1.2, "position": [ 720, 0 ], "parameters": { "operation": "text", "binaryPropertyName": "data", "options": {}, "destinationKey": "data" }, "onError": "continueRegularOutput" }, { "id": "265adf3b-b364-50ba-81ab-46dc9c8ea83f", "name": "Check for duplicates", "type": "n8n-nodes-base.code", "typeVersion": 2, "position": [ 960, 0 ], "parameters": { "mode": "runOnceForAllItems", "jsCode": "/* LEDGER_CORE v1.0.0\n * Pure, dependency-free invoice parsing + ledger logic.\n * Inlined into each template's Code node by tools/build_workflows.py as the\n * subset of units that node's own code calls (tools/core_subset.py); the whole\n * file is unit-tested directly from Node (see tests/js/core.test.js).\n *\n * No network, no filesystem, no credentials, no environment access.\n * Every function is deterministic: same input -> same output, always.\n */\nfunction ledgerCore() {\n 'use strict';\n\n function normSpace(s) {\n return String(s == null ? '' : s).replace(/\\u00a0/g, ' ').replace(/\\s+/g, ' ').trim();\n }\n\n function stripDiacritics(s) {\n return String(s == null ? '' : s).normalize('NFD').replace(/[\\u0300-\\u036f]/g, '');\n }\n\n // ------------------------------------------------------------------- numbers\n // Decide what \".\" and \",\" mean in a numeric token.\n // Rules (documented, tested):\n // * both separators present -> the LAST one is the decimal separator\n // * one separator, 2 digits after -> decimal (\"1,50\" / \"1.50\")\n // * one separator, 3 digits after and 1-3 digits before -> thousands (\"1.234\" / \"1,234\")\n // * one separator, 1 digit after -> decimal (\"1,5\")\n // * repeated separator -> thousands (\"1.234.567\")\n function parseAmount(raw) {\n if (raw == null) return null;\n let s = String(raw).trim();\n if (!s) return null;\n\n let negative = false;\n if (/^\\(.*\\)$/.test(s)) { negative = true; s = s.slice(1, -1); }\n if (/-\\s*$/.test(s)) { negative = true; s = s.replace(/-\\s*$/, ''); }\n if (/^\\s*-/.test(s)) { negative = true; s = s.replace(/^\\s*-/, ''); }\n\n const stripped = s.replace(/[^0-9.,]/g, '');\n if (!/[0-9]/.test(stripped)) return null;\n\n const lastDot = stripped.lastIndexOf('.');\n const lastComma = stripped.lastIndexOf(',');\n let normalized;\n\n if (lastDot !== -1 && lastComma !== -1) {\n const decimalIsComma = lastComma > lastDot;\n normalized = decimalIsComma\n ? stripped.replace(/\\./g, '').replace(',', '.')\n : stripped.replace(/,/g, '');\n } else if (lastDot === -1 && lastComma === -1) {\n normalized = stripped;\n } else {\n const sep = lastDot !== -1 ? '.' : ',';\n const parts = stripped.split(sep);\n const occurrences = parts.length - 1;\n const tail = parts[parts.length - 1];\n const head = parts[0];\n const isThousands = occurrences > 1\n ? parts.slice(1).every((p) => p.length === 3)\n : (tail.length === 3 && head.length >= 1 && head.length <= 3 && /^[0-9]{3}$/.test(tail) && head !== '0');\n normalized = isThousands ? parts.join('') : parts.slice(0, -1).join('') + '.' + tail;\n }\n\n const value = Number(normalized);\n if (!Number.isFinite(value)) return null;\n return negative ? -value : value;\n }\n\n function round2(n) {\n return Math.round((Number(n) + Number.EPSILON) * 100) / 100;\n }\n\n /** Numbers arrive as strings from CSV; treat empty as absent, never concatenate. */\n\n function num(v) {\n if (v == null || v === '') return null;\n const n = Number(v);\n return Number.isFinite(n) ? n : null;\n }\n\n // ------------------------------------------------------------------ currency\n const CURRENCY_SYMBOLS = [\n ['€', 'EUR'], ['£', 'GBP'], ['$', 'USD'], ['₺', 'TRY'], ['¥', 'JPY'],\n ['₽', 'RUB'], ['₹', 'INR'], ['zł', 'PLN'], ['Kč', 'CZK'], ['kr', 'SEK'],\n ];\n\n const CURRENCY_CODES = [\n 'EUR', 'USD', 'GBP', 'TRY', 'CHF', 'SEK', 'NOK', 'DKK', 'PLN', 'CZK', 'HUF',\n 'RON', 'BGN', 'JPY', 'CAD', 'AUD', 'NZD', 'INR', 'BRL', 'MXN', 'ZAR', 'AED', 'SAR',\n ];\n\n function detectCurrency(text) {\n const s = String(text == null ? '' : text);\n const upper = s.toUpperCase();\n // An explicit ISO code next to an amount or a colon wins.\n for (const code of CURRENCY_CODES) {\n const re = new RegExp('(^|[^A-Z])' + code + '([^A-Z]|$)');\n if (re.test(upper)) return { code, source: 'iso-code', confidence: 0.9 };\n }\n for (const [symbol, code] of CURRENCY_SYMBOLS) {\n if (s.indexOf(symbol) !== -1) {\n // \"$\" is ambiguous (USD/CAD/AUD); note it.\n if (symbol === '$') return { code: 'USD', source: 'symbol', confidence: 0.6, ambiguous: true };\n return { code, source: 'symbol', confidence: 0.8 };\n }\n }\n return { code: null, source: 'none', confidence: 0 };\n }\n\n // --------------------------------------------------------------------- dates\n const MONTHS = {\n jan: 1, feb: 2, mar: 3, apr: 4, may: 5, jun: 6, jul: 7, aug: 8, sep: 9, sept: 9,\n oct: 10, nov: 11, dec: 12,\n january: 1, february: 2, march: 3, april: 4, june: 6, july: 7, august: 8,\n september: 9, october: 10, november: 11, december: 12,\n januar: 1, februar: 2, maerz: 3, marz: 3, mai: 5, juni: 6, juli: 7,\n oktober: 10, dezember: 12,\n janvier: 1, fevrier: 2, mars: 3, avril: 4, mai_fr: 5, juin: 6, juillet: 7, aout: 8,\n septembre: 9, octobre: 10, decembre: 12,\n };\n\n function pad2(n) { return String(n).padStart(2, '0'); }\n\n function isoFromParts(y, m, d) {\n if (!(y >= 1900 && y <= 2200) || !(m >= 1 && m <= 12) || !(d >= 1 && d <= 31)) return null;\n const dt = new Date(Date.UTC(y, m - 1, d));\n if (dt.getUTCFullYear() !== y || dt.getUTCMonth() !== m - 1 || dt.getUTCDate() !== d) return null;\n return `${y}-${pad2(m)}-${pad2(d)}`;\n }\n\n // order: 'auto' | 'dmy' | 'mdy'\n function parseDate(raw, order) {\n if (raw == null) return null;\n const s = normSpace(raw).replace(/^[^\\dA-Za-z]+|[^\\dA-Za-z]+$/g, '');\n if (!s) return null;\n const mode = order === 'mdy' ? 'mdy' : order === 'dmy' ? 'dmy' : 'auto';\n\n let m = s.match(/^(\\d{4})[-/.](\\d{1,2})[-/.](\\d{1,2})$/); // 2026-10-21\n if (m) return isoFromParts(+m[1], +m[2], +m[3]);\n\n m = s.match(/^(\\d{1,2})[-/.](\\d{1,2})[-/.](\\d{2,4})$/); // 21.10.2026\n if (m) {\n let [, a, b, y] = m;\n if (y.length === 2) y = String(2000 + Number(y));\n const na = +a, nb = +b;\n let d, mo;\n if (mode === 'mdy') { mo = na; d = nb; }\n else if (mode === 'dmy') { d = na; mo = nb; }\n else if (na > 12 && nb <= 12) { d = na; mo = nb; }\n else if (nb > 12 && na <= 12) { mo = na; d = nb; }\n else { d = na; mo = nb; } // ambiguous -> day-first, the common case outside the US\n return isoFromParts(+y, mo, d);\n }\n\n m = s.match(/^(\\d{1,2})\\.?\\s+([A-Za-z]{3,9})\\.?\\s+(\\d{4})$/); // 5 October 2026 / 5. Oktober 2026\n if (m) {\n const mo = MONTHS[m[2].toLowerCase()];\n if (mo) return isoFromParts(+m[3], mo, +m[1]);\n }\n\n m = s.match(/^([A-Za-z]{3,9})\\.?\\s+(\\d{1,2}),?\\s+(\\d{4})$/); // October 5, 2026\n if (m) {\n const mo = MONTHS[m[1].toLowerCase()];\n if (mo) return isoFromParts(+m[3], mo, +m[2]);\n }\n\n m = s.match(/^(\\d{1,2})\\s+([A-Za-z]{3,9})\\.?\\s+(\\d{2})$/); // 5 Oct 26\n if (m) {\n const mo = MONTHS[m[2].toLowerCase()];\n if (mo) return isoFromParts(2000 + Number(m[3]), mo, +m[1]);\n }\n return null;\n }\n\n // ------------------------------------------------------------------- supplier\n const LEGAL_SUFFIXES = [\n 'ltd', 'limited', 'llc', 'inc', 'incorporated', 'corp', 'corporation', 'co',\n 'gmbh', 'gmbh & co kg', 'ag', 'ug', 'ohg', 'kg', 'se',\n 'bv', 'b.v.', 'nv', 'n.v.', 'sa', 's.a.', 'sas', 'sarl', 'srl', 's.r.l.', 'spa', 's.p.a.',\n 'ab', 'as', 'a.s.', 'oy', 'aps', 'plc', 'pty', 'pte', 'sl', 's.l.', 'lda', 'kft', 'doo', 'd.o.o.',\n ];\n\n function normaliseSupplierKey(name) {\n let s = stripDiacritics(name || '').toLowerCase();\n s = s.replace(/&/g, ' and ');\n s = s.replace(/[^a-z0-9+ ]+/g, ' ');\n s = normSpace(s);\n // Match suffixes in the same canonical form as the string (\"S.r.l.\" -> \"s r l\").\n const canonicalSuffixes = LEGAL_SUFFIXES\n .map((x) => normSpace(x.replace(/[^a-z0-9 ]+/g, ' ')))\n .sort((a, b) => b.length - a.length);\n let changed = true;\n while (changed) {\n changed = false;\n for (const suffix of canonicalSuffixes) {\n if (!suffix) continue;\n const re = new RegExp('(^| )' + escapeForSuffix(suffix) + '$');\n if (re.test(s) && s.length > suffix.length) {\n s = normSpace(s.replace(re, ''));\n changed = true;\n }\n }\n }\n s = normSpace(s.replace(/(^| )(and|und|et|e)$/, ''));\n return s.replace(/ +/g, '-');\n }\n\n function escapeForSuffix(s) {\n return s.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\$&');\n }\n\n // RFC4180 reader: handles quoted fields, embedded commas/quotes/newlines, CRLF.\n function parseCsv(text) {\n const src = String(text == null ? '' : text).replace(/^\\uFEFF/, '');\n const rows = [];\n let row = [];\n let field = '';\n let inQuotes = false;\n for (let i = 0; i < src.length; i++) {\n const ch = src[i];\n if (inQuotes) {\n if (ch === '\"') {\n if (src[i + 1] === '\"') { field += '\"'; i++; } else { inQuotes = false; }\n } else { field += ch; }\n continue;\n }\n if (ch === '\"') { inQuotes = true; continue; }\n if (ch === ',') { row.push(field); field = ''; continue; }\n if (ch === '\\r') continue;\n if (ch === '\\n') { row.push(field); rows.push(row); row = []; field = ''; continue; }\n field += ch;\n }\n if (field !== '' || row.length) { row.push(field); rows.push(row); }\n if (!rows.length) return [];\n const headers = rows[0].map((h) => String(h).trim());\n const out = [];\n for (let r = 1; r < rows.length; r++) {\n const cells = rows[r];\n if (cells.length === 1 && cells[0] === '') continue;\n const obj = {};\n headers.forEach((h, i) => { obj[h] = cells[i] == null ? '' : cells[i]; });\n out.push(obj);\n }\n return out;\n }\n\n // ------------------------------------------------------- csv column mapping (free-03)\n // A CSV a user already has carries THEIR header names. These are the spellings this\n // module recognises, per field. Nothing here is a locale guess: a header that is not\n // listed stays unmapped, and the caller reports what it could not find rather than\n // picking a column that might be wrong.\n const CSV_FIELDS = ['supplier', 'invoice_number', 'invoice_date', 'gross', 'currency'];\n\n const CSV_REQUIRED = ['supplier', 'invoice_number', 'gross'];\n\n const CSV_ALIASES = {\n supplier: ['supplier', 'vendor', 'seller', 'merchant', 'payee', 'company', 'counterparty',\n 'supplier name', 'vendor name', 'company name', 'name', 'from'],\n invoice_number: ['invoice number', 'invoice no', 'invoice nr', 'invoice', 'invoice #',\n 'number', 'no', 'num', 'reference', 'ref', 'invoice reference', 'invoice ref',\n 'document number', 'doc number', 'bill number', 'bill no', 'inv no', 'inv number'],\n invoice_date: ['invoice date', 'date', 'bill date', 'document date', 'issue date',\n 'issued date', 'invoice dt'],\n gross: ['total', 'gross', 'amount', 'total amount', 'invoice total', 'gross total',\n 'grand total', 'sum', 'total gross', 'amount total'],\n currency: ['currency', 'ccy', 'cur', 'currency code'],\n };\n\n // A header containing one of these is NOT the field: \"Net Total\" is the net amount and\n // must never be used as the gross, or every total comparison silently shifts.\n const CSV_EXCLUDE = { gross: ['net', 'tax', 'vat', 'sub', 'without'] };\n\n function headerTokens(header) {\n return stripDiacritics(String(header == null ? '' : header)).toLowerCase()\n .replace(/[^a-z0-9]+/g, ' ').trim().split(' ').filter(Boolean);\n }\n\n function tokensMatch(header, alias, exclude) {\n const h = headerTokens(header);\n const a = alias.split(' ');\n if (exclude && exclude.some((bad) => h.indexOf(bad) !== -1)) return false;\n for (let i = 0; i + a.length <= h.length; i++) {\n let ok = true;\n for (let j = 0; j < a.length; j++) if (h[i + j] !== a[j]) { ok = false; break; }\n if (ok) return true;\n }\n return false;\n }\n\n /**\n * Decide which column holds which field. Exact alias matches first, then a contiguous\n * token match (\"Sum (EUR)\" -> sum). Each header is used at most once.\n * Returns {map, missingRequired, missingOptional, unmappedHeaders}\n */\n\n function guessCsvColumns(headers) {\n const cols = (headers || []).map((h) => String(h == null ? '' : h));\n const map = {};\n const used = {};\n for (const exact of [true, false]) {\n for (const field of CSV_FIELDS) {\n if (map[field]) continue;\n const exclude = CSV_EXCLUDE[field];\n let best = null;\n for (const header of cols) {\n if (used[header]) continue;\n let longest = 0;\n for (const alias of (CSV_ALIASES[field] || [])) {\n const hit = exact\n ? headerTokens(header).join(' ') === alias\n : tokensMatch(header, alias, exclude);\n if (hit && alias.length > longest) longest = alias.length;\n }\n // More specific alias wins; an earlier header only wins a tie. \"Vendor\" beats\n // \"Name\" for the supplier even when \"Name\" comes first in the file.\n if (longest > 0 && (best === null || longest > best.length)) best = { header, length: longest };\n }\n if (best) { map[field] = best.header; used[best.header] = true; }\n }\n }\n return {\n map,\n missingRequired: CSV_REQUIRED.filter((f) => !map[f]),\n missingOptional: CSV_FIELDS.filter((f) => !CSV_REQUIRED.includes(f) && !map[f]),\n unmappedHeaders: cols.filter((h) => !used[h]),\n };\n }\n\n /**\n * Turn parsed CSV rows into the five fields the audit compares, keeping the row number a\n * spreadsheet would show (header = row 1) so the user can find the row in their own file.\n * Every value it could not read becomes a `problems` entry instead of a silent blank.\n */\n\n function normaliseCsvRows(rows, columnMap, opts) {\n const o = opts || {};\n const map = columnMap || {};\n const out = [];\n (rows || []).forEach((raw, i) => {\n const cell = (field) => (map[field] ? (raw || {})[map[field]] : undefined);\n const supplier = normSpace(cell('supplier'));\n const supplierKey = supplier ? normaliseSupplierKey(supplier) : '';\n const invoiceNumber = normSpace(cell('invoice_number')).toUpperCase();\n const dateRaw = normSpace(cell('invoice_date'));\n const grossRaw = normSpace(cell('gross'));\n const currencyRaw = normSpace(cell('currency'));\n\n const invoiceDate = dateRaw ? parseDate(dateRaw, o.dateOrder || 'auto') : null;\n const gross = grossRaw ? parseAmount(grossRaw) : null;\n const detected = currencyRaw ? detectCurrency(currencyRaw).code : null;\n const currency = detected || o.defaultCurrency || null;\n\n const problems = [];\n if (!supplierKey) problems.push('no supplier name');\n if (!invoiceNumber) problems.push('no invoice number');\n if (grossRaw && gross == null) problems.push('total not readable');\n if (dateRaw && invoiceDate == null) problems.push('date not readable');\n\n // A row is checkable when it has a supplier and an invoice number. A row without a\n // number is reported, never grouped: two identical rows with no number could be two\n // identical purchases, and calling them duplicates would be a guess.\n const checkable = Boolean(supplierKey && invoiceNumber);\n\n out.push({\n row: i + 2, supplier, supplier_key: supplierKey, invoice_number: invoiceNumber,\n invoice_date: invoiceDate, gross, currency, problems, checkable,\n });\n });\n return out;\n }\n\n /**\n * Find rows that are the same bill twice. Two exact checks only:\n * same_invoice_number — one supplier, one invoice number, two lines\n * same_supplier_date_and_total — one supplier, same date and total, two invoice numbers\n * No window and no amount tolerance: two bills 9 days apart with totals 1% apart are not\n * called duplicates here (that is the ledger's near-duplicate rule, not this audit's job).\n */\n\n function findExactDuplicates(rows) {\n const list = (rows || []).filter(Boolean);\n const groups = [];\n const flagged = {};\n const uncheckable = [];\n\n for (const r of list) {\n if (!r.checkable) { uncheckable.push({ row: r.row, problems: r.problems || [] }); continue; }\n if (!r.supplier_key || !r.invoice_number) continue;\n const key = `${r.supplier_key}|${String(r.invoice_number).toUpperCase().replace(/[^A-Z0-9]/g, '')}`;\n r.__key = key;\n }\n\n const byNumber = {};\n for (const r of list) {\n if (!r.__key) continue;\n (byNumber[r.__key] = byNumber[r.__key] || []).push(r);\n }\n for (const key of Object.keys(byNumber)) {\n const bucket = byNumber[key];\n if (bucket.length < 2) continue;\n bucket.forEach((r) => { flagged[r.row] = true; });\n groups.push({\n kind: 'same_invoice_number',\n key,\n rows: bucket.map((r) => r.row),\n supplier: bucket[0].supplier,\n invoice_numbers: bucket.map((r) => r.invoice_number),\n });\n }\n\n const byBill = {};\n for (const r of list) {\n if (!r.checkable || flagged[r.row]) continue;\n if (!r.invoice_date || r.gross == null) continue;\n const key = `${r.supplier_key}|${r.invoice_date}|${round2(r.gross)}|${r.currency || ''}`;\n (byBill[key] = byBill[key] || []).push(r);\n }\n for (const key of Object.keys(byBill)) {\n const bucket = byBill[key];\n if (bucket.length < 2) continue;\n const numbers = bucket.map((r) => r.invoice_number).filter(Boolean);\n bucket.forEach((r) => { flagged[r.row] = true; });\n groups.push({\n kind: 'same_supplier_date_and_total',\n key,\n rows: bucket.map((r) => r.row),\n supplier: bucket[0].supplier,\n invoice_numbers: numbers,\n });\n }\n\n // __key is internal: strip it so a caller cannot mistake it for output data.\n for (const r of list) delete r.__key;\n\n return {\n groups,\n flaggedRows: Object.keys(flagged).map(Number).sort((a, b) => a - b),\n checkedRows: list.filter((r) => r.checkable).length,\n uncheckable,\n };\n }\n\n return {\n // text\n normSpace, stripDiacritics,\n // numbers + dates + currency\n parseAmount, round2, detectCurrency, parseDate, isoFromParts, pad2,\n // suppliers\n normaliseSupplierKey,\n // output\n parseCsv,\n // csv audit (free-03)\n guessCsvColumns, normaliseCsvRows, findExactDuplicates,\n // version\n VERSION: '1.0.0',\n };\n}\n// Read the CSV, say which column is which, then look for the same bill twice.\n// Every branch returns data — none of them throws at the user in the browser.\nconst C = ledgerCore();\nconst settings = $('Settings').first().json || {};\nconst text = $input.first().json.data || $input.first().json.text || '';\nconst file = $('Pick the file').first().json;\nconst base = {\n file_name: (file && file.file_name) || 'invoices.csv',\n rows_read: 0,\n headers: [],\n columns: { map: {}, missingRequired: [], missingOptional: [], unmappedHeaders: [] },\n checked_rows: 0,\n duplicate_groups: 0,\n duplicate_rows: 0,\n groups: [],\n flagged: {},\n skipped: [],\n warnings: [],\n};\n\nif (!String(text).trim()) {\n return [{ json: Object.assign({}, base, { status: 'no_text' }) }];\n}\n\nconst rows = C.parseCsv(text);\nif (!rows.length) {\n return [{ json: Object.assign({}, base, { status: 'no_rows' }) }];\n}\n\nconst headers = Object.keys(rows[0]);\nconst columns = C.guessCsvColumns(headers);\nif (columns.missingRequired.length) {\n return [{ json: Object.assign({}, base, {\n status: 'columns_missing', rows_read: rows.length, headers, columns,\n }) }];\n}\n\nconst normalised = C.normaliseCsvRows(rows, columns.map, {\n dateOrder: settings.dateOrder || 'auto',\n defaultCurrency: settings.defaultCurrency || null,\n});\nconst audit = C.findExactDuplicates(normalised);\n\nconst byRow = {};\nfor (const r of normalised) byRow[r.row] = r;\nconst flagged = {};\nfor (const n of audit.flaggedRows) {\n const r = byRow[n] || {};\n flagged[n] = {\n invoice_number: r.invoice_number || '',\n invoice_date: r.invoice_date || null,\n gross: r.gross == null ? null : r.gross,\n currency: r.currency || '',\n };\n}\n\nreturn [{ json: Object.assign({}, base, {\n status: 'ok',\n rows_read: rows.length,\n headers,\n columns,\n checked_rows: audit.checkedRows,\n duplicate_groups: audit.groups.length,\n duplicate_rows: audit.flaggedRows.length,\n groups: audit.groups,\n flagged,\n skipped: audit.uncheckable,\n warnings: normalised.filter((r) => r.checkable && r.problems.length)\n .map((r) => ({ row: r.row, invoice_number: r.invoice_number, problems: r.problems })),\n}) }];" } }, { "id": "7734b06d-b978-57c0-bff4-1ce74266d6fc", "name": "Result", "type": "n8n-nodes-base.code", "typeVersion": 2, "position": [ 1200, 0 ], "parameters": { "mode": "runOnceForAllItems", "jsCode": "// One readable answer: what was checked, what repeats, what could not be checked.\nconst r = $input.first().json;\nconst name = r.file_name || 'the CSV';\nconst lines = [];\n\nif (r.status === 'no_text') {\n lines.push('No text could be read from ' + name + '.');\n lines.push('');\n lines.push('Save the export as CSV (comma separated, UTF-8) and upload it again.');\n} else if (r.status === 'no_rows') {\n lines.push('The CSV has a header row and no data rows under it.');\n lines.push('Export at least one invoice and upload it again.');\n} else if (r.status === 'columns_missing') {\n // Human words, not the internal field names. This refusal is read by the person who\n // uploaded the file, and \"no invoice_number column\" tells them nothing.\n const NAMES = { supplier: 'supplier', invoice_number: 'invoice number', gross: 'total' };\n const missing = r.columns.missingRequired.map((f) => NAMES[f] || f);\n lines.push('This CSV was not checked: no ' + missing.join(' and no ') + ' column.');\n lines.push('');\n lines.push('Columns found: ' + (r.headers.join(', ') || '(none)'));\n if (r.columns.unmappedHeaders.length) {\n lines.push('Columns it did not need: ' + r.columns.unmappedHeaders.join(', '));\n }\n lines.push('');\n lines.push('Name one column for the supplier, one for the invoice number and one for the');\n lines.push('total — for example \"Supplier\", \"Invoice No\", \"Total\" — and upload it again.');\n lines.push('A PDF, an XLSX file or a semicolon-separated export is not read: save it as');\n lines.push('comma-separated CSV first.');\n} else {\n const c = r.columns.map;\n const used = ['supplier = \"' + c.supplier + '\"', 'invoice number = \"' + c.invoice_number + '\"'];\n if (c.invoice_date) used.push('date = \"' + c.invoice_date + '\"');\n if (c.gross) used.push('total = \"' + c.gross + '\"');\n if (c.currency) used.push('currency = \"' + c.currency + '\"');\n lines.push('Checked ' + name + ': ' + r.rows_read + ' data row(s).');\n lines.push('Columns used: ' + used.join(', '));\n lines.push('Rows checked: ' + r.checked_rows + '. Rows skipped: ' + r.skipped.length + '.');\n lines.push('');\n if (!r.duplicate_groups) {\n lines.push('No duplicate rows found.');\n } else {\n lines.push(r.duplicate_groups + ' duplicate group(s), covering ' + r.duplicate_rows + ' row(s):');\n for (const g of r.groups) {\n const what = g.kind === 'same_invoice_number'\n ? 'the same invoice number ' + (g.invoice_numbers[0] || '')\n : 'the same supplier, date and total under ' + g.invoice_numbers.join(' / ');\n const amounts = [];\n for (const n of g.rows) {\n const d = r.flagged[n] || {};\n if (d.gross != null) amounts.push(d.gross + (d.currency ? ' ' + d.currency : ''));\n }\n lines.push('- rows ' + g.rows.join(', ') + ': ' + g.supplier + ' — ' + what +\n (amounts.length ? ' (' + amounts.join(' / ') + ')' : ''));\n }\n }\n if (r.warnings.length) {\n lines.push('');\n lines.push('Read, but not compared on every field:');\n for (const w of r.warnings) {\n lines.push('- row ' + w.row + ' (' + (w.invoice_number || 'no number') + '): ' + w.problems.join('; '));\n }\n }\n if (r.skipped.length) {\n lines.push('');\n lines.push('Skipped, so not checked at all:');\n for (const s of r.skipped) lines.push('- row ' + s.row + ': ' + s.problems.join('; '));\n }\n lines.push('');\n lines.push('A row needs a supplier and an invoice number to be checked. Two rows with the same');\n lines.push('number, or the same supplier, date and total under different numbers, are reported.');\n lines.push('Totals 1% apart and bills days apart are NOT compared: that near-duplicate rule, and');\n lines.push('anything written to a ledger, is what the paid pack does.');\n}\n\nlines.push('');\nlines.push('Nothing was written to a ledger, and no invoice left this machine. n8n still');\nlines.push('keeps this run in its own execution log until it prunes old executions.');\n\nreturn [{ json: {\n status: r.status,\n rows_read: r.rows_read,\n checked_rows: r.checked_rows,\n duplicate_groups: r.duplicate_groups,\n duplicate_rows: r.duplicate_rows,\n skipped_rows: r.skipped.length,\n warning_rows: r.warnings.length,\n summary: lines.join('\\n'),\n} }];" } }, { "id": "eac2dbec-35c4-5fdd-9f83-32f01d87896c", "name": "Answer the form", "type": "n8n-nodes-base.respondToWebhook", "typeVersion": 1.5, "position": [ 1440, 0 ], "parameters": { "respondWith": "json", "responseBody": "={{ JSON.stringify($json) }}", "options": {} } }, { "id": "6e237352-61e3-5b26-9546-d8e02ccdf7ae", "name": "Note: Upload an invoice CSV you already have a", "type": "n8n-nodes-base.stickyNote", "typeVersion": 1, "position": [ 0, -700 ], "parameters": { "content": "Upload an invoice CSV you already have and get a read-only report of the rows that\nrepeat: the same invoice number twice, or the same supplier, date and total booked\nunder two numbers. It needs no account, no credential and no AI model, and it writes\nnothing: the CSV stays on the machine that runs n8n.\n\n### How it works\n- *Form: upload an invoice CSV* takes one CSV export.\n- *Pick the file* passes the upload on as file data.\n- *CSV to text* reads the file as text.\n- *Check for duplicates* decides which column is the supplier, the invoice number,\n the date and the total, then compares rows. A row with no supplier or no invoice\n number is reported, never grouped.\n- *Result* prints the columns it used, every duplicate group with its row numbers,\n and every row it could not check, plus the reason.\n\n### Setup\nNo credential and no install. Click *Test workflow*, open the form URL n8n shows,\nand upload a CSV export from your bookkeeping or spreadsheet.\n\n### Customization\n`dateOrder` (auto / dmy / mdy) and `defaultCurrency` are in *Settings*. If a column\nname is not recognised, rename it in the CSV or add the spelling to the alias lists\nin the *Check for duplicates* code.", "width": 680, "height": 560, "color": 1 } }, { "id": "f94b6036-753f-53a6-9218-0f48ede25041", "name": "Note: Upload a CSV, see which rows repeat, wri", "type": "n8n-nodes-base.stickyNote", "typeVersion": 1, "position": [ 0, -80 ], "parameters": { "content": "### Upload a CSV, see which rows repeat, write nothing", "width": 1700, "height": 60, "color": 7 } } ], "connections": { "Form: upload an invoice CSV": { "main": [ [ { "node": "Settings", "type": "main", "index": 0 } ] ] }, "Settings": { "main": [ [ { "node": "Pick the file", "type": "main", "index": 0 } ] ] }, "Pick the file": { "main": [ [ { "node": "CSV to text", "type": "main", "index": 0 } ] ] }, "CSV to text": { "main": [ [ { "node": "Check for duplicates", "type": "main", "index": 0 } ] ] }, "Check for duplicates": { "main": [ [ { "node": "Result", "type": "main", "index": 0 } ] ] }, "Result": { "main": [ [ { "node": "Answer the form", "type": "main", "index": 0 } ] ] } }, "settings": { "executionOrder": "v1", "saveDataSuccessExecution": "all" }, "active": false }