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accounted/extensions/ai-categorization/categorizer.ts
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2026-02-19 09:48:02 +01:00

270 lines
8.9 KiB
TypeScript

/**
* AI Categorization Engine
*
* SERVER-ONLY: Uses the Anthropic SDK and must only be imported
* in server components or API routes.
*
* Provider-abstracted AI categorization for Swedish BAS account mapping.
* Default implementation uses Claude Haiku for cost efficiency.
*/
import 'server-only'
import Anthropic from '@anthropic-ai/sdk'
import type { TransactionCategory, EntityType } from '@/types'
// ============================================================
// Types
// ============================================================
export interface TransactionForCategorization {
id: string
description: string
amount: number
date: string
merchant_name: string | null
mcc_code: number | null
currency: string
}
export interface CategorizationContext {
entityType: EntityType
recentHistory: { description: string; category: string }[]
}
export interface CategorizationSuggestion {
transactionId: string
category: TransactionCategory
basAccount: string
taxCode: string | null
confidence: number
reasoning: string
isPrivate: boolean
}
export interface CategorizationProvider {
categorize(
transactions: TransactionForCategorization[],
context: CategorizationContext
): Promise<CategorizationSuggestion[]>
}
// ============================================================
// BAS Account + Category Mapping (used in prompt)
// ============================================================
const CATEGORY_ACCOUNT_MAP: Record<string, { account: string; label: string }> = {
income_services: { account: '3001', label: 'Tjänsteförsäljning' },
income_products: { account: '3001', label: 'Varuförsäljning' },
income_other: { account: '3900', label: 'Övriga intäkter' },
expense_equipment: { account: '5410', label: 'Förbrukningsinventarier' },
expense_software: { account: '5420', label: 'Programvara' },
expense_travel: { account: '5800', label: 'Resekostnader' },
expense_office: { account: '5010', label: 'Lokalhyra/kontorskostnad' },
expense_marketing: { account: '5910', label: 'Annonsering/marknadsföring' },
expense_professional_services: { account: '6530', label: 'Redovisning/konsulttjänster' },
expense_education: { account: '6991', label: 'Utbildning' },
expense_bank_fees: { account: '6570', label: 'Bankavgifter' },
expense_card_fees: { account: '6570', label: 'Kortavgifter' },
expense_currency_exchange: { account: '7960', label: 'Valutakursförluster' },
expense_other: { account: '6991', label: 'Övriga kostnader' },
private: { account: '2013', label: 'Privat uttag (EF) / Skuld till ägare (AB)' },
}
const NON_DEDUCTIBLE_RULES = `
ICKE-AVDRAGSGILLA KOSTNADER (svensk skatterätt):
- Kläder: Normalt inte avdragsgilla (RÅ 1988 ref. 35)
- Gym/träning: Inte avdragsgilla som personlig kostnad (IL 9 kap 2§)
- Kosmetika/hudvård: Normalt inte avdragsgillt
- Frisör: Normalt privat kostnad
- Representation/måltider: Max 300 kr/person exkl. moms (IL 16 kap 2§)
- Gåvor: Reklamgåvor max 300 kr/mottagare, representationsgåvor max 180 kr
- Telefon/dator vid blandad användning: Bara yrkesmässig del avdragsgill
`
// ============================================================
// Anthropic Provider
// ============================================================
const MAX_RETRIES = 3
const RETRY_DELAY_MS = 1000
const MAX_BATCH_SIZE = 20
export class AnthropicCategorizationProvider implements CategorizationProvider {
private client: Anthropic
private model: string
constructor(model = 'claude-haiku-4-5-20251001') {
this.client = new Anthropic()
this.model = model
}
async categorize(
transactions: TransactionForCategorization[],
context: CategorizationContext
): Promise<CategorizationSuggestion[]> {
// Cap batch size
const batch = transactions.slice(0, MAX_BATCH_SIZE)
if (batch.length === 0) return []
const privateAccount = context.entityType === 'aktiebolag' ? '2893' : '2013'
const systemPrompt = `Du är expert på svensk bokföring och kategorisering av banktransaktioner enligt BAS-kontoplanen.
Din uppgift är att kategorisera varje transaktion till rätt kategori och BAS-konto.
KATEGORIER OCH BAS-KONTON:
${Object.entries(CATEGORY_ACCOUNT_MAP)
.map(([cat, info]) => `- ${cat}: ${info.account} (${info.label})`)
.join('\n')}
Företagsform: ${context.entityType === 'aktiebolag' ? 'Aktiebolag (AB)' : 'Enskild firma (EF)'}
Privatkonto: ${privateAccount}
MOMSHANTERING:
- Bankavgifter, kortavgifter, valutaväxling: MOMSFRIA
- Övriga affärskostnader: Normalt 25% moms (ingående moms, MPI)
- Intäkter: Normalt 25% moms (utgående moms, MP1)
${NON_DEDUCTIBLE_RULES}
REGLER:
1. Negativa belopp = utgifter, positiva = intäkter
2. Markera transaktioner som troligen är privata med isPrivate: true
3. Ange confidence 0.0-1.0 baserat på hur säker du är
4. Ange kort reasoning på svenska
5. Om en transaktion liknar privat konsumtion (kläder, gym, etc.), sätt category: "private"
6. taxCode: "MPI" för avdragsgilla affärskostnader med moms, "MP1" för intäkter med moms, null för momsfria/privata`
const historyContext =
context.recentHistory.length > 0
? `\nAnvändarens senaste kategoriseringar (lär dig mönster):\n${context.recentHistory
.slice(0, 30)
.map((h) => `- "${h.description}" → ${h.category}`)
.join('\n')}`
: ''
const transactionList = batch
.map(
(t, i) =>
`${i + 1}. ID: ${t.id}
Beskrivning: ${t.description}
Belopp: ${t.amount} ${t.currency}
Datum: ${t.date}${t.merchant_name ? `\n Handlare: ${t.merchant_name}` : ''}${t.mcc_code ? `\n MCC: ${t.mcc_code}` : ''}`
)
.join('\n\n')
const userPrompt = `Kategorisera följande transaktioner:
${historyContext}
TRANSAKTIONER:
${transactionList}
Returnera ett JSON-objekt med följande struktur:
{
"suggestions": [
{
"transactionId": "id",
"category": "expense_software",
"basAccount": "5420",
"taxCode": "MPI",
"confidence": 0.9,
"reasoning": "Spotify-prenumeration, typisk programvarukostnad",
"isPrivate": false
}
]
}
Returnera ENDAST JSON-objektet, ingen annan text.`
let lastError: Error | null = null
for (let attempt = 0; attempt < MAX_RETRIES; attempt++) {
try {
const message = await this.client.messages.create({
model: this.model,
max_tokens: 4096,
system: systemPrompt,
messages: [
{
role: 'user',
content: userPrompt,
},
],
})
const content = message.content[0]
if (content.type !== 'text') {
throw new Error('Unexpected response type from AI')
}
// Strip markdown code blocks if present
let jsonText = content.text.trim()
if (jsonText.startsWith('```json')) {
jsonText = jsonText.slice(7)
} else if (jsonText.startsWith('```')) {
jsonText = jsonText.slice(3)
}
if (jsonText.endsWith('```')) {
jsonText = jsonText.slice(0, -3)
}
jsonText = jsonText.trim()
const parsed = JSON.parse(jsonText)
return this.validateSuggestions(parsed.suggestions || [], batch)
} catch (error) {
lastError = error instanceof Error ? error : new Error('Unknown error')
// Don't retry on parse errors
if (error instanceof SyntaxError) {
throw new Error(`Failed to parse AI response: ${lastError.message}`)
}
if (attempt < MAX_RETRIES - 1) {
await sleep(RETRY_DELAY_MS * (attempt + 1))
}
}
}
throw new Error(
`AI categorization failed after ${MAX_RETRIES} attempts: ${lastError?.message}`
)
}
private validateSuggestions(
raw: unknown[],
transactions: TransactionForCategorization[]
): CategorizationSuggestion[] {
if (!Array.isArray(raw)) return []
const validTransactionIds = new Set(transactions.map((t) => t.id))
const validCategories = new Set(Object.keys(CATEGORY_ACCOUNT_MAP).concat(['uncategorized']))
return raw
.filter(
(s): s is Record<string, unknown> =>
s !== null && typeof s === 'object' && 'transactionId' in s
)
.filter((s) => validTransactionIds.has(s.transactionId as string))
.map((s) => {
const category = validCategories.has(s.category as string)
? (s.category as TransactionCategory)
: 'expense_other'
const accountInfo = CATEGORY_ACCOUNT_MAP[category]
return {
transactionId: s.transactionId as string,
category,
basAccount: accountInfo?.account || (s.basAccount as string) || '6991',
taxCode: (s.taxCode as string) || null,
confidence: Math.max(0, Math.min(1, Number(s.confidence) || 0.5)),
reasoning: (s.reasoning as string) || '',
isPrivate: category === 'private' || Boolean(s.isPrivate),
}
})
}
}
function sleep(ms: number): Promise<void> {
return new Promise((resolve) => setTimeout(resolve, ms))
}