feat(mcp): currency param on create_article and update_article (#1184)

Fixes #1168. articles.currency exists in the DB and REST API, but the
staged-operation schemas and the two MCP tools had no currency param,
so agent-created articles were always SEK and an agent asked to create
an EUR-priced article could not.

- CreateArticleParamsSchema/UpdateArticleParamsSchema accept an
  optional ISO 4217 code (normalized to upper case; empty/null =
  unset). The currencies-table FK stays the allow-list: a 23503 on the
  currency FK maps to a clear 400 instead of a raw 500.
- commitCreateArticle inserts currency ?? 'SEK'; the sparse update
  executor passes it through only when staged.
- gnubok_create_article / gnubok_update_article expose the param.

Co-authored-by: Claude Fable 5 <noreply@anthropic.com>

extensions/general/mcp-server/server.ts

@@ -3911,6 +3911,7 @@ export const tools: McpTool[] = [
         type: { type: 'string', enum: ['vara', 'tjanst'], description: 'Good (vara) or service (tjanst). Default tjanst.' },
         unit: { type: 'string', description: 'Unit, e.g. st, tim, kg. Default st.' },
         price_excl_vat: { type: 'number', description: 'Unit price EXCLUDING VAT.' },
+        currency: { type: 'string', description: 'Price currency as ISO 4217 code (e.g. EUR). Default SEK. Pre-fills the invoice currency when the article is added.' },
         vat_rate: { type: 'number', enum: [0, 6, 12, 25], description: 'VAT rate percent. Default 25.' },
         revenue_account: { type: 'string', description: 'Optional BAS class-3 revenue account (e.g. 3041). Omit to derive from VAT.' },
         cost_price: { type: 'number', description: 'Optional cost price (margin only; never booked).' },
@@ -3942,6 +3943,7 @@ export const tools: McpTool[] = [
         type: (args.type as string) || 'tjanst',
         unit: (args.unit as string) || undefined,
         price_excl_vat: args.price_excl_vat,
+        currency: (args.currency as string) || undefined,
         vat_rate: typeof args.vat_rate === 'number' ? args.vat_rate : 25,
         revenue_account: (args.revenue_account as string) || null,
         cost_price: typeof args.cost_price === 'number' ? args.cost_price : null,
@@ -3983,6 +3985,7 @@ export const tools: McpTool[] = [
         type: { type: 'string', enum: ['vara', 'tjanst'] },
         unit: { type: 'string' },
         price_excl_vat: { type: 'number' },
+        currency: { type: 'string', description: 'Price currency as ISO 4217 code (e.g. EUR), or omit to leave unchanged.' },
         vat_rate: { type: 'number', enum: [0, 6, 12, 25] },
         revenue_account: { type: 'string', description: 'BAS class-3 revenue account, or omit to leave unchanged.' },
         cost_price: { type: 'number' },
@@ -4008,7 +4011,7 @@ export const tools: McpTool[] = [
 
       const params: Record<string, unknown> = { article_id: articleId }
       for (const key of [
-        'name', 'type', 'unit', 'price_excl_vat', 'vat_rate', 'revenue_account',
+        'name', 'type', 'unit', 'price_excl_vat', 'currency', 'vat_rate', 'revenue_account',
         'cost_price', 'ean', 'housework_type', 'name_en', 'notes', 'active',
       ]) {
         if (args[key] !== undefined) params[key] = args[key]

lib/pending-operations/commit.ts

@@ -488,6 +488,7 @@ async function commitCreateArticle(
       type: validated.type,
       unit: validated.unit ?? 'st',
       price_excl_vat: validated.price_excl_vat,
+      currency: validated.currency ?? 'SEK',
       vat_rate: validated.vat_rate,
       revenue_account: validated.revenue_account ?? null,
       cost_price: validated.cost_price ?? null,
@@ -499,7 +500,13 @@ async function commitCreateArticle(
     .select()
     .single()
 
-  if (error) return { error: error.message, status: 500 }
+  if (error) {
+    // FK to public.currencies: the reference table is the allow-list.
+    if (error.code === '23503' && error.message.includes('currency')) {
+      return { error: `Currency ${validated.currency} is not supported`, status: 400 }
+    }
+    return { error: error.message, status: 500 }
+  }
 
   if (!data.article_number) {
     try {
@@ -552,6 +559,10 @@ async function commitUpdateArticle(
 
   if (error) {
     if (error.code === 'PGRST116') return { error: 'Article not found', status: 404 }
+    // FK to public.currencies: the reference table is the allow-list.
+    if (error.code === '23503' && error.message.includes('currency')) {
+      return { error: `Currency ${validated.currency} is not supported`, status: 400 }
+    }
     return { error: error.message, status: 500 }
   }
 

lib/pending-operations/schemas/__tests__/article.test.ts

@@ -0,0 +1,36 @@
+import { describe, it, expect } from 'vitest'
+import { CreateArticleParamsSchema, UpdateArticleParamsSchema } from '../article'
+
+const base = { name: 'EU-konsulting', price_excl_vat: 950 }
+
+describe('CreateArticleParamsSchema currency', () => {
+  it('accepts and normalizes an ISO code to upper case', () => {
+    const parsed = CreateArticleParamsSchema.parse({ ...base, currency: 'eur' })
+    expect(parsed.currency).toBe('EUR')
+  })
+
+  it('treats empty string and null as unset (commit defaults to SEK)', () => {
+    expect(CreateArticleParamsSchema.parse({ ...base, currency: '' }).currency).toBeUndefined()
+    expect(CreateArticleParamsSchema.parse({ ...base, currency: null }).currency).toBeUndefined()
+    expect(CreateArticleParamsSchema.parse(base).currency).toBeUndefined()
+  })
+
+  it('rejects non-ISO shapes', () => {
+    expect(() => CreateArticleParamsSchema.parse({ ...base, currency: 'EURO' })).toThrow()
+    expect(() => CreateArticleParamsSchema.parse({ ...base, currency: 'E1' })).toThrow()
+  })
+})
+
+describe('UpdateArticleParamsSchema currency', () => {
+  const id = { article_id: '3a9ac4d2-163a-4d43-8fa3-1b32827505fa' }
+
+  it('accepts a currency-only update', () => {
+    const parsed = UpdateArticleParamsSchema.parse({ ...id, currency: 'usd' })
+    expect(parsed.currency).toBe('USD')
+  })
+
+  it('leaves currency undefined when omitted (sparse update must not touch it)', () => {
+    const parsed = UpdateArticleParamsSchema.parse({ ...id, name: 'Nytt namn' })
+    expect(parsed.currency).toBeUndefined()
+  })
+})

lib/pending-operations/schemas/article.ts

@@ -21,11 +21,20 @@ const trimmedName = z.preprocess(
   z.string().min(1, 'Article name is required').max(200),
 )
 
+// ISO 4217 shape, normalized to upper case; the currencies-table FK on
+// articles.currency is the authoritative allow-list (unknown codes fail at
+// commit with a clear message). Empty string / null → undefined.
+const currencyCode = z.preprocess(
+  (v) => (v == null || v === '' ? undefined : typeof v === 'string' ? v.trim().toUpperCase() : v),
+  z.string().regex(/^[A-Z]{3}$/, 'Currency must be a 3-letter ISO 4217 code (e.g. EUR)').optional(),
+)
+
 export const CreateArticleParamsSchema = z.object({
   name: trimmedName,
   type: z.enum(['vara', 'tjanst']).default('tjanst'),
   unit: optString(32),
   price_excl_vat: z.number().nonnegative(),
+  currency: currencyCode,
   vat_rate: vatRatePercent.default(25),
   revenue_account: invoicePostingAccount.nullable().optional(),
   cost_price: z.number().nonnegative().nullable().optional(),
@@ -42,6 +51,7 @@ export const UpdateArticleParamsSchema = z.object({
   type: z.enum(['vara', 'tjanst']).optional(),
   unit: optString(32),
   price_excl_vat: z.number().nonnegative().optional(),
+  currency: currencyCode,
   vat_rate: vatRatePercent.optional(),
   revenue_account: invoicePostingAccount.nullable().optional(),
   cost_price: z.number().nonnegative().nullable().optional(),