fix(eid-wallet): show the identity verification screens in the app's language

infrastructure/eid-wallet/src/routes/(app)/ePassport/+page.svelte

@@ -7,6 +7,7 @@ import {
 import { AppNav, IdentityCard } from "$lib/fragments";
 import type { GlobalState } from "$lib/global";
 import { m } from "$lib/i18n";
+import { getLocale } from "$lib/paraglide/runtime";
 import { ButtonAction, CopyableEName } from "$lib/ui";
 import {
     addCounterpartySignature,
@@ -178,7 +179,7 @@ async function startKycUpgrade() {
 
         const { data } = await axios.post(
             new URL("/verification/v2", PUBLIC_PROVISIONER_URL).toString(),
-            {},
+            { language: getLocale() },
             {
                 headers: {
                     "x-shared-secret": PUBLIC_PROVISIONER_SHARED_SECRET,

infrastructure/eid-wallet/src/routes/(app)/main/legacy/KycUpgradeOverlay.svelte

@@ -14,6 +14,7 @@ import {
 } from "$env/static/public";
 import type { GlobalState } from "$lib/global";
 import { m } from "$lib/i18n";
+import { getLocale } from "$lib/paraglide/runtime";
 import { CopyableEName } from "$lib/ui";
 import * as Button from "$lib/ui/Button";
 import { capitalize } from "$lib/utils";
@@ -164,7 +165,7 @@ async function startKycUpgrade() {
 
         const { data } = await axios.post(
             new URL("/verification/v2", PUBLIC_PROVISIONER_URL).toString(),
-            {},
+            { language: getLocale() },
             {
                 headers: {
                     "x-shared-secret": PUBLIC_PROVISIONER_SHARED_SECRET,

infrastructure/eid-wallet/src/routes/(auth)/onboarding/+page.svelte

@@ -9,6 +9,7 @@ import {
 import { Hero } from "$lib/fragments";
 import { GlobalState } from "$lib/global";
 import { m } from "$lib/i18n";
+import { getLocale } from "$lib/paraglide/runtime";
 import { pendingRecovery } from "$lib/stores/pendingRecovery";
 import { ButtonAction, CopyableEName, LoadingSheet } from "$lib/ui";
 import { capitalize, getCanonicalBindingDocString } from "$lib/utils";
@@ -458,7 +459,7 @@ const handleKycNext = async () => {
 
         const { data } = await axios.post(
             new URL("/verification/v2", PUBLIC_PROVISIONER_URL).toString(),
-            {},
+            { language: getLocale() },
             {
                 headers: {
                     "x-shared-secret": PUBLIC_PROVISIONER_SHARED_SECRET,

infrastructure/eid-wallet/src/routes/(public)/recover/+page.svelte

@@ -206,6 +206,7 @@ async function startVerifiedRecovery() {
                 "/recovery/start-session",
                 PUBLIC_PROVISIONER_URL,
             ).toString(),
+            { language: getLocale() },
         );
 
         if (!data.verificationUrl) {

infrastructure/evault-core/src/controllers/RecoveryController.ts

@@ -4,6 +4,7 @@ import FormData from "form-data";
 import { validate as uuidValidate } from "uuid";
 import type { VerificationService } from "../services/VerificationService";
 import { signAsProvisioner } from "../core/utils/provisioner-signer";
+import { verificationLanguage } from "../utils/verificationLanguage";
 
 const diditClient = Axios.create({ baseURL: "https://verification.didit.me" });
 
@@ -225,11 +226,16 @@ export class RecoveryController {
             }
 
             try {
+                const language = verificationLanguage(req.body?.language);
                 const verification = await this.verificationService.create({});
 
                 const { data: diditSession } = await diditClient.post(
                     "/v3/session/",
-                    { workflow_id: workflowId, vendor_data: verification.id },
+                    {
+                        workflow_id: workflowId,
+                        vendor_data: verification.id,
+                        language,
+                    },
                     { headers: { "x-api-key": apiKey, "Content-Type": "application/json" } },
                 );
 
@@ -238,7 +244,7 @@ export class RecoveryController {
                 const verificationUrl: string =
                     diditSession.verification_url ??
                     diditSession.url ??
-                    `https://verify.didit.me/session/${sessionToken}`;
+                    `https://verify.didit.me/${language}/session/${sessionToken}`;
 
                 await this.verificationService.findByIdAndUpdate(verification.id, {
                     diditSessionId: sessionId,

infrastructure/evault-core/src/controllers/VerificationController.ts

@@ -3,6 +3,7 @@ import { default as Axios } from "axios";
 import { validate as uuidValidate } from "uuid";
 import { VerificationService } from "../services/VerificationService";
 import type { ProvisioningService } from "../services/ProvisioningService";
+import { verificationLanguage } from "../utils/verificationLanguage";
 
 const diditClient = Axios.create({
     baseURL: "https://verification.didit.me",
@@ -50,6 +51,7 @@ export class VerificationController {
             if (!requireSharedSecret(req, res)) return;
             console.log("Creating new Didit verification session");
             const { referenceId } = req.body;
+            const language = verificationLanguage(req.body?.language);
 
             if (referenceId) {
                 const existing = await this.verificationService.findOne({ referenceId });
@@ -73,6 +75,7 @@ export class VerificationController {
                     {
                         workflow_id: workflowId,
                         vendor_data: verification.id,
+                        language,
                     },
                     {
                         headers: {
@@ -99,7 +102,7 @@ export class VerificationController {
             const verificationUrl: string =
                 diditSession.verification_url ??
                 diditSession.url ??
-                `https://verify.didit.me/session/${sessionToken}`;
+                `https://verify.didit.me/${language}/session/${sessionToken}`;
 
             await this.verificationService.findByIdAndUpdate(verification.id, {
                 diditSessionId: sessionId,

infrastructure/evault-core/src/utils/verificationLanguage.spec.ts

@@ -0,0 +1,27 @@
+import { describe, expect, it } from "vitest";
+import { verificationLanguage } from "./verificationLanguage";
+
+describe("verificationLanguage", () => {
+	it.each(["en", "ru", "uk", "pt-BR", "zh-TW"])(
+		"passes the supported code %s through",
+		(code) => {
+			expect(verificationLanguage(code)).toBe(code);
+		},
+	);
+
+	// Well-formed but not offered by Didit. Forwarding these risks a rejected
+	// session, which would stop verification starting at all.
+	it.each(["es-MX", "zz", "en-GB", "uk-UA"])(
+		"falls back to en for the unsupported code %s",
+		(code) => {
+			expect(verificationLanguage(code)).toBe("en");
+		},
+	);
+
+	it.each([undefined, null, "", "english", "RU", 42, {}])(
+		"falls back to en for %s",
+		(value) => {
+			expect(verificationLanguage(value)).toBe("en");
+		},
+	);
+});

infrastructure/evault-core/src/utils/verificationLanguage.ts

@@ -0,0 +1,23 @@
+/**
+ * Didit renders its verification UI in the language passed at session
+ * creation. Without it Didit falls back to detecting the browser language,
+ * which does not work inside the wallet's webview, so the screens come out in
+ * English however the app is set.
+ *
+ * Codes Didit documents, as of 2026-09. An unlisted code falls back to `en`
+ * rather than reaching Didit: a rejected session creation would stop
+ * verification and recovery from starting at all.
+ * See https://docs.didit.me/sessions-api/create-session
+ */
+
+const SUPPORTED = new Set([
+    "ar", "bg", "bn", "bs", "ca", "cnr", "cs", "da", "de", "el", "en", "es",
+    "et", "fa", "fi", "fr", "he", "hi", "hr", "hu", "hy", "id", "it", "ja",
+    "ka", "kk", "ko", "ky", "lt", "lv", "mk", "mn", "ms", "nl", "no", "pl",
+    "pt", "pt-BR", "ro", "ru", "sk", "sl", "so", "sq", "sr", "sv", "th", "tr",
+    "uk", "uz", "vi", "zh", "zh-CN", "zh-TW",
+]);
+
+export function verificationLanguage(value: unknown): string {
+    return typeof value === "string" && SUPPORTED.has(value) ? value : "en";
+}