From 8349f2b861347b344c474f828808fcbe5d3e680f Mon Sep 17 00:00:00 2001
From: Sebastian Pietras <me@spietras.dev>
Date: Tue, 21 Jul 2026 19:46:32 +0200
Subject: [PATCH] Improved parsing user data from headers

---
 src/package-lock.json.jinja                   | 13 ++++++++
 src/package.json.jinja                        |  1 +
 .../lib/get-user/main.ts                      |  6 ++--
 .../lib/get-user/schemas.ts                   |  5 ---
 .../lib/get-user/utils.ts                     | 32 +++++++++++++++++++
 5 files changed, 49 insertions(+), 8 deletions(-)
 delete mode 100644 src/src/server/{% if identity %}identity{% endif %}/lib/get-user/schemas.ts
 create mode 100644 src/src/server/{% if identity %}identity{% endif %}/lib/get-user/utils.ts

diff --git a/src/package-lock.json.jinja b/src/package-lock.json.jinja
index 15a2a6d..7478b5a 100644
--- a/src/package-lock.json.jinja
+++ b/src/package-lock.json.jinja
@@ -23,6 +23,7 @@
         "client-only": "~0.0",
         "dayjs": "~1.11",
         "es-toolkit": "~1.43",
+        "flat": "~6.0",
         "next": "16.1.5",
         "react": "~19.2",
         "react-dom": "~19.2",
@@ -6633,6 +6634,18 @@
         "url": "https://github.com/sponsors/sindresorhus"
       }
     },
+    "node_modules/flat": {
+      "version": "6.0.1",
+      "resolved": "https://registry.npmjs.org/flat/-/flat-6.0.1.tgz",
+      "integrity": "sha512-/3FfIa8mbrg3xE7+wAhWeV+bd7L2Mof+xtZb5dRDKZ+wDvYJK4WDYeIOuOhre5Yv5aQObZrlbRmk3RTSiuQBtw==",
+      "license": "BSD-3-Clause",
+      "bin": {
+        "flat": "cli.js"
+      },
+      "engines": {
+        "node": ">=18"
+      }
+    },
     "node_modules/flat-cache": {
       "version": "4.0.1",
       "resolved": "https://registry.npmjs.org/flat-cache/-/flat-cache-4.0.1.tgz",
diff --git a/src/package.json.jinja b/src/package.json.jinja
index a19e93c..8691f5b 100644
--- a/src/package.json.jinja
+++ b/src/package.json.jinja
@@ -29,6 +29,7 @@
     "client-only": "~0.0",
     "dayjs": "~1.11",
     "es-toolkit": "~1.43",
+    "flat": "~6.0",
     "next": "16.1.5",
     "react": "~19.2",
     "react-dom": "~19.2",
diff --git a/src/src/server/{% if identity %}identity{% endif %}/lib/get-user/main.ts b/src/src/server/{% if identity %}identity{% endif %}/lib/get-user/main.ts
index b94a08f..aed7bd1 100644
--- a/src/src/server/{% if identity %}identity{% endif %}/lib/get-user/main.ts	
+++ b/src/src/server/{% if identity %}identity{% endif %}/lib/get-user/main.ts	
@@ -1,13 +1,13 @@
 import type { GetUserInput, GetUserOutput } from "./types";
 
-import { Schemas } from "./schemas";
+import { parseUserFromHeaders } from "./utils";
 
 export async function getUser({
   headers,
 }: GetUserInput): Promise<GetUserOutput> {
-  const id = await Schemas.Id.safeParseAsync(headers.get("X-User-ID"));
+  const result = await parseUserFromHeaders(headers);
 
-  const user = id.success ? { id: id.data } : null;
+  const user = result.success ? result.data : null;
 
   return { user: user };
 }
diff --git a/src/src/server/{% if identity %}identity{% endif %}/lib/get-user/schemas.ts b/src/src/server/{% if identity %}identity{% endif %}/lib/get-user/schemas.ts
deleted file mode 100644
index f3a0d48..0000000
--- a/src/src/server/{% if identity %}identity{% endif %}/lib/get-user/schemas.ts	
+++ /dev/null
@@ -1,5 +0,0 @@
-import { IdentitySchemas } from "../../../../common/identity/schemas";
-
-export const Schemas = {
-  Id: IdentitySchemas.User.shape.id,
-};
diff --git a/src/src/server/{% if identity %}identity{% endif %}/lib/get-user/utils.ts b/src/src/server/{% if identity %}identity{% endif %}/lib/get-user/utils.ts
new file mode 100644
index 0000000..8f61077
--- /dev/null
+++ b/src/src/server/{% if identity %}identity{% endif %}/lib/get-user/utils.ts	
@@ -0,0 +1,32 @@
+import { isJSONArray, isJSONObject } from "es-toolkit/predicate";
+import { unflatten } from "flat";
+
+import { IdentitySchemas } from "../../../../common/identity/schemas";
+
+export function parseValue(value: string) {
+  try {
+    const parsed = JSON.parse(value) as unknown;
+    return isJSONObject(parsed) || isJSONArray(parsed) ? parsed : value;
+  } catch {
+    return value;
+  }
+}
+
+export async function parseUserFromHeaders(headers: Headers) {
+  const delimiter = ".";
+
+  const flat = Object.fromEntries(
+    headers
+      .entries()
+      .map(([key, value]) => [key.toLowerCase(), value] as [string, string])
+      .filter(([key]) => key === "x-user" || key.startsWith("x-user-"))
+      .map(([key, value]) => [
+        key.replace(/^x-/, "").replaceAll("-", "."),
+        parseValue(value),
+      ]),
+  );
+
+  const raw = unflatten(flat, { delimiter: delimiter });
+  const user = (raw as { user?: unknown }).user;
+  return await IdentitySchemas.User.safeParseAsync(user);
+}