From 832e35270a74e667754023a4bf008da71e5482eb Mon Sep 17 00:00:00 2001
From: Sudip <sudip@Sudips-MacBook-Pro.local>
Date: Wed, 5 Aug 2026 12:56:43 +0100
Subject: [PATCH] fix: pass Windows AppData vars into MCP child env

APPDATA and LOCALAPPDATA are commonly required by Windows MCP servers
for config/cache paths. Forward them in the stdio child allowlist.
---
 .changeset/mcp-child-env-appdata.md |  5 +++++
 src/connectors/mcp-client.ts        |  9 ++++++---
 test/mcp-client.test.ts             | 16 +++++++++++++++-
 3 files changed, 26 insertions(+), 4 deletions(-)
 create mode 100644 .changeset/mcp-child-env-appdata.md

diff --git a/.changeset/mcp-child-env-appdata.md b/.changeset/mcp-child-env-appdata.md
new file mode 100644
index 00000000..2725ec0a
--- /dev/null
+++ b/.changeset/mcp-child-env-appdata.md
@@ -0,0 +1,5 @@
+---
+"openwiki": patch
+---
+
+Pass Windows `APPDATA` and `LOCALAPPDATA` into stdio MCP child environments so local MCP servers can resolve their config and cache directories.
diff --git a/src/connectors/mcp-client.ts b/src/connectors/mcp-client.ts
index ef5b9c62..33e48897 100644
--- a/src/connectors/mcp-client.ts
+++ b/src/connectors/mcp-client.ts
@@ -733,15 +733,18 @@ function resolveChildEnv(
 }
 
 // Base environment variables an MCP subprocess may legitimately need to run
-// (locating binaries, resolving the home dir, temp paths, terminal behavior).
-// Deliberately excludes OpenWiki credentials so a spawned MCP server command
-// cannot read the user's API keys and OAuth refresh tokens out of process.env.
+// (locating binaries, resolving the home dir, AppData caches on Windows, temp
+// paths, terminal behavior). Deliberately excludes OpenWiki credentials so a
+// spawned MCP server command cannot read the user's API keys and OAuth refresh
+// tokens out of process.env.
 const CHILD_ENV_ALLOWLIST = [
   "PATH",
   "HOME",
   "HOMEPATH",
   "HOMEDRIVE",
   "USERPROFILE",
+  "APPDATA",
+  "LOCALAPPDATA",
   "TMPDIR",
   "TEMP",
   "TMP",
diff --git a/test/mcp-client.test.ts b/test/mcp-client.test.ts
index 44cc55e5..1824df43 100644
--- a/test/mcp-client.test.ts
+++ b/test/mcp-client.test.ts
@@ -13,13 +13,21 @@ describe("buildChildEnv", () => {
   const saved: Record<string, string | undefined> = {};
 
   beforeEach(() => {
-    for (const key of [...SECRET_KEYS, "PATH", "MCP_SERVER_TOKEN"]) {
+    for (const key of [
+      ...SECRET_KEYS,
+      "PATH",
+      "APPDATA",
+      "LOCALAPPDATA",
+      "MCP_SERVER_TOKEN",
+    ]) {
       saved[key] = process.env[key];
     }
     for (const key of SECRET_KEYS) {
       process.env[key] = `secret-value-for-${key}`;
     }
     process.env.PATH = "/usr/bin:/bin";
+    process.env.APPDATA = "C:\\Users\\example\\AppData\\Roaming";
+    process.env.LOCALAPPDATA = "C:\\Users\\example\\AppData\\Local";
     process.env.MCP_SERVER_TOKEN = "declared-token-123";
   });
 
@@ -49,6 +57,12 @@ describe("buildChildEnv", () => {
     expect(childEnv.PATH).toBe("/usr/bin:/bin");
   });
 
+  test("passes through Windows AppData paths used by many MCP servers", () => {
+    const childEnv = buildChildEnv({});
+    expect(childEnv.APPDATA).toBe("C:\\Users\\example\\AppData\\Roaming");
+    expect(childEnv.LOCALAPPDATA).toBe("C:\\Users\\example\\AppData\\Local");
+  });
+
   test("resolves only the credentials the transport explicitly declares", () => {
     const childEnv = buildChildEnv({ MCP_TOKEN: "${MCP_SERVER_TOKEN}" });
     expect(childEnv.MCP_TOKEN).toBe("declared-token-123");