From d91d3cc0f00d1fb7663b18ba8a97fa717163ee30 Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Sun, 5 Apr 2026 08:29:48 +0100
Subject: [PATCH] fix: respect custom env snapshots for vertex auth

---
 extensions/anthropic-vertex/region.ts         | 20 ++++++++++++++-----
 .../anthropic-vertex-auth-presence.ts         | 17 +++++++++++-----
 2 files changed, 27 insertions(+), 10 deletions(-)

diff --git a/extensions/anthropic-vertex/region.ts b/extensions/anthropic-vertex/region.ts
index 298cb25c15a..d7407ba2c91 100644
--- a/extensions/anthropic-vertex/region.ts
+++ b/extensions/anthropic-vertex/region.ts
@@ -79,15 +79,22 @@ function resolveAnthropicVertexDefaultAdcPath(env: NodeJS.ProcessEnv = process.e
 
 function resolveAnthropicVertexAdcCredentialsPathCandidate(
   env: NodeJS.ProcessEnv = process.env,
-): string {
-  return (
-    normalizeOptionalSecretInput(env.GOOGLE_APPLICATION_CREDENTIALS) ??
-    resolveAnthropicVertexDefaultAdcPath(env)
-  );
+): string | undefined {
+  const explicit = normalizeOptionalSecretInput(env.GOOGLE_APPLICATION_CREDENTIALS);
+  if (explicit) {
+    return explicit;
+  }
+  if (env !== process.env) {
+    return undefined;
+  }
+  return resolveAnthropicVertexDefaultAdcPath(env);
 }
 
 function canReadAnthropicVertexAdc(env: NodeJS.ProcessEnv = process.env): boolean {
   const credentialsPath = resolveAnthropicVertexAdcCredentialsPathCandidate(env);
+  if (!credentialsPath) {
+    return false;
+  }
   try {
     readFileSync(credentialsPath, "utf8");
     return true;
@@ -100,6 +107,9 @@ function resolveAnthropicVertexProjectIdFromAdc(
   env: NodeJS.ProcessEnv = process.env,
 ): string | undefined {
   const credentialsPath = resolveAnthropicVertexAdcCredentialsPathCandidate(env);
+  if (!credentialsPath) {
+    return undefined;
+  }
   try {
     const parsed = JSON.parse(readFileSync(credentialsPath, "utf8")) as AdcProjectFile;
     return (
diff --git a/src/plugin-sdk/anthropic-vertex-auth-presence.ts b/src/plugin-sdk/anthropic-vertex-auth-presence.ts
index 1e391331c0d..0413c06eb98 100644
--- a/src/plugin-sdk/anthropic-vertex-auth-presence.ts
+++ b/src/plugin-sdk/anthropic-vertex-auth-presence.ts
@@ -35,15 +35,22 @@ function resolveAnthropicVertexDefaultAdcPath(env: NodeJS.ProcessEnv = process.e
 
 function resolveAnthropicVertexAdcCredentialsPathCandidate(
   env: NodeJS.ProcessEnv = process.env,
-): string {
-  return (
-    normalizeOptionalPathInput(env.GOOGLE_APPLICATION_CREDENTIALS) ??
-    resolveAnthropicVertexDefaultAdcPath(env)
-  );
+): string | undefined {
+  const explicit = normalizeOptionalPathInput(env.GOOGLE_APPLICATION_CREDENTIALS);
+  if (explicit) {
+    return explicit;
+  }
+  if (env !== process.env) {
+    return undefined;
+  }
+  return resolveAnthropicVertexDefaultAdcPath(env);
 }
 
 function canReadAnthropicVertexAdc(env: NodeJS.ProcessEnv = process.env): boolean {
   const credentialsPath = resolveAnthropicVertexAdcCredentialsPathCandidate(env);
+  if (!credentialsPath) {
+    return false;
+  }
   try {
     readFileSync(credentialsPath, "utf8");
     return true;