diff --git a/src/shared/EnvManager.ts b/src/shared/EnvManager.ts
index ed9159a6..eca3120e 100644
--- a/src/shared/EnvManager.ts
+++ b/src/shared/EnvManager.ts
@@ -40,6 +40,7 @@ export const MANAGED_CREDENTIAL_KEYS = [
 export interface ClaudeMemEnv {
   // Credentials (optional - empty means use CLI billing for Claude)
   ANTHROPIC_API_KEY?: string;
+  ANTHROPIC_BASE_URL?: string;
   GEMINI_API_KEY?: string;
   OPENROUTER_API_KEY?: string;
 }
@@ -115,6 +116,7 @@ export function loadClaudeMemEnv(): ClaudeMemEnv {
     // Only return managed credential keys
     const result: ClaudeMemEnv = {};
     if (parsed.ANTHROPIC_API_KEY) result.ANTHROPIC_API_KEY = parsed.ANTHROPIC_API_KEY;
+    if (parsed.ANTHROPIC_BASE_URL) result.ANTHROPIC_BASE_URL = parsed.ANTHROPIC_BASE_URL;
     if (parsed.GEMINI_API_KEY) result.GEMINI_API_KEY = parsed.GEMINI_API_KEY;
     if (parsed.OPENROUTER_API_KEY) result.OPENROUTER_API_KEY = parsed.OPENROUTER_API_KEY;
 
@@ -151,6 +153,13 @@ export function saveClaudeMemEnv(env: ClaudeMemEnv): void {
         delete updated.ANTHROPIC_API_KEY;
       }
     }
+    if (env.ANTHROPIC_BASE_URL !== undefined) {
+      if (env.ANTHROPIC_BASE_URL) {
+        updated.ANTHROPIC_BASE_URL = env.ANTHROPIC_BASE_URL;
+      } else {
+        delete updated.ANTHROPIC_BASE_URL;
+      }
+    }
     if (env.GEMINI_API_KEY !== undefined) {
       if (env.GEMINI_API_KEY) {
         updated.GEMINI_API_KEY = env.GEMINI_API_KEY;
@@ -210,6 +219,12 @@ export function buildIsolatedEnv(includeCredentials: boolean = true): Record<str
     if (credentials.ANTHROPIC_API_KEY) {
       isolatedEnv.ANTHROPIC_API_KEY = credentials.ANTHROPIC_API_KEY;
     }
+    // Override ANTHROPIC_BASE_URL from .env if configured
+    // This ensures the SDK subprocess uses a stable API endpoint instead of
+    // inheriting a dynamic local proxy port that may become stale
+    if (credentials.ANTHROPIC_BASE_URL) {
+      isolatedEnv.ANTHROPIC_BASE_URL = credentials.ANTHROPIC_BASE_URL;
+    }
     // Note: GEMINI_API_KEY and OPENROUTER_API_KEY pass through from process.env,
     // but claude-mem's .env takes precedence if configured
     if (credentials.GEMINI_API_KEY) {