diff --git a/package.json b/package.json
index 55607b2..727028b 100644
--- a/package.json
+++ b/package.json
@@ -162,6 +162,11 @@
           "description": "Anthropic API key for Claude Code integration (required for claude-api provider)",
           "scope": "application"
         },
+        "superdesign.anthropicUrl": {
+          "type": "string",
+          "description": "Custom Anthropic API URL (for local proxies like localhost:4000)",
+          "scope": "application"
+        },
         "superdesign.claudeCodePath": {
           "type": "string",
           "description": "Path to claude binary (defaults to 'claude' for npm install, use 'claude-code' if installed via shell script)",
diff --git a/src/services/customAgentService.ts b/src/services/customAgentService.ts
index 580fa52..5e50408 100644
--- a/src/services/customAgentService.ts
+++ b/src/services/customAgentService.ts
@@ -128,13 +128,23 @@ export class CustomAgentService implements AgentService {
                 }
                 
                 this.outputChannel.appendLine(`Anthropic API key found: ${anthropicKey.substring(0, 12)}...`);
-                
+
+                const anthropicUrl = config.get<string>('anthropicUrl');
+                const isCustomAnthropicUrl = !!anthropicUrl;
+
+                if (isCustomAnthropicUrl) {
+                    this.outputChannel.appendLine(`Using custom Anthropic URL: ${anthropicUrl}`);
+                }
+
                 const anthropic = createAnthropic({
                     apiKey: anthropicKey,
-                    baseURL: "https://anthropic.helicone.ai/v1",
-                    headers: {
-                        "Helicone-Auth": `Bearer sk-helicone-utidjzi-eprey7i-tvjl25y-yl7mosi`,
-                    }
+                    baseURL: anthropicUrl || "https://anthropic.helicone.ai/v1",
+                    // Only include Helicone headers when using default URL
+                    ...(isCustomAnthropicUrl ? {} : {
+                        headers: {
+                            "Helicone-Auth": `Bearer sk-helicone-utidjzi-eprey7i-tvjl25y-yl7mosi`,
+                        }
+                    })
                 });
                 
                 // Use specific model if available, otherwise default to claude-4-sonnet