feat: use gateway service (#373)

Author: joshsny

.env.example

@@ -9,7 +9,4 @@ APPLE_CODESIGN_KEYCHAIN_PASSWORD="xxx"
 
 VITE_POSTHOG_API_KEY=xxx
 VITE_POSTHOG_API_HOST=xxx
-VITE_POSTHOG_UI_HOST=xxx
-
-# Use new LLM gateway locally (experimental, needs to be started in mprocs)
-LLM_GATEWAY_URL=http://localhost:3308
+VITE_POSTHOG_UI_HOST=xxx

apps/array/src/constants/oauth.ts

@@ -9,6 +9,7 @@ export const OAUTH_SCOPES = [
   "user:read",
   "project:read",
   "task:write",
+  "llm_gateway:read",
   "integration:read",
   "introspection",
   "dashboard:read",

apps/array/src/main/services/agent/service.ts

@@ -10,7 +10,7 @@ import {
   type RequestPermissionRequest,
   type RequestPermissionResponse,
 } from "@agentclientprotocol/sdk";
-import { Agent, type OnLogCallback } from "@posthog/agent";
+import { Agent, getLlmGatewayUrl, type OnLogCallback } from "@posthog/agent";
 import { app } from "electron";
 import { injectable } from "inversify";
 import type { AcpMessage } from "../../../shared/types/session-events.js";
@@ -457,10 +457,7 @@ export class AgentService extends TypedEventEmitter<AgentServiceEvents> {
     process.env.ANTHROPIC_API_KEY = token;
     process.env.ANTHROPIC_AUTH_TOKEN = token;
 
-    const llmGatewayUrl =
-      process.env.LLM_GATEWAY_URL ||
-      `${credentials.apiHost}/api/projects/${credentials.projectId}/llm_gateway`;
-    process.env.ANTHROPIC_BASE_URL = llmGatewayUrl;
+    process.env.ANTHROPIC_BASE_URL = getLlmGatewayUrl(credentials.apiHost);
 
     process.env.CLAUDE_CODE_EXECUTABLE = getClaudeCliPath();
 

packages/agent/example.ts

@@ -7,6 +7,7 @@ import { config } from "dotenv";
 config();
 
 import { Agent, PermissionMode } from "./src/agent.js";
+import { getLlmGatewayUrl } from "./src/utils/gateway.js";
 
 function hasUncommittedChanges(repoPath: string): boolean {
   try {
@@ -143,9 +144,9 @@ async function testAgent() {
           POSTHOG_AUTH_HEADER: `Bearer ${process.env.POSTHOG_API_KEY}`,
           ANTHROPIC_API_KEY: process.env.POSTHOG_API_KEY,
           ANTHROPIC_AUTH_TOKEN: process.env.POSTHOG_API_KEY,
-          ANTHROPIC_BASE_URL:
-            process.env.LLM_GATEWAY_URL ||
-            `${process.env.POSTHOG_API_URL}/api/projects/${process.env.POSTHOG_PROJECT_ID}/llm_gateway`,
+          ANTHROPIC_BASE_URL: getLlmGatewayUrl(
+            process.env.POSTHOG_API_URL || "",
+          ),
         },
       },
     });

packages/agent/index.ts

@@ -68,6 +68,7 @@ export type {
 } from "./src/types.js";
 export { PermissionMode } from "./src/types.js";
 
+export { getLlmGatewayUrl } from "./src/utils/gateway.js";
 export type { LoggerConfig } from "./src/utils/logger.js";
 export { Logger, LogLevel } from "./src/utils/logger.js";
 

packages/agent/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@posthog/agent",
-  "version": "1.29.0",
+  "version": "1.30.0",
   "repository": "https://github.com/PostHog/array",
   "description": "TypeScript agent framework wrapping Claude Agent SDK with Git-based task execution for PostHog",
   "main": "./dist/index.js",

packages/agent/src/adapters/claude/claude.ts

@@ -673,16 +673,13 @@ export class ClaudeAcpAgent implements Agent {
             throw RequestError.authRequired();
           }
 
-          // When using the gateway service, text/thinking is streamed via stream_event,
-          // so skip them here to avoid duplication.
+          // Text/thinking is streamed via stream_event, so skip them here to avoid duplication.
           const content = message.message.content;
-          const isUsingGatewayService = !!process.env.LLM_GATEWAY_URL;
-          const contentToProcess =
-            isUsingGatewayService && Array.isArray(content)
-              ? content.filter(
-                  (block) => block.type !== "text" && block.type !== "thinking",
-                )
-              : content;
+          const contentToProcess = Array.isArray(content)
+            ? content.filter(
+                (block) => block.type !== "text" && block.type !== "thinking",
+              )
+            : content;
 
           for (const notification of toAcpNotifications(
             contentToProcess as typeof content,

packages/agent/src/agent.ts

@@ -126,16 +126,15 @@ export class Agent {
   }
 
   /**
-   * Configure LLM gateway environment variables for Claude Code CLI
+   * Configure LLM gateway environment variables for Claude Code CLI.
    */
   private async _configureLlmGateway(): Promise<void> {
     if (!this.posthogAPI) {
       return;
     }
 
     try {
-      const gatewayUrl =
-        process.env.LLM_GATEWAY_URL || this.posthogAPI.getLlmGatewayUrl();
+      const gatewayUrl = this.posthogAPI.getLlmGatewayUrl();
       const apiKey = this.posthogAPI.getApiKey();
       process.env.ANTHROPIC_BASE_URL = gatewayUrl;
       process.env.ANTHROPIC_AUTH_TOKEN = apiKey;

packages/agent/src/posthog-api.ts

@@ -8,6 +8,7 @@ import type {
   TaskRunArtifact,
   UrlMention,
 } from "./types.js";
+import { getLlmGatewayUrl } from "./utils/gateway.js";
 
 interface PostHogApiResponse<T> {
   results?: T[];
@@ -88,8 +89,7 @@ export class PostHogAPIClient {
   }
 
   getLlmGatewayUrl(): string {
-    const teamId = this.getTeamId();
-    return `${this.baseUrl}/api/projects/${teamId}/llm_gateway`;
+    return getLlmGatewayUrl(this.baseUrl);
   }
 
   async fetchTask(taskId: string): Promise<Task> {

packages/agent/src/utils/gateway.ts

@@ -0,0 +1,15 @@
+export function getLlmGatewayUrl(posthogHost: string): string {
+  const url = new URL(posthogHost);
+  const hostname = url.hostname;
+
+  if (hostname === "localhost" || hostname === "127.0.0.1") {
+    return `${url.protocol}//localhost:3308`;
+  }
+
+  // Extract region from hostname (us.posthog.com, eu.posthog.com)
+  // app.posthog.com is legacy US
+  const regionMatch = hostname.match(/^(us|eu)\.posthog\.com$/);
+  const region = regionMatch ? regionMatch[1] : "us";
+
+  return `https://gateway.${region}.posthog.com`;
+}