diff --git a/packages/ai/CHANGELOG.md b/packages/ai/CHANGELOG.md
index 6b1be74a..4bb5d27e 100644
--- a/packages/ai/CHANGELOG.md
+++ b/packages/ai/CHANGELOG.md
@@ -5,6 +5,7 @@
 ### Fixed
 
 - Fixed `cacheRetention` option not being passed through in `buildBaseOptions` ([#1154](https://github.com/badlogic/pi-mono/issues/1154))
+- Fixed OAuth login/refresh not using HTTP proxy settings (`HTTP_PROXY`, `HTTPS_PROXY` env vars) ([#1132](https://github.com/badlogic/pi-mono/issues/1132))
 
 ## [0.50.9] - 2026-02-01
 
diff --git a/packages/ai/src/stream.ts b/packages/ai/src/stream.ts
index b1d27e62..fdb4494b 100644
--- a/packages/ai/src/stream.ts
+++ b/packages/ai/src/stream.ts
@@ -1,4 +1,5 @@
 import "./providers/register-builtins.js";
+import "./utils/http-proxy.js";
 
 import { getApiProvider } from "./api-registry.js";
 import type {
@@ -14,15 +15,6 @@ import type {
 
 export { getEnvApiKey } from "./env-api-keys.js";
 
-// Set up http proxy according to env variables for `fetch` based SDKs in Node.js.
-// Bun has builtin support for this.
-if (typeof process !== "undefined" && process.versions?.node) {
-	import("undici").then((m) => {
-		const { EnvHttpProxyAgent, setGlobalDispatcher } = m;
-		setGlobalDispatcher(new EnvHttpProxyAgent());
-	});
-}
-
 function resolveApiProvider(api: Api) {
 	const provider = getApiProvider(api);
 	if (!provider) {
diff --git a/packages/ai/src/utils/http-proxy.ts b/packages/ai/src/utils/http-proxy.ts
new file mode 100644
index 00000000..1102e875
--- /dev/null
+++ b/packages/ai/src/utils/http-proxy.ts
@@ -0,0 +1,13 @@
+/**
+ * Set up HTTP proxy according to env variables for `fetch` based SDKs in Node.js.
+ * Bun has builtin support for this.
+ *
+ * This module should be imported early by any code that needs proxy support for fetch().
+ * ES modules are cached, so importing multiple times is safe - setup only runs once.
+ */
+if (typeof process !== "undefined" && process.versions?.node) {
+	import("undici").then((m) => {
+		const { EnvHttpProxyAgent, setGlobalDispatcher } = m;
+		setGlobalDispatcher(new EnvHttpProxyAgent());
+	});
+}
diff --git a/packages/ai/src/utils/oauth/index.ts b/packages/ai/src/utils/oauth/index.ts
index 1077d748..a4bb5892 100644
--- a/packages/ai/src/utils/oauth/index.ts
+++ b/packages/ai/src/utils/oauth/index.ts
@@ -9,6 +9,9 @@
  * - Antigravity (Gemini 3, Claude, GPT-OSS via Google Cloud)
  */
 
+// Set up HTTP proxy for fetch() calls (respects HTTP_PROXY, HTTPS_PROXY env vars)
+import "../http-proxy.js";
+
 // Anthropic
 export { anthropicOAuthProvider, loginAnthropic, refreshAnthropicToken } from "./anthropic.js";
 // GitHub Copilot