diff --git a/nanobot/providers/openai_codex_provider.py b/nanobot/providers/openai_codex_provider.py
index dee66c073..c0afdf572 100644
--- a/nanobot/providers/openai_codex_provider.py
+++ b/nanobot/providers/openai_codex_provider.py
@@ -5,6 +5,7 @@ from __future__ import annotations
 import asyncio
 import hashlib
 import json
+import os
 from collections.abc import Awaitable, Callable
 from typing import Any
 
@@ -177,7 +178,8 @@ async def _request_codex(
     on_content_delta: Callable[[str], Awaitable[None]] | None = None,
     on_tool_call_delta: Callable[[dict[str, Any]], Awaitable[None]] | None = None,
 ) -> tuple[str, list[ToolCallRequest], str]:
-    async with httpx.AsyncClient(timeout=60.0, verify=verify) as client:
+    idle_timeout_s = int(os.environ.get("NANOBOT_STREAM_IDLE_TIMEOUT_S", "90"))
+    async with httpx.AsyncClient(timeout=idle_timeout_s, verify=verify) as client:
         async with client.stream("POST", url, headers=headers, json=body) as response:
             if response.status_code != 200:
                 text = await response.aread()
diff --git a/tests/providers/test_openai_codex_provider.py b/tests/providers/test_openai_codex_provider.py
index 02e43638a..b3089e994 100644
--- a/tests/providers/test_openai_codex_provider.py
+++ b/tests/providers/test_openai_codex_provider.py
@@ -76,8 +76,8 @@ async def test_codex_request_non_200_populates_http_metadata(monkeypatch) -> Non
             request=request,
         )
 
-    def fake_client(*, timeout: float, verify: bool) -> httpx.AsyncClient:
-        assert timeout == 60.0
+    def fake_client(*, timeout: int, verify: bool) -> httpx.AsyncClient:
+        assert timeout == 90
         assert verify is True
         return original_client(transport=httpx.MockTransport(handler), timeout=timeout)
 
@@ -95,6 +95,27 @@ async def test_codex_request_non_200_populates_http_metadata(monkeypatch) -> Non
     assert error.should_retry is True
 
 
+@pytest.mark.asyncio
+async def test_codex_request_honors_stream_idle_timeout_env(monkeypatch) -> None:
+    """NANOBOT_STREAM_IDLE_TIMEOUT_S overrides the default Codex stream timeout."""
+    monkeypatch.setenv("NANOBOT_STREAM_IDLE_TIMEOUT_S", "5")
+    original_client = httpx.AsyncClient
+    seen: dict[str, int] = {}
+
+    def handler(request: httpx.Request) -> httpx.Response:
+        return httpx.Response(200, request=request)
+
+    def fake_client(*, timeout: int, verify: bool) -> httpx.AsyncClient:
+        seen["timeout"] = timeout
+        return original_client(transport=httpx.MockTransport(handler), timeout=timeout)
+
+    monkeypatch.setattr("nanobot.providers.openai_codex_provider.httpx.AsyncClient", fake_client)
+
+    await _request_codex("https://codex.example/responses", {}, {"input": []}, verify=True)
+
+    assert seen["timeout"] == 5
+
+
 @pytest.mark.asyncio
 async def test_codex_prompt_cache_key_uses_stable_conversation_prefix(monkeypatch) -> None:
     bodies: list[dict] = []