diff --git a/docs/configuration.md b/docs/configuration.md
index dbe03c60..8b309ecb 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -240,6 +240,7 @@ Tracing covers the providers that go through nanobot's OpenAI-compatible client
 > - **Xiaomi MiMo thinking mode**: MiMo models (e.g. `mimo-v2.5-pro`) default to enabled thinking. Use `agents.defaults.reasoningEffort: "none"` to disable it, or `"low"` / `"medium"` / `"high"` to keep it on. Omitting the field preserves the provider's per-model default.
 > - **Xiaomi MiMo Token Plan**: If you're on MiMo's token plan, set `"apiBase": "https://token-plan-sgp.xiaomimimo.com/v1"` in your xiaomi_mimo provider config.
 > - **Custom OpenAI-compatible providers**: Besides the built-in `custom` provider, any extra key under `providers` can define its own OpenAI-compatible endpoint. For example, `providers.companyProxy.apiBase` plus `modelPresets.primary.provider: "companyProxy"` creates a separate custom provider. Set `apiBase`; set `apiKey` only when the endpoint requires it. This named-custom path uses the OpenAI-compatible request format only. For Anthropic-compatible proxies, use `providers.anthropic.apiBase` with `provider: "anthropic"`.
+> - **Provider-scoped proxy**: `providers.<name>.proxy` routes only that provider through an HTTP proxy. It is supported for OpenAI-compatible providers and `openai_codex`. Native provider backends such as `anthropic`, `bedrock`, `azure_openai`, and `github_copilot` reject `proxy`.
 
 | Provider | Purpose | Get API Key |
 |----------|---------|-------------|
@@ -632,20 +633,37 @@ nanobot agent -m "Reply with one short sentence."
 <details>
 <summary><b>OpenAI Codex (OAuth)</b></summary>
 
-Codex uses OAuth instead of API keys. Requires a ChatGPT Plus or Pro account. No `providers.openaiCodex` block is needed in `config.json`; `nanobot provider login` stores the OAuth session outside config.
+Codex uses OAuth instead of API keys. Requires a ChatGPT Plus or Pro account. `nanobot provider login` stores the OAuth session outside config. A `providers.openai_codex` block is optional and is only needed for provider-specific settings such as a proxy.
 
 **1. Login:**
 ```bash
 nanobot provider login openai-codex
 ```
 
-**2. Set model** (merge into `~/.nanobot/config.json`):
+If the machine running nanobot cannot open a graphical browser, copy the printed URL into a real browser. For remote SSH login, open the URL locally, then paste the final `http://localhost:1455/auth/callback?...` redirect URL back into the terminal when prompted.
+
+**2. Optional proxy** (merge into `~/.nanobot/config.json` if Codex OAuth or Codex API traffic must use a proxy):
+
+```json
+{
+  "providers": {
+    "openai_codex": {
+      "proxy": "http://127.0.0.1:7890"
+    }
+  }
+}
+```
+
+The proxy applies to Codex OAuth token refresh, interactive token exchange, and Codex Responses API requests. It does not affect other providers; configure `proxy` separately on each supported provider that needs it.
+
+**3. Set model** (merge into `~/.nanobot/config.json`):
 ```json
 {
   "modelPresets": {
     "codex": {
       "provider": "openai_codex",
-      "model": "openai-codex/gpt-5.1-codex"
+      "model": "gpt-5.1-codex",
+      "reasoningEffort": "high"
     }
   },
   "agents": {
@@ -656,7 +674,9 @@ nanobot provider login openai-codex
 }
 ```
 
-**3. Chat:**
+Use `reasoningEffort` in the preset to send a Codex reasoning effort such as `"low"`, `"medium"`, `"high"`, or another value supported by the selected model. When `provider` is explicitly `openai_codex`, the model name does not need the `openai-codex/` prefix.
+
+**4. Chat:**
 ```bash
 nanobot agent -m "Hello!"
 
@@ -675,7 +695,7 @@ nanobot agent -c ~/.nanobot-telegram/config.json -w /tmp/nanobot-telegram-test -
 <details>
 <summary><b>GitHub Copilot (OAuth)</b></summary>
 
-GitHub Copilot uses OAuth instead of API keys. Requires a [GitHub account with a plan](https://github.com/features/copilot/plans) configured. No `providers.githubCopilot` block is needed in `config.json`; `nanobot provider login` stores the OAuth session outside config.
+GitHub Copilot uses OAuth instead of API keys. Requires a [GitHub account with a plan](https://github.com/features/copilot/plans) configured. No `providers.github_copilot` block is needed in `config.json`; `nanobot provider login` stores the OAuth session outside config.
 
 For GitHub Enterprise / Copilot for Business, set the endpoint overrides you need before login:
 ```bash
diff --git a/docs/providers.md b/docs/providers.md
index 697173fb..028d92b2 100644
--- a/docs/providers.md
+++ b/docs/providers.md
@@ -61,9 +61,12 @@ These fields answer different questions:
 | `model` | `modelPresets.<name>.model` | The model ID expected by that provider or gateway. |
 | `apiKey` | `providers.<provider>.apiKey` | Credential for that provider. Use `${ENV_VAR}` for secrets. |
 | `apiBase` | `providers.<provider>.apiBase` | HTTP base URL of the provider endpoint. |
+| `proxy` | `providers.<provider>.proxy` | Optional HTTP proxy for this provider only. Supported for OpenAI-compatible providers and OpenAI Codex. |
 
 You usually omit `apiBase` for hosted built-in providers such as OpenRouter, Anthropic direct, OpenAI direct, Groq, or Bedrock because nanobot knows their default endpoints. Set `apiBase` for `custom`, local OpenAI-compatible servers, provider proxies, regional endpoints, or subscription endpoints. Include the API version path when the endpoint requires it, for example `https://api.example.com/v1` or `http://localhost:11434/v1`.
 
+Use `proxy` when one provider must send HTTP traffic through a proxy without changing process-wide `HTTP_PROXY` / `HTTPS_PROXY`. This is supported for providers that use nanobot's OpenAI-compatible client, including `openai`, `custom`, named custom providers, OpenRouter-style gateways, local OpenAI-compatible servers, and similar registry entries. It is also supported for `openai_codex`, including Codex OAuth token exchange/refresh and Codex Responses API requests. Native provider backends such as `anthropic`, `bedrock`, `azure_openai`, and `github_copilot` reject `proxy`; use their endpoint-specific configuration instead.
+
 ## Common Provider Patterns
 
 ### OpenRouter Gateway
@@ -422,6 +425,32 @@ nanobot provider login github-copilot
 
 Then explicitly select the provider and model in a preset. OAuth providers are not valid automatic fallbacks.
 
+For OpenAI Codex, add `providers.openai_codex.proxy` only when Codex OAuth/token refresh or Codex API requests must use a proxy:
+
+```json
+{
+  "providers": {
+    "openai_codex": {
+      "proxy": "http://127.0.0.1:7890"
+    }
+  },
+  "modelPresets": {
+    "codex": {
+      "provider": "openai_codex",
+      "model": "gpt-5.1-codex",
+      "reasoningEffort": "high"
+    }
+  },
+  "agents": {
+    "defaults": {
+      "modelPreset": "codex"
+    }
+  }
+}
+```
+
+If you run the login command on a remote/headless machine and open the authorization URL in a local browser, paste the final `http://localhost:1455/auth/callback?...` redirect URL back into the terminal when prompted. See [`configuration.md#providers`](./configuration.md#providers) for the full OAuth provider notes.
+
 ## Provider Resolution
 
 The recommended path is a named preset selected by `agents.defaults.modelPreset`. The effective model parameters come from:
diff --git a/nanobot/cli/commands.py b/nanobot/cli/commands.py
index 67d70dbd..499c9753 100644
--- a/nanobot/cli/commands.py
+++ b/nanobot/cli/commands.py
@@ -1812,14 +1812,23 @@ def _login_openai_codex() -> None:
     try:
         from oauth_cli_kit import get_token, login_oauth_interactive
 
+        from nanobot.config.loader import load_config, resolve_config_env_vars
+
+        proxy = None
+        try:
+            proxy = resolve_config_env_vars(load_config()).providers.openai_codex.proxy or None
+        except ValueError as e:
+            console.print(f"[red]{e}[/red]")
+            raise typer.Exit(1) from e
         token = None
         with suppress(Exception):
-            token = get_token()
+            token = get_token(proxy=proxy)
         if not (token and token.access):
             console.print("[cyan]Starting interactive OAuth login...[/cyan]\n")
             token = login_oauth_interactive(
                 print_fn=lambda s: console.print(s),
                 prompt_fn=lambda s: typer.prompt(s),
+                proxy=proxy,
             )
         if not (token and token.access):
             console.print("[red]✗ Authentication failed[/red]")
diff --git a/nanobot/config/loader.py b/nanobot/config/loader.py
index 0addc842..384f0f5a 100644
--- a/nanobot/config/loader.py
+++ b/nanobot/config/loader.py
@@ -80,6 +80,10 @@ def save_config(config: Config, config_path: Path | None = None) -> None:
     path.parent.mkdir(parents=True, exist_ok=True)
 
     data = config.model_dump(mode="json", by_alias=True)
+    if config.providers.openai_codex.proxy is not None:
+        data.setdefault("providers", {})["openaiCodex"] = {
+            "proxy": config.providers.openai_codex.proxy,
+        }
 
     with open(path, "w", encoding="utf-8") as f:
         json.dump(data, f, indent=2, ensure_ascii=False)
diff --git a/nanobot/config/schema.py b/nanobot/config/schema.py
index 9e8b0ce4..5b50407e 100644
--- a/nanobot/config/schema.py
+++ b/nanobot/config/schema.py
@@ -179,6 +179,7 @@ class ProviderConfig(Base):
     extra_headers: dict[str, str] | None = None  # Custom headers (e.g. APP-Code for AiHubMix)
     extra_body: dict[str, Any] | None = None  # Extra provider request fields; shape depends on provider/API surface
     extra_query: dict[str, str] | None = None  # Extra query params (e.g. api-version for Azure-style gateways)
+    proxy: str | None = None  # OpenAI-compatible/Codex HTTP proxy URL
     thinking_style: str | None = None  # Thinking/reasoning style for custom providers
 
     # Valid values mirror the keys of _THINKING_STYLE_MAP in
diff --git a/nanobot/providers/factory.py b/nanobot/providers/factory.py
index 4fd75cdd..756eadc5 100644
--- a/nanobot/providers/factory.py
+++ b/nanobot/providers/factory.py
@@ -58,6 +58,11 @@ def _make_provider_core(
     if spec and spec.is_transcription_only:
         raise ValueError(f"Provider '{provider_name}' only supports transcription.")
     backend = spec.backend if spec else "openai_compat"
+    if p and p.proxy and backend not in {"openai_compat", "openai_codex"}:
+        raise ValueError(
+            f"providers.{provider_name}.proxy is only supported for "
+            "OpenAI-compatible providers and OpenAI Codex."
+        )
 
     if backend == "azure_openai":
         if not p or not p.api_base:
@@ -79,7 +84,10 @@ def _make_provider_core(
     if backend == "openai_codex":
         from nanobot.providers.openai_codex_provider import OpenAICodexProvider
 
-        provider = OpenAICodexProvider(default_model=model)
+        provider = OpenAICodexProvider(
+            default_model=model,
+            proxy=getattr(p, "proxy", None) if p else None,
+        )
     elif backend == "azure_openai":
         from nanobot.providers.azure_openai_provider import AzureOpenAIProvider
 
@@ -124,6 +132,7 @@ def _make_provider_core(
             extra_body=p.extra_body if p else None,
             api_type=p.api_type if p and provider_name == "openai" else "auto",
             extra_query=p.extra_query if p else None,
+            proxy=p.proxy if p else None,
         )
 
     provider.generation = resolved.to_generation_settings()
@@ -218,6 +227,7 @@ def provider_signature(
             fallback.temperature,
             fallback.reasoning_effort,
             fallback.context_window_tokens,
+            getattr(fp, "proxy", None) if fp else None,
         )
 
     provider_name = config.get_provider_name(resolved.model, preset=resolved)
@@ -237,6 +247,7 @@ def provider_signature(
         resolved.temperature,
         resolved.reasoning_effort,
         resolved.context_window_tokens,
+        getattr(p, "proxy", None) if p else None,
         tuple(_fallback_signature(fallback) for fallback in fallback_presets),
     )
 
diff --git a/nanobot/providers/openai_codex_provider.py b/nanobot/providers/openai_codex_provider.py
index 64430cdc..b544bad4 100644
--- a/nanobot/providers/openai_codex_provider.py
+++ b/nanobot/providers/openai_codex_provider.py
@@ -33,9 +33,14 @@ class OpenAICodexProvider(LLMProvider):
 
     supports_progress_deltas = True
 
-    def __init__(self, default_model: str = "openai-codex/gpt-5.1-codex"):
+    def __init__(
+        self,
+        default_model: str = "openai-codex/gpt-5.1-codex",
+        proxy: str | None = None,
+    ):
         super().__init__(api_key=None, api_base=None)
         self.default_model = default_model
+        self.proxy = proxy or None
 
     async def _call_codex(
         self,
@@ -52,9 +57,6 @@ class OpenAICodexProvider(LLMProvider):
         model = model or self.default_model
         system_prompt, input_items = convert_messages(messages)
 
-        token = await asyncio.to_thread(get_codex_token)
-        headers = _build_headers(token.account_id, token.access)
-
         body: dict[str, Any] = {
             "model": _strip_model_prefix(model),
             "store": False,
@@ -74,9 +76,13 @@ class OpenAICodexProvider(LLMProvider):
             body["tools"] = convert_tools(tools)
 
         try:
+            token = await asyncio.to_thread(get_codex_token, proxy=self.proxy)
+            headers = _build_headers(token.account_id, token.access)
+
             try:
                 content, tool_calls, finish_reason, usage, reasoning_content = await _request_codex(
                     DEFAULT_CODEX_URL, headers, body, verify=True,
+                    proxy=self.proxy,
                     on_content_delta=on_content_delta,
                     on_thinking_delta=on_thinking_delta,
                     on_tool_call_delta=on_tool_call_delta,
@@ -87,6 +93,7 @@ class OpenAICodexProvider(LLMProvider):
                 logger.warning("SSL verification failed for Codex API; retrying with verify=False")
                 content, tool_calls, finish_reason, usage, reasoning_content = await _request_codex(
                     DEFAULT_CODEX_URL, headers, body, verify=False,
+                    proxy=self.proxy,
                     on_content_delta=on_content_delta,
                     on_thinking_delta=on_thinking_delta,
                     on_tool_call_delta=on_tool_call_delta,
@@ -199,12 +206,17 @@ async def _request_codex(
     headers: dict[str, str],
     body: dict[str, Any],
     verify: bool,
+    proxy: str | None = None,
     on_content_delta: Callable[[str], Awaitable[None]] | None = None,
     on_thinking_delta: Callable[[str], Awaitable[None]] | None = None,
     on_tool_call_delta: Callable[[dict[str, Any]], Awaitable[None]] | None = None,
 ) -> tuple[str, list[ToolCallRequest], str, dict[str, int], str | None]:
     idle_timeout_s = resolve_stream_idle_timeout_s()
-    async with httpx.AsyncClient(timeout=idle_timeout_s, verify=verify) as client:
+    client_kwargs: dict[str, Any] = {"timeout": idle_timeout_s, "verify": verify}
+    if proxy:
+        client_kwargs["proxy"] = proxy
+        client_kwargs["trust_env"] = False
+    async with httpx.AsyncClient(**client_kwargs) 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/nanobot/providers/openai_compat_provider.py b/nanobot/providers/openai_compat_provider.py
index 7aec961c..57eccdb6 100644
--- a/nanobot/providers/openai_compat_provider.py
+++ b/nanobot/providers/openai_compat_provider.py
@@ -358,6 +358,7 @@ class OpenAICompatProvider(LLMProvider):
         extra_body: dict[str, Any] | None = None,
         api_type: str = "auto",
         extra_query: dict[str, str] | None = None,
+        proxy: str | None = None,
     ):
         super().__init__(api_key, api_base)
         self.default_model = default_model
@@ -366,6 +367,7 @@ class OpenAICompatProvider(LLMProvider):
         self._extra_body = extra_body or {}
         self._api_type = api_type if spec and spec.name == "openai" else "auto"
         self._extra_query = extra_query or {}
+        self._proxy = proxy or None
 
         if api_key and spec and spec.env_key:
             self._setup_env(api_key, api_base)
@@ -396,7 +398,14 @@ class OpenAICompatProvider(LLMProvider):
 
         timeout_s = _openai_compat_timeout_s()
         http_client: httpx.AsyncClient | None = None
-        if self._is_local:
+        if self._proxy:
+            http_client = httpx.AsyncClient(
+                timeout=timeout_s,
+                proxy=self._proxy,
+                trust_env=False,
+                follow_redirects=True,
+            )
+        elif self._is_local:
             # Local model servers (Ollama, llama.cpp, vLLM) often close idle
             # HTTP connections before the client-side keepalive expires. When
             # two LLM calls happen seconds apart (e.g. heartbeat _decide then
diff --git a/nanobot/webui/settings_api.py b/nanobot/webui/settings_api.py
index 8d378b15..5b1f9bb4 100644
--- a/nanobot/webui/settings_api.py
+++ b/nanobot/webui/settings_api.py
@@ -22,7 +22,7 @@ from nanobot.audio.transcription_registry import (
     resolve_transcription_provider,
     transcription_provider_names,
 )
-from nanobot.config.loader import get_config_path, load_config, save_config
+from nanobot.config.loader import get_config_path, load_config, resolve_config_env_vars, save_config
 from nanobot.config.schema import ModelPresetConfig, ProviderConfig
 from nanobot.providers.image_generation import (
     get_image_gen_provider,
@@ -1166,14 +1166,19 @@ def login_oauth_provider(query: QueryParams) -> dict[str, Any]:
         except ImportError:
             raise WebUISettingsError("oauth_cli_kit is not installed", status=500) from None
 
+        try:
+            proxy = resolve_config_env_vars(load_config()).providers.openai_codex.proxy or None
+        except ValueError as e:
+            raise WebUISettingsError(str(e), status=400) from e
         token = None
         with suppress(Exception):
-            token = get_token()
+            token = get_token(proxy=proxy)
         if not (token and token.access):
             messages: list[str] = []
             token = login_oauth_interactive(
                 print_fn=lambda message: messages.append(str(message)),
                 prompt_fn=lambda _prompt: "",
+                proxy=proxy,
             )
         if not (token and token.access):
             raise WebUISettingsError("OAuth login failed", status=401)
diff --git a/pyproject.toml b/pyproject.toml
index 285078b5..cdc6cc0f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -31,7 +31,7 @@ dependencies = [
     "websocket-client>=1.9.0,<2.0.0",
     "httpx>=0.28.0,<1.0.0",
     "ddgs>=9.5.5,<10.0.0",
-    "oauth-cli-kit>=0.1.3,<1.0.0",
+    "oauth-cli-kit>=0.1.6,<1.0.0",
     "loguru>=0.7.3,<1.0.0",
     "readability-lxml>=0.8.4,<1.0.0",
     "lxml-html-clean>=0.4.0,<1.0.0",
diff --git a/tests/cli/test_commands.py b/tests/cli/test_commands.py
index 3d9e79c6..e265d1c2 100644
--- a/tests/cli/test_commands.py
+++ b/tests/cli/test_commands.py
@@ -5,6 +5,7 @@ import shutil
 import signal
 from contextlib import suppress
 from pathlib import Path
+from types import SimpleNamespace
 from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
@@ -19,7 +20,7 @@ from nanobot.cron.service import CronJobSkippedError
 from nanobot.cron.session_turns import CRON_DEFER_UNTIL_IDLE_META, CRON_TRIGGER_META
 from nanobot.cron.types import CronJob, CronPayload
 from nanobot.cron.webui_metadata import cron_proactive_delivery_metadata
-from nanobot.providers.factory import ProviderSnapshot, make_provider
+from nanobot.providers.factory import ProviderSnapshot, make_provider, provider_signature
 from nanobot.providers.openai_codex_provider import _strip_model_prefix
 from nanobot.providers.registry import find_by_name
 from nanobot.webui.metadata import (
@@ -434,6 +435,60 @@ def test_provider_login_rejects_unknown_provider():
     assert "Unknown OAuth provider" in result.stdout
 
 
+def test_provider_login_openai_codex_passes_configured_proxy(monkeypatch):
+    proxy = "http://127.0.0.1:23458"
+    monkeypatch.setattr(
+        "nanobot.config.loader.load_config",
+        lambda: Config.model_validate({"providers": {"openaiCodex": {"proxy": proxy}}}),
+    )
+
+    import oauth_cli_kit
+
+    def fake_get_token(**_kwargs):
+        raise RuntimeError("no-token")
+
+    monkeypatch.setattr(oauth_cli_kit, "get_token", fake_get_token)
+
+    captured: dict[str, str | None] = {}
+
+    def fake_login(*, print_fn, prompt_fn, proxy=None):
+        captured["proxy"] = proxy
+        return SimpleNamespace(access="access-token", account_id="acct-test")
+
+    monkeypatch.setattr(oauth_cli_kit, "login_oauth_interactive", fake_login)
+
+    result = runner.invoke(app, ["provider", "login", "openai-codex"])
+
+    assert result.exit_code == 0
+    assert captured["proxy"] == proxy
+
+
+def test_provider_login_openai_codex_resolves_proxy_env_ref(monkeypatch):
+    proxy = "http://127.0.0.1:23458"
+    monkeypatch.setenv("CODEX_PROXY_FOR_TEST", proxy)
+    monkeypatch.setattr(
+        "nanobot.config.loader.load_config",
+        lambda: Config.model_validate(
+            {"providers": {"openaiCodex": {"proxy": "${CODEX_PROXY_FOR_TEST}"}}}
+        ),
+    )
+
+    import oauth_cli_kit
+
+    captured: dict[str, str | None] = {}
+
+    def fake_get_token(*, proxy=None):
+        captured["proxy"] = proxy
+        return SimpleNamespace(access="access-token", account_id="acct-test")
+
+    monkeypatch.setattr(oauth_cli_kit, "get_token", fake_get_token)
+
+    result = runner.invoke(app, ["provider", "login", "openai-codex"])
+
+    assert result.exit_code == 0
+    assert captured["proxy"] == proxy
+
+
 def test_config_matches_explicit_ollama_prefix_without_api_key():
     config = Config()
     config.agents.defaults.model = "ollama/llama3.2"
@@ -685,6 +740,54 @@ def test_make_provider_uses_github_copilot_backend():
     assert provider.__class__.__name__ == "GitHubCopilotProvider"
 
 
+def test_openai_codex_proxy_config_affects_provider_and_signature():
+    def config_with_proxy(proxy: str) -> Config:
+        return Config.model_validate(
+            {
+                "agents": {
+                    "defaults": {
+                        "provider": "openai-codex",
+                        "model": "openai-codex/gpt-5.5",
+                    }
+                },
+                "providers": {"openaiCodex": {"proxy": proxy}},
+            }
+        )
+
+    proxy = "http://127.0.0.1:23458"
+    config = config_with_proxy(proxy)
+
+    provider = make_provider(config)
+
+    assert provider.__class__.__name__ == "OpenAICodexProvider"
+    assert provider.proxy == proxy
+    assert provider_signature(config) != provider_signature(
+        config_with_proxy("http://127.0.0.1:23459")
+    )
+
+
+def test_provider_proxy_rejects_unsupported_backend():
+    config = Config.model_validate(
+        {
+            "agents": {
+                "defaults": {
+                    "provider": "anthropic",
+                    "model": "anthropic/claude-opus-4-5",
+                }
+            },
+            "providers": {
+                "anthropic": {
+                    "apiKey": "sk-test",
+                    "proxy": "http://127.0.0.1:23458",
+                }
+            },
+        }
+    )
+
+    with pytest.raises(ValueError, match=r"providers\.anthropic\.proxy"):
+        make_provider(config)
+
+
 def test_github_copilot_provider_strips_prefixed_model_name():
     from nanobot.providers.github_copilot_provider import GitHubCopilotProvider
 
@@ -752,7 +855,7 @@ def test_make_provider_passes_extra_headers_to_custom_provider():
                         "x-session-affinity": "sticky-session",
                     },
                 }
-            },
+            }
         }
     )
 
diff --git a/tests/config/test_env_interpolation.py b/tests/config/test_env_interpolation.py
index dad44382..329010cc 100644
--- a/tests/config/test_env_interpolation.py
+++ b/tests/config/test_env_interpolation.py
@@ -8,6 +8,7 @@ from nanobot.config.loader import (
     resolve_config_env_vars,
     save_config,
 )
+from nanobot.config.schema import Config
 
 
 class TestResolveEnvVars:
@@ -127,6 +128,31 @@ class TestResolveConfig:
         assert "githubCopilot" not in saved["providers"]
         assert saved["providers"]["groq"]["apiKey"] == "groq-secret"
 
+    def test_save_preserves_openai_codex_proxy_config(self, tmp_path):
+        config_path = tmp_path / "config.json"
+        proxy = "http://127.0.0.1:23458"
+        config = Config.model_validate(
+            {
+                "providers": {
+                    "openaiCodex": {
+                        "apiKey": "codex-secret",
+                        "proxy": proxy,
+                    },
+                    "groq": {"apiKey": "groq-secret"},
+                }
+            }
+        )
+
+        save_config(config, config_path)
+
+        saved = json.loads(config_path.read_text(encoding="utf-8"))
+        assert saved["providers"]["openaiCodex"] == {"proxy": proxy}
+        assert saved["providers"]["groq"]["apiKey"] == "groq-secret"
+
+        reloaded = load_config(config_path)
+        assert reloaded.providers.openai_codex.proxy == proxy
+        assert reloaded.providers.openai_codex.api_key is None
+
     def test_preserves_excluded_fields_when_no_env_refs(self, tmp_path):
         """Regression: fields with ``exclude=True`` (e.g. ProviderConfig.openai_codex)
         must survive ``resolve_config_env_vars`` when the config has no
diff --git a/tests/providers/test_openai_codex_provider.py b/tests/providers/test_openai_codex_provider.py
index cbd3ed48..8cba9df0 100644
--- a/tests/providers/test_openai_codex_provider.py
+++ b/tests/providers/test_openai_codex_provider.py
@@ -21,9 +21,12 @@ from nanobot.providers.openai_codex_provider import (
 
 
 def _mock_codex_token(monkeypatch: pytest.MonkeyPatch) -> None:
+    def fake_token(**_kwargs):
+        return SimpleNamespace(account_id="acct", access="token")
+
     monkeypatch.setattr(
         "nanobot.providers.openai_codex_provider.get_codex_token",
-        lambda: SimpleNamespace(account_id="acct", access="token"),
+        fake_token,
     )
 
 
@@ -77,7 +80,12 @@ async def test_codex_request_non_200_populates_http_metadata(monkeypatch) -> Non
             request=request,
         )
 
-    def fake_client(*, timeout: int, verify: bool) -> httpx.AsyncClient:
+    def fake_client(
+        *,
+        timeout: int,
+        verify: bool,
+        **_kwargs: object,
+    ) -> httpx.AsyncClient:
         assert timeout == 90
         assert verify is True
         return original_client(transport=httpx.MockTransport(handler), timeout=timeout)
@@ -106,7 +114,12 @@ async def test_codex_request_honors_stream_idle_timeout_env(monkeypatch) -> None
     def handler(request: httpx.Request) -> httpx.Response:
         return httpx.Response(200, request=request)
 
-    def fake_client(*, timeout: int, verify: bool) -> httpx.AsyncClient:
+    def fake_client(
+        *,
+        timeout: int,
+        verify: bool,
+        **_kwargs: object,
+    ) -> httpx.AsyncClient:
         seen["timeout"] = timeout
         return original_client(transport=httpx.MockTransport(handler), timeout=timeout)
 
@@ -117,6 +130,39 @@ async def test_codex_request_honors_stream_idle_timeout_env(monkeypatch) -> None
     assert seen["timeout"] == 5
 
 
+@pytest.mark.asyncio
+async def test_codex_request_uses_configured_proxy(monkeypatch) -> None:
+    original_client = httpx.AsyncClient
+    seen: dict[str, object] = {}
+    proxy = "http://127.0.0.1:23458"
+
+    def handler(request: httpx.Request) -> httpx.Response:
+        return httpx.Response(200, request=request)
+
+    def fake_client(
+        *,
+        timeout: int,
+        verify: bool,
+        proxy: str | None = None,
+        trust_env: bool = True,
+    ) -> httpx.AsyncClient:
+        seen["proxy"] = proxy
+        seen["trust_env"] = trust_env
+        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,
+        proxy=proxy,
+    )
+
+    assert seen == {"proxy": proxy, "trust_env": False}
+
+
 @pytest.mark.asyncio
 async def test_codex_prompt_cache_key_uses_stable_conversation_prefix(monkeypatch) -> None:
     bodies: list[dict] = []
@@ -128,11 +174,12 @@ async def test_codex_prompt_cache_key_uses_stable_conversation_prefix(monkeypatc
         headers,
         body,
         verify,
+        proxy=None,
         on_content_delta=None,
         on_thinking_delta=None,
         on_tool_call_delta=None,
     ):
-        _ = on_thinking_delta, on_tool_call_delta
+        _ = proxy, on_thinking_delta, on_tool_call_delta
         bodies.append(body)
         return "ok", [], "stop", {}, None
 
@@ -186,6 +233,40 @@ async def test_codex_timeout_error_is_typed_and_retryable(monkeypatch) -> None:
     assert response.error_should_retry is True
 
 
+@pytest.mark.asyncio
+async def test_codex_provider_passes_proxy_to_oauth_and_response_request(monkeypatch) -> None:
+    proxy = "http://127.0.0.1:23458"
+    seen: dict[str, object] = {}
+
+    def fake_token(*, proxy=None):
+        seen["token_proxy"] = proxy
+        return SimpleNamespace(account_id="acct", access="token")
+
+    async def fake_request(
+        url,
+        headers,
+        body,
+        verify,
+        proxy=None,
+        on_content_delta=None,
+        on_thinking_delta=None,
+        on_tool_call_delta=None,
+    ):
+        _ = url, headers, body, verify, on_content_delta, on_thinking_delta, on_tool_call_delta
+        seen["request_proxy"] = proxy
+        return "ok", [], "stop", {}, None
+
+    monkeypatch.setattr("nanobot.providers.openai_codex_provider.get_codex_token", fake_token)
+    monkeypatch.setattr("nanobot.providers.openai_codex_provider._request_codex", fake_request)
+
+    provider = OpenAICodexProvider(proxy=proxy)
+    response = await provider.chat([{"role": "user", "content": "hello"}])
+
+    assert response.content == "ok"
+    assert seen["token_proxy"] == proxy
+    assert seen["request_proxy"] == proxy
+
+
 @pytest.mark.asyncio
 async def test_codex_timeout_error_writes_diagnostic_log(monkeypatch) -> None:
     log_capture = _capture_codex_warnings(monkeypatch)
@@ -409,9 +490,12 @@ def test_codex_reasoning_options_request_summary_without_forcing_effort() -> Non
 
 @pytest.mark.asyncio
 async def test_codex_stream_surfaces_reasoning_summary(monkeypatch) -> None:
+    def fake_token(**_kwargs):
+        return SimpleNamespace(account_id="acct", access="token")
+
     monkeypatch.setattr(
         "nanobot.providers.openai_codex_provider.get_codex_token",
-        lambda: SimpleNamespace(account_id="acct", access="token"),
+        fake_token,
     )
 
     async def fake_request(
@@ -419,11 +503,12 @@ async def test_codex_stream_surfaces_reasoning_summary(monkeypatch) -> None:
         headers,
         body,
         verify,
+        proxy=None,
         on_content_delta=None,
         on_thinking_delta=None,
         on_tool_call_delta=None,
     ):
-        _ = url, headers, verify, on_tool_call_delta
+        _ = url, headers, verify, proxy, on_tool_call_delta
         assert body["reasoning"] == {"summary": "auto", "effort": "medium"}
         if on_content_delta:
             await on_content_delta("answer")
diff --git a/tests/providers/test_proxy_env.py b/tests/providers/test_proxy_env.py
index 640c9dfb..340d1bc5 100644
--- a/tests/providers/test_proxy_env.py
+++ b/tests/providers/test_proxy_env.py
@@ -4,6 +4,7 @@ from unittest.mock import MagicMock
 
 import httpx
 
+import nanobot.providers.openai_compat_provider as openai_compat_provider
 from nanobot.providers.openai_compat_provider import OpenAICompatProvider
 
 
@@ -54,3 +55,32 @@ class TestCloudEndpointProxyEnabled:
         client = provider._client._client
         # trust_env should be True so httpx reads HTTP_PROXY etc.
         assert client._trust_env is True
+
+    async def test_explicit_provider_proxy_overrides_env(self, monkeypatch):
+        spec = _make_spec(is_local=False)
+        spec.env_key = ""
+        spec.default_api_base = "https://api.openai.com/v1"
+        proxy = "http://127.0.0.1:23458"
+        monkeypatch.delenv("NANOBOT_OPENAI_COMPAT_TIMEOUT_S", raising=False)
+
+        http_client = MagicMock()
+        async_client = MagicMock(return_value=http_client)
+        openai_client = MagicMock(return_value=object())
+        monkeypatch.setattr(httpx, "AsyncClient", async_client)
+        monkeypatch.setattr(openai_compat_provider, "AsyncOpenAI", openai_client)
+
+        provider = OpenAICompatProvider(
+            api_key="test",
+            api_base=None,
+            spec=spec,
+            proxy=proxy,
+        )
+        provider._build_client()
+
+        async_client.assert_called_once_with(
+            timeout=120.0,
+            proxy=proxy,
+            trust_env=False,
+            follow_redirects=True,
+        )
+        assert openai_client.call_args.kwargs["http_client"] is http_client
diff --git a/tests/webui/test_settings_api.py b/tests/webui/test_settings_api.py
index 4a41328f..f772ce5a 100644
--- a/tests/webui/test_settings_api.py
+++ b/tests/webui/test_settings_api.py
@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import json
+from types import SimpleNamespace
 
 import httpx
 import pytest
@@ -12,6 +13,7 @@ from nanobot.webui.settings_api import (
     WebUISettingsError,
     _oauth_provider_status,
     create_model_configuration,
+    login_oauth_provider,
     provider_models_payload,
     settings_payload,
     settings_usage_payload,
@@ -844,6 +846,39 @@ def test_openai_codex_oauth_status_rejects_unavailable_token(
     assert status["account"] is None
 
 
+def test_openai_codex_oauth_login_passes_configured_proxy(
+    tmp_path,
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    proxy = "http://127.0.0.1:23458"
+    config_path = tmp_path / "config.json"
+    save_config(
+        Config.model_validate({"providers": {"openaiCodex": {"proxy": "${CODEX_PROXY_TEST}"}}}),
+        config_path,
+    )
+    monkeypatch.setenv("CODEX_PROXY_TEST", proxy)
+    monkeypatch.setattr("nanobot.config.loader._current_config_path", config_path)
+
+    import oauth_cli_kit
+
+    captured: dict[str, str | None] = {}
+
+    def fake_get_token(*, proxy=None):
+        captured["get_proxy"] = proxy
+        raise RuntimeError("no-token")
+
+    def fake_login(*, print_fn, prompt_fn, proxy=None):
+        captured["login_proxy"] = proxy
+        return SimpleNamespace(access="access-token", account_id="acct-test")
+
+    monkeypatch.setattr(oauth_cli_kit, "get_token", fake_get_token)
+    monkeypatch.setattr(oauth_cli_kit, "login_oauth_interactive", fake_login)
+
+    login_oauth_provider({"provider": ["openai-codex"]})
+
+    assert captured == {"get_proxy": proxy, "login_proxy": proxy}
+
+
 def test_provider_models_payload_fetches_openai_compatible_models(
     tmp_path,
     monkeypatch: pytest.MonkeyPatch,