diff --git a/hermes_cli/auth.py b/hermes_cli/auth.py
index f087062b006..6f4fc344636 100644
--- a/hermes_cli/auth.py
+++ b/hermes_cli/auth.py
@@ -197,6 +197,14 @@ PROVIDER_REGISTRY: Dict[str, ProviderConfig] = {
         auth_type="oauth_external",
         inference_base_url=DEFAULT_CODEX_BASE_URL,
     ),
+    "openai-api": ProviderConfig(
+        id="openai-api",
+        name="OpenAI API",
+        auth_type="api_key",
+        inference_base_url="https://api.openai.com/v1",
+        api_key_env_vars=("OPENAI_API_KEY",),
+        base_url_env_var="OPENAI_BASE_URL",
+    ),
     "xai-oauth": ProviderConfig(
         id="xai-oauth",
         name="xAI Grok OAuth (SuperGrok / Premium+)",
diff --git a/hermes_cli/main.py b/hermes_cli/main.py
index 2a6fb9e4435..393a7bc0dc4 100644
--- a/hermes_cli/main.py
+++ b/hermes_cli/main.py
@@ -2412,6 +2412,7 @@ def select_provider_and_model(args=None):
     elif selected_provider == "azure-foundry":
         _model_flow_azure_foundry(config, current_model)
     elif selected_provider in {
+        "openai-api",
         "gemini",
         "deepseek",
         "xai",
diff --git a/hermes_cli/models.py b/hermes_cli/models.py
index 3ef4f04ecf2..ee4da1f3fad 100644
--- a/hermes_cli/models.py
+++ b/hermes_cli/models.py
@@ -199,6 +199,16 @@ _PROVIDER_MODELS: dict[str, list[str]] = {
         "gpt-4o",
         "gpt-4o-mini",
     ],
+    "openai-api": [
+        "gpt-5.5",
+        "gpt-5.4",
+        "gpt-5.4-mini",
+        "gpt-5.4-nano",
+        "gpt-5-mini",
+        "gpt-4.1",
+        "gpt-4o",
+        "gpt-4o-mini",
+    ],
     "openai-codex": _codex_curated_models(),
     "xai-oauth": _xai_curated_models(),
     "copilot-acp": [
@@ -928,6 +938,7 @@ CANONICAL_PROVIDERS: list[ProviderEntry] = [
     ProviderEntry("lmstudio",       "LM Studio",                "LM Studio (local desktop app with built-in model server)"),
     ProviderEntry("anthropic",      "Anthropic",                "Anthropic (Claude models — API key or Claude Code)"),
     ProviderEntry("openai-codex",   "OpenAI Codex",             "OpenAI Codex"),
+    ProviderEntry("openai-api",     "OpenAI API",               "OpenAI API (api.openai.com, API key)"),
     ProviderEntry("alibaba",        "Qwen Cloud",               "Qwen Cloud / DashScope Coding (Qwen + multi-provider)"),
     ProviderEntry("xai-oauth",      "xAI Grok OAuth (SuperGrok / Premium+)", "xAI Grok OAuth (SuperGrok / Premium+)"),
     ProviderEntry("xiaomi",         "Xiaomi MiMo",              "Xiaomi MiMo (MiMo-V2.5 and V2 models — pro, omni, flash)"),
diff --git a/hermes_cli/providers.py b/hermes_cli/providers.py
index e3cf87c8a2a..2490bad802a 100644
--- a/hermes_cli/providers.py
+++ b/hermes_cli/providers.py
@@ -60,6 +60,11 @@ HERMES_OVERLAYS: Dict[str, HermesOverlay] = {
         auth_type="oauth_external",
         base_url_override="https://chatgpt.com/backend-api/codex",
     ),
+    "openai-api": HermesOverlay(
+        transport="codex_responses",
+        base_url_override="https://api.openai.com/v1",
+        base_url_env_var="OPENAI_BASE_URL",
+    ),
     "xai-oauth": HermesOverlay(
         transport="codex_responses",
         auth_type="oauth_external",