diff --git a/plugins/model-providers/deepinfra/__init__.py b/plugins/model-providers/deepinfra/__init__.py
index 2ba8fee8dd..21a3d0423b 100644
--- a/plugins/model-providers/deepinfra/__init__.py
+++ b/plugins/model-providers/deepinfra/__init__.py
@@ -3,11 +3,7 @@ their own plugin subsystems)."""
 
 from typing import Any
 
-from agent.reasoning_effort import (
-    OPENAI_COMPAT_WIRE_EFFORTS,
-    clamp_effort,
-    requested_effort,
-)
+from agent.reasoning_effort import OPENAI_COMPAT_WIRE_EFFORTS, clamp_effort, requested_effort
 from providers import register_provider
 from providers.base import ProviderProfile
 
@@ -19,25 +15,19 @@ class _DeepInfraProfile(ProviderProfile):
     def build_api_kwargs_extras(
         self, *, reasoning_config: dict | None = None, **context: Any
     ) -> tuple[dict[str, Any], dict[str, Any]]:
-        """Map Hermes reasoning controls to DeepInfra's top-level wire field.
+        """Map Hermes reasoning controls to DeepInfra's top-level ``reasoning_effort``.
 
-        DeepInfra applies a per-model default when the field is absent, while
-        ``none`` is its explicit off switch. This route does not advertise a
-        reasoning capability to the shared transport, so it must not be gated
-        on ``supports_reasoning``.
+        DeepInfra applies a per-model default when the field is absent (DeepSeek-V4.x off,
+        GLM/Qwen-Thinking on), so ``none`` is the only working off switch and an unset effort
+        is omitted rather than guessed. The core ``_supports_reasoning_extra_body`` allowlist
+        does not know this host, so the transport always passes ``supports_reasoning=False``
+        here — gating on it would make the method a permanent no-op (#111872).
         """
-        if (
-            isinstance(reasoning_config, dict)
-            and reasoning_config.get("enabled") is False
-        ):
+        if isinstance(reasoning_config, dict) and reasoning_config.get("enabled") is False:
             return {}, {"reasoning_effort": "none"}
         effort = requested_effort(reasoning_config)
         clamped = clamp_effort(effort, OPENAI_COMPAT_WIRE_EFFORTS)
-        return (
-            ({}, {"reasoning_effort": clamped})
-            if clamped in OPENAI_COMPAT_WIRE_EFFORTS
-            else ({}, {})
-        )
+        return ({}, {"reasoning_effort": clamped}) if clamped in OPENAI_COMPAT_WIRE_EFFORTS else ({}, {})
 
     def default_vision_model(self):  # type: ignore[override]
         """First vision-capable *chat* model from the live catalog, or None. Key-gated so a box
@@ -49,7 +39,6 @@ class _DeepInfraProfile(ProviderProfile):
             return None
         try:
             from hermes_cli.models import _fetch_deepinfra_models_by_tag
-
             items = _fetch_deepinfra_models_by_tag("chat")
         except Exception:
             return None
@@ -62,13 +51,9 @@ class _DeepInfraProfile(ProviderProfile):
 
 
 deepinfra = _DeepInfraProfile(
-    name="deepinfra",
-    aliases=("deep-infra", "deepinfra-ai"),
-    display_name="DeepInfra",
-    description="DeepInfra — 100+ open models, pay-per-use",
-    signup_url="https://deepinfra.com/dash/api_keys",
-    env_vars=("DEEPINFRA_API_KEY", "DEEPINFRA_BASE_URL"),
-    base_url="https://api.deepinfra.com/v1/openai",
+    name="deepinfra", aliases=("deep-infra", "deepinfra-ai"), display_name="DeepInfra",
+    description="DeepInfra — 100+ open models, pay-per-use", signup_url="https://deepinfra.com/dash/api_keys",
+    env_vars=("DEEPINFRA_API_KEY", "DEEPINFRA_BASE_URL"), base_url="https://api.deepinfra.com/v1/openai",
     auth_type="api_key",
     default_max_tokens=None,  # DeepInfra applies its documented per-model limit
     # The only hardcoded DeepInfra model: aux resolution is synchronous, so it
diff --git a/tests/plugins/model_providers/test_deepinfra_profile.py b/tests/plugins/model_providers/test_deepinfra_profile.py
index f76c1fbb0d..cfbf280bfb 100644
--- a/tests/plugins/model_providers/test_deepinfra_profile.py
+++ b/tests/plugins/model_providers/test_deepinfra_profile.py
@@ -1,4 +1,11 @@
-"""Regression coverage for DeepInfra's top-level reasoning_effort wire field."""
+"""DeepInfra profile puts the reasoning switch on the wire (#111872).
+
+DeepInfra's OpenAI-compatible endpoint reads one top-level ``reasoning_effort`` field validated
+against a gateway-wide enum (``none``..``max``; Hermes-internal ``ultra`` is rejected). The
+profile is the ONLY source of that field on the transport's profile path, and the core
+``_supports_reasoning_extra_body`` allowlist passes ``supports_reasoning=False`` for this host,
+so the profile must emit without gating on it.
+"""
 
 from __future__ import annotations
 
@@ -7,8 +14,7 @@ import pytest
 
 @pytest.fixture
 def deepinfra_profile():
-    """Resolve the registered profile through the normal plugin discovery path."""
-    import model_tools  # noqa: F401
+    import model_tools  # noqa: F401  (plugin discovery registers the profile)
     import providers
 
     profile = providers.get_provider_profile("deepinfra")
@@ -16,59 +22,43 @@ def deepinfra_profile():
     return profile
 
 
-class TestDeepInfraReasoningEffort:
-    def test_default_preserves_the_model_default(self, deepinfra_profile):
-        assert deepinfra_profile.build_api_kwargs_extras(reasoning_config=None) == (
-            {},
-            {},
-        )
-
-    @pytest.mark.parametrize(
-        "effort", ("minimal", "low", "medium", "high", "xhigh", "max")
+@pytest.mark.parametrize(
+    "reasoning_config, expected_top_level",
+    [
+        ({"enabled": True, "effort": "high"}, {"reasoning_effort": "high"}),
+        ({"enabled": True, "effort": "xhigh"}, {"reasoning_effort": "xhigh"}),  # native, never folded into max
+        ({"enabled": True, "effort": "ultra"}, {"reasoning_effort": "max"}),  # Hermes-internal tier clamps
+        ({"enabled": False}, {"reasoning_effort": "none"}),  # the only off switch for default-on models
+        ({"enabled": True, "effort": "none"}, {"reasoning_effort": "none"}),
+        (None, {}),  # nothing requested → keep DeepInfra's per-model default
+        ({"enabled": True}, {}),
+        ({"enabled": True, "effort": "future-tier"}, {}),  # unknown level omitted rather than 422
+    ],
+)
+def test_profile_translates_reasoning_config_to_top_level_effort(deepinfra_profile, reasoning_config, expected_top_level):
+    extra_body, top_level = deepinfra_profile.build_api_kwargs_extras(
+        reasoning_config=reasoning_config, supports_reasoning=False, model="deepseek-ai/DeepSeek-V4.1-Flash",
     )
-    def test_explicit_efforts_are_sent_verbatim(self, deepinfra_profile, effort):
-        assert deepinfra_profile.build_api_kwargs_extras(
-            reasoning_config={"enabled": True, "effort": effort}
-        ) == ({}, {"reasoning_effort": effort})
+    assert extra_body == {}
+    assert top_level == expected_top_level
 
-    def test_ultra_clamps_to_deepinfra_maximum(self, deepinfra_profile):
-        assert deepinfra_profile.build_api_kwargs_extras(
-            reasoning_config={"enabled": True, "effort": "ultra"}
-        ) == ({}, {"reasoning_effort": "max"})
 
-    @pytest.mark.parametrize(
-        "reasoning_config", ({"enabled": False}, {"enabled": False, "effort": "high"})
+def test_transport_main_turn_carries_reasoning_effort_without_capability_gate(deepinfra_profile):
+    """The main turn builds through ``_build_kwargs_from_profile`` with ``supports_reasoning=False``
+    (core allowlist excludes this host) — the field must still reach the request."""
+    from agent.transports.chat_completions import ChatCompletionsTransport
+
+    build = ChatCompletionsTransport().build_kwargs
+    on = build(
+        model="deepseek-ai/DeepSeek-V4.1-Flash", messages=[{"role": "user", "content": "ping"}], tools=None,
+        provider_profile=deepinfra_profile, provider_name="deepinfra",
+        reasoning_config={"enabled": True, "effort": "high"}, supports_reasoning=False,
     )
-    def test_disabled_sends_the_explicit_off_value(
-        self, deepinfra_profile, reasoning_config
-    ):
-        assert deepinfra_profile.build_api_kwargs_extras(
-            reasoning_config=reasoning_config
-        ) == ({}, {"reasoning_effort": "none"})
-
-    @pytest.mark.parametrize(
-        "reasoning_config",
-        ({}, {"enabled": True}, {"enabled": True, "effort": "future-tier"}),
+    off = build(
+        model="zai-org/GLM-4.6", messages=[{"role": "user", "content": "ping"}], tools=None,
+        provider_profile=deepinfra_profile, provider_name="deepinfra",
+        reasoning_config={"enabled": False}, supports_reasoning=False,
     )
-    def test_missing_or_unknown_effort_preserves_the_model_default(
-        self, deepinfra_profile, reasoning_config
-    ):
-        assert deepinfra_profile.build_api_kwargs_extras(
-            reasoning_config=reasoning_config
-        ) == ({}, {})
-
-    def test_transport_includes_top_level_reasoning_effort_without_capability_gate(
-        self, deepinfra_profile
-    ):
-        from agent.transports.chat_completions import ChatCompletionsTransport
-
-        kwargs = ChatCompletionsTransport().build_kwargs(
-            model="deepseek-ai/DeepSeek-V4.1-Flash",
-            messages=[{"role": "user", "content": "ping"}],
-            tools=None,
-            provider_profile=deepinfra_profile,
-            provider_name="deepinfra",
-            reasoning_config={"enabled": True, "effort": "high"},
-            supports_reasoning=False,
-        )
-        assert kwargs["reasoning_effort"] == "high"
+    assert on["reasoning_effort"] == "high"
+    assert off["reasoning_effort"] == "none"
+    assert "reasoning" not in (on.get("extra_body") or {})
diff --git a/website/docs/integrations/providers.md b/website/docs/integrations/providers.md
index 759aed3dac..546e04392b 100644
--- a/website/docs/integrations/providers.md
+++ b/website/docs/integrations/providers.md
@@ -426,6 +426,10 @@ The model catalog is fetched dynamically from `ollama.com/v1/models` and cached
 Both speak the same OpenAI-compatible API. Cloud is a first-class provider (`--provider ollama-cloud`, `OLLAMA_API_KEY`); local Ollama is reached via the Custom Endpoint flow (base URL `http://localhost:11434/v1`, no key). Use cloud for large models you can't run locally; use local for privacy or offline work.
 :::
 
+### DeepInfra
+
+DeepInfra (`--provider deepinfra`, `DEEPINFRA_API_KEY`) is discovered live from its catalog. Reasoning is controlled through DeepInfra's top-level `reasoning_effort` field, so `agent.reasoning_effort`, `/reasoning <level>`, `--reasoning` and per-model `agent.reasoning_overrides` work in **both directions**: an effort turns thinking on for models that default off (DeepSeek-V4.x), `/reasoning none` turns it off for models that default on (GLM-4.6, Qwen3-Thinking). Leaving reasoning unset keeps DeepInfra's per-model default; `xhigh` is native and `ultra` is sent as `max`.
+
 ### AWS Bedrock
 
 Anthropic Claude, Amazon Nova, DeepSeek v3.2, Meta Llama 4, and other models via AWS Bedrock. Uses the AWS SDK (`boto3`) credential chain — no API key, just standard AWS auth.