From 437c6215f2dd6ec7da1f1ff257e5e71154eb95f6 Mon Sep 17 00:00:00 2001
From: Quang Huy <huynq23091@gmail.com>
Date: Wed, 12 Aug 2026 12:21:12 +0700
Subject: [PATCH] feat(provider): add none reasoning variant for DeepSeek V4

---
 packages/opencode/src/provider/transform.ts       | 10 ++++++++++
 packages/opencode/test/provider/transform.test.ts | 14 ++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/packages/opencode/src/provider/transform.ts b/packages/opencode/src/provider/transform.ts
index 4a2738e875ee..8e9da54c21df 100644
--- a/packages/opencode/src/provider/transform.ts
+++ b/packages/opencode/src/provider/transform.ts
@@ -1656,6 +1656,16 @@ export function reasoningVariants(model: ModelsDev.Model, target: Provider.Model
   if (options === undefined) return
   if (options.length === 0) return {}
 
+  // DeepSeek V4 exposes a thinking toggle; `reasoning_effort: "none"` turns it
+  // off. Add a `none` variant alongside its effort tiers so thinking can be
+  // disabled from the model variants menu.
+  if (target.api.id.toLowerCase().includes("deepseek-v4")) {
+    return nonEmptyVariants({
+      none: { reasoningEffort: "none" },
+      ...effortVariants(target, options.find((option) => option.type === "effort")?.values ?? []),
+    })
+  }
+
   const effort = options.find((option) => option.type === "effort")
   if (effort) return effortVariants(target, effort.values)
 
diff --git a/packages/opencode/test/provider/transform.test.ts b/packages/opencode/test/provider/transform.test.ts
index d1e437642e65..b22d39a301a9 100644
--- a/packages/opencode/test/provider/transform.test.ts
+++ b/packages/opencode/test/provider/transform.test.ts
@@ -3378,6 +3378,20 @@ describe("ProviderTransform.reasoningVariants", () => {
     )
   })
 
+  test("adds a none variant to disable thinking for DeepSeek V4", () => {
+    expect(
+      ProviderTransform.reasoningVariants(
+        model([{ type: "toggle" }, { type: "effort", values: ["low", "high", "max"] }]),
+        target("@ai-sdk/openai-compatible", "deepseek-v4-flash"),
+      ),
+    ).toEqual({
+      none: { reasoningEffort: "none" },
+      low: { reasoningEffort: "low" },
+      high: { reasoningEffort: "high" },
+      max: { reasoningEffort: "max" },
+    })
+  })
+
   test("combines effort with extended thinking for Claude Opus 4.5", () => {
     expect(
       ProviderTransform.reasoningVariants(