tweak: make interleaved reasoning_content default to true for openai compat deepseek setups (#24630)

2 files changed, 76 insertions, 8 deletions

diff --git a/packages/opencode/src/provider/provider.ts b/packages/opencode/src/provider/provider.ts
index 9aa1b6304..04d53a685 100644
--- a/packages/opencode/src/provider/provider.ts
+++ b/packages/opencode/src/provider/provider.ts
@@ -1135,6 +1135,13 @@ const layer: Layer.Layer<
 
           for (const [modelID, model] of Object.entries(provider.models ?? {})) {
             const existingModel = parsed.models[model.id ?? modelID]
+            const apiID = model.id ?? existingModel?.api.id ?? modelID
+            const apiNpm =
+              model.provider?.npm ??
+              provider.npm ??
+              existingModel?.api.npm ??
+              modelsDev[providerID]?.npm ??
+              "@ai-sdk/openai-compatible"
             const name = iife(() => {
               if (model.name) return model.name
               if (model.id && model.id !== modelID) return modelID
@@ -1143,13 +1150,8 @@ const layer: Layer.Layer<
             const parsedModel: Model = {
               id: ModelID.make(modelID),
               api: {
-                id: model.id ?? existingModel?.api.id ?? modelID,
-                npm:
-                  model.provider?.npm ??
-                  provider.npm ??
-                  existingModel?.api.npm ??
-                  modelsDev[providerID]?.npm ??
-                  "@ai-sdk/openai-compatible",
+                id: apiID,
+                npm: apiNpm,
                 url: model.provider?.api ?? provider?.api ?? existingModel?.api.url ?? modelsDev[providerID]?.api ?? "",
               },
               status: model.status ?? existingModel?.status ?? "active",
@@ -1177,7 +1179,12 @@ const layer: Layer.Layer<
                     model.modalities?.output?.includes("video") ?? existingModel?.capabilities.output.video ?? false,
                   pdf: model.modalities?.output?.includes("pdf") ?? existingModel?.capabilities.output.pdf ?? false,
                 },
-                interleaved: model.interleaved ?? existingModel?.capabilities.interleaved ?? false,
+                interleaved:
+                  model.interleaved ??
+                  existingModel?.capabilities.interleaved ??
+                  (!existingModel && apiNpm === "@ai-sdk/openai-compatible" && apiID.includes("deepseek")
+                    ? { field: "reasoning_content" }
+                    : false),
               },
               cost: {
                 input: model?.cost?.input ?? existingModel?.cost?.input ?? 0,
diff --git a/packages/opencode/test/provider/provider.test.ts b/packages/opencode/test/provider/provider.test.ts
index da98496c3..1480b2314 100644
--- a/packages/opencode/test/provider/provider.test.ts
+++ b/packages/opencode/test/provider/provider.test.ts
@@ -312,6 +312,67 @@ test("custom provider with npm package", async () => {
   })
 })
 
+test("custom DeepSeek openai-compatible model defaults interleaved reasoning field", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      await Bun.write(
+        path.join(dir, "opencode.json"),
+        JSON.stringify({
+          $schema: "https://opencode.ai/config.json",
+          provider: {
+            "custom-provider": {
+              name: "Custom Provider",
+              npm: "@ai-sdk/openai-compatible",
+              api: "https://api.custom.com/v1",
+              models: {
+                "deepseek-r1": {
+                  name: "DeepSeek R1",
+                },
+                "deepseek-details": {
+                  name: "DeepSeek Details",
+                  interleaved: { field: "reasoning_details" },
+                },
+                "custom-model": {
+                  name: "Custom Model",
+                },
+              },
+              options: {
+                apiKey: "custom-key",
+              },
+            },
+            "custom-anthropic-provider": {
+              name: "Custom Anthropic Provider",
+              npm: "@ai-sdk/anthropic",
+              api: "https://api.custom.com/v1",
+              models: {
+                "deepseek-r1": {
+                  name: "DeepSeek R1",
+                },
+              },
+              options: {
+                apiKey: "custom-key",
+              },
+            },
+          },
+        }),
+      )
+    },
+  })
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      const providers = await list()
+      const provider = providers[ProviderID.make("custom-provider")]
+      expect(provider.models["deepseek-r1"].capabilities.interleaved).toEqual({ field: "reasoning_content" })
+      expect(provider.models["deepseek-details"].capabilities.interleaved).toEqual({ field: "reasoning_details" })
+      expect(provider.models["custom-model"].capabilities.interleaved).toBe(false)
+      expect(
+        providers[ProviderID.make("custom-anthropic-provider")].models["deepseek-r1"].capabilities.interleaved,
+      ).toBe(false)
+    },
+  })
+})
+
 test("env variable takes precedence, config merges options", async () => {
   await using tmp = await tmpdir({
     init: async (dir) => {