fix(core): derive models.dev reasoning variants (#34726)

packages/llm/test/provider/anthropic-messages.test.ts

@@ -57,6 +57,23 @@ describe("Anthropic Messages route", () => {
     }),
   )
 
+  it.effect("lowers adaptive thinking settings with effort", () =>
+    Effect.gen(function* () {
+      const prepared = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(
+        LLM.updateRequest(request, {
+          providerOptions: {
+            anthropic: { thinking: { type: "adaptive", display: "summarized" }, effort: "low" },
+          },
+        }),
+      )
+
+      expect(prepared.body).toMatchObject({
+        thinking: { type: "adaptive", display: "summarized" },
+        output_config: { effort: "low" },
+      })
+    }),
+  )
+
   it.effect("lowers chronological system updates natively for Claude Opus 4.8 with cache hints", () =>
     Effect.gen(function* () {
       const prepared = yield* LLMClient.prepare<AnthropicMessages.AnthropicMessagesBody>(

packages/llm/test/provider/openai-chat.test.ts

@@ -98,12 +98,26 @@ describe("OpenAI Chat route", () => {
         LLM.request({
           model: OpenAI.configure({ baseURL: "https://api.openai.test/v1/", apiKey: "test" }).chat("gpt-4o-mini"),
           prompt: "think",
-          providerOptions: { openai: { reasoningEffort: "low" } },
+          providerOptions: { openai: { reasoningEffort: "max" } },
         }),
       )
 
       expect(prepared.body.store).toBe(false)
-      expect(prepared.body.reasoning_effort).toBe("low")
+      expect(prepared.body.reasoning_effort).toBe("max")
+    }),
+  )
+
+  it.effect("passes through custom OpenAI-compatible reasoning effort strings", () =>
+    Effect.gen(function* () {
+      const prepared = yield* LLMClient.prepare<OpenAIChat.OpenAIChatBody>(
+        LLM.request({
+          model,
+          prompt: "think",
+          providerOptions: { openai: { reasoningEffort: "experimental" } },
+        }),
+      )
+
+      expect(prepared.body.reasoning_effort).toBe("experimental")
     }),
   )
 

packages/llm/test/provider/openai-responses.test.ts

@@ -69,6 +69,16 @@ describe("OpenAI Responses route", () => {
     }),
   )
 
+  it.effect("passes through custom OpenAI reasoning effort strings", () =>
+    Effect.gen(function* () {
+      const prepared = yield* LLMClient.prepare<OpenAIResponses.OpenAIResponsesBody>(
+        LLM.updateRequest(request, { providerOptions: { openai: { reasoningEffort: "experimental" } } }),
+      )
+
+      expect(prepared.body.reasoning).toEqual({ effort: "experimental" })
+    }),
+  )
+
   it.effect("omits unsupported semantic service tiers", () =>
     Effect.gen(function* () {
       const prepared = yield* LLMClient.prepare(