fix: add reasoning content field support in chat body

core/llm/index.ts

@@ -90,6 +90,7 @@ export abstract class BaseLLM implements ILLM {
   // Provider capabilities (overridable by subclasses)
   protected supportsReasoningField: boolean = false;
   protected supportsReasoningDetailsField: boolean = false;
+  protected supportsReasoningContentField: boolean = false;
 
   get providerName(): string {
     return (this.constructor as typeof BaseLLM).providerName;
@@ -1182,6 +1183,7 @@ export abstract class BaseLLM implements ILLM {
           let body = toChatBody(messages, completionOptions, {
             includeReasoningField: this.supportsReasoningField,
             includeReasoningDetailsField: this.supportsReasoningDetailsField,
+            includeReasoningContentField: this.supportsReasoningContentField,
           });
           body = this.modifyChatBody(body);
 

core/llm/llms/Deepseek.ts

@@ -6,8 +6,9 @@ import OpenAI from "./OpenAI.js";
 
 class Deepseek extends OpenAI {
   static providerName = "deepseek";
-  protected supportsReasoningField = true;
+  protected supportsReasoningField = false;
   protected supportsReasoningDetailsField = false;
+  protected supportsReasoningContentField = true;
   static defaultOptions: Partial<LLMOptions> = {
     apiBase: "https://api.deepseek.com/",
     model: "deepseek-coder",

core/llm/llms/OpenAI.ts

@@ -4,6 +4,12 @@ import {
 } from "openai/resources/index";
 
 import { streamSse } from "@continuedev/fetch";
+import {
+  ResponseCreateParamsBase,
+  ResponseInputItem,
+  ResponseInputMessageContentList,
+  Tool as ResponsesTool,
+} from "openai/resources/responses/responses.mjs";
 import {
   ChatMessage,
   CompletionOptions,
@@ -19,13 +25,6 @@ import {
   toChatBody,
   toResponsesInput,
 } from "../openaiTypeConverters.js";
-import {
-  ResponseInput,
-  ResponseInputItem,
-  ResponseInputMessageContentList,
-  ResponseCreateParamsBase,
-  Tool as ResponsesTool,
-} from "openai/resources/responses/responses.mjs";
 
 const NON_CHAT_MODELS = [
   "text-davinci-002",
@@ -279,6 +278,7 @@ class OpenAI extends BaseLLM {
     const finalOptions = toChatBody(messages, options, {
       includeReasoningField: this.supportsReasoningField,
       includeReasoningDetailsField: this.supportsReasoningDetailsField,
+      includeReasoningContentField: this.supportsReasoningContentField,
     });
 
     finalOptions.stop = options.stop?.slice(0, this.getMaxStopWords());

core/llm/openaiTypeConverters.ts

@@ -40,20 +40,24 @@ import {
 function appendReasoningFieldsIfSupported(
   msg: ChatCompletionAssistantMessageParam & {
     reasoning?: string;
+    reasoning_content?: string;
     reasoning_details?: any[];
   },
   options: CompletionOptions,
   prevMessage?: ChatMessage,
   providerFlags?: {
     includeReasoningField?: boolean;
     includeReasoningDetailsField?: boolean;
+    includeReasoningContentField?: boolean;
   },
 ) {
   if (!prevMessage || prevMessage.role !== "thinking") return;
 
   const includeReasoning = !!providerFlags?.includeReasoningField;
   const includeReasoningDetails = !!providerFlags?.includeReasoningDetailsField;
-  if (!includeReasoning && !includeReasoningDetails) return;
+  const includeReasoningContent = !!providerFlags?.includeReasoningContentField;
+  if (!includeReasoning && !includeReasoningDetails && !includeReasoningContent)
+    return;
 
   const reasoningDetailsValue =
     prevMessage.reasoning_details ||
@@ -84,6 +88,9 @@ function appendReasoningFieldsIfSupported(
   if (includeReasoning) {
     msg.reasoning = prevMessage.content as string;
   }
+  if (includeReasoningContent) {
+    msg.reasoning_content = prevMessage.content as string;
+  }
 }
 
 export function toChatMessage(
@@ -93,6 +100,7 @@ export function toChatMessage(
   providerFlags?: {
     includeReasoningField?: boolean;
     includeReasoningDetailsField?: boolean;
+    includeReasoningContentField?: boolean;
   },
 ): ChatCompletionMessageParam | null {
   if (message.role === "tool") {
@@ -117,6 +125,7 @@ export function toChatMessage(
     // Base assistant message
     const msg: ChatCompletionAssistantMessageParam & {
       reasoning?: string;
+      reasoning_content?: string;
       reasoning_details?: {
         [key: string]: any;
         signature?: string | undefined;
@@ -191,6 +200,7 @@ export function toChatBody(
   providerFlags?: {
     includeReasoningField?: boolean;
     includeReasoningDetailsField?: boolean;
+    includeReasoningContentField?: boolean;
   },
 ): ChatCompletionCreateParams {
   const params: ChatCompletionCreateParams = {