From beef72ead7dc8860cd35f210badec0f05f3eaf75 Mon Sep 17 00:00:00 2001
From: Chaos <chaos@local>
Date: Tue, 4 Aug 2026 11:08:38 +0200
Subject: [PATCH] fix(openai): preserve reasoning for local OpenAI-compatible
 models via R1 toggle
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The openAiR1FormatEnabled toggle (UI + provider-settings) only forced the
R1 request format, but getModel() never set info.preserveReasoning. As a
result Task.ts (shouldPreserveForApi = info.preserveReasoning === true)
stripped reasoning_content from follow-up context for every local
OpenAI-compatible reasoning model (llama.cpp, LM Studio, Ollama) — there
was no way to feed the chain back.

Enable the toggle and getModel() now sets preserveReasoning: true so the
reasoning chain is preserved in the next-turn context. Default behaviour
unchanged.
---
 src/api/providers/__tests__/openai.spec.ts | 14 ++++++++++++++
 src/api/providers/openai.ts                | 10 +++++++++-
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/api/providers/__tests__/openai.spec.ts b/src/api/providers/__tests__/openai.spec.ts
index 3e18f03a4c..ec4daef5d9 100644
--- a/src/api/providers/__tests__/openai.spec.ts
+++ b/src/api/providers/__tests__/openai.spec.ts
@@ -837,6 +837,20 @@ describe("OpenAiHandler", () => {
 			expect(model.id).toBe("")
 			expect(model.info).toBeDefined()
 		})
+
+		it("should set preserveReasoning when openAiR1FormatEnabled is on", () => {
+			const r1Handler = new OpenAiHandler({
+				...mockOptions,
+				openAiR1FormatEnabled: true,
+			})
+			const model = r1Handler.getModel()
+			expect(model.info.preserveReasoning).toBe(true)
+		})
+
+		it("should not set preserveReasoning by default", () => {
+			const model = handler.getModel()
+			expect(model.info.preserveReasoning).toBeUndefined()
+		})
 	})
 
 	describe("Azure AI Inference Service", () => {
diff --git a/src/api/providers/openai.ts b/src/api/providers/openai.ts
index 9545068794..0774642bcf 100644
--- a/src/api/providers/openai.ts
+++ b/src/api/providers/openai.ts
@@ -293,7 +293,15 @@ export class OpenAiHandler extends BaseProvider implements SingleCompletionHandl
 			settings: this.options,
 			defaultTemperature: 0,
 		})
-		return { id, info, ...params }
+		// Local OpenAI-compatible reasoning models (llama.cpp, LM Studio, Ollama)
+		// stream reasoning_content, but Roo strips it from the follow-up context
+		// unless info.preserveReasoning is set. When the user enables the R1 format
+		// toggle, treat the model as preserving reasoning so the chain is fed back.
+		return {
+			id,
+			info: this.options.openAiR1FormatEnabled ? { ...info, preserveReasoning: true } : info,
+			...params,
+		}
 	}
 
 	async completePrompt(prompt: string, options?: CompletePromptOptions): Promise<string> {