diff --git a/src/api/providers/__tests__/openrouter.spec.ts b/src/api/providers/__tests__/openrouter.spec.ts
index 304811a48c..f9f3ed4748 100644
--- a/src/api/providers/__tests__/openrouter.spec.ts
+++ b/src/api/providers/__tests__/openrouter.spec.ts
@@ -339,8 +339,8 @@ describe("OpenRouterHandler", () => {
 		})
 	})
 
-	describe("DeepSeek V3 Model Handling", () => {
-		// Note: OpenRouter only has deepseek/deepseek-v3.2, not deepseek/deepseek-v3
+	describe("DeepSeek Model Handling", () => {
+		// Test DeepSeek V3.2 model (uses standard format)
 		it("should NOT use R1 format for DeepSeek V3.2 models", async () => {
 			const deepseek32Handler = new OpenRouterHandler({
 				...mockOptions,
@@ -422,5 +422,131 @@ describe("OpenRouterHandler", () => {
 				undefined,
 			)
 		})
+
+		// Test DeepSeek Chat V3.1 model (uses standard format, NOT R1)
+		it("should NOT use R1 format for DeepSeek Chat V3.1 models", async () => {
+			const deepseekChatHandler = new OpenRouterHandler({
+				...mockOptions,
+				openRouterModelId: "deepseek/deepseek-chat-v3.1",
+			})
+
+			const mockStream = {
+				[Symbol.asyncIterator]: async function* () {
+					yield {
+						choices: [{ delta: { content: "test" }, finish_reason: null }],
+						usage: null,
+					}
+					yield {
+						choices: [{ delta: {}, finish_reason: "stop" }],
+						usage: { prompt_tokens: 10, completion_tokens: 5 },
+					}
+				},
+			}
+
+			const mockCreate = vitest.fn().mockResolvedValue(mockStream)
+			;(OpenAI as any).prototype.chat = {
+				completions: { create: mockCreate },
+			} as any
+
+			const generator = deepseekChatHandler.createMessage("system prompt", [])
+			const chunks = []
+			for await (const chunk of generator) {
+				chunks.push(chunk)
+			}
+
+			// Verify that the messages were NOT converted to R1 format (system role preserved)
+			expect(mockCreate).toHaveBeenCalledWith(
+				expect.objectContaining({
+					messages: expect.arrayContaining([
+						expect.objectContaining({ role: "system", content: expect.anything() }),
+					]),
+				}),
+				undefined,
+			)
+		})
+
+		// Test DeepSeek R1-0528 variant (uses R1 format)
+		it("should use R1 format for DeepSeek R1-0528 models", async () => {
+			const deepseekR1Handler = new OpenRouterHandler({
+				...mockOptions,
+				openRouterModelId: "deepseek/deepseek-r1-0528",
+			})
+
+			const mockStream = {
+				[Symbol.asyncIterator]: async function* () {
+					yield {
+						choices: [{ delta: { content: "test" }, finish_reason: null }],
+						usage: null,
+					}
+					yield {
+						choices: [{ delta: {}, finish_reason: "stop" }],
+						usage: { prompt_tokens: 10, completion_tokens: 5 },
+					}
+				},
+			}
+
+			const mockCreate = vitest.fn().mockResolvedValue(mockStream)
+			;(OpenAI as any).prototype.chat = {
+				completions: { create: mockCreate },
+			} as any
+
+			const generator = deepseekR1Handler.createMessage("system prompt", [])
+			const chunks = []
+			for await (const chunk of generator) {
+				chunks.push(chunk)
+			}
+
+			// Verify that the messages WERE converted to R1 format (user role instead of system)
+			expect(mockCreate).toHaveBeenCalledWith(
+				expect.objectContaining({
+					messages: expect.arrayContaining([
+						expect.objectContaining({ role: "user", content: expect.anything() }),
+					]),
+				}),
+				undefined,
+			)
+		})
+
+		// Test DeepSeek Prover V2 model (uses R1 format as it's a reasoning model)
+		it("should use R1 format for DeepSeek Prover V2 models", async () => {
+			const deepseekProverHandler = new OpenRouterHandler({
+				...mockOptions,
+				openRouterModelId: "deepseek/deepseek-prover-v2",
+			})
+
+			const mockStream = {
+				[Symbol.asyncIterator]: async function* () {
+					yield {
+						choices: [{ delta: { content: "test" }, finish_reason: null }],
+						usage: null,
+					}
+					yield {
+						choices: [{ delta: {}, finish_reason: "stop" }],
+						usage: { prompt_tokens: 10, completion_tokens: 5 },
+					}
+				},
+			}
+
+			const mockCreate = vitest.fn().mockResolvedValue(mockStream)
+			;(OpenAI as any).prototype.chat = {
+				completions: { create: mockCreate },
+			} as any
+
+			const generator = deepseekProverHandler.createMessage("system prompt", [])
+			const chunks = []
+			for await (const chunk of generator) {
+				chunks.push(chunk)
+			}
+
+			// Verify that the messages WERE converted to R1 format (user role instead of system)
+			expect(mockCreate).toHaveBeenCalledWith(
+				expect.objectContaining({
+					messages: expect.arrayContaining([
+						expect.objectContaining({ role: "user", content: expect.anything() }),
+					]),
+				}),
+				undefined,
+			)
+		})
 	})
 })
diff --git a/src/api/providers/fetchers/openrouter.ts b/src/api/providers/fetchers/openrouter.ts
index 4deb0d206c..66b82f0419 100644
--- a/src/api/providers/fetchers/openrouter.ts
+++ b/src/api/providers/fetchers/openrouter.ts
@@ -266,12 +266,12 @@ export const parseOpenRouterModel = ({
 		modelInfo.maxTokens = 32768
 	}
 
-	// Configure DeepSeek V3 models properly
+	// Configure DeepSeek V3/Chat models properly
 	// These models support standard tool calling but NOT R1 format
-	// OpenRouter uses deepseek/deepseek-v3 and deepseek/deepseek-v3.2 naming
+	// OpenRouter uses deepseek/deepseek-v3, deepseek/deepseek-v3.2, deepseek/deepseek-chat-v3.1, etc.
 	if (
-		id.startsWith("deepseek/deepseek-v3") || // Matches deepseek/deepseek-v3, deepseek/deepseek-v3.2, etc.
-		id === "deepseek/deepseek-chat"
+		id.startsWith("deepseek/deepseek-v3") || // Matches deepseek/deepseek-v3, deepseek/deepseek-v3.2, deepseek/deepseek-v3.1-terminus, etc.
+		id.startsWith("deepseek/deepseek-chat") // Matches deepseek/deepseek-chat, deepseek/deepseek-chat-v3.1, deepseek/deepseek-chat-v3-0324, etc.
 	) {
 		// Ensure these models are marked as supporting native tools
 		// but NOT reasoning format (they're not R1 models)
diff --git a/src/api/providers/openrouter.ts b/src/api/providers/openrouter.ts
index c56f3858c9..d6adbe8ac2 100644
--- a/src/api/providers/openrouter.ts
+++ b/src/api/providers/openrouter.ts
@@ -135,9 +135,13 @@ export class OpenRouterHandler extends BaseProvider implements SingleCompletionH
 			...convertToOpenAiMessages(messages),
 		]
 
-		// DeepSeek R1 models require user instead of system role.
-		// Note: DeepSeek V3 models (deepseek-v3, deepseek-v3.2, etc.) do NOT use R1 format
-		if (modelId.startsWith("deepseek/deepseek-r1") || modelId === "perplexity/sonar-reasoning") {
+		// DeepSeek R1 and Prover models require user instead of system role.
+		// Note: DeepSeek V3/Chat models (deepseek-v3, deepseek-v3.2, deepseek-chat-v3.1, etc.) do NOT use R1 format
+		if (
+			modelId.startsWith("deepseek/deepseek-r1") ||
+			modelId.startsWith("deepseek/deepseek-prover") ||
+			modelId === "perplexity/sonar-reasoning"
+		) {
 			openAiMessages = convertToR1Format([{ role: "user", content: systemPrompt }, ...messages])
 		}
 
@@ -389,12 +393,15 @@ export class OpenRouterHandler extends BaseProvider implements SingleCompletionH
 			info = this.endpoints[this.options.openRouterSpecificProvider]
 		}
 
-		// Only DeepSeek R1 models use special temperature and topP settings
-		// DeepSeek V3 models (v3, v3.2, etc.) use standard settings
-		const isDeepSeekR1 = id.startsWith("deepseek/deepseek-r1") || id === "perplexity/sonar-reasoning"
+		// Only DeepSeek R1 and Prover models use special temperature and topP settings
+		// DeepSeek V3/Chat models (v3, v3.2, chat-v3.1, etc.) use standard settings
+		const isDeepSeekR1 =
+			id.startsWith("deepseek/deepseek-r1") ||
+			id.startsWith("deepseek/deepseek-prover") ||
+			id === "perplexity/sonar-reasoning"
 		const isDeepSeekV3 =
 			id.startsWith("deepseek/deepseek-v3") || // Matches deepseek/deepseek-v3, deepseek/deepseek-v3.2, etc.
-			id === "deepseek/deepseek-chat"
+			id.startsWith("deepseek/deepseek-chat") // Matches deepseek/deepseek-chat, deepseek/deepseek-chat-v3.1, etc.
 
 		const params = getModelParams({
 			format: "openrouter",