diff --git a/packages/ai-config/src/model-capabilities/model-apis-helpers.ts b/packages/ai-config/src/model-capabilities/model-apis-helpers.ts
index 70eb52d..269a120 100644
--- a/packages/ai-config/src/model-capabilities/model-apis-helpers.ts
+++ b/packages/ai-config/src/model-capabilities/model-apis-helpers.ts
@@ -45,6 +45,16 @@ const MODEL_APIS_CAPABILITIES: Record<string, Partial<ModelInfo>> = {
 		maxContextLength: 250_000,
 		maxInputTokens: 250_000,
 	},
+	"deepseek-ai/DeepSeek-V4-Flash-0731": {
+		family: "deepseek-v4",
+		thinkingEffortLevels: ["off", "low", "high", "max"],
+		supportsImages: false,
+		supportsToolResultImages: false,
+		supportedInputMediaTypes: [],
+		maxOutputTokens: 384_000,
+		maxContextLength: 250_000,
+		maxInputTokens: 250_000,
+	},
 };
 
 /**
diff --git a/packages/ai-provider-bridge/src/__tests__/utils.test.ts b/packages/ai-provider-bridge/src/__tests__/utils.test.ts
index 49a1c5f..178f7f4 100644
--- a/packages/ai-provider-bridge/src/__tests__/utils.test.ts
+++ b/packages/ai-provider-bridge/src/__tests__/utils.test.ts
@@ -8,6 +8,7 @@ import {
 	buildSnowflakeCortexUrl,
 	buildSnowflakeCortexUrlFromHost,
 	normalizeProviderBaseUrl,
+	positAiThinkingRequestFields,
 	thinkingRequestFields,
 } from "../utils";
 
@@ -33,6 +34,19 @@ describe("thinkingRequestFields", () => {
 	});
 });
 
+describe("positAiThinkingRequestFields", () => {
+	it("maps DeepSeek off to none and reuses named efforts", () => {
+		expect(
+			positAiThinkingRequestFields("deepseek-ai/DeepSeek-V4-Flash-0731", "off", false),
+		).toEqual({
+			reasoning_effort: "none",
+		});
+		expect(
+			positAiThinkingRequestFields("deepseek-ai/DeepSeek-V4-Flash-0731", "high", false),
+		).toEqual({ reasoning_effort: "high" });
+	});
+});
+
 describe("normalizeProviderBaseUrl", () => {
 	const HOST = "https://api.anthropic.com";
 
diff --git a/packages/ai-provider-bridge/src/model-clients/PositAiClient.ts b/packages/ai-provider-bridge/src/model-clients/PositAiClient.ts
index 07cf2ea..45a5400 100644
--- a/packages/ai-provider-bridge/src/model-clients/PositAiClient.ts
+++ b/packages/ai-provider-bridge/src/model-clients/PositAiClient.ts
@@ -29,7 +29,7 @@ import {
 	isClaudeModel,
 	isThinkingEnabled,
 	joinPath,
-	thinkingRequestFields,
+	positAiThinkingRequestFields,
 } from "../utils";
 import {
 	convertAiSdkStreamToPlatform,
@@ -238,7 +238,8 @@ export class PositAiClient implements ModelClient {
 
 			return convertAiSdkStreamToPlatform(result.fullStream, cleanup);
 		} else if (normalizedProtocol === "openai-chat") {
-			const thinkingFields = thinkingRequestFields(
+			const thinkingFields = positAiThinkingRequestFields(
+				params.model,
 				params.thinkingEffort,
 				params.requiresChatTemplateKwargs ?? false,
 			);
diff --git a/packages/ai-provider-bridge/src/utils.ts b/packages/ai-provider-bridge/src/utils.ts
index 448aef2..5514677 100644
--- a/packages/ai-provider-bridge/src/utils.ts
+++ b/packages/ai-provider-bridge/src/utils.ts
@@ -41,6 +41,17 @@ export function thinkingRequestFields(
 		: undefined;
 }
 
+export function positAiThinkingRequestFields(
+	modelId: string,
+	effort: string | undefined,
+	requiresChatTemplateKwargs: boolean,
+): Record<string, unknown> | undefined {
+	if (modelId === "deepseek-ai/DeepSeek-V4-Flash-0731" && effort === "off") {
+		return { reasoning_effort: "none" };
+	}
+	return thinkingRequestFields(effort, requiresChatTemplateKwargs);
+}
+
 // ---------------------------------------------------------------------------
 // Model ID helpers
 // ---------------------------------------------------------------------------