diff --git a/src/api/providers/__tests__/openai-native.spec.ts b/src/api/providers/__tests__/openai-native.spec.ts
index c68c138bc40..73c79aebd9a 100644
--- a/src/api/providers/__tests__/openai-native.spec.ts
+++ b/src/api/providers/__tests__/openai-native.spec.ts
@@ -159,6 +159,9 @@ describe("OpenAiNativeHandler", () => {
 						},
 					],
 				}),
+				expect.objectContaining({
+					signal: expect.any(Object),
+				}),
 			)
 		})
 
@@ -1136,6 +1139,9 @@ describe("GPT-5 streaming event coverage (additional)", () => {
 					stream: false,
 					store: false,
 				}),
+				expect.objectContaining({
+					signal: expect.any(Object),
+				}),
 			)
 		})
 
diff --git a/src/api/providers/openai-native.ts b/src/api/providers/openai-native.ts
index accae66f271..743c1f42d12 100644
--- a/src/api/providers/openai-native.ts
+++ b/src/api/providers/openai-native.ts
@@ -34,6 +34,8 @@ export class OpenAiNativeHandler extends BaseProvider implements SingleCompletio
 	private lastResponseOutput: any[] | undefined
 	// Last top-level response id from Responses API (for troubleshooting)
 	private lastResponseId: string | undefined
+	// Abort controller for cancelling ongoing requests
+	private abortController?: AbortController
 
 	// Event types handled by the shared event processor to avoid duplication
 	private readonly coreHandledEventTypes = new Set<string>([
@@ -255,9 +257,14 @@ export class OpenAiNativeHandler extends BaseProvider implements SingleCompletio
 		systemPrompt?: string,
 		messages?: Anthropic.Messages.MessageParam[],
 	): ApiStream {
+		// Create AbortController for cancellation
+		this.abortController = new AbortController()
+
 		try {
 			// Use the official SDK
-			const stream = (await (this.client as any).responses.create(requestBody)) as AsyncIterable<any>
+			const stream = (await (this.client as any).responses.create(requestBody, {
+				signal: this.abortController.signal,
+			})) as AsyncIterable<any>
 
 			if (typeof (stream as any)[Symbol.asyncIterator] !== "function") {
 				throw new Error(
@@ -266,6 +273,11 @@ export class OpenAiNativeHandler extends BaseProvider implements SingleCompletio
 			}
 
 			for await (const event of stream) {
+				// Check if request was aborted
+				if (this.abortController.signal.aborted) {
+					break
+				}
+
 				for await (const outChunk of this.processEvent(event, model)) {
 					yield outChunk
 				}
@@ -273,6 +285,8 @@ export class OpenAiNativeHandler extends BaseProvider implements SingleCompletio
 		} catch (sdkErr: any) {
 			// For errors, fallback to manual SSE via fetch
 			yield* this.makeResponsesApiRequest(requestBody, model, metadata, systemPrompt, messages)
+		} finally {
+			this.abortController = undefined
 		}
 	}
 
@@ -342,6 +356,9 @@ export class OpenAiNativeHandler extends BaseProvider implements SingleCompletio
 		const baseUrl = this.options.openAiNativeBaseUrl || "https://api.openai.com"
 		const url = `${baseUrl}/v1/responses`
 
+		// Create AbortController for cancellation
+		this.abortController = new AbortController()
+
 		try {
 			const response = await fetch(url, {
 				method: "POST",
@@ -351,6 +368,7 @@ export class OpenAiNativeHandler extends BaseProvider implements SingleCompletio
 					Accept: "text/event-stream",
 				},
 				body: JSON.stringify(requestBody),
+				signal: this.abortController.signal,
 			})
 
 			if (!response.ok) {
@@ -426,6 +444,8 @@ export class OpenAiNativeHandler extends BaseProvider implements SingleCompletio
 			}
 			// Handle non-Error objects
 			throw new Error(`Unexpected error connecting to Responses API`)
+		} finally {
+			this.abortController = undefined
 		}
 	}
 
@@ -446,6 +466,11 @@ export class OpenAiNativeHandler extends BaseProvider implements SingleCompletio
 
 		try {
 			while (true) {
+				// Check if request was aborted
+				if (this.abortController?.signal.aborted) {
+					break
+				}
+
 				const { done, value } = await reader.read()
 				if (done) break
 
@@ -1076,6 +1101,9 @@ export class OpenAiNativeHandler extends BaseProvider implements SingleCompletio
 	}
 
 	async completePrompt(prompt: string): Promise<string> {
+		// Create AbortController for cancellation
+		this.abortController = new AbortController()
+
 		try {
 			const model = this.getModel()
 			const { verbosity, reasoning } = model
@@ -1135,7 +1163,9 @@ export class OpenAiNativeHandler extends BaseProvider implements SingleCompletio
 			}
 
 			// Make the non-streaming request
-			const response = await (this.client as any).responses.create(requestBody)
+			const response = await (this.client as any).responses.create(requestBody, {
+				signal: this.abortController.signal,
+			})
 
 			// Extract text from the response
 			if (response?.output && Array.isArray(response.output)) {
@@ -1161,6 +1191,8 @@ export class OpenAiNativeHandler extends BaseProvider implements SingleCompletio
 				throw new Error(`OpenAI Native completion error: ${error.message}`)
 			}
 			throw error
+		} finally {
+			this.abortController = undefined
 		}
 	}
 }