feat(ai): Add start event emission to all providers

- Emit start event with model and provider info after creating stream
- Add abort signal tests for all providers
- Update README abort signal section to reflect non-throwing API
- Fix model references in README examples

packages/ai/README.md

@@ -101,7 +101,7 @@ if (toolCalls.length > 0) {
   // Continue conversation with tool results
   const followUp = await llm.complete({ messages, tools });
   messages.push(followUp);
-  
+
   // Print text blocks from the response
   for (const block of followUp.content) {
     if (block.type === 'text') {
@@ -160,24 +160,25 @@ const response = await llm.complete({
 ```typescript
 const controller = new AbortController();
 
-// Abort after 5 seconds
-setTimeout(() => controller.abort(), 5000);
+// Abort after 2 seconds
+setTimeout(() => controller.abort(), 2000);
 
-try {
-  const response = await llm.complete({
-    messages: [{ role: 'user', content: 'Write a long story' }]
-  }, {
-    signal: controller.signal,
-    onEvent: (event) => {
-      if (event.type === 'text_delta') {
-        process.stdout.write(event.delta);
-      }
+const response = await llm.complete({
+  messages: [{ role: 'user', content: 'Write a long story' }]
+}, {
+  signal: controller.signal,
+  onEvent: (event) => {
+    if (event.type === 'text_delta') {
+      process.stdout.write(event.delta);
     }
-  });
-} catch (error) {
-  if (error.name === 'AbortError') {
-    console.log('Request was aborted');
   }
+});
+
+// Check if the request was aborted
+if (response.stopReason === 'error' && response.error) {
+  console.log('Request was aborted:', response.error);
+} else {
+  console.log('Request completed successfully');
 }
 ```
 
@@ -206,7 +207,7 @@ await llm.complete(context, {
 
 ### Google Gemini Thinking
 ```typescript
-const llm = createLLM('google', 'gemini-2.0-flash-thinking-exp');
+const llm = createLLM('google', 'gemini-2.5-pro');
 
 await llm.complete(context, {
   thinking: { enabled: true }
@@ -220,14 +221,14 @@ await llm.complete(context, {
 import { OpenAICompletionsLLM } from '@mariozechner/pi-ai';
 
 const model = {
-  id: 'llama3.1:8b',
+  id: 'gpt-oss:20b',
   provider: 'ollama',
   baseUrl: 'http://localhost:11434/v1',
   reasoning: false,
   input: ['text'],
   cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
-  contextWindow: 8192,
-  maxTokens: 4096,
+  contextWindow: 126000,
+  maxTokens: 32000,
   name: 'Llama 3.1 8B'
 };
 

packages/ai/src/providers/anthropic.ts

@@ -129,6 +129,8 @@ export class AnthropicLLM implements LLM<AnthropicLLMOptions> {
 				},
 			);
 
+			options?.onEvent?.({ type: "start", model: this.modelInfo.id, provider: this.modelInfo.provider });
+
 			let blockType: "text" | "thinking" | "toolUse" | "other" = "other";
 			let blockContent = "";
 			let toolCall: (ToolCall & { partialJson: string }) | null = null;

packages/ai/src/providers/google.ts

@@ -89,6 +89,14 @@ export class GoogleLLM implements LLM<GoogleLLMOptions> {
 				};
 			}
 
+			// Abort signal
+			if (options?.signal) {
+				if (options.signal.aborted) {
+					throw new Error("Request aborted");
+				}
+				config.abortSignal = options.signal;
+			}
+
 			// Build the request parameters
 			const params: GenerateContentParameters = {
 				model: this.model.id,
@@ -98,6 +106,8 @@ export class GoogleLLM implements LLM<GoogleLLMOptions> {
 
 			const stream = await this.client.models.generateContentStream(params);
 
+			options?.onEvent?.({ type: "start", model: this.model.id, provider: this.model.provider });
+
 			const blocks: AssistantMessage["content"] = [];
 			let currentBlock: TextContent | ThinkingContent | null = null;
 			let usage: Usage = {

packages/ai/src/providers/openai-completions.ts

@@ -92,6 +92,8 @@ export class OpenAICompletionsLLM implements LLM<OpenAICompletionsLLMOptions> {
 				signal: options?.signal,
 			});
 
+			options?.onEvent?.({ type: "start", model: this.modelInfo.id, provider: this.modelInfo.provider });
+
 			const blocks: AssistantMessage["content"] = [];
 			let currentBlock: TextContent | ThinkingContent | (ToolCall & { partialArgs?: string }) | null = null;
 			let usage: Usage = {

packages/ai/src/providers/openai-responses.ts

@@ -85,6 +85,8 @@ export class OpenAIResponsesLLM implements LLM<OpenAIResponsesLLMOptions> {
 				signal: options?.signal,
 			});
 
+			options?.onEvent?.({ type: "start", model: this.modelInfo.id, provider: this.modelInfo.provider });
+
 			const outputItems: (ResponseReasoningItem | ResponseOutputMessage | ResponseFunctionToolCall)[] = []; // any for function_call items
 			let currentTextAccum = ""; // For delta accumulation
 			let currentThinkingAccum = ""; // For delta accumulation
@@ -184,9 +186,25 @@ export class OpenAIResponsesLLM implements LLM<OpenAIResponsesLLMOptions> {
 					} satisfies AssistantMessage;
 					options?.onEvent?.({ type: "error", error: errorOutput.error || "Unknown error" });
 					return errorOutput;
+				} else if (event.type === "response.failed") {
+					const errorOutput = {
+						role: "assistant",
+						content: [],
+						provider: this.modelInfo.provider,
+						model: this.modelInfo.id,
+						usage,
+						stopReason: "error",
+						error: "Unknown error",
+					} satisfies AssistantMessage;
+					options?.onEvent?.({ type: "error", error: errorOutput.error || "Unknown error" });
+					return errorOutput;
 				}
 			}
 
+			if (options?.signal?.aborted) {
+				throw new Error("Request was aborted");
+			}
+
 			// Convert output items to blocks
 			const blocks: AssistantMessage["content"] = [];
 

packages/ai/test/abort.test.ts

@@ -0,0 +1,114 @@
+import { describe, it, beforeAll, expect } from "vitest";
+import { GoogleLLM } from "../src/providers/google.js";
+import { OpenAICompletionsLLM } from "../src/providers/openai-completions.js";
+import { OpenAIResponsesLLM } from "../src/providers/openai-responses.js";
+import { AnthropicLLM } from "../src/providers/anthropic.js";
+import type { LLM, LLMOptions, Context } from "../src/types.js";
+import { getModel } from "../src/models.js";
+
+async function testAbortSignal<T extends LLMOptions>(llm: LLM<T>) {
+    const controller = new AbortController();
+
+    // Abort after 100ms
+    setTimeout(() => controller.abort(), 1000);
+
+    const context: Context = {
+        messages: [{
+            role: "user",
+            content: "Write a very long story about a dragon that lives in a mountain. Include lots of details about the dragon's appearance, its daily life, the treasures it guards, and its interactions with nearby villages. Make it at least 1000 words long."
+        }]
+    };
+
+    const response = await llm.complete(context, {
+        signal: controller.signal
+    } as T);
+
+    // If we get here without throwing, the abort didn't work
+    expect(response.stopReason).toBe("error");
+}
+
+async function testImmediateAbort<T extends LLMOptions>(llm: LLM<T>) {
+    const controller = new AbortController();
+
+    // Abort immediately
+    controller.abort();
+
+    const context: Context = {
+        messages: [{ role: "user", content: "Hello" }]
+    };
+
+    const response = await llm.complete(context, {
+        signal: controller.signal
+    } as T);
+    expect(response.stopReason).toBe("error");
+}
+
+describe("AI Providers Abort Tests", () => {
+    describe.skipIf(!process.env.GEMINI_API_KEY)("Google Provider Abort", () => {
+        let llm: GoogleLLM;
+
+        beforeAll(() => {
+            llm = new GoogleLLM(getModel("google", "gemini-2.5-flash")!, process.env.GEMINI_API_KEY!);
+        });
+
+        it("should abort mid-stream", async () => {
+            await testAbortSignal(llm);
+        });
+
+        it("should handle immediate abort", async () => {
+            await testImmediateAbort(llm);
+        });
+    });
+
+    describe.skipIf(!process.env.OPENAI_API_KEY)("OpenAI Completions Provider Abort", () => {
+        let llm: OpenAICompletionsLLM;
+
+        beforeAll(() => {
+            llm = new OpenAICompletionsLLM(getModel("openai", "gpt-4o-mini")!, process.env.OPENAI_API_KEY!);
+        });
+
+        it("should abort mid-stream", async () => {
+            await testAbortSignal(llm);
+        });
+
+        it("should handle immediate abort", async () => {
+            await testImmediateAbort(llm);
+        });
+    });
+
+    describe.skipIf(!process.env.OPENAI_API_KEY)("OpenAI Responses Provider Abort", () => {
+        let llm: OpenAIResponsesLLM;
+
+        beforeAll(() => {
+            const model = getModel("openai", "gpt-5-mini");
+            if (!model) {
+                throw new Error("Model not found");
+            }
+            llm = new OpenAIResponsesLLM(model, process.env.OPENAI_API_KEY!);
+        });
+
+        it("should abort mid-stream", async () => {
+            await testAbortSignal(llm);
+        });
+
+        it("should handle immediate abort", async () => {
+            await testImmediateAbort(llm);
+        });
+    });
+
+    describe.skipIf(!process.env.ANTHROPIC_API_KEY)("Anthropic Provider Abort", () => {
+        let llm: AnthropicLLM;
+
+        beforeAll(() => {
+            llm = new AnthropicLLM(getModel("anthropic", "claude-3-5-haiku-latest")!, process.env.ANTHROPIC_API_KEY!);
+        });
+
+        it("should abort mid-stream", async () => {
+            await testAbortSignal(llm);
+        });
+
+        it("should handle immediate abort", async () => {
+            await testImmediateAbort(llm);
+        });
+    });
+});