Fix X-Initiator header logic for GitHub Copilot

Check last message role instead of any message in history.
This matches the original correct implementation from PR #200.

fixes #209

package-lock.json

@@ -6555,7 +6555,7 @@
 				"chalk": "^5.5.0"
 			},
 			"bin": {
-				"pi": "dist/cli.js"
+				"pi-pods": "dist/cli.js"
 			},
 			"devDependencies": {},
 			"engines": {

packages/ai/src/models.generated.ts

@@ -3225,7 +3225,7 @@ export const MODELS = {
 			cost: {
 				input: 0.24,
 				output: 0.38,
-				cacheRead: 0.19,
+				cacheRead: 0.11,
 				cacheWrite: 0,
 			},
 			contextWindow: 163840,

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

@@ -302,9 +302,11 @@ function createClient(model: Model<"openai-completions">, context: Context, apiK
 	const headers = { ...model.headers };
 	if (model.provider === "github-copilot") {
 		// Copilot expects X-Initiator to indicate whether the request is user-initiated
-		// or agent-initiated. It's an agent call if ANY message in history has assistant/tool role.
+		// or agent-initiated (e.g. follow-up after assistant/tool messages). If there is
+		// no prior message, default to user-initiated.
 		const messages = context.messages || [];
-		const isAgentCall = messages.some((msg) => msg.role === "assistant" || msg.role === "toolResult");
+		const lastMessage = messages[messages.length - 1];
+		const isAgentCall = lastMessage ? lastMessage.role !== "user" : false;
 		headers["X-Initiator"] = isAgentCall ? "agent" : "user";
 		headers["Openai-Intent"] = "conversation-edits";
 	}

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

@@ -310,9 +310,11 @@ function createClient(model: Model<"openai-responses">, context: Context, apiKey
 	const headers = { ...model.headers };
 	if (model.provider === "github-copilot") {
 		// Copilot expects X-Initiator to indicate whether the request is user-initiated
-		// or agent-initiated. It's an agent call if ANY message in history has assistant/tool role.
+		// or agent-initiated (e.g. follow-up after assistant/tool messages). If there is
+		// no prior message, default to user-initiated.
 		const messages = context.messages || [];
-		const isAgentCall = messages.some((msg) => msg.role === "assistant" || msg.role === "toolResult");
+		const lastMessage = messages[messages.length - 1];
+		const isAgentCall = lastMessage ? lastMessage.role !== "user" : false;
 		headers["X-Initiator"] = isAgentCall ? "agent" : "user";
 		headers["Openai-Intent"] = "conversation-edits";
 	}

packages/ai/test/copilot-initiator.test.ts

@@ -175,7 +175,7 @@ describe("GitHub Copilot Headers", () => {
 			expect(lastOpenAIConfig?.defaultHeaders?.["X-Initiator"]).toBe("user");
 		});
 
-		it("sets X-Initiator: agent when assistant message exists in history", async () => {
+		it("sets X-Initiator: agent when last message is assistant", async () => {
 			const context: Context = {
 				messages: [{ role: "user", content: "Hello", timestamp: Date.now() }, assistantMessage],
 			};
@@ -186,7 +186,7 @@ describe("GitHub Copilot Headers", () => {
 			expect(lastOpenAIConfig?.defaultHeaders?.["X-Initiator"]).toBe("agent");
 		});
 
-		it("sets X-Initiator: agent when toolResult exists in history", async () => {
+		it("sets X-Initiator: agent when last message is toolResult", async () => {
 			const context: Context = {
 				messages: [{ role: "user", content: "Hello", timestamp: Date.now() }, toolResultMessage],
 			};
@@ -197,7 +197,7 @@ describe("GitHub Copilot Headers", () => {
 			expect(lastOpenAIConfig?.defaultHeaders?.["X-Initiator"]).toBe("agent");
 		});
 
-		it("sets X-Initiator: agent for multi-turn conversation (last is user, but assistant in history)", async () => {
+		it("sets X-Initiator: user for multi-turn conversation when last message is user", async () => {
 			const context: Context = {
 				messages: [
 					{ role: "user", content: "Hello", timestamp: Date.now() },
@@ -209,7 +209,7 @@ describe("GitHub Copilot Headers", () => {
 			const stream = streamOpenAICompletions(copilotCompletionsModel, context, { apiKey: "test-key" });
 			await consumeStream(stream);
 
-			expect(lastOpenAIConfig?.defaultHeaders?.["X-Initiator"]).toBe("agent");
+			expect(lastOpenAIConfig?.defaultHeaders?.["X-Initiator"]).toBe("user");
 		});
 
 		it("sets X-Initiator: user when there are no messages", async () => {
@@ -259,7 +259,7 @@ describe("GitHub Copilot Headers", () => {
 			expect(lastOpenAIConfig?.defaultHeaders?.["X-Initiator"]).toBe("user");
 		});
 
-		it("sets X-Initiator: agent when assistant message exists in history", async () => {
+		it("sets X-Initiator: agent when last message is assistant", async () => {
 			const context: Context = {
 				messages: [
 					{ role: "user", content: "Hello", timestamp: Date.now() },
@@ -273,7 +273,7 @@ describe("GitHub Copilot Headers", () => {
 			expect(lastOpenAIConfig?.defaultHeaders?.["X-Initiator"]).toBe("agent");
 		});
 
-		it("sets X-Initiator: agent when toolResult exists in history", async () => {
+		it("sets X-Initiator: agent when last message is toolResult", async () => {
 			const context: Context = {
 				messages: [{ role: "user", content: "Hello", timestamp: Date.now() }, toolResultMessage],
 			};
@@ -284,7 +284,7 @@ describe("GitHub Copilot Headers", () => {
 			expect(lastOpenAIConfig?.defaultHeaders?.["X-Initiator"]).toBe("agent");
 		});
 
-		it("sets X-Initiator: agent for multi-turn conversation (last is user, but assistant in history)", async () => {
+		it("sets X-Initiator: user for multi-turn conversation when last message is user", async () => {
 			const context: Context = {
 				messages: [
 					{ role: "user", content: "Hello", timestamp: Date.now() },
@@ -296,7 +296,7 @@ describe("GitHub Copilot Headers", () => {
 			const stream = streamOpenAIResponses(copilotResponsesModel, context, { apiKey: "test-key" });
 			await consumeStream(stream);
 
-			expect(lastOpenAIConfig?.defaultHeaders?.["X-Initiator"]).toBe("agent");
+			expect(lastOpenAIConfig?.defaultHeaders?.["X-Initiator"]).toBe("user");
 		});
 
 		it("sets X-Initiator: user when there are no messages", async () => {