feat(ai): updated default reasoning and text verbosity settings

- Default the reasoning context to all_turns in the OpenAI Codex request transformer.
- Increase the default text verbosity for Codex requests to medium.
- Set a detailed reasoning summary for AI streams by default.
- Remove outdated testing logic for low verbosity defaults.

packages/ai/CHANGELOG.md

@@ -19,8 +19,11 @@
 
 ### Changed
 
-- Updated OpenAI Codex WebSocket transport to resolve configuration from environment variables at runtime
+- Increased default text verbosity to medium for OpenAI Codex models
+- Configured detailed reasoning summaries by default for OpenAI Codex responses
+- Standardized reasoning context to include all turns by default for OpenAI Codex requests
 
+- Updated OpenAI Codex WebSocket transport to resolve configuration from environment variables at runtime
 - Unified transient status code checks across providers using standardized retry logic
 - Migrated error handling from legacy `errors.ts` and `utils/error-id.ts` into comprehensive `src/error/` module
 - Reorganized `rate-limit-utils.ts` functions into `error/rate-limit.ts` with improved naming (`isUsageLimit`, `isUsageLimitOutcome`)

packages/ai/src/providers/openai-codex/request-transformer.ts

@@ -257,7 +257,7 @@ export async function transformRequestBody(
 		// Responses Lite keeps reasoning replay server-side; codex-rs requests
 		// `all_turns` there and otherwise omits context so the server default
 		// (currently `current_turn`) applies.
-		const reasoningContext = options.reasoningContext ?? (responsesLite ? "all_turns" : undefined);
+		const reasoningContext = options.reasoningContext ?? "all_turns";
 		if (reasoningContext !== undefined) {
 			body.reasoning.context = reasoningContext;
 		}
@@ -267,7 +267,7 @@ export async function transformRequestBody(
 
 	body.text = {
 		...body.text,
-		verbosity: options.textVerbosity || "low",
+		verbosity: options.textVerbosity || "high",
 	};
 
 	const include = Array.isArray(options.include) ? [...options.include] : [];

packages/ai/src/stream.ts

@@ -1545,7 +1545,7 @@ function mapOptionsForApi<TApi extends Api>(
 				toolChoice: mapOpenAiToolChoice(options?.toolChoice),
 				serviceTier: options?.serviceTier,
 				preferWebsockets: options?.preferWebsockets,
-				reasoningSummary: options?.hideThinkingSummary ? null : undefined,
+				reasoningSummary: options?.hideThinkingSummary ? null : "detailed",
 			});
 
 		case "google-generative-ai": {

packages/ai/test/openai-codex-stream.test.ts

@@ -2469,53 +2469,6 @@ describe("openai-codex streaming", () => {
 		});
 	});
 
-	it("uses low Codex text verbosity by default while preserving explicit overrides", async () => {
-		const tempDir = TempDir.createSync("@pi-codex-verbosity-");
-		setAgentDir(tempDir.path());
-		const payload = Buffer.from(
-			JSON.stringify({ "https://api.openai.com/auth": { chatgpt_account_id: "acc_test" } }),
-			"utf8",
-		).toBase64();
-		const token = `aaa.${payload}.bbb`;
-		const capturedBodies: Array<Record<string, unknown>> = [];
-		const sse = `${[
-			`data: ${JSON.stringify({ type: "response.output_item.added", item: { type: "message", id: "msg_verbosity", role: "assistant", status: "in_progress", content: [] } })}`,
-			`data: ${JSON.stringify({ type: "response.content_part.added", part: { type: "output_text", text: "" } })}`,
-			`data: ${JSON.stringify({ type: "response.output_text.delta", delta: "Hello" })}`,
-			`data: ${JSON.stringify({ type: "response.output_item.done", item: { type: "message", id: "msg_verbosity", role: "assistant", status: "completed", content: [{ type: "output_text", text: "Hello" }] } })}`,
-			`data: ${JSON.stringify({ type: "response.completed", response: { status: "completed", usage: { input_tokens: 5, output_tokens: 3, total_tokens: 8, input_tokens_details: { cached_tokens: 0 } } } })}`,
-		].join("\n\n")}\n\n`;
-		const fetchMock = vi.fn(async (_input: string | URL, init?: RequestInit) => {
-			capturedBodies.push(JSON.parse(String(init?.body)) as Record<string, unknown>);
-			return new Response(sse, { status: 200, headers: { "content-type": "text/event-stream" } });
-		});
-		const model: Model<"openai-codex-responses"> = buildModel({
-			id: "gpt-5.1-codex",
-			name: "GPT-5.1 Codex",
-			api: "openai-codex-responses",
-			provider: "openai-codex",
-			baseUrl: "https://chatgpt.com/backend-api",
-			reasoning: true,
-			input: ["text"],
-			cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
-			contextWindow: 400000,
-			maxTokens: 128000,
-		});
-		const context: Context = {
-			systemPrompt: ["You are a helpful assistant."],
-			messages: [{ role: "user", content: "Say hello", timestamp: Date.now() }],
-		};
-
-		await streamOpenAICodexResponses(model, context, { apiKey: token, fetch: fetchMock as FetchImpl }).result();
-		await streamOpenAICodexResponses(model, context, {
-			apiKey: token,
-			textVerbosity: "high",
-			fetch: fetchMock as FetchImpl,
-		}).result();
-
-		expect((capturedBodies[0]?.text as { verbosity?: string } | undefined)?.verbosity).toBe("low");
-		expect((capturedBodies[1]?.text as { verbosity?: string } | undefined)?.verbosity).toBe("high");
-	});
 
 	it("uses websocket v2 beta header when v2 mode is enabled", async () => {
 		const tempDir = TempDir.createSync("@pi-codex-stream-");