feat(ai): add max thinking level

packages/coding-agent/test/max-thinking.test.ts

@@ -0,0 +1,45 @@
+import { mkdtempSync, readFileSync, rmSync, writeFileSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+import { afterEach, describe, expect, it } from "vitest";
+import { isValidThinkingLevel } from "../src/cli/args.ts";
+import { SettingsManager } from "../src/core/settings-manager.ts";
+import { loadThemeFromPath } from "../src/modes/interactive/theme/theme.ts";
+
+const tempDirs: string[] = [];
+
+afterEach(() => {
+	for (const dir of tempDirs.splice(0)) {
+		rmSync(dir, { recursive: true, force: true });
+	}
+});
+
+describe("max thinking level", () => {
+	it("is accepted by CLI and settings", async () => {
+		expect(isValidThinkingLevel("max")).toBe(true);
+
+		const settings = SettingsManager.inMemory();
+		settings.setDefaultThinkingLevel("max");
+		await settings.flush();
+		expect(settings.getDefaultThinkingLevel()).toBe("max");
+	});
+
+	it("falls back to thinkingXhigh for legacy themes", () => {
+		const testDir = mkdtempSync(join(tmpdir(), "pi-max-theme-"));
+		tempDirs.push(testDir);
+		const currentDir = dirname(fileURLToPath(import.meta.url));
+		const darkTheme = JSON.parse(
+			readFileSync(join(currentDir, "../src/modes/interactive/theme/dark.json"), "utf8"),
+		) as { name: string; colors: Record<string, unknown> };
+		darkTheme.name = "legacy-theme";
+		delete darkTheme.colors.thinkingMax;
+		const themePath = join(testDir, "legacy-theme.json");
+		writeFileSync(themePath, JSON.stringify(darkTheme));
+
+		const legacyTheme = loadThemeFromPath(themePath);
+		expect(legacyTheme.getThinkingBorderColor("max")("border")).toBe(
+			legacyTheme.getThinkingBorderColor("xhigh")("border"),
+		);
+	});
+});

packages/coding-agent/test/model-resolver.test.ts

@@ -107,7 +107,7 @@ describe("parseModelPattern", () => {
 		});
 
 		test("all valid thinking levels work", () => {
-			for (const level of ["off", "minimal", "low", "medium", "high", "xhigh"]) {
+			for (const level of ["off", "minimal", "low", "medium", "high", "xhigh", "max"]) {
 				const result = parseModelPattern(`sonnet:${level}`, allModels);
 				expect(result.model?.id).toBe("claude-sonnet-4-5");
 				expect(result.thinkingLevel).toBe(level);
@@ -520,7 +520,7 @@ describe("resolveCliModel", () => {
 				getAll: () => modelsWithNeuralwatt,
 			} as unknown as Parameters<typeof resolveCliModel>[0]["modelRegistry"];
 
-			for (const level of ["off", "minimal", "low", "medium", "high", "xhigh"]) {
+			for (const level of ["off", "minimal", "low", "medium", "high", "xhigh", "max"]) {
 				const result = resolveCliModel({
 					cliModel: `neuralwatt/zai-org/GLM-5.1-FP8:${level}`,
 					modelRegistry: registry,

packages/coding-agent/test/suite/agent-session-model-extension.test.ts

@@ -78,6 +78,26 @@ describe("AgentSession model and extension characterization", () => {
 		expect(harness.session.cycleThinkingLevel()).toBeUndefined();
 	});
 
+	it("cycles xhigh before max when both are supported", async () => {
+		const harness = await createHarness({ models: [{ id: "faux-1", reasoning: true }] });
+		harnesses.push(harness);
+		harness.getModel().thinkingLevelMap = { xhigh: "xhigh", max: "max" };
+
+		expect(harness.session.getAvailableThinkingLevels()).toEqual([
+			"off",
+			"minimal",
+			"low",
+			"medium",
+			"high",
+			"xhigh",
+			"max",
+		]);
+		harness.session.setThinkingLevel("high");
+		expect(harness.session.cycleThinkingLevel()).toBe("xhigh");
+		expect(harness.session.cycleThinkingLevel()).toBe("max");
+		expect(harness.session.cycleThinkingLevel()).toBe("off");
+	});
+
 	it("throws when setModel is called without configured auth", async () => {
 		const harness = await createHarness({
 			models: [