Default thinking level to xhigh

packages/coding-agent/CHANGELOG.md

@@ -4,6 +4,7 @@
 
 ### Changed
 
+- Changed the built-in default thinking level to `xhigh` when no user or project default is configured.
 - Changed the IPython system prompt section to use the upstream rlm-harness IPYTHON_CONTROL_PROMPT: IPython is framed as a persistent control environment, not the target project's runtime. Shell commands should use `%%bash` cells instead of `!cmd` escapes. The agent should not install dependencies into the IPython kernel but use the project's own environment instead.
 - Removed the `.venv` interpreter hint from the system prompt (no longer needed with the control-environment framing).
 

packages/coding-agent/docs/settings.md

@@ -17,7 +17,7 @@ Edit directly or use `/settings` for common options.
 |---------|------|---------|-------------|
 | `defaultProvider` | string | - | Default provider (e.g., `"anthropic"`, `"openai"`) |
 | `defaultModel` | string | - | Default model ID |
-| `defaultThinkingLevel` | string | - | `"off"`, `"minimal"`, `"low"`, `"medium"`, `"high"`, `"xhigh"` |
+| `defaultThinkingLevel` | string | `"xhigh"` | `"off"`, `"minimal"`, `"low"`, `"medium"`, `"high"`, `"xhigh"` |
 | `hideThinkingBlock` | boolean | `false` | Hide thinking blocks in output |
 | `thinkingBudgets` | object | - | Custom token budgets per thinking level |
 
@@ -247,7 +247,7 @@ See [packages.md](packages.md) for package management details.
 {
   "defaultProvider": "anthropic",
   "defaultModel": "claude-sonnet-4-20250514",
-  "defaultThinkingLevel": "medium",
+  "defaultThinkingLevel": "xhigh",
   "theme": "dark",
   "compaction": {
     "enabled": true,

packages/coding-agent/src/core/defaults.ts

@@ -1,3 +1,3 @@
 import type { ThinkingLevel } from "@earendil-works/pi-agent-core";
 
-export const DEFAULT_THINKING_LEVEL: ThinkingLevel = "medium";
+export const DEFAULT_THINKING_LEVEL: ThinkingLevel = "xhigh";

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

@@ -407,6 +407,22 @@ describe("default model selection", () => {
 		expect(result.model?.id).toBe("openai/ghost-model");
 	});
 
+	test("findInitialModel uses xhigh as the built-in default thinking level", async () => {
+		const reasoningModel = mockModels[0];
+		const registry = {
+			getAvailable: async () => [reasoningModel],
+		} as unknown as Parameters<typeof findInitialModel>[0]["modelRegistry"];
+
+		const result = await findInitialModel({
+			scopedModels: [],
+			isContinuing: false,
+			modelRegistry: registry,
+		});
+
+		expect(result.model).toBe(reasoningModel);
+		expect(result.thinkingLevel).toBe("xhigh");
+	});
+
 	test("findInitialModel selects ai-gateway default when available", async () => {
 		const aiGatewayModel: Model<"anthropic-messages"> = {
 			id: "anthropic/claude-opus-4-6",