diff --git a/packages/coding-agent/src/discovery/builtin.ts b/packages/coding-agent/src/discovery/builtin.ts
index 64d2fe5b1..33ee2d261 100644
--- a/packages/coding-agent/src/discovery/builtin.ts
+++ b/packages/coding-agent/src/discovery/builtin.ts
@@ -5,6 +5,7 @@
  */
 import * as path from "node:path";
 import { logger, parseFrontmatter, tryParseJson } from "@oh-my-pi/pi-utils";
+import { YAML } from "bun";
 import { registerProvider } from "../capability";
 import { type ContextFile, contextFileCapability } from "../capability/context-file";
 import { type Extension, type ExtensionManifest, extensionCapability } from "../capability/extension";
@@ -778,22 +779,46 @@ async function loadSettings(ctx: LoadContext): Promise<LoadResult<Settings>> {
 	const items: Settings[] = [];
 	const warnings: string[] = [];
 
+	const parseYamlSettings = (content: string, filePath: string): Record<string, unknown> | null => {
+		try {
+			const data = YAML.parse(content);
+			if (!data || typeof data !== "object" || Array.isArray(data)) return {};
+			return data as Record<string, unknown>;
+		} catch {
+			warnings.push(`Failed to parse ${filePath}`);
+			return null;
+		}
+	};
+
 	for (const { dir, level } of await getConfigDirs(ctx)) {
 		const settingsPath = path.join(dir, "settings.json");
-		const content = await readFile(settingsPath);
-		if (!content) continue;
-
-		const data = tryParseJson<Record<string, unknown>>(content);
-		if (!data) {
-			warnings.push(`Failed to parse ${settingsPath}`);
-			continue;
+		const settingsContent = await readFile(settingsPath);
+		if (settingsContent) {
+			const data = tryParseJson<Record<string, unknown>>(settingsContent);
+			if (data) {
+				items.push({
+					path: settingsPath,
+					data,
+					level,
+					_source: createSourceMeta(PROVIDER_ID, settingsPath, level),
+				});
+			} else {
+				warnings.push(`Failed to parse ${settingsPath}`);
+			}
 		}
 
+		const configPath = path.join(dir, "config.yml");
+		const configContent = await readFile(configPath);
+		if (!configContent) continue;
+
+		const data = parseYamlSettings(configContent, configPath);
+		if (!data) continue;
+
 		items.push({
-			path: settingsPath,
+			path: configPath,
 			data,
 			level,
-			_source: createSourceMeta(PROVIDER_ID, settingsPath, level),
+			_source: createSourceMeta(PROVIDER_ID, configPath, level),
 		});
 	}
 
diff --git a/packages/coding-agent/test/autocomplete-max-visible.test.ts b/packages/coding-agent/test/autocomplete-max-visible.test.ts
index 4e03f0614..25b536a06 100644
--- a/packages/coding-agent/test/autocomplete-max-visible.test.ts
+++ b/packages/coding-agent/test/autocomplete-max-visible.test.ts
@@ -54,6 +54,15 @@ describe("autocompleteMaxVisible setting", () => {
 		const settings = await Settings.init({ cwd: projectDir, agentDir });
 		expect(settings.get("autocompleteMaxVisible")).toBe(15);
 	});
+ 
+	it("should let project config.yml override global config.yml", async () => {
+		await Bun.write(path.join(agentDir, "config.yml"), YAML.stringify({ autocompleteMaxVisible: 15 }, null, 2));
+		await Bun.write(path.join(getProjectAgentDir(projectDir), "config.yml"), YAML.stringify({ autocompleteMaxVisible: 20 }, null, 2));
+ 
+		const settings = await Settings.init({ cwd: projectDir, agentDir });
+ 
+		expect(settings.get("autocompleteMaxVisible")).toBe(20);
+	});
 
 	it("should coerce submenu string values for live editor updates", () => {
 		const setAutocompleteMaxVisible = vi.fn();