Add SDK usage examples

12 examples showing increasing levels of customization:
- 01-minimal: all defaults
- 02-custom-model: model and thinking level
- 03-custom-prompt: replace or modify prompt
- 04-skills: discover, filter, merge skills
- 05-tools: built-in tools, custom tools
- 06-hooks: logging, blocking, result modification
- 07-context-files: AGENTS.md files
- 08-slash-commands: file-based commands
- 09-api-keys-and-oauth: API key resolution, OAuth config
- 10-settings: compaction, retry, terminal settings
- 11-sessions: persistence options
- 12-full-control: replace everything

Also exports FileSlashCommand type from index.ts

packages/coding-agent/examples/sdk/12-full-control.ts

@@ -0,0 +1,84 @@
+/**
+ * Full Control
+ *
+ * Replace everything - no discovery, explicit configuration.
+ * Still uses OAuth from ~/.pi/agent for convenience.
+ */
+
+import { Type } from "@sinclair/typebox";
+import {
+	createAgentSession,
+	configureOAuthStorage,
+	defaultGetApiKey,
+	findModel,
+	SessionManager,
+	readTool,
+	bashTool,
+	type HookFactory,
+	type CustomAgentTool,
+} from "../../src/index.js";
+import { getAgentDir } from "../../src/config.js";
+
+// Use OAuth from default location
+configureOAuthStorage(getAgentDir());
+
+// Custom API key with fallback
+const getApiKey = async (model: { provider: string }) => {
+	if (model.provider === "anthropic" && process.env.MY_ANTHROPIC_KEY) {
+		return process.env.MY_ANTHROPIC_KEY;
+	}
+	return defaultGetApiKey()(model as any);
+};
+
+// Inline hook
+const auditHook: HookFactory = (api) => {
+	api.on("tool_call", async (event) => {
+		console.log(`[Audit] ${event.toolName}`);
+		return undefined;
+	});
+};
+
+// Inline custom tool
+const statusTool: CustomAgentTool = {
+	name: "status",
+	label: "Status",
+	description: "Get system status",
+	parameters: Type.Object({}),
+	execute: async () => ({
+		content: [{ type: "text", text: `Uptime: ${process.uptime()}s, Node: ${process.version}` }],
+		details: {},
+	}),
+};
+
+const { model } = findModel("anthropic", "claude-sonnet-4-20250514");
+if (!model) throw new Error("Model not found");
+
+const { session } = await createAgentSession({
+	cwd: process.cwd(),
+	agentDir: "/tmp/my-agent",
+
+	model,
+	thinkingLevel: "off",
+	getApiKey,
+
+	systemPrompt: `You are a minimal assistant.
+Available: read, bash, status. Be concise.`,
+
+	tools: [readTool, bashTool],
+	customTools: [{ tool: statusTool }],
+	hooks: [{ factory: auditHook }],
+	skills: [],
+	contextFiles: [],
+	slashCommands: [],
+	sessionManager: SessionManager.inMemory(),
+	settings: { compaction: { enabled: false } },
+});
+
+session.subscribe((event) => {
+	if (event.type === "message_update" && event.assistantMessageEvent.type === "text_delta") {
+		process.stdout.write(event.assistantMessageEvent.delta);
+	}
+});
+
+await session.prompt("Get status and list files.");
+console.log();