feat: add skills system, hooks integration, and OpenAI-compatible provider

- Add skill system with types, registry, SkillTool, and 5 bundled skills
  (simplify, commit, review, debug, test)
- Integrate hooks into QueryEngine at 9 lifecycle points (SessionStart,
  UserPromptSubmit, PreToolUse, PostToolUse, PostToolUseFailure,
  PreCompact, PostCompact, Stop, SessionEnd)
- Add LLM provider abstraction supporting both Anthropic Messages API
  and OpenAI Chat Completions API (works with GPT, DeepSeek, Qwen, etc.)
- Add CODEANY_API_TYPE env var ('anthropic-messages' | 'openai-completions')
  with auto-detection from model name
- Remove all ANTHROPIC_* env var references, only support CODEANY_* prefix
- Add model pricing and context windows for OpenAI/DeepSeek models
- Remove direct @anthropic-ai/sdk dependency from all files except the
  Anthropic provider (types.ts, engine.ts, etc. are now provider-agnostic)
- Add PermissionBehavior type export
- Bump version to 0.2.0

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

examples/12-skills.ts

@@ -0,0 +1,88 @@
+/**
+ * Example 12: Skills
+ *
+ * Shows how to use the skill system: bundled skills, custom skills,
+ * and invoking skills programmatically.
+ *
+ * Run: npx tsx examples/12-skills.ts
+ */
+import {
+  createAgent,
+  registerSkill,
+  getAllSkills,
+  getUserInvocableSkills,
+  getSkill,
+  initBundledSkills,
+} from '../src/index.js'
+import type { SkillContentBlock } from '../src/index.js'
+
+async function main() {
+  console.log('--- Example 12: Skills ---\n')
+
+  // Bundled skills are auto-initialized when creating an Agent,
+  // but you can also init them explicitly:
+  initBundledSkills()
+
+  // List all registered skills
+  const all = getAllSkills()
+  console.log(`Registered skills (${all.length}):`)
+  for (const skill of all) {
+    console.log(`  - ${skill.name}: ${skill.description.slice(0, 80)}...`)
+  }
+
+  // Register a custom skill
+  registerSkill({
+    name: 'explain',
+    description: 'Explain a concept or piece of code in simple terms.',
+    aliases: ['eli5'],
+    userInvocable: true,
+    async getPrompt(args): Promise<SkillContentBlock[]> {
+      return [{
+        type: 'text',
+        text: `Explain the following in simple, clear terms that a beginner could understand. Use analogies where helpful.\n\nTopic: ${args || 'Ask the user what they want explained.'}`,
+      }]
+    },
+  })
+
+  console.log(`\nAfter registering custom skill: ${getAllSkills().length} total`)
+  console.log(`User-invocable: ${getUserInvocableSkills().length}`)
+
+  // Get a specific skill
+  const commitSkill = getSkill('commit')
+  if (commitSkill) {
+    const blocks = await commitSkill.getPrompt('', { cwd: process.cwd() })
+    console.log(`\nCommit skill prompt (first 200 chars):`)
+    console.log(blocks[0]?.type === 'text' ? blocks[0].text.slice(0, 200) + '...' : '(non-text)')
+  }
+
+  // Use skills with an agent - the model can invoke them via the Skill tool
+  console.log('\n--- Using skills with an agent ---\n')
+
+  const agent = createAgent({
+    model: process.env.CODEANY_MODEL || 'claude-sonnet-4-6',
+    maxTurns: 5,
+  })
+
+  for await (const event of agent.query(
+    'Use the "explain" skill to explain what git rebase does.',
+  )) {
+    const msg = event as any
+    if (msg.type === 'assistant') {
+      for (const block of msg.message?.content || []) {
+        if (block.type === 'tool_use') {
+          console.log(`[Tool: ${block.name}] ${JSON.stringify(block.input)}`)
+        }
+        if (block.type === 'text' && block.text.trim()) {
+          console.log(block.text)
+        }
+      }
+    }
+    if (msg.type === 'result') {
+      console.log(`\n--- ${msg.subtype} ---`)
+    }
+  }
+
+  await agent.close()
+}
+
+main().catch(console.error)

examples/13-hooks.ts

@@ -0,0 +1,88 @@
+/**
+ * Example 13: Hooks
+ *
+ * Shows how to use lifecycle hooks to intercept agent behavior.
+ * Hooks fire at key points: session start/end, before/after tool use,
+ * compaction, etc.
+ *
+ * Run: npx tsx examples/13-hooks.ts
+ */
+import { createAgent, createHookRegistry } from '../src/index.js'
+import type { HookInput } from '../src/index.js'
+
+async function main() {
+  console.log('--- Example 13: Hooks ---\n')
+
+  // Create a hook registry with custom handlers
+  const registry = createHookRegistry({
+    SessionStart: [{
+      handler: async (input: HookInput) => {
+        console.log(`[Hook] Session started: ${input.sessionId}`)
+      },
+    }],
+    PreToolUse: [{
+      handler: async (input: HookInput) => {
+        console.log(`[Hook] About to use tool: ${input.toolName}`)
+        // You can block a tool by returning { block: true }
+        // return { block: true, message: 'Tool blocked by hook' }
+      },
+    }],
+    PostToolUse: [{
+      handler: async (input: HookInput) => {
+        const output = typeof input.toolOutput === 'string'
+          ? input.toolOutput.slice(0, 100)
+          : JSON.stringify(input.toolOutput).slice(0, 100)
+        console.log(`[Hook] Tool ${input.toolName} completed: ${output}...`)
+      },
+    }],
+    PostToolUseFailure: [{
+      handler: async (input: HookInput) => {
+        console.log(`[Hook] Tool ${input.toolName} FAILED: ${input.error}`)
+      },
+    }],
+    Stop: [{
+      handler: async () => {
+        console.log('[Hook] Agent loop completed')
+      },
+    }],
+    SessionEnd: [{
+      handler: async () => {
+        console.log('[Hook] Session ended')
+      },
+    }],
+  })
+
+  // Create agent with hook registry
+  // Note: For direct HookRegistry usage, we pass hooks via the engine config.
+  // The AgentOptions.hooks format also works (see below).
+  const agent = createAgent({
+    model: process.env.CODEANY_MODEL || 'claude-sonnet-4-6',
+    maxTurns: 5,
+    // Alternative: use AgentOptions.hooks format
+    hooks: {
+      PreToolUse: [{
+        hooks: [async (input: any, toolUseId: string) => {
+          console.log(`[AgentHook] PreToolUse: ${input.toolName} (${toolUseId})`)
+        }],
+      }],
+    },
+  })
+
+  for await (const event of agent.query('What files are in the current directory? Be brief.')) {
+    const msg = event as any
+    if (msg.type === 'assistant') {
+      for (const block of msg.message?.content || []) {
+        if (block.type === 'text' && block.text.trim()) {
+          console.log(`\nAssistant: ${block.text.slice(0, 200)}`)
+        }
+      }
+    }
+    if (msg.type === 'result') {
+      console.log(`\n--- ${msg.subtype} ---`)
+    }
+  }
+
+  await agent.close()
+}
+
+main().catch(console.error)

examples/14-openai-compat.ts

@@ -0,0 +1,71 @@
+/**
+ * Example 14: OpenAI-Compatible Models
+ *
+ * Shows how to use the SDK with OpenAI's API or any OpenAI-compatible
+ * endpoint (e.g., DeepSeek, Qwen, vLLM, Ollama).
+ *
+ * Environment variables:
+ *   CODEANY_API_KEY=sk-...          # Your OpenAI API key
+ *   CODEANY_BASE_URL=https://api.openai.com/v1   # Optional, defaults to OpenAI
+ *   CODEANY_API_TYPE=openai-completions           # Optional, auto-detected from model name
+ *
+ * Run: npx tsx examples/14-openai-compat.ts
+ */
+import { createAgent } from '../src/index.js'
+
+async function main() {
+  console.log('--- Example 14: OpenAI-Compatible Models ---\n')
+
+  // Option 1: Explicit apiType
+  const agent = createAgent({
+    apiType: 'openai-completions',
+    model: process.env.CODEANY_MODEL || 'gpt-4o',
+    apiKey: process.env.CODEANY_API_KEY,
+    baseURL: process.env.CODEANY_BASE_URL || 'https://api.openai.com/v1',
+    maxTurns: 5,
+  })
+
+  console.log(`API Type: ${agent.getApiType()}`)
+  console.log(`Model: ${process.env.CODEANY_MODEL || 'gpt-4o'}\n`)
+
+  // Option 2: Auto-detected from model name (uncomment to try)
+  // const agent = createAgent({
+  //   model: 'gpt-4o',  // Auto-detects 'openai-completions'
+  //   apiKey: process.env.CODEANY_API_KEY,
+  // })
+
+  // Option 3: DeepSeek example (uncomment to try)
+  // const agent = createAgent({
+  //   model: 'deepseek-chat',
+  //   apiKey: process.env.CODEANY_API_KEY,
+  //   baseURL: 'https://api.deepseek.com/v1',
+  // })
+
+  // Option 4: Via environment variables only
+  // CODEANY_API_TYPE=openai-completions
+  // CODEANY_MODEL=gpt-4o
+  // CODEANY_API_KEY=sk-...
+  // CODEANY_BASE_URL=https://api.openai.com/v1
+  // const agent = createAgent()
+
+  for await (const event of agent.query('What is 2+2? Reply in one sentence.')) {
+    const msg = event as any
+    if (msg.type === 'assistant') {
+      for (const block of msg.message?.content || []) {
+        if (block.type === 'text' && block.text.trim()) {
+          console.log(`Assistant: ${block.text}`)
+        }
+        if (block.type === 'tool_use') {
+          console.log(`[Tool: ${block.name}] ${JSON.stringify(block.input)}`)
+        }
+      }
+    }
+    if (msg.type === 'result') {
+      console.log(`\n--- ${msg.subtype} (${msg.usage?.input_tokens}+${msg.usage?.output_tokens} tokens) ---`)
+    }
+  }
+
+  await agent.close()
+}
+
+main().catch(console.error)