4.4 KiB
API Lookup Tool
The apilookup tool ensures you get current, accurate API/SDK documentation by forcing the AI to search for the latest information rather than relying on outdated training data. This is especially critical for OS-tied APIs (iOS, macOS, Android, etc.) where the AI's knowledge cutoff may be months or years old.
Most importantly, it does this within in a sub-process / sub-agent, saving you precious tokens within your working context window.
Why Use This Tool?
Without Zen (Using Standard AI)
User: "How do I add glass look to a button in Swift?"
AI: [Searches based on training data knowledge cutoff]
"SwiftUI glass morphism frosted glass effect button iOS 18 2025"
Result: You get outdated APIs for iOS 18, not the iOS 26 effect you're after
With Zen (Using apilookup)
User: "use apilookup how do I add glass look to a button in swift?"
AI: Step 1 - Search: "what is the latest iOS version 2025"
→ Finds: iOS 26 is current
Step 2 - Search: "iOS 26 SwiftUI glass effect button 2025"
→ Gets current APIs specific to iOS 26
Result: You get the correct, current APIs that work with today's iOS version
Key Features
1. OS Version Detection (Critical!)
For any OS-tied request (iOS, macOS, Windows, Android, watchOS, tvOS), apilookup MUST:
- First search for the current OS version ("what is the latest iOS version 2025")
- Never rely on the AI's training data for version numbers
- Only after confirming current version, search for APIs/SDKs for that specific version
2. Authoritative Sources Only
Prioritizes official documentation:
- Project documentation sites
- GitHub repositories
- Package registries (npm, PyPI, crates.io, Maven Central, etc.)
- Official blogs and release notes
3. Actionable, Concise Results
- Current version numbers and release dates
- Breaking changes and migration notes
- Code examples and configuration options
- Deprecation warnings and security advisories
When to Use
- You need current API/SDK documentation or version info
- You're working with OS-specific frameworks (SwiftUI, UIKit, Jetpack Compose, etc.)
- You want to verify which version supports a feature
- You need migration guides or breaking change notes
- You're checking for deprecations or security advisories
Usage Examples
OS-Specific APIs
use apilookup how do I add glass look to a button in swift?
use apilookup what's the latest way to handle permissions in Android?
use apilookup how do I use the new macOS window management APIs?
Library/Framework Versions
use apilookup find the latest Stripe Python SDK version and note any breaking changes since v7
use apilookup what's the current AWS CDK release and list migration steps from v2
use apilookup check the latest React version and any new hooks introduced in 2025
Feature Compatibility
use apilookup does the latest TypeScript support decorators natively?
use apilookup what's the current status of Swift async/await on Linux?
How It Works
- Receives your query with API/SDK/framework name
- Injects mandatory instructions that force current-year searches
- For OS-tied requests: Requires two-step search (OS version first, then API)
- Returns structured guidance with instructions for web search
- AI executes searches and provides authoritative, current documentation
Output Format
The tool returns JSON with:
status: "web_lookup_needed"instructions: Detailed search strategy and requirementsuser_prompt: Your original request
The AI then performs the actual web searches and synthesizes the results into actionable documentation.
Codex CLI Configuration Reminder
If you use Zen through the Codex CLI, the assistant needs Codex's native web-search tool to fetch current documentation. After adding the Zen MCP entry to ~/.codex/config.toml, confirm the file also contains:
[tools]
web_search = true
If [tools] is missing, append the block manually. Without this flag, apilookup will keep requesting web searches that Codex cannot execute, and you'll see repeated attempts at using curl incorrectly.