Appendix A: Tool Reference
This appendix provides a complete reference for every OpenClaw tool available to practitioners. Whether you're debugging a tool call, designing a new automation, or writing skill definitions — this is the canonical reference. The tools are the primitives that all higher-level patterns are built from, and understanding their parameters, behaviors, and constraints is foundational to everything in this handbook.
The most frequently used tools are read, write, edit, and exec — covering file operations and shell command execution. These four handle the majority of automation tasks. More specialized tools like browser, web_search, and message extend capabilities into web scraping, research, and external communications. Advanced practitioners will also use process for managing background sessions, canvas for UI presentation, and nodes for paired device control.
Each tool has required and optional parameters. Required parameters are marked with an asterisk. Understanding which parameters are truly required versus which have sensible defaults will save you from common automation errors — especially when shell scripts run in constrained environments where default paths and environment variables may behave differently than in your terminal.
The exec tool deserves special attention because it underlies most script-based automation. It runs shell commands with configurable working directory, timeout, PTY mode for interactive programs, security modes for allowlist-based restrictions, and environment variable injection. The process tool is its companion for managing long-running background commands. Together they provide complete control over shell execution from within OpenClaw.
Key Items
- **read** — File content reader with offset/limit pagination; supports images (jpg, png, gif, webp) as attachments; 2000-line or 50KB output cap; essential for loading context files, source data, and configuration
- **exec + process** — Shell command runner and background session manager; exec handles the primary run with timeout/PTY/security options; process polls, logs, writes, or kills background sessions; together they cover all CLI automation needs
- **browser** — Web browser automation with snapshot/screenshot/act (click/type/press/hover/drag/evaluate/wait) pattern; critical for JavaScript-rendered pages, login flows, and visual monitoring; profile selection (openclaw vs chrome relay) determines cookie/auth scope
- **web_search + web_fetch** — Web research pair; web_search queries Brave API with freshness/country/language filters; web_fetch extracts page content as markdown or plain text with character limits; combined they enable comprehensive research pipelines
- **message** — Multi-channel messaging hub (send, react, poll) for WhatsApp, SMS, Discord, Telegram, and more; supports media (images, audio, documents) with captions; thread management for group conversations; essential for alert delivery and daily briefings
Related Concepts
- [[kelly-handbook-ch3-file-automation]] for file tools and pipeline patterns
- [[kelly-handbook-ch4-web-automation]] for browser and web scraping techniques
- [[kelly-handbook-ch7-multi-agent]] for sub-agent spawning and coordination
- [[karpathy-llm-wiki]] for the LLM wiki pattern this KB follows