LangChain and CrewAI are code libraries for building agent pipelines. You write Python or TypeScript to chain LLM calls and tools with memory. They're flexible, but you build everything from scratch.
OpenClaw gives you that infrastructure out of the box. A WebSocket gateway with channel connectors and vector search memory. Skills come built in. You configure files rather than write pipeline code. A single SKILL.md replaces dozens of lines of LangChain orchestration.
The multi-agent model differs too. CrewAI agents collaborate on backend tasks. OpenClaw's agents are user-facing personas sharing one server. Think of it this way: you could run a coding assistant on Discord and a writing assistant on Telegram, both from the same Gateway.