LangChain Open Deep Research Open-source deep-research agent built on LangGraph; configurable models, tools, and MCP servers. 0340 Multistep Agents# agent# deep research# LangChain
Perplexity Deep Research Autonomous mode that searches widely, reads sources, and synthesizes multi-source findings. 0420 Multistep Agents# autonomous# citations# deep research
ChatGPT Deep Research Agentic, multi-step web research that reads sources, reasons, and produces cited reports. 0370 Multistep Agents# citations# deep research# multi-step