Teaching LLMs to think out loud before they act
Research notebooks from the ICLR 2023 paper showing that interleaving reasoning traces with actions improves LLM task performance.

What it does This repository holds the original GPT-3 prompting notebooks for the ReAct paper, which tests whether LLMs perform better when they generate step-by-step reasoning before taking actions like web searches or environment commands. It covers four benchmarks—HotpotQA, FEVER, AlfWorld, and WebShop—and compares PaLM-540B against GPT-3 davinci-002. The README is upfront that this is paper-specific code and points practitioners to LangChain for broader use.
The interesting bit The project demonstrates that forcing a model to write out its reasoning trace before each tool call creates a human-readable audit trail and improves accuracy over acting or reasoning alone. The notebooks make this tangible by showing the exact prompt patterns that interleave “thought” steps with “action” steps in a single coherent transcript.
Key highlights
- Reproduces four benchmark suites: HotpotQA, FEVER, AlfWorld, and WebShop
- Includes published results comparing PaLM-540B and GPT-3 (davinci-002) side by side
- Uses plain Jupyter notebooks instead of a heavyweight agent framework
- Requires only an OpenAI API key and the
alfworlddependency - The README candidly redirects production users to LangChain’s zero-shot ReAct agent
Caveats
- This is research glue code, not a maintained library or reusable package
- HotpotQA and FEVER evaluations are limited to 500 random examples each
- Setup assumes an OpenAI API key and a separate AlfWorld installation
Verdict Worth a look if you want to study the original ReAct prompting mechanics or reproduce the ICLR paper’s benchmarks. Otherwise, reach for LangChain or another agent framework instead.
Frequently asked
- What is ysymyth/ReAct?
- Research notebooks from the ICLR 2023 paper showing that interleaving reasoning traces with actions improves LLM task performance.
- Is ReAct open source?
- Yes — ysymyth/ReAct is open source, released under the MIT license.
- What language is ReAct written in?
- ysymyth/ReAct is primarily written in Jupyter Notebook.
- How popular is ReAct?
- ysymyth/ReAct has 4.1k stars on GitHub.
- Where can I find ReAct?
- ysymyth/ReAct is on GitHub at https://github.com/ysymyth/ReAct.