Manus (meaning hand in Latin) is an autonomous artificial intelligence agent developed by Butterfly Effect, a company founded in China and based in Singapore.

Xiao founded Butterfly Effect in 2022, two months before the public launch of OpenAI's ChatGPT. The company maintained offices in Beijing and Wuhan and targeted markets outside China, primarily North America, Japan, and South Korea.

In 2023, Butterfly Effect released Monica, a ChatGPT-powered browser extension that aggregated multiple commercial large language models behind a single interface for translation, summarization, and writing assistance.

In 2024, ByteDance approached Butterfly Effect with an acquisition offer of approximately US$30 million, according to reporting by 36Kr. Xiao declined the offer.

Ji Yichao, born in 1992 and raised in Colorado and Beijing, joined Butterfly Effect as a co-founder of the Manus product and serves as the company's chief scientist. Known by the nickname "Peak," Ji studied computer science in Beijing, and while in high school created Mammoth Browser, a web browser application for Apple's iPhone. In 2012, he founded Peak Labs with backing from ZhenFund and HSG (then known as Sequoia China) and was named to Forbes China's 30 Under 30 ranking in 2012 and 2013.

Zhang Tao joined the founding team as product director. In October 2024, Butterfly Effect began developing Manus, drawing inspiration from the San Francisco-based AI coding tool Cursor. The product's name was taken from the Latin motto of the Massachusetts Institute of Technology, "Mens et Manus," meaning "mind and hand." Most of Butterfly Effect's researchers and engineers were based in China at the time, and Manus was designed for markets outside China because it relied on American AI models that were unavailable domestically.

Manus launched in invitation-only beta on March 6, 2025. The launch demo video, which depicted the agent autonomously completing tasks such as resume screening and stock analysis, drew more than one million views within twenty hours. Demand for invitation codes drove a secondary market in which codes were resold on Chinese platforms such as Xianyu and on social-media and e-commerce sites for prices reportedly between ¥50,000 and ¥100,000 (approximately US$7,000 to US$13,800 at the time), according to state-owned China Daily. The Wall Street Journal reported that codes were resold for more than US$1,000.

Earlier funding rounds for Butterfly Effect included a 2023 seed round led by ZhenFund and a Series A in November 2024 that brought in Sequoia China (now known as HSG) and Tencent. In April 2025, the company raised approximately US$75 million in a Series B round led by Benchmark, valuing the company at approximately US$500 million. Earlier investors including Tencent, HSG, and ZhenFund participated, alongside additional investors such as Wang Huiwen, the co-founder of Meituan, and Old Friendship Capital. As part of the Benchmark deal, Benchmark general partner Chetan Puttagunta joined the company's board.