Claude Code reaches $1B run-rate; Anthropic acquires Bun

Background

Claude Code became generally available in May 2025. Run-rate revenue is a recent period's revenue projected over a full year, so a $1 billion run rate means that pace of income would add up to $1 billion in a year.

What happened

On 3 December 2025 Anthropic announced that Claude Code had reached $1 billion in run-rate revenue in November 2025.^[1] The milestone came about six months after Claude Code became generally available in May 2025.^[1] In the same announcement Anthropic agreed to acquire Bun.^[1] The deal is dated to 2 December 2025.^[2]

Key details

Bun is an all-in-one JavaScript toolkit: a runtime, package manager, bundler and test runner. Jarred Sumner founded it in 2021.^[1] Before the deal Bun had over 7 million monthly downloads and more than 82,000 GitHub stars. It had also worked with Anthropic on Claude Code's native installer.^[1]

Anthropic said Bun would remain open source under the MIT license.^[1]

The Claude Code customers named in the announcement included Netflix, Spotify, KPMG, L'Oréal and Salesforce.^[1]

Impact

The acquisition placed a widely used open-source JavaScript toolchain inside the company that builds one of the tools relying on it, while Anthropic kept the project open source under the MIT license.^[1]