From Contributing Half of Revenue to Supply Chain Disruption, Claude Code Forces Cursor to Urgently Develop an In-house Model

According to Insightful AI, the nuanced symbiotic relationship spanning several years between the AI programming tool Cursor and the main model provider Anthropic has been exposed by Business Insider. Internal sources described the relationship between the two companies as highly peculiar, with Cursor deeply relying on Anthropic's API to power its core coding functionalities, and Anthropic initially deriving nearly 40% to 50% of its revenue from Cursor user calls. However, in a mutually beneficial arrangement, Anthropic was also secretly developing a similar competing tool.

Prior to the launch of the end-user programming tool Claude Code, senior executives at Anthropic privately reassured Cursor's management, stating that Claude Code was merely an academic research initiative with no significant commercialization plans. However, after the launch of Claude Code, it quickly gained popularity within the developer community, with its annualized revenue surging to $25 billion in February 2026, surpassing Cursor's current $20 billion in annualized revenue. Facing the loss of technological exclusivity, Cursor soon experienced a wave of user defections, as a large number of developers took to social media to announce their unsubscriptions from Cursor in favor of adopting Claude Code.

Deeper panic arose from the threat of model discontinuation. During negotiations for the acquisition of the AI programming tool Windsurf by OpenAI, Anthropic abruptly cut off the model supply to Windsurf. This discontinuation event served as a wake-up call to Cursor. On January 5th, Michael Truell convened an emergency all-hands meeting, deciding to fully focus on developing proprietary models. Subsequently, based on the open-source model from the dark side of the moon, Cursor developed the Composer series. In the release of Composer 2.5 in May of this year, the team's internally developed work ratio has exceeded 85%, maintaining a low cost and high concurrency advantage while reducing reliance on interfaces from leading tech giants.