Anthropic is delegating a growing share of its AI development to the AI systems, and it may develop its own successor, calling the idea "recursive self-improvement."

"We are not there yet, and recursive self-improvement is not inevitable. But it could come sooner than most institutions are prepared for," the company wrote in a recent blog post.

The report describes a shift inside Anthropic from early workflows dominated by human-written code toward software agents that can execute tasks, run code, and hand off work to other agents. It frames that progression as a pathway that could, over time, close the loop from assisting engineers to training and improving models with minimal supervision.

Using internal metrics, the Anthropic Institute said Claude was responsible for more than 80% of code merged into Anthropic's codebase by May 2026, up from low single-digit levels in February 2025.

The company also reported a sharp rise in engineer productivity after AI agents evolved from suggesting code snippets to independently executing and iterating on longer tasks, with engineers merging roughly eight times more code per day in Q2 2026 than in 2024.

Anthropic cautioned that raw code volume can overstate productivity gains, calling lines of code an imperfect measure, though internal feedback suggests AI is enabling employees to complete core tasks significantly faster.

In a March 2026 internal survey of 130 research staff, respondents estimated they produced about 4 times as much output using Mythos Preview as when working without AI tools.

"We expect that the true degree of uplift in March was somewhat lower. Nevertheless, we find the overall claim plausible, and in line with our other observations: a significant fraction of Anthropic technical staff is accomplishing their core work multiple times faster than they could without AI assistance," the company wrote.

The institute also pointed to work it said would likely not have been prioritized without agents, including exploratory tooling and long-deferred cleanup. In one example, it said Claude delivered more than 800 fixes that cut a category of API errors by a factor of 1,000. The supervising engineer estimated the same effort would have taken a human about four years to complete.

AI Models Improve At A Faster Rate

Anthropic also noted that the length of tasks AI can reliably complete on their own has been doubling roughly every four months. That’s up from an earlier trend of doubling every seven months.

"In March 2024, Claude Opus 3 could complete software tasks that take humans about four minutes to complete. A year later, Claude Sonnet 3.7 managed tasks that took about an hour and a half. A year after that, Claude Opus 4.6 managed 12-hour tasks.¹ If this trend holds, tasks that take a skilled person days could come into range this year. In 2027, AI systems could be capable of tasks that take a person weeks," the company stated.

The report also highlighted benchmark progress, including SWE-bench and CORE-Bench, where it said scores moved from low levels to near-ceiling performance over relatively short timeframes. It added that METR found Claude Mythos Preview could work for "at least" 16 hours and was "at the upper end of what [METR] can measure without new tasks."

The Biggest Remaining Gap? Judgment

Models may execute well-defined tasks, but they still lag behind humans in deciding which goals to pursue in engineering and research. 

The institute argued that closing that gap would be central to any future system that could design its own successor, and said that possibility would raise the stakes for security, monitoring, and behavior-shaping controls.

Earlier this month, Anthropic confidentially filed a draft Form S-1 with the U.S. Securities and Exchange Commission, giving the artificial intelligence company the option to go public after the SEC completes its review.

Last month, Anthropic overtook OpenAI as the world's most valuable startup after raising $65 billion in Series H, valuing the company at $965 billion. Altimeter Capital, Dragoneer, Greenoaks and Sequoia Capital led the funding round.

If Anthropic goes public at a $1 trillion valuation, it would instantly rank among the most valuable companies globally and could become the second- or third-largest IPO in history, trailing SpaceX and Saudi Aramco.

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