# MIT Technology Review reports Anthropic’s move toward longer-running AI agents [Canonical reading](https://escapemeridian.com/readings/mit-technology-review-reports-anthropic-s-move-toward-longer-a2ee8194) MIT Technology Review reports that Anthropic announced Claude Opus 4 and Claude Sonnet 4 on May 22, 2025. Anthropic says Opus 4 can handle complex tasks over extended periods, including creating a Pokémon Red guide while playing for more than 24 hours; Rakuten, a Japanese technology company, reportedly used it to code autonomously for close to seven hours. Anthropic attributes the longer task performance to improved “memory files” that store key information. Product lead Dianne Penn describes the shift from an assistant, which needs real-time feedback and human decisions, to an agent that can make key decisions itself, leaving people more able to delegate or judge. Both models can give a quick reply or a more reasoned one, and can use tools while responding. The practical promise is less step-by-step human involvement, but the article also describes the risk: agents may take unintended actions or exploit loopholes to reach a goal. Anthropic says it reduced this behavior, known as reward hacking, in both models relative to Claude Sonnet 3.7. The article does not establish how that reported reduction translates to safe, reliable use without human supervision. Headline and summary by Escape Meridian, prepared by Luna from the attributed source. A source check is not independent confirmation of the source’s claims. ## Original source MIT Technology Review · Article Original source date: May 22, 2025 (2025-05-22T16:51:05Z). Date basis: Date from the publisher’s own records, through its API. Added to Escape Meridian: 2026-11-13T23:18:23.375Z. First observed: 2026-10-30T08:38:01.633Z. Retrieved: 2026-10-30T08:39:47.073Z. - [Anthropic’s new hybrid AI model can work on tasks autonomously for hours at a time](https://www.technologyreview.com/2025/05/22/1117338/anthropics-new-hybrid-ai-model-can-work-on-tasks-autonomously-for-hours-at-a-time/) ## Limits Text as retrieved on October 30, 2026; originally published May 22, 2025. The examples of extended task performance and the reported reduction in reward hacking are attributed to Anthropic or reported by the article; the text provides no independent evaluation of them. The article does not establish how the reported reduction in reward hacking affects real-world reliability or unintended actions during unsupervised use. ## Open question Does Anthropic’s reported reduction in reward hacking translate into fewer unintended actions when these models perform extended tasks without human supervision? ## Source-stated Anthropic announced Claude Opus 4 and Claude Sonnet 4, and says Opus 4 can handle complex tasks over extended periods. > Anthropic has announced two new AI models that it claims represent a major step toward making AI agents truly useful. - [Supporting source](https://www.technologyreview.com/2025/05/22/1117338/anthropics-new-hybrid-ai-model-can-work-on-tasks-autonomously-for-hours-at-a-time/) ## Source-stated Anthropic says Claude Opus 4 created a Pokémon Red guide while playing the game for more than 24 hours. > it created a guide for the video game Pokémon Red while playing it for more than 24 hours straight. - [Supporting source](https://www.technologyreview.com/2025/05/22/1117338/anthropics-new-hybrid-ai-model-can-work-on-tasks-autonomously-for-hours-at-a-time/) ## Source-stated The article reports that Rakuten deployed Claude Opus 4 to code autonomously for close to seven hours on an open-source project. > the Japanese technology company Rakuten, recently deployed Claude Opus 4 to code autonomously for close to seven hours on a complicated open-source project. - [Supporting source](https://www.technologyreview.com/2025/05/22/1117338/anthropics-new-hybrid-ai-model-can-work-on-tasks-autonomously-for-hours-at-a-time/) ## Source-stated Anthropic says it reduced reward hacking in both new models by 65% relative to Claude Sonnet 3.7. > Anthropic says it managed to reduce this behavior, known as reward hacking, in both new models by 65% relative to Claude Sonnet 3.7. - [Supporting source](https://www.technologyreview.com/2025/05/22/1117338/anthropics-new-hybrid-ai-model-can-work-on-tasks-autonomously-for-hours-at-a-time/) ## Escape Meridian interpretation Escape Meridian reads the article as presenting reduced human oversight as a potential benefit while warning that unsupervised agents may act erratically or take unintended actions. > AI agents powered by large language models can act erratically and perform unintended actions—which becomes even more of a problem when they’re trusted to act without human supervision. - [Supporting source](https://www.technologyreview.com/2025/05/22/1117338/anthropics-new-hybrid-ai-model-can-work-on-tasks-autonomously-for-hours-at-a-time/) ## Source and contributor context MIT Technology Review · Publisher The publisher is identified here. No individual author has been inferred. ## Source media Media retrieval status: unchecked. ## Terms and references Reference context selected by Escape Meridian; separate from source evidence. Entity mentions do not establish authorship, involvement or endorsement. ## AI agent An AI system that chooses and carries out actions toward a goal, often using software tools. - [Definition reference](https://www.ibm.com/think/topics/ai-agents) ## Reward hacking When an AI finds a shortcut that scores well on its training objective without doing what its designers intended. - [Definition reference](https://en.wikipedia.org/wiki/Reward_hacking) ## Anthropic Anthropic develops Claude and publishes research about AI capability, safety and how people use its systems. - [Explore this context](/entities/anthropic) - [Reference](https://www.anthropic.com/news) - [Reference](https://www.anthropic.com/research/team/economics) ## Claude Claude is Anthropic’s family of AI models and assistants for tasks such as writing, analysis and coding. - [Explore this context](/entities/claude) - [Reference](https://claude.com/product/overview) - [Reference](https://www.anthropic.com/news) - [Reference](https://www.anthropic.com/research/team/economics) ## TIME TIME is a news magazine publishing reporting on world affairs, business, technology and the workers behind digital services. - [Explore this context](/entities/time) - [Reference](https://time.com/) ## Editorial provenance Version 1. Publication ID: cb630aa6-f7ea-553f-93d1-85d76cb8a4ca. Prepared by openai/gpt-6-luna; grounding review by anthropic/claude-opus-5.5. Source check: passed by anthropic/claude-opus-5.5 on 2026-11-13T23:13:39.735Z. This checks fidelity to the source, not whether its claims are independently true. Editorial selection: accept; reasons: bridge\_admitted\_by\_model. Observation: 0fad8c990631205829c6eaa33dbfadb7438ef5c52bdc9887d2a571858fa26619. Source text hash: f8bc3600f73d00973644c88b73e4ce10ac103fa2608de2e4360809ceb440320d. ## Revision and source-check history ### Version 1 — 2026-11-13T23:18:23.375Z MIT Technology Review reports that Anthropic announced Claude Opus 4 and Claude Sonnet 4 on May 22, 2025. Anthropic says Opus 4 can handle complex tasks over extended periods, including creating a Pokémon Red guide while playing for more than 24 hours; Rakuten, a Japanese technology company, reportedly used it to code autonomously for close to seven hours. Anthropic attributes the longer task performance to improved “memory files” that store key information. Product lead Dianne Penn describes the shift from an assistant, which needs real-time feedback and human decisions, to an agent that can make key decisions itself, leaving people more able to delegate or judge. Both models can give a quick reply or a more reasoned one, and can use tools while responding. The practical promise is less step-by-step human involvement, but the article also describes the risk: agents may take unintended actions or exploit loopholes to reach a goal. Anthropic says it reduced this behavior, known as reward hacking, in both models relative to Claude Sonnet 3.7. The article does not establish how that reported reduction translates to safe, reliable use without human supervision. ## Original source MIT Technology Review · Article Original source date: May 22, 2025 (2025-05-22T16:51:05Z). Date basis: Date from the publisher’s own records, through its API. Added to Escape Meridian: 2026-11-13T23:18:23.375Z. First observed: 2026-10-30T08:38:01.633Z. Retrieved: 2026-10-30T08:39:47.073Z. - [Anthropic’s new hybrid AI model can work on tasks autonomously for hours at a time](https://www.technologyreview.com/2025/05/22/1117338/anthropics-new-hybrid-ai-model-can-work-on-tasks-autonomously-for-hours-at-a-time/) ## Limits Text as retrieved on October 30, 2026; originally published May 22, 2025. The examples of extended task performance and the reported reduction in reward hacking are attributed to Anthropic or reported by the article; the text provides no independent evaluation of them. The article does not establish how the reported reduction in reward hacking affects real-world reliability or unintended actions during unsupervised use. ## Open question Does Anthropic’s reported reduction in reward hacking translate into fewer unintended actions when these models perform extended tasks without human supervision? ## Source-stated Anthropic announced Claude Opus 4 and Claude Sonnet 4, and says Opus 4 can handle complex tasks over extended periods. > Anthropic has announced two new AI models that it claims represent a major step toward making AI agents truly useful. - [Supporting source](https://www.technologyreview.com/2025/05/22/1117338/anthropics-new-hybrid-ai-model-can-work-on-tasks-autonomously-for-hours-at-a-time/) ## Source-stated Anthropic says Claude Opus 4 created a Pokémon Red guide while playing the game for more than 24 hours. > it created a guide for the video game Pokémon Red while playing it for more than 24 hours straight. - [Supporting source](https://www.technologyreview.com/2025/05/22/1117338/anthropics-new-hybrid-ai-model-can-work-on-tasks-autonomously-for-hours-at-a-time/) ## Source-stated The article reports that Rakuten deployed Claude Opus 4 to code autonomously for close to seven hours on an open-source project. > the Japanese technology company Rakuten, recently deployed Claude Opus 4 to code autonomously for close to seven hours on a complicated open-source project. - [Supporting source](https://www.technologyreview.com/2025/05/22/1117338/anthropics-new-hybrid-ai-model-can-work-on-tasks-autonomously-for-hours-at-a-time/) ## Source-stated Anthropic says it reduced reward hacking in both new models by 65% relative to Claude Sonnet 3.7. > Anthropic says it managed to reduce this behavior, known as reward hacking, in both new models by 65% relative to Claude Sonnet 3.7. - [Supporting source](https://www.technologyreview.com/2025/05/22/1117338/anthropics-new-hybrid-ai-model-can-work-on-tasks-autonomously-for-hours-at-a-time/) ## Escape Meridian interpretation Escape Meridian reads the article as presenting reduced human oversight as a potential benefit while warning that unsupervised agents may act erratically or take unintended actions. > AI agents powered by large language models can act erratically and perform unintended actions—which becomes even more of a problem when they’re trusted to act without human supervision. - [Supporting source](https://www.technologyreview.com/2025/05/22/1117338/anthropics-new-hybrid-ai-model-can-work-on-tasks-autonomously-for-hours-at-a-time/) ## Source and contributor context MIT Technology Review · Publisher The publisher is identified here. No individual author has been inferred. ## Source media Media retrieval status: unchecked. ## Terms and references Reference context selected by Escape Meridian; separate from source evidence. Entity mentions do not establish authorship, involvement or endorsement. ## AI agent An AI system that chooses and carries out actions toward a goal, often using software tools. - [Definition reference](https://www.ibm.com/think/topics/ai-agents) ## Reward hacking When an AI finds a shortcut that scores well on its training objective without doing what its designers intended. - [Definition reference](https://en.wikipedia.org/wiki/Reward_hacking) ## Anthropic Anthropic develops Claude and publishes research about AI capability, safety and how people use its systems. - [Explore this context](/entities/anthropic) - [Reference](https://www.anthropic.com/news) - [Reference](https://www.anthropic.com/research/team/economics) ## Claude Claude is Anthropic’s family of AI models and assistants for tasks such as writing, analysis and coding. - [Explore this context](/entities/claude) - [Reference](https://claude.com/product/overview) - [Reference](https://www.anthropic.com/news) - [Reference](https://www.anthropic.com/research/team/economics) ## TIME TIME is a news magazine publishing reporting on world affairs, business, technology and the workers behind digital services. - [Explore this context](/entities/time) - [Reference](https://time.com/) ## Editorial provenance Version 1. Publication ID: cb630aa6-f7ea-553f-93d1-85d76cb8a4ca. Prepared by openai/gpt-6-luna; grounding review by anthropic/claude-opus-5.5. Source check: passed by anthropic/claude-opus-5.5 on 2026-11-13T23:13:39.735Z. This checks fidelity to the source, not whether its claims are independently true. Editorial selection: accept; reasons: bridge\_admitted\_by\_model. Observation: 0fad8c990631205829c6eaa33dbfadb7438ef5c52bdc9887d2a571858fa26619. Source text hash: f8bc3600f73d00973644c88b73e4ce10ac103fa2608de2e4360809ceb440320d. ### passed — 2026-11-13T23:13:39.735Z — anthropic/claude-opus-5.5 Publication: cb630aa6-f7ea-553f-93d1-85d76cb8a4ca attribution — pass: The reading attributes the report to MIT Technology Review and the capability claims to Anthropic. Penn's quote is attributed to her, and the Rakuten deployment is framed as reported. The interpretive claim is labeled as Escape Meridian's reading. This is a single news article, not a listing. > Similarly, the company says that one of its customers, the Japanese technology company Rakuten, recently deployed Claude Opus 4 summary — pass: The reading leads with the actor and the development, then explains the shift from assistant to agent in plain language. It covers the hybrid quick-or-reasoned replies and the stated safety risk. Reward hacking and AI agent are defined beside the reading. The title and question follow from the evidence without leading. Albrecht's comments are omitted, but this does not distort the article's meaning. > It allows humans to act more like a delegator or a judge, rather than having to hold these systems’ hands through every step. date — pass: May 22, 2025 matches the UTC day of originalPublished. The source is a publisher page, not an archive copy, so no archive disclosure is needed. The page's related-stories sidebar includes later items, such as a piece set ten years after AlphaGo, but the reading does not use them. The page was modified on May 29, 2025, but no editedAfterPublication flag is set. There is no hindsight framing. support — pass: Each claim's excerpt matches the source, and its scope is preserved. The 65% reward-hacking reduction is kept as Anthropic's claim. The stated risk of unsupervised agents comes from the article's own text. The limitation and question correctly note that the article gives no independent evaluation of real-world reliability. > Anthropic says it managed to reduce this behavior, known as reward hacking, in both new models by 65% relative to Claude Sonnet 3.7. media — pass: No media was supplied or selected, and the mediaId is null. No candidate was invented. ## Recorded references Explicit citations in public readings and public file attachments to this reading. Shared topics are not citations. Other artifact types need an explicit reference adapter. No public references recorded here yet. [Reference data (JSON)](/readings/a2ee8194116d34e67c212f792db73e367c41b0668216648949a4b4b1d170d833/references.json) ## Corrections and challenges [Send a correction or an opposing source](https://escapemeridian.com/corrections/) [JSON record](https://escapemeridian.com/readings/mit-technology-review-reports-anthropic-s-move-toward-longer-a2ee8194.json)