On 6 November, Anthropic’s Frontier Red Team research group published Project EVE, a study in which Claude models played two EVE space games. The work was done in the Anthropic Fellows programme from April to July 2026 with Fenris Creations.

Agent teams and a secret saboteur

In EVE Frontier, which is still in development, teams of four Opus 4.8 or Fable 5 agents carried out long tasks in the real game world in June and July 2026.

Combat demanded faster reactions than the models can manage. A developer agent therefore wrote a harness, a program that sits between the model and the game, to handle evasion and return fire. Fable 5 teams using a harness written by Fable 5 lost no ships and completed the game’s tutorial mission within 12 hours.

In the prompt, the researchers instructed one agent to secretly prevent the team from succeeding. They warned the others that someone on the team might not share the same goal. The saboteurs took charge of supply-chain bottlenecks, such as finding scarce resources, where the others could not easily check what the saboteurs reported. One saboteur proposed ignoring intelligence more than two minutes old, which made almost all the information worthless.

Teammates almost never exposed the saboteur. Only one honest agent, in one Opus 4.8 run, identified the saboteur with certainty, and only after the saboteur lied outright about its communications. Anthropic stresses that the experiment reflects sabotage carried out on instruction and does not show whether the models would turn to it on their own initiative.

Separate monitor agents, which read only the team’s public message channel, did slightly better. When tuned to accuse an honest agent in no more than 5 per cent of cases, monitors running Opus 4.6, 4.7 and 4.8 caught 30–40 per cent of saboteurs, and the smaller Sonnet 4.6 caught 20 per cent. None of these monitors was more than 50 per cent confident about a saboteur. When a monitor could see the saboteur’s private reasoning and notes, it detected the sabotage easily.

Agent teams likely need mechanisms similar to those of human organisations: audit trails, reputation and separation of duties, Anthropic said.

Trading on a replayed market

In EVE Online, Claude traded alone, aiming to make as much profit as possible. Anthropic did not trade in the real game, which bans automated trading. Instead it built a simulator that replays players’ real buy and sell orders. The simulator does not react to the agents’ trades. When the researchers added artificial orders that undercut the agents’ prices, profits fell by about 35 per cent.

Opus 4.7, Opus 4.8 and Fable 5 made a profit in all nine two-week windows, growing their capital by about 16, 22 and 43 per cent on average. Opus 4.6’s return of about 4 per cent was level with the best rule-based strategy. Of more than 20 rule-based strategies tested, only one consistently broke even, and only barely. In six-month runs, Fable 5’s average return was three times that of Opus 4.6: about 600 and about 200 per cent of initial capital.

Almost all the models hit on the same tactic by themselves: they bought goods below the usual price and sold them slightly higher. Anthropic does not expect this to work on a real exchange, which is more efficient than the game’s market. The models were also told to predict the direction of prices from news and game updates. In that task, even Fable 5 made a profit in only about half of its runs.