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November 8, 2026 / Issue 84 / 4 min read

OpenAI's GPT-6 Astra, the best of ten AI coding models, fully finished 26% of 273 real app changes. Before an agent touches your app, write the pass/fail list yourself

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Researchers at Alibaba, Fudan University and other Asian universities have published a useful test of whether AI coding agents finish the job. An agent here means an AI tool that can open files, run code and make changes on its own, not just reply in a chat. Co-Design Bench(opens in a new tab) took 273 change requests recovered from real coding sessions, handed each model a working app, and graded the result against 2,331 hidden requirements written by experts. The best of ten models, OpenAI's GPT-6 Astra, met 69.9% of the requirements on average but fully finished only 26.4% of tasks(opens in a new tab). On coordinated changes across a whole codebase, that fell to 17.9%.

Read the number fairly. The tasks were chosen partly because real users had struggled with them, each request was fixed with no follow-up allowed, AI judges did the grading, and Alibaba makes one of the tested model families, though an OpenAI model won. So 26% is not how often your own agent will succeed. The useful part is the gap. Work that is 70% right can look finished, and the missing 30% lands on whoever ships it. Spending more tokens, the units AI vendors bill by, did not reliably close it: on smaller edits GLM-5.2 used 7.29 million per task against 1.24 million for GPT-6 Astra, and met fewer requirements.

Three findings in the paper(opens in a new tab) point to what to do. First, let the tool check itself. In a side trial on 150 other tasks, one older model produced fully correct work 32.7% of the time from a single answer and 69.3% when it worked as an agent with tools. That is a direction, not a forecast. Second, the tool around the model matters. The same Qwen3.8-27B model scored 56% in one coding tool and 74.9% in another on codebase changes. Third, broad requests do more damage. On codebase changes, those mixing three or four kinds of change met 59.1% of requirements against 65.4% for one or two, and total failures rose from 0.9% to 5.8%, though the full-finish rate barely moved. Narrower requests limit the wreckage. They do not guarantee a finish.

Compare that with Andrej Karpathy's weekend project(opens in a new tab), a video site mined from 43 million Hacker News comments with Claude Code, where his manual steps were an API key, a server and a domain. Starting from nothing is a different job from changing something people already rely on, and Karpathy is one of the field's best-known experts, now working at Anthropic, which makes Claude Code. The benchmark measures the second job, which is the one anyone with a working site or tool faces.

If you use an AI agent to change a website, tool or app this week, write your pass/fail list before you ask. The benchmark averaged between 5 and 6 checks on small edits and about 10 on codebase changes. Yours can be plain: "the total updates when I change the quantity," "the page still works on a phone." Put the list in the request, use a tool that can run the app and look at the result, ask for one or two kinds of change at a time, and tick every check yourself before you accept the work. The study did not test this exact routine. It is an inference from its results, and it costs little to try.

Action items

Researchers at Alibaba, Fudan University and other Asian universities have published a useful test of whether AI coding agents finish the job. An agent here means an AI tool that can open files, run code and make changes on its own, not just reply in a chat. Co-Design Bench took 273 change requests recovered from real coding sessions, handed each model a working app, and graded the result against 2,331 hidden requirements written by experts. The best of ten models, OpenAI's GPT-6 Astra, met 69.9% of the requirements on average but fully finished only 26.4% of tasks. On coordinated changes across a whole codebase, that fell to 17.9%.

Read the number fairly. The tasks were chosen partly because real users had struggled with them, each request was fixed with no follow-up allowed, AI judges did the grading, and Alibaba makes one of the tested model families, though an OpenAI model won. So 26% is not how often your own agent will succeed. The useful part is the gap. Work that is 70% right can look finished, and the missing 30% lands on whoever ships it. Spending more tokens, the units AI vendors bill by, did not reliably close it: on smaller edits GLM-5.2 used 7.29 million per task against 1.24 million for GPT-6 Astra, and met fewer requirements.

Three findings in the paper point to what to do. First, let the tool check itself. In a side trial on 150 other tasks, one older model produced fully correct work 32.7% of the time from a single answer and 69.3% when it worked as an agent with tools. That is a direction, not a forecast. Second, the tool around the model matters. The same Qwen3.8-27B model scored 56% in one coding tool and 74.9% in another on codebase changes. Third, broad requests do more damage. On codebase changes, those mixing three or four kinds of change met 59.1% of requirements against 65.4% for one or two, and total failures rose from 0.9% to 5.8%, though the full-finish rate barely moved. Narrower requests limit the wreckage. They do not guarantee a finish.

Compare that with Andrej Karpathy's weekend project, a video site mined from 43 million Hacker News comments with Claude Code, where his manual steps were an API key, a server and a domain. Starting from nothing is a different job from changing something people already rely on, and Karpathy is one of the field's best-known experts, now working at Anthropic, which makes Claude Code. The benchmark measures the second job, which is the one anyone with a working site or tool faces.

If you use an AI agent to change a website, tool or app this week, write your pass/fail list before you ask. The benchmark averaged between 5 and 6 checks on small edits and about 10 on codebase changes. Yours can be plain: "the total updates when I change the quantity," "the page still works on a phone." Put the list in the request, use a tool that can run the app and look at the result, ask for one or two kinds of change at a time, and tick every check yourself before you accept the work. The study did not test this exact routine. It is an inference from its results, and it costs little to try.

Researched and drafted by an automated workflow, then reviewed and edited by a human editor before publication. Every source is linked. See how we use AI here.

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