E2E-SWE: Benchmarking LLMs on Building Working Codebases from Scratch
Source
arxiv.org
Author
Hantian Ding, Chloe Bi, Jiacheng Zhu, John Yang, Matt Deitke, Pengcheng Yin, Zijian Wang, Rui Hou
Date
Context
E2E-SWE asks whether a coding AI agentAn AI system that doesn't just answer once but works toward a goal in a loop — taking actions, reading the results, and deciding what to do next.Full definition → can turn a written specification and an empty workspace into a complete, installable project. Its 186 tasks span eleven programming languages, and hidden tests check whether the resulting software implements the required behavior.
Across thirteen evaluated models, the authors report first-attempt success rates from 11.7% to 67.7%. This gives a different view of coding ability from fixing a localized defect: the agent must assemble a working project whose parts satisfy the specification together. The strongest reported result still leaves substantial room for improvement on these tasks.
Key takeaways · AI-distilled
E2E-SWE has 186 whole-repository tasks across 11 languages. Given only a natural-language spec and an empty workspace, the agent must build a complete, installable project that passes a comprehensive hidden test suite.
Each task is written by a software engineer working with an LLMA large language model — the neural network behind tools like Claude and ChatGPT, trained on huge amounts of text to predict what comes next.Full definition → to produce the tests and an implementation-independent spec, then audited by autonomous agents that repair defects using static inspection and failures seen in real model rollouts.
Across 13 frontier models, pass@1 ranged from 11.7% to 67.7%, which the authors say separates models clearly while leaving considerable headroom.
Trajectory analysis found long, front-loaded reasoning, which the authors read as a sign that building a working codebase from scratch depends on planning and system-level reasoning up front.
Terms in this piece · Glossary
AI agent — An AI system that doesn't just answer once but works toward a goal in a loop — taking actions, reading the results, and deciding what to do next.
LLM — A large language model — the neural network behind tools like Claude and ChatGPT, trained on huge amounts of text to predict what comes next.