Source note

DeNovoSWE: Scaling Long-Horizon Environments for Generating Entire Repositories from Scratch

DeNovoSWE is a 4,818-instance training set for agents that generate complete software repositories from documentation. Fine-tuning Qwen3-30B-A3B on it raises BeyondSWE-Doc2Repo score from 5.8% to 47.2%.

  • Code-agent training data is mostly issue-fix data, so it gives little supervision for planning and building whole repositories.
  • Whole-repository generation needs documentation that matches executable behavior, tests that can verify the result, and sandboxing that blocks access to the original code.
  • This matters for automated software production because the task spans files, APIs, dependencies, and component interactions.
  • The pipeline selects real repositories with stable Docker environments, at least 90% original test pass rate, and more than 50% test coverage.
  • It splits each repository into functional capabilities, maps tests and traced functions/classes to those capabilities, and documents direct plus behavior-critical indirect components.
  • Draft, critic, and repair agents write and revise capability-level documentation inside a sandbox, then merge it into one document-to-repository task.
  • Cleanup removes source code, tests, package caches, build artifacts, and Git history; runtime command rules and LLM trace audits block attempts to recover the reference implementation.
  • Difficulty-aware filtering keeps training trajectories using per-instance thresholds based on executable line count, two LLM difficulty scores, and observed rollout pass rates.
  • DeNovoSWE contains 4,818 document-to-repository instances, about 46× larger than NL2RepoBench's 104 tasks and much larger than BeyondSWE-Doc2Repo's 50 tasks.
  • Fine-tuning Qwen3-30B-A3B on DeNovoSWE raises BeyondSWE-Doc2Repo performance from 5.8% to 47.2%, a +41.4 percentage-point gain.
  • Dataset repositories average 205.0 unit tests, with median 79.0, P75 197.0, P90 464.0, and maximum 8,903.
  • Average test coverage is 85.5%, with median 89.6%, P75 96.5%, P90 99.9%, and maximum 100%.
  • Evaluation spans repository structure: measured source files average 19.3, with median 9.0, P75 21.0, P90 42.0, and maximum 1,995.