SWE-Bench Pro

SWE-Bench Pro: Can AI Agents Solve Long-Horizon Software Engineering Tasks?

↑ SWE-bench Verified

1,865 human-verified, long-horizon software engineering tasks from 41 repositories (public set: 731 tasks from copyleft-licensed OSS repos; commercial set: 276 tasks from proprietary startup codebases; held-out set: 858 tasks). Each task gives an augmented problem statement, requirements and optional interface; the patch is scored by fail-to-pass and pass-to-pass tests. Reference solutions average about 107 changed lines across 4 files, so it measures multi-file, enterprise-style work that SWE-bench Verified no longer separates.

61.5%
Muse Spark 1.1
official
2025-09-21 → 2026-09-04: 17.8% → 61.5%
Released
2025-09
Maintainer
Scale AI
Status
active
Contamination
medium
Metric
resolve rate (percent, ↑)
Tasks
1,865
Domains
software-engineering code tool-use
human
no measured baseline

Notes. Scale's current leaderboard runs models with an uncapped cost and a 250-turn limit; the paper-era runs (capped cost, 50 turns) are kept on a deprecated leaderboard and are not comparable. Rows marked with an asterisk on the leaderboard use the mini-swe-agent harness, the others SWE-Agent. Contamination is mitigated by GPL-style licensing rather than by secrecy, so 'medium'.

Full ledger

SystemDeveloperScoreDateSourceConditions
Muse Spark 1.1Meta61.5%officialsplit: public scaffold: mini-swe-agent
Marked NEW on the leaderboard, +/-3.10 CI. Uncapped cost, 250-turn limit. No per-row date; date is the day observed.
gpt-5.4 (xHigh)OpenAI59.1%officialsplit: public scaffold: mini-swe-agent reasoning_effort: xhigh
Uncapped cost, 250-turn limit. Leaderboard shows no per-row date; date is the day observed.
claude-opus-4-5-20251101Anthropic45.89%officialsplit: public scaffold: SWE-Agent
Uncapped cost, 250-turn limit. Leaderboard shows no per-row date; date is the day observed.
OpenAI GPT-5 (medium)OpenAI23.3%papersplit: public scaffold: SWE-Agent
Table 5 of the paper; capped at 50 turns and a cost limit.
Claude Opus 4.1Anthropic22.7%papersplit: public scaffold: SWE-Agent
Table 5 of the paper; capped at 50 turns and a cost limit.
Claude Opus 4.1 (commercial set)Anthropic17.8%papersplit: commercial scaffold: SWE-Agent
Commercial (private startup) subset, Table 2 of the paper.