SWE-Clar

One hundred greenfield software projects from real Upwork jobs that each paid at least $4,000, every one starting from an incomplete client request. The agent questions a simulated client until it is ready, then builds the software with no further contact. Acceptance tests score the implementation, and a separate run scores the agent’s answers to questions about what the client asked for. Upwork ran every model once at its maximum reasoning effort.

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Results

SWE-Clar results, ranked by score (implementation), highest first. Last updated Oct 28, 2026.
RankModelProviderScore (implementation)Cost (USD / task)Duration (seconds / task)
1GPT-6 AstraOpenAI67.0%$5.391,477
2Claude Opus 5Anthropic63.0%$9.693,207
3Claude Fable 5.1Anthropic60.0%$11.034,410
4GPT-5.6 SolOpenAI57.0%$1.971,150
5Qwen 3.8 MaxAlibaba55.0%$1.701,768
6GLM 5.3Z.ai54.0%$1.393,047
7Kimi K3Moonshot AI49.0%$1.341,811
8GPT-5.6 LunaOpenAI49.0%$0.10611
9GLM 5.3 FlashZ.ai39.0%$0.095849