RuBench: A Repository-Level Agentic Coding Benchmark with Natively Authored Russian Task Specifications
Summary
RuBench 1.0 is a new repository-level agentic coding benchmark designed to evaluate product-grade coding agents on real-world maintenance tasks specified in native languages. It features 25 tasks derived from recent fix commits in five live open-source repositories (aiohttp, aiogram, Laravel, NestJS, Fastify) across Python, PHP, TypeScript, and JavaScript. Each task is natively authored in Russian, mimicking actual customer requests, and judged by upstream maintainer regression tests, which are withheld. All fix commits postdate the training data cutoffs of evaluated models, ensuring a strong contamination argument. The benchmark evaluates deployed product configurations, including Claude Code with Opus 4.8, Sonnet 5, and Haiku 4.5, and Codex CLI with GPT-5.5, reporting pass@1, cost, and token usage. The top configuration achieved 78.7% task resolution. A critical finding from auditing a fifth configuration revealed silent model substitution on 20% of tasks, where HTTP-protocol fixes were re-routed to Opus 4.8, demonstrating that the deployed product, not just the model, is the true unit of measurement. Task statements, metadata, full agent trajectories, and diffs are released.
Key takeaway
For AI Engineers developing or deploying coding agents, you must consider native language task specifications and product-level behavior, not solely model performance. Your evaluation metrics should account for real-world customer request styles and potential silent model substitutions within agent products. This ensures robust, production-ready agent development and accurate performance assessment.
Key insights
Real-world coding agent benchmarks require native language tasks and reveal product-level measurement challenges beyond just model performance.
Principles
- Native language task specifications are crucial for real-world agent evaluation.
- Deployed product configurations, not just models, are the true unit of measurement.
- Benchmark integrity requires tasks postdating model training data cutoffs.
Method
Mine recent fix commits from live open-source repositories. Author tasks natively in customer-request style. Use upstream maintainer's regression tests for judging. Evaluate deployed CLI agent + model + reasoning effort configurations.
In practice
- Evaluate coding agents with native language, customer-style requests.
- Monitor for silent model substitutions in deployed agent products.
- Use post-cutoff commits to ensure benchmark integrity.
Topics
- RuBench
- Agentic Coding
- Benchmarking
- Large Language Models
- Code Generation
- Open-Source
- Russian Language
Best for: Research Scientist, Machine Learning Engineer, NLP Engineer, AI Scientist, AI Engineer, MLOps Engineer
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Editorial summary, takeaway, and curation by AIssential. Original article published by Artificial Intelligence.