Refact.ai Agent achieved a 93.3% score on Aider's Polyglot Benchmark Read More
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Refact.ai Agent scores highest on Aider's Polyglot Benchmark: 93.3% with Thinking Mode, 92.9% without

April 1, 2025
by Katia Bystrakova
7 min read

Refact.ai Agent, powered by Claude 3.7 Sonnet, has achieved top performance on the Aider Polyglot Benchmark:

This 20-point lead over the highest listed score (72.9% by Aider with Gemini 2.5 Pro) showcases Refact.ai’s superior autonomous coding capabilities. It handles programming tasks end-to-end in IDE — planning, execution, testing, refinement — and delivers a highly accurate result with zero human intervention.

Top performance on the Aider Polyglot Benchmark

Aider’s Polyglot benchmark evaluates how well AI models handle 225 of the hardest coding exercises from Exercism across C++, Go, Java, JavaScript, Python, and Rust. Unlike SWE-Bench, which focuses solely on Python and single-file edits within 12 repos, Polyglot tests AI ability to write and integrate new code across diverse, multi-language projects, making it much closer to real-world developer workflows.

Our approach: How Refact.ai achieved #1 in the polyglot leaderboard

Refact.ai Agent takes a fully autonomous, iterative approach. It plans, executes, tests, self-corrects, and repeats steps as needed to fully complete tasks with high accuracy — without human input.

Other approaches may follow a more manual, structured workflow, where some steps are controlled by human input + pre-defined scripts. Aider’s benchmark setup looks similar to this, following the trajectory:

This workflow requires ongoing user involvement — manually providing context, running tests, and guiding the AI. The model itself doesn’t form a strategy, search for files, or decide when to test. Of course, this approach saves tokens, it also lacks autonomy.

Refact.ai has a different, autonomy-first AI workflow:

So, Refact.ai interacts with the development environment, verifies its own work, and optimizes resources to fully solve the task end-to-end, delivering efficient and practical programming flow with a full-scope autonomy.

This is much closer to real-world software development and vibe coding: developers can delegate entire tasks to AI Agent while doing other work, then simply receive the final result. It enables teams to get 2x more done in parallel, get the best out of AI models, and focus on big things instead of basic coding.

Key aspects of Refact.ai Agent approach:

1️⃣ 100% autonomy at each step

We at Refact.ai focus on making our AI Agent as autonomous, reliable, and trustworthy as possible. To complete tasks, it follows a structured prompt — since Refact.ai is open-source, you can explore our AI Agent prompt on GitHub. Below is an excerpt:

PROMPT_AGENTIC_TOOLS: | You are Refact Agent, an autonomous bot for coding tasks. STRATEGY Step 1: Gather Existing Knowledge - Goal: Get information about the project and previous similar tasks. - Always call the knowledge() tool to get initial information about the project and the task. - This tool gives you access to memories, and external data, example trajectories (🗃️) to help understand and solve the task. Step 2: Gather Context - Goal: Fully understand the task by gathering all important details. - Do the following: - Use tree() to check the project structure. - Use locate() with the task description to find all necessary files automatically. - Use additional tools like search(), regex_search(), cat(), definition(), and references() and any other to collect relevant information. - Check any files that might indirectly relate to the task. - Running available validation tools preliminary - is a good idea. Step 3: Make a Clear Plan - Goal: Create a clear, validated plan before making changes. - After gathering context (Step 2), create your plan independently. - Only call deep_think() if: - The task is very complex, - You face complicated issues or loops, - The user specifically asks for it. - When using deep_think(), clearly state the task, what the outcome should look like, and carefully check the plan. - After planning, use create_knowledge() to save important ideas, decisions, and strategies. Step 4: Make Changes Step-by-Step - Goal: Follow the validated plan carefully. - Make changes step-by-step using *_textdoc() tools. - Clearly comment each step and its results. - After making changes, go to the assessment step. Step 5: Check and Improve Your Work - Goal: Make sure your changes are correct, complete, and really working. - After changes: - Run available build validation tools (cmdline_cargo_check(), cmdline_pytest*(), cmdline_npm_test(), etc…). - If you find any issues, go back to Step 4 and fix them. - If you cannot solve an issue even after multiple attempts, go back to Step 3 and use deep_think(). - Do not pay attention to skipped tests, they don’t indicate any problems


In short: The AI analyzes files → creates a task plan → executes it → tests results → refines the solution — all without human intervention. It independently decides what to check, fix, and retry. You don’t need to force this manually or copy-paste anything.

2️⃣ Deep environment interaction

The model fully integrates with the development environment. It can autonomously read files, call tools, modify code, run tests, and more as needed, whenever needed.

3️⃣ Capped at 30 steps

AI Agent has 30 messages to complete a task. Here, a “message” doesn’t mean human input — AI only needs one: the task description. A message refers to each AI action, such as modifying a file, listing directories, or running tests.

This cap ensures efficiency while avoiding unlimited retries or token inflation. AI Agent decides when and how to use these messages, leading to clear, controlled solutions.

4️⃣ Self-testing with a possibility to check previous steps

Tests are essential for autonomous AI to validate correctness and ensure the final output is reliable.

Refact.ai Agent can run tests multiple times. It doesn’t just test the final output — it can go back to earlier steps, correct mistakes, and retry. If test failures reveal deeper issues, the model may decide to revise previous actions and then create and test a new solution. Plus, the model sometimes runs tests even before trying to write a solution to gather a better preliminary context.

* * *

Our approach may slightly differ from what Aider used for solving this benchmark, as our AI agent strategy and vision focus on:

Refact.ai Agent improvements & benchmark progress

Two weeks ago, we published that Refact.ai had achieved 76.4% on Polyglot with Claude 3.7 Sonnet No-Thinking, already outperforming other listed results. However, the benchmark run revealed areas for improvement: in some cases, AI lacked enough steps to finish tasks, or skipped testing. Now, we introduced general improvements to Refact.ai Agent:

These enhancements made Refact.ai Agent more effective for all users — also boosting the score from 76.4% to 92.9%, and reaching 93.3% score with Thinking.

Thinking vs. No-Thinking mode: What’s the difference?

“I think, therefore I am.” — René Descartes said. For AI, thinking isn’t philosophical, but practical. It refers to a state where models allocate additional computational resources for deeper reasoning.

Completing the Polyglot benchmark, Claude 3.7 Sonnet with Thinking received +4K extra tokens per response to use reasoning when requested. A quick recap of the results:

This suggests that while Thinking enhances reasoning capabilities, Refact.ai’s autonomous iterative approach — planning, executing, testing, and refining — ensures high accuracy in solving programming tasks even without thinking enabled.

For production use, we recommend enabling Thinking when working on longer, multi-step problems requiring deeper analysis, or handling high-risk code changes where additional reasoning helps avoid errors.

💡 You can try Thinking with Refact.ai Agent: just click the button to enable it. Available to all Refact.ai Pro plan users.

Thinking vs. No-Thinking mode

Key features of Refact.ai’s autonomous AI Agent

Refact.ai’s advanced AI Agent thinks and acts like a developer, handling software engineering tasks end-to-end.

Why this matters for developers

This isn’t just about ranking highly on a benchmark — it’s about real-world coding impact. Refact.ai’s AI agent helps developers and software companies:


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Refact.ai’s autonomous AI Agent works like a senior developer in your IDE:

Thinking vs. No-Thinking mode

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