Reasonix is a terminal-based AI coding agent specifically engineered for DeepSeek models, focusing on minimizing operational costs and maximizing performance through a unique cache-first loop. It targets developers who require efficient, low-cost AI code assistance directly within their terminal workflow, offering significant cost savings and a responsive experience by deeply integrating with DeepSeek's prefix-cache mechanism.

How It Works

Reasonix's core innovation lies in its loop architecture, meticulously designed around DeepSeek's byte-stable prefix-cache. Unlike other agents that may reorder or compact prompts, Reasonix maintains append-only growth and avoids cache-breaking operations. This invariant ensures a high prefix-cache hit rate (94% live), drastically reducing input costs compared to generic loops that invalidate the cache. The framework also incorporates specific fixes for DeepSeek's nuances, such as scavenging tool-call JSON from reasoning blocks, auto-flattening deeply-nested parameters, repairing malformed tool calls, and exposing a reasoning_effort knob for cost control.

Quick Start & Requirements

• Install/Run: Navigate to your project directory and run npx reasonix code. A DeepSeek API key is required on first run and persists afterward.
• Prerequisites: Node.js version 22 or higher. Tested on macOS, Linux, and Windows (PowerShell, Git Bash, Windows Terminal).
• Links: Website (implied by context, not explicitly linked in README text), DeepSeek API Key (implied).

Highlighted Details

• Cost Efficiency: Significantly lower cost per typical task (¥0.01–0.04) compared to competitors like Claude Code (¥0.40–4), attributed to the 94% DeepSeek prefix-cache hit rate.
• Cache Economics: Leverages DeepSeek's byte-stable prefix-cache, achieving roughly 2.5x input cost savings over generic loops by maintaining cache invariants.
• Features: Includes an embedded web dashboard, persistent per-workspace sessions, plan mode, edit review, skills, hooks, and sandboxing.
• DeepSeek Specifics: Implements fixes for DeepSeek's handling of tool schemas, reasoning output, and tool-call arguments.

Maintenance & Community

Reasonix is currently solo-maintained but designed for scalability, with scoped starter tickets available under the "good first issue" label for contributors. Open discussions are hosted on GitHub for CLI/TUI design, dashboard feedback, and future feature wishlists.

Licensing & Compatibility

The project is licensed under the MIT license, permitting commercial use and closed-source linking.

Limitations & Caveats

Reasonix is intentionally DeepSeek-only, coupling tightly to its specific cache mechanics and pricing model, thus sacrificing multi-provider flexibility. It is a terminal-first tool and does not offer IDE integration, functioning as a companion rather than a replacement for IDEs like Cursor. For highly complex reasoning tasks beyond typical coding assistance, models like Claude Opus may still offer superior performance. Requires a paid DeepSeek API key.