Kilo Code Review 2026: The All-in-One OSS Coding Agent

Overview

Kilo Code is an open-source agentic coding extension for VS Code that promises an all-in-one workflow: plan, build, and iterate with any AI model. I spent time testing its capabilities, pricing model, and comparing it to other OSS extensions like Cline and Roo. Here's my honest take.

What Is Kilo Code?

Kilo Code positions itself as a complete agentic coding platform inside your editor. Unlike many extensions that only assist with code completion, Kilo Code aims to handle the full cycle: from planning architecture to writing code to iterating on feedback. It's fully open source, with a GitHub repository under Kilo-Org/kilocode that has already gathered over 20,046 stars as of early 2026.

The extension is free to install, but you pay for the AI models you use through your own API keys. This is a standard pattern among OSS coding agents, but Kilo Code differentiates itself by supporting a wide range of models out of the box, including the latest from OpenAI and Anthropic.

Pricing: Free Extension, Pay-as-You-Go Models

The core extension costs $0/month. However, to actually use it you need to bring your own API keys for the models. The pricing snapshot below shows the per-token costs (input and output per million tokens) for popular models. Kilo Code lets you switch between models at any time, so you can choose the cheapest option for simple tasks and the most powerful for complex ones.

• OpenAI o1-pro: $150/M input, $600/M output
• Anthropic Claude Opus 4.7-fast: $30/M input, $150/M output
• OpenAI GPT-5.5-pro: $30/M input, $180/M output
• Anthropic Claude Opus 4.6-fast: $30/M input, $150/M output
• OpenAI GPT-5.4-pro: $30/M input, $180/M output
• OpenAI GPT-4-0314: $30/M input, $60/M output
• OpenAI GPT-4: $30/M input, $60/M output
• OpenAI GPT-5.2-pro: $21/M input, $168/M output
• OpenAI o3-pro: $20/M input, $80/M output
• OpenAI GPT-5-pro: $15/M input, $120/M output
• Anthropic Claude Opus 4.1: $15/M input, $75/M output
• Anthropic Claude Opus 4: $15/M input, $75/M output
• OpenAI o1: $15/M input, $60/M output
• OpenAI GPT-5-image: $10/M input, $10/M output
• OpenAI o3-deep-research: $10/M input, $40/M output

This flexibility is a double-edged sword: you avoid vendor lock-in but must manage multiple API bills and rate limits. For heavy usage, costs can climb quickly with premium models like o1-pro.

Plan/Build/Iterate Workflow

Kilo Code's standout feature is its three-phase workflow built into the extension. You start with a Plan phase where you describe the problem, and the agent generates a high-level architecture or step-by-step plan. Then move to Build to implement the code. Finally, Iterate lets you refine based on tests or feedback. This structure helps keep the agent on track and reduces hallucinated code that doesn't match requirements.

During testing, I found the Plan phase particularly useful for complex refactors. The agent produced clear outlines before writing code, making it easier to review and spot issues early. The Iterate phase picked up on my corrections without starting from scratch.

Strengths vs. the Crowded OSS Extension Field

The open-source coding agent space is heating up: Cline, Roo, and others compete for the same user base. Kilo Code's main advantages are:

• All-in-one workflow – Most competitors focus on build-only; Kilo Code integrates planning and iteration natively.
• Model flexibility – You can switch models mid-session. Cline and Roo often lock you into one provider or require manual config changes.
• Active development – With 20k+ stars and frequent commits, the project shows strong momentum.
• Truly open source – No hidden telemetry or proprietary layers. Full visibility into the code.

On the downside, Kilo Code is still relatively new compared to Cline (which has a larger community and more integrations). The plan-build-iterate flow can feel rigid for simple tasks where you just want quick code generation.

GitHub Momentum and Community

Kilo Code's GitHub repository at Kilo-Org/kilocode boasts 20,046 stars – an impressive number for a project that started in 2025. The contributor count is healthy, with regular releases and an active Discord community. The project uses a clear roadmap and accepts community contributions through pull requests. This level of openness gives confidence that the extension will continue to improve.

For comparison, Cline has around 15k stars, so Kilo Code has already surpassed it in popularity. However, stars are just one metric; actual usage and third-party extensions for Cline are more mature. Kilo Code is catching up fast.

Verdict

Kilo Code is a refreshing addition to the OSS coding agent landscape. Its integrated plan/build/iterate workflow sets it apart from tools that only generate code in one shot. The model flexibility and active community make it a strong choice for developers who want control and transparency. If you're comfortable managing your own API keys and want a more structured agent, Kilo Code is worth trying.