What if You Run Out of Codex or Claude Code Paid Limits? Trying Out Free Coding Agents

I usually use Codex (GPT-5.6 Terra at the time of writing) with ChatGPT Plus as my main tool for daily coding.

While I am generally satisfied with its performance and usability, since the GPT-5.5 generation, I feel I reach the usage limits much faster than before.

However, I do not code enough to justify paying dozens of dollars a month to upgrade to a higher plan, nor do I have that much budget to spare.

What I need is not a complete replacement for Codex, but a "backup" coding agent to keep working for free until the Plus limit resets. If you are using other paid coding agents like Claude Code, you might find yourself in the same situation.

So, I tried the following agents that officially provide free models:

• OpenCode
• Hermes Agent
• Cline
• Kilo Code

To jump straight to the conclusion, I have settled on using Kilo Code as my free backup agent.

Why I Excluded Local LLMs

One way to use AI models for free is to run local LLMs using LM Studio or Ollama.

However, my PC is not high-spec enough to run large models comfortably. It also consumes memory and storage, and requires downloading and updating models.

While Ollama has models that can be accessed via the cloud, its primary nature is handling local models, so I excluded it from the comparison this time.

I was looking for a service that meets the following criteria:

• Does not require a high-performance GPU
• No need to manage multiple API keys
• Can be tested without purchasing credits
• Can be used as an IDE extension or feels close to Codex
• Can be used to keep working until the Codex limit resets

Note that I rarely use TUIs. Instead of terminal usability, I focused on whether it integrates into IDEs like VS Code or can be used as a replacement for Codex without feeling out of place.

Other Potential Candidates

While there are other coding support services like Cursor, GitHub Copilot, Devin Desktop (formerly Windsurf), Google Antigravity, and Manus also famous, I excluded them for the following reasons:

• Cursor / GitHub Copilot / Devin Desktop
  These act more like comprehensive "AI editors or IDEs" that include autocompletion and chat. Since their free limits are complex and broad, they fall outside the scope of a simple backup agent.
• Google Antigravity
  I have a subscription that allows me to use it, but when I used Gemini models for coding, I often felt uneasy about their accuracy and comprehension of existing code, so I did not actively choose it.
• Manus
  Manus is a general-purpose agent that handles research, document creation, and automation, rather than a dedicated coding tool. Its usage differs from tools that continuously edit local repositories.

Agents, Providers, and Models Are Different

When you start researching this field, app names, model names, and provider names can easily get mixed up.

Broadly speaking, they are split into three layers:

Agent App
├─ OpenCode
├─ Hermes Agent
├─ Cline
└─ Kilo Code

Official Provider
├─ OpenCode Zen
├─ Nous Portal
├─ Cline Provider
└─ Kilo Gateway

AI Model
├─ Step
├─ Nemotron
├─ DeepSeek
├─ Qwen
└─ Others

Including external providers like OpenRouter would exponentially increase the combinations and complicate the comparison. Therefore, I only used the free models officially provided by each agent's provider.

OpenCode: My Favorite App Usability

OpenCode is an open-source coding agent. It offers multiple interfaces, including TUI, desktop app, and IDE extensions.

I mainly used the desktop app and IDE extension. Among the tools I tried, OpenCode had my favorite app usability.

Sessions are easy to organize, and it feels close to Codex. Since you can freely choose models and providers, it is highly appealing to those who want to customize their environment.

OpenCode Zen, the official provider, also offers free models, and DeepSeek V4 Flash ran comfortably.

However, I found it tedious to keep track of which temporary free models are suited for which tasks. I found myself wishing for a feature like OpenRouter's Free Model Router, which automatically routes requests.

Pros

• Easy to use in both desktop app and IDE extensions
• Easy to organize sessions
• High flexibility in choosing models and providers
• Great for building a customized environment

Cons

• High flexibility can make it confusing when only looking for free models

Hermes Agent: The Concept of a Growing Agent is Fascinating

Hermes Agent is a general-purpose AI agent developed by Nous Research.

The first thing that catches your eye is the visual style, featuring 90s PC game/anime-style illustrations. It has a strong personality compared to typical sterile development tools.

Rather than just generating code, it highlights self-improvement mechanisms, such as building and improving "Skills" from past experience and maintaining memory across sessions.

You can connect it to the official Nous Portal which allows free accounts to use several free models like Nemotron 3 Ultra.

The concept of Hermes Agent is very interesting, and I see potential if used as a resident agent for tasks beyond coding.

On the other hand, my main goal was a tool to keep editing code until the Codex limit resets. For that purpose, features like memory, Skills, and tools sometimes felt over-engineered.

Also, note that free accounts cannot use managed Tool Gateways, such as Web search.

Pros

• Memorable visuals reminiscent of 90s games
• Fascinating agent philosophy
• Automatically builds memory and Skills
• Available in CLI and desktop app formats

Cons

• Acts more like a general-purpose agent than a dedicated coding tool
• Too feature-heavy for light code modifications
• Hard to gauge the actual effectiveness of auto-generated memory and Skills
• Free accounts lack access to some managed tools

Cline: A Staple VS Code Agent

Cline is a long-standing staple tool for coding in VS Code.

It reads code, edits files, and executes commands while letting you review each step. It also supports MCP, Rules, and Skills, and has a large community, making it easy to find information.

Cline Provider is prepared, and you can choose free models by selecting the "free" tab in the model selection screen.

While it is solid and transparent, the default settings require frequent approvals, which can feel tedious when trying to make quick, repetitive modifications.

Pros

• Runs entirely within VS Code
• Large community makes troubleshooting easy
• Robust features like MCP and Skills
• Clear approval flow for every action
• Free models available on the official provider

Cons

• Frequent approval prompts can slow down the workflow
• Requires manually choosing free models

Kilo Code: Just Choose Auto Free

Kilo Code is an open-source coding agent that runs on VS Code, JetBrains, and CLI.

The official Kilo Gateway registers many models, offering both paid and free options.

The standout feature is Auto Free (identifier: kilo-auto/free).

When you select Auto Free, Kilo automatically chooses the best available free model at that moment. You do not need to register individual API keys or credit cards.

Not having to manually research free models or track their availability and shutdowns was a major practical benefit.

According to the official Kilo documentation, the Kilo-side rate limit for Auto Free is 200 requests per hour per IP. While it is subject to upstream provider limits, in my environment it often lasted longer than OpenRouter's Free Models Router, and the limits felt quite generous.

Pros

• Runs by just choosing Auto Free, which can also select specific free models
• No API keys or credit cards required
• Works by simply installing the extension in VS Code
• Good enough performance for minor implementations

Cons

• The connected model is not fixed
• Quality can vary depending on the session
• The extension's startup feels slightly slow

Key Differences After Using All Four

Here is a summary of the results after trying each agent:

Free model availability and terms change frequently. The table above reflects the status as of July 2026.

While OpenCode was my favorite in terms of app usability, Kilo Code best fit my goal: continuing work for free without wasting time on configuration once Codex paid limits are reached.

Free Models in July 2026 Are Highly Practical

In this test, we mainly used free models like DeepSeek V4 Flash, Step 3.7 Flash, Nemotron 3 Ultra, and Hy3 through Kilo Gateway or OpenCode Zen.

For daily tasks such as minor feature additions, bug fixes, resolving type errors, and adding unit tests, I felt I could work at the same pace as when using paid models like the GPT-5.4 or 5.5 generation.

This does not mean they match the overall capability. For large-scale system design, complex debugging, maintaining long context windows, and precise tool call selection, paid models like GPT or Claude are still noticeably more stable.

Nonetheless, as a backup or temporary "bridge" when paid limits run out, these free models are surprisingly practical.

Key Considerations for Using Free Models

Data handling varies by provider and model.

Kilo Code's documentation notes that Auto Free may route prompts and outputs to providers that use them for service improvement.

Especially for NVIDIA's free endpoints, which are meant for trial purposes, avoid sending sensitive information. As a baseline, you should avoid sending or checking in customer code, API keys, .env files, personal information, or confidential documents.

I use it for minor personal development, so I don't worry too much about it, but cautious evaluation is needed for business use.

Also, free models change without notice. When the connected model changes, the model's Japanese comprehension, coding style, and tool usage ability can shift. An instruction that worked yesterday might not work today.

For tasks that require reproducibility, you should pin a specific model instead of using auto-routing services like Auto Free.

While free models are great for simple edits or code reviews, it is best to switch back to paid models for crucial changes like overall system design, authentication/authorization, payment integration, security updates, or production incident response.

Conclusion

If you prioritize app polish and extensibility, OpenCode is a well-designed tool that remains a highly attractive option for those who want to choose their own models and providers.

If you want to easily run an IDE extension agent for free, Kilo Code is a great fit. I chose it as my free backup agent. It runs out of the box with Auto Free, requires no API keys or credit cards, has generous rate limits, and the free model quality is highly practical.

Use Kilo Code when paid limits are tight or when you want reviews from a different model, while keeping the main paid agent as your primary driver.

As AI model quality and costs continue to evolve, this workflow may eventually change. For now, I am satisfied with this setup.

I look forward to testing and comparing other services as better options emerge.

Reference Links

• OpenCode Official Site
• Hermes Agent Official Site
• Cline Official Site
• Kilo Code Official Site