Free Models and APIs for OpenClaw: How to Run AI Agents at Zero Cost

Running OpenClaw can get expensive fast if you're hitting paid APIs with every request. But what if you could run a powerful AI agent at zero cost?

OpenRouter makes this possible by aggregating over 600 models, including dozens of free options. Some are surprisingly capable - good enough for daily automation, code assistance, and research tasks.

Let me show you how to find free models, configure them in OpenClaw, and test them effectively.

Checking Your Current Setup

Before switching models, verify what you're currently using. Ask your running OpenClaw agent:

"What provider and model are you using?"

Or run from the command line:

openclaw models list

This shows your primary model and any configured fallbacks. In my setup, I was running google/gemini-2.5-flash-preview through OpenRouter.

Finding Free Models on OpenRouter

Head to openrouter.ai/models. You'll see 621 models (and counting). The interface lets you filter by input/output modalities and cost.

To find free options, type "free" in the search box:

You'll see models marked with $0.00 pricing. These are completely free to use, though they often have rate limits or lower priority in queues.

Filtering by Modalities

Want to narrow down further? Use the modality filters.

Text-Only Models

Select Text under both Input and Output for traditional text-based models:

These are your best options for coding assistance, writing, research, and general automation tasks.

Image-to-Text Models

Select Image under Input and Text under Output for vision models:

Free vision models can scan documents, analyze screenshots, extract text from images, and describe visual content. Surprisingly useful for automation workflows.

Image Generation?

Check Image under Output to see if any free image generation models exist:

At the time of writing, there are no free image generation models on OpenRouter. Text-based and image-to-text models are the only free options.

Configuring a Free Model in OpenClaw

Once you've picked a model, note its model ID (shown in the card on OpenRouter). Then configure it as your primary model.

Edit your OpenClaw config (usually ~/.config/openclaw/openclaw.json):

{
  "provider": "openrouter",
  "model": "google/gemma-2-9b-it:free",
  "models": {
    "openrouter": {
      "apiKey": "your-openrouter-key"
    }
  }
}

Restart the gateway:

openclaw gateway restart

Verify the switch:

openclaw models list

The primary model should now show your selected free option.

Testing Your Free Model

Send a quick prompt to test responses:

openclaw agent run --session-id test

Ask something practical:

"Summarize the key features of Next.js 15 in bullet points"

Free models will be slower than premium options and may have lower quality responses, but for many tasks they're more than adequate.

What Works Well with Free Models

• Code snippets - Basic syntax, common patterns
• Research summaries - Condensing information
• Text processing - Formatting, cleaning, extracting data
• Scheduling automation - Simple logic, reminders
• Documentation parsing - Reading and summarizing docs

What Doesn't Work Well

• Complex reasoning - Multi-step logic, math
• Long-form writing - Quality drops on longer outputs
• Nuanced judgment - Understanding context, tone
• Real-time speed - Rate limits mean slower responses

Local Alternatives

If you want to avoid external APIs entirely, consider running models locally with Ollama. OpenClaw has forks optimized for Ollama:

• ZeroClaw - Lightweight OpenClaw fork with Ollama support
• PicoClaw - Minimal resource usage
• NullClaw - Stripped-down version

These run entirely on your hardware with zero external API calls. Slower than cloud models but completely private and free.

Cost vs Capability Trade-offs

Free models make sense when:

• You're testing OpenClaw for the first time
• Running low-priority background tasks
• Automating simple, repetitive work
• Budget is a hard constraint

Paid models make sense when:

• You need reliable, fast responses
• Quality matters (writing, code generation)
• Complex reasoning or long context required
• Production use cases with real users

Most productive setups use ClawRouter to blend both - routing simple requests to free models and complex ones to paid models automatically.

Final Thoughts

OpenRouter's free tier gives you genuine access to capable models at zero cost. The quality won't match GPT-4 or Claude, but for automation workflows and experimentation, it's more than enough.

Start with a free text model, test it on your actual use cases, and upgrade selectively to paid models where quality matters. You can save hundreds of dollars per month with smart routing.

And if privacy is a concern, go fully local with Ollama and the ZeroClaw fork. No external APIs, no usage logs, just your AI running on your hardware.