OpenClaw With GPT-4 and GPT-5: OpenAI API Setup Guide [2026]

OpenAI's GPT models are a popular choice for powering OpenClaw. If you are already familiar with ChatGPT or have an existing OpenAI account, using GPT as your LLM backend is a natural choice. OpenClaw supports the full range of OpenAI models, including GPT-4o, GPT-4o Mini, and GPT-5.

This guide covers the complete setup process, model selection guidance, and tips for optimizing your GPT-powered OpenClaw deployment.

What Does the OpenAI Integration Do?

The OpenAI integration provides the "brain" behind your OpenClaw agent. When you send a message through WhatsApp, Telegram, or any other channel, OpenClaw sends it to the GPT API for processing. GPT generates a response, decides which tools to call, and OpenClaw executes the actions.

• Function calling — GPT decides which tools to use based on your request
• Streaming responses — real-time response generation for lower perceived latency
• Vision support — GPT-4o and GPT-5 can process images sent through messaging channels
• JSON mode — structured output for reliable data extraction
• Multi-model routing — use different GPT models for different task types

What Do You Need Before Starting?

• A running OpenClaw instance
• An OpenAI platform account at platform.openai.com
• A payment method added to your OpenAI account
• API credits (new accounts typically start with $5 free credits)

How Do You Configure GPT With OpenClaw?

Step 1 — Get your API key

Go to platform.openai.com/api-keys and create a new secret key. Give it a descriptive name like "OpenClaw Production". Copy the key immediately.

Step 2 — Configure OpenClaw

llm:
  provider: "openai"
  model: "gpt-4o"
  api_key: "sk-your-openai-key-here"
  max_tokens: 4096
  temperature: 0.7
  streaming: true

Step 3 — Set spending limits

In the OpenAI dashboard under Settings → Limits, set a monthly hard cap and a soft notification threshold:

# Recommended starting limits:
# Hard limit: $50/month
# Soft limit: $30/month (sends email notification)

Step 4 — Configure model routing (optional)

llm:
  provider: "openai"
  default_model: "gpt-4o"
  model_routing:
    complex_reasoning: "gpt-5"
    simple_tasks: "gpt-4o-mini"
    vision_tasks: "gpt-4o"

Step 5 — Start and test

openclaw start

Send a message through your messaging channel and verify the response. Check logs to confirm OpenAI API calls are completing successfully.

Which GPT Model Should You Use?

For most OpenClaw deployments, GPT-4o is the best starting point. It is fast, capable, and cost-effective. GPT-5 is worth the premium for deployments that handle complex analysis, legal work, or multi-step automation chains.

How Do You Fix Common OpenAI API Issues?

• 401 Invalid API key: Check that you copied the full key. OpenAI keys start with sk-. Also ensure the key has not been rotated or deleted in the dashboard.
• 429 Rate limit: You are hitting the tokens-per-minute or requests-per-minute limit. New accounts have lower limits. Apply for a rate limit increase in the OpenAI dashboard or reduce concurrency.
• Billing error (402): Your account has run out of credits or hit the spending cap. Add more credits or increase the hard limit in Settings.
• Function calling not working: Ensure your model supports function calling. GPT-4o and GPT-5 support it natively. Older models like GPT-3.5 have limited function calling support.
• Slow responses: Enable streaming in your config. For faster responses on simple tasks, use GPT-4o Mini instead of GPT-4o.

FAQ

Should I use GPT or Claude with OpenClaw?

Both work well. Claude is generally recommended for its more reliable tool use and instruction following. GPT-4o is a strong alternative, especially if you already have an OpenAI subscription. GPT-5 offers competitive performance. Try both and compare — OpenClaw makes switching easy.

Can I use the free ChatGPT tier with OpenClaw?

No. OpenClaw requires API access, which is separate from the ChatGPT subscription. You need to create an API key at platform.openai.com and add billing. The ChatGPT Plus subscription does not include API credits.

Does OpenClaw support GPT-5?

Yes. OpenClaw supports GPT-5 through the standard OpenAI API. Set the model to gpt-5 in your config. GPT-5 offers improved reasoning and tool use compared to GPT-4o.

How do I reduce my OpenAI API costs?

Use GPT-4o Mini for simple tasks, set max_tokens limits, enable conversation summarization to reduce context length, and configure model routing so only complex tasks use the more expensive models. Also set a hard monthly spending limit in the OpenAI dashboard.

*Last updated: March 2026. Published by the Remote OpenClaw team at remoteopenclaw.com.*