Grok Code Fast for OpenClaw: Pricing, Setup, and What It's Good At

Current as of March 2026. Grok Code Fast is xAI’s code-specific model — $0.20/M input, $1.50/M output, 256K context. The pitch is obvious: feed it a large codebase for almost nothing and get working code back cheaply. Whether that holds up depends on what you’re asking it to do.

Specs

Provider	xAI
Input cost	$0.20 / M tokens
Output cost	$1.50 / M tokens
Context window	256K tokens
Max output	256K tokens
Parameters	N/A
Features	function_calling, reasoning

What it’s good at

Context window for code

256K tokens is enough to load a substantial repository in one shot. At $0.20/M input, scanning 200K tokens of code for patterns or vulnerabilities costs about $0.04. That changes the economics of repository-wide analysis.

Refactoring throughput

Fast inference plus low output cost ($1.50/M) makes repetitive code cleanup tasks cheap to run at volume — reformatting, renaming, adding documentation, extracting interfaces. The work where correctness matters less than throughput.

Where it falls short

Reasoning consistency

It handles common patterns well but stumbles on complex architectural logic and deeply nested dependencies. Claude 3.5 Sonnet is materially better at reasoning through unfamiliar codebases. Grok Code Fast is faster and cheaper, but it takes shortcuts.

Context saturation

Near the 256K limit, instruction following degrades. Negative constraints — “don’t modify X” or “preserve the interface” — get ignored more frequently. This can cause subtle bugs in refactoring output that look correct at first glance.

Best use cases with OpenClaw

• Repository-wide analysis — Security scans, pattern detection, dependency mapping across dozens of files. The cost per run is low enough to do this routinely.
• High-volume refactoring — Repetitive cleanup tasks where a human reviews the output anyway. The speed and price make it practical as a first pass.

Not ideal for

• Mission-critical logic — It hallucinates obscure library syntax that more established models get right. Always verify output for anything going to production without review.
• System design — High-level architectural decisions need a slower, more careful model. This one produces plausible-looking answers that can miss important constraints.

Run it through Haimaker

Skip juggling API keys. One Haimaker key gives you access to every model on the platform. Tell OpenClaw:

Add Haimaker as a custom provider to my OpenClaw config. Use these details:

- Provider name: haimaker
- Base URL: https://api.haimaker.ai/v1
- API key: [PASTE YOUR HAIMAKER API KEY HERE]
- API type: openai-completions

Add the auto-router model:
- haimaker/auto (reasoning: false, context: 128000, max tokens: 32000)

Create an alias "auto" for easy switching. Apply the config when done.

Or skip model selection entirely — Haimaker’s auto-router picks the best model for each task so you don’t have to.

OpenClaw setup

Configure a custom provider pointing to api.x.ai/v1 using your xAI API key. Since it uses an OpenAI-compatible API, integration is straightforward as long as you set the correct base URL.

{
  "models": {
    "mode": "merge",
    "providers": {
      "xai": {
        "baseUrl": "https://api.x.ai/v1",
        "apiKey": "YOUR-XAI-API-KEY",
        "api": "openai-completions",
        "models": [
          {
            "id": "grok-code-fast",
            "name": "Grok Code Fast",
            "cost": {
              "input": 0.2,
              "output": 1.5
            },
            "contextWindow": 256000,
            "maxTokens": 256000
          }
        ]
      }
    }
  }
}

How it compares

• vs GPT-4o-mini — Grok Code Fast provides double the context window (256K vs 128K) and generally handles raw code syntax more effectively.
• vs Claude 3.5 Haiku — Haiku has better nuance for general chat, but Grok’s $0.20/M input price is more competitive for bulk data processing.

Bottom line

Good for bulk code analysis and repetitive refactoring where you’re reviewing the output anyway. Not the right tool for complex logic or anything where the model needs to reason carefully through unfamiliar code.

TRY GROK CODE FAST ON HAIMAKER

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For setup instructions, see our API key guide. For all available models, see the complete models guide.