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About GPT-5.1-Codex-Max
Agentic coding assistant for large codebases: speeds multi-file refactors, supports streaming, function-calls, image I/O, long-context compaction, and repo-aware testing (high-accuracy, lower token use).
Technical Specifications
- Model ID
- gpt-5.1-codex-max
- Category
- LLM Models
- Task
- Text Generation
- Price
- $5.63 per million tokens
- Added
- December 11, 2025
Key Features
- Chat completion and multi-turn conversation API
- Streaming response with token-by-token output
- Function calling and tool use support
- System prompts and role-based messaging
- JSON mode and structured output
Quick Start
Integrate GPT-5.1-Codex-Max into your application with a single API call. Get your API key from the pricing page to get started.
import requestsimport jsonurl = "https://modelslab.com/api/v7/llm/chat/completions"headers = {"Content-Type": "application/json"}data = {"model_id": "gpt-5.1-codex-max","messages": [{"role": "user","content": "Hello!"}],"max_tokens": 1000,"key": "YOUR_API_KEY"}try:response = requests.post(url, headers=headers, json=data)response.raise_for_status() # Raises an HTTPError for bad responses (4XX or 5XX)result = response.json()print("API Response:")print(json.dumps(result, indent=2))except requests.exceptions.HTTPError as http_err:print(f"HTTP error occurred: {http_err} - {response.text}")except Exception as err:print(f"Other error occurred: {err}")
Pricing
GPT-5.1-Codex-Max API costs $5.63 per million tokens. Pay only for what you use with no minimum commitments. View pricing plans
Use Cases
- AI chatbots and virtual assistants
- Code generation and developer tools
- Content writing and copywriting automation
- Data analysis, summarization, and extraction
GPT-5.1-Codex-Max FAQ
Agentic coding assistant for large codebases: speeds multi-file refactors, supports streaming, function-calls, image I/O, long-context compaction, and repo-aware testing (high-accuracy, lower token use).
You can integrate GPT-5.1-Codex-Max into your application with a single API call. Sign up on ModelsLab to get your API key, then use the model ID "gpt-5.1-codex-max" in your API requests. We provide SDKs for Python, JavaScript, and cURL examples in the API documentation.
GPT-5.1-Codex-Max costs $5.63 per million tokens. ModelsLab plans start at $21/month (Basic), and the $149/month Open Source plan includes unlimited generation on open-source models.
The model ID for GPT-5.1-Codex-Max is "gpt-5.1-codex-max". Use this ID in your API requests to specify this model.
Yes. ModelsLab is subscription-based with no free tier — plans start at $21/month (Basic, 3,250 API calls). The $149/month Open Source Unlimited plan includes unlimited generation across open-source models; premium third-party models are billed per call from your wallet.