OpenAIFastUltra

GPT-4.1

OpenAI's most capable model for coding and instruction following. Features a 1M token context window, 32K output tokens, and major improvements in coding, complex prompts, and long-context tasks. 20% cheaper than GPT-4o on output.

3 credits

per 1K tokens (avg)

1M token context window

32K max output tokens

Best-in-class coding performance

Superior instruction following

Native vision (text + image)

Function calling & JSON mode

Structured outputs

Use with AI Assistant

Copy usage instructions for Claude, ChatGPT, or other AI

llms.txt

Model Specifications

Context Window

1.0M

tokens

Max Output

33K

tokens

Training Cutoff

2024-05

Compatible SDK

OpenAI

Capabilities

Vision

Function Calling

Streaming

JSON Mode

System Prompt

Token Pricing (per 1M tokens)

Token Type	Credits	USD Equivalent
Input Tokens	2,000	$2.00
Output Tokens	8,000	$8.00
Cached Tokens	500	$0.50

* 1 credit ≈ $0.001 (actual charges may vary based on usage)

Quick Start

curl -X POST "https://api.core.today/llm/openai/v1/chat/completions" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer cdt_your_api_key" \
  -d '{
  "model": "gpt-4.1",
  "messages": [
    {
      "role": "system",
      "content": "You are an expert code reviewer. Analyze the codebase and suggest improvements."
    },
    {
      "role": "user",
      "content": "Review this Python project and identify potential performance bottlenecks, security issues, and suggest refactoring opportunities."
    }
  ],
  "temperature": 0.3,
  "max_tokens": 4000
}'

Parameters

Parameter	Type	Required	Default	Description
`messages`	array	Yes	-	Array of message objects with role and content
`model`	string	Yes	gpt-4.1	Model identifier
`temperature`	float	No	1.0	Sampling temperature (0-2). Lower = more focused, higher = more creative
`max_tokens`	integer	No	4096	Maximum tokens in response (up to 32768)
`stream`	boolean	No	false	Enable Server-Sent Events streaming
`response_format`	object	No	-	Format of response: { type: 'json_object' } for JSON mode
`tools`	array	No	-	List of tools (functions) the model can call
`top_p`	float	No	1.0	Nucleus sampling threshold (0-1)

Examples

Long Code Analysis

Analyze and refactor a large codebase with 1M context

curl -X POST "https://api.core.today/llm/openai/v1/chat/completions" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer cdt_your_api_key" \
  -d '{
  "model": "gpt-4.1",
  "messages": [
    {
      "role": "system",
      "content": "You are an expert code reviewer. Analyze the codebase and suggest improvements."
    },
    {
      "role": "user",
      "content": "Review this Python project and identify potential performance bottlenecks, security issues, and suggest refactoring opportunities."
    }
  ],
  "temperature": 0.3,
  "max_tokens": 4000
}'

Instruction Following

Complex multi-step task with precise formatting

curl -X POST "https://api.core.today/llm/openai/v1/chat/completions" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer cdt_your_api_key" \
  -d '{
  "model": "gpt-4.1",
  "messages": [
    {
      "role": "system",
      "content": "Follow the user's instructions exactly. Format output as specified."
    },
    {
      "role": "user",
      "content": "Create a technical specification document with sections: Overview, Architecture, API Design, Security Considerations, and Deployment Plan. Use markdown headers and include code examples where relevant."
    }
  ],
  "temperature": 0.5,
  "max_tokens": 8000
}'

JSON Data Extraction

Extract structured data from unstructured text

curl -X POST "https://api.core.today/llm/openai/v1/chat/completions" \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer cdt_your_api_key" \
  -d '{
  "model": "gpt-4.1",
  "messages": [
    {
      "role": "system",
      "content": "Extract structured data from the given text. Always respond with valid JSON."
    },
    {
      "role": "user",
      "content": "Parse this invoice: 'Invoice #2025-0342 from Acme Corp to Beta LLC, dated March 1 2025. Items: 10x Widget A at $25.00, 5x Widget B at $50.00. Tax: 10%. Shipping: $15.00'"
    }
  ],
  "response_format": {
    "type": "json_object"
  },
  "max_tokens": 1000
}'