# o1 Pro - Core.Today AI API

> Legacy pro-tier reasoning model. Uses more compute than o1 for the most reliable answers on hard problems. Predecessor to o3-pro, which offers better value.

- **Provider**: OpenAI
- **Model ID**: o1-pro
- **Category**: LLM
- **Credits**: 697 per 1K tokens (avg)
- **Speed**: Slow
- **Quality**: Ultra

## Model Specifications
- **Context Window**: 200K tokens
- **Max Output**: 100K tokens
- **Training Cutoff**: 2023-10
- **Supported Formats**: text, json, markdown
- **Compatible SDK**: OpenAI

### Capabilities
- Vision (image input)
- Function Calling
- Streaming
- JSON Mode
- System Prompt

### Token Pricing (per 1M tokens)
- **Input Tokens**: 278,700 credits ($186)
- **Output Tokens**: 1,114,800 credits ($743)

## Features
- Pro-tier chain-of-thought reasoning
- 200K context window
- 100K max output tokens
- Vision capabilities
- Function calling support

## Use Cases
- Legacy workloads pinned to o1 Pro behavior
- High-reliability scientific reasoning
- Complex mathematical problems
- Critical code verification

## API Endpoint

Base URL: https://api.core.today
Endpoint: POST /llm/openai/v1/chat/completions

## Authentication
Header: Authorization: Bearer YOUR_API_KEY

Note: LLM endpoints use OpenAI-compatible format with Authorization Bearer token.

## Input Parameters

### Required
- **messages**: array - Array of message objects
- **model**: string (default: o1-pro) - Model identifier

### Optional
- **max_completion_tokens**: integer - Maximum tokens for completion (includes reasoning tokens)
- **reasoning_effort**: string - Reasoning effort level: low, medium, high
  Options: low, medium, high

## Examples

### Deep Reasoning
High-reliability reasoning with o1 Pro
```json
{
  "model": "o1-pro",
  "messages": [
    {
      "role": "user",
      "content": "Prove or disprove: every planar graph is 4-colorable. Outline the structure of the argument step by step."
    }
  ],
  "max_completion_tokens": 8000
}
```

## Response Format
```json
{
  "id": "chatcmpl-abc123",
  "object": "chat.completion",
  "choices": [
    {
      "index": 0,
      "message": {
        "role": "assistant",
        "content": "Response text here"
      },
      "finish_reason": "stop"
    }
  ],
  "usage": {
    "prompt_tokens": 100,
    "completion_tokens": 50,
    "total_tokens": 150
  }
}
```

## Tips
- Works with the OpenAI SDK - set base_url to https://ai.api.core.today/llm/openai/v1
- Legacy model - consider o3-pro for better value (stronger reasoning at a fraction of the price)
- Use max_completion_tokens instead of max_tokens - temperature is not supported
- Responses take significantly longer due to extended internal reasoning

## Documentation
https://platform.openai.com/docs/models/o1-pro