傳 OpenAI 正考慮大幅調降 Token 價格

OpenAI models process text by breaking it down into 'tokens,' which are fundamental units of text.

• Token Definition: Tokens are text 'chunks' representing commonly occurring sequences of characters in large language training datasets. They can be a single character, a fraction of a word, or an entire word.
• Tokenization Process: Text data (e.g., a prompt) is deconstructed into a sequence of tokens. The model then generates the next token in sequence for text completion.
• Byte Pair Encoding (BPE): OpenAI utilizes BPE for tokenization, a data compression algorithm that replaces frequent pairs of bytes with a single byte, reducing text size and facilitating processing.
• Tiktoken: OpenAI developed tiktoken, an open-source tool specifically for tokenizing text, which is used to count tokens and understand associated API costs.
• Token Limits: Every model has a 'context window,' defining the maximum number of tokens it can process for a single request (input + output). Exceeding this limit requires shortening prompts or breaking down text.
• Token Types for Billing: Token usage is tracked in categories including input tokens (in your request), output tokens (generated in response), cached tokens (reused, often at a reduced rate), and reasoning tokens (internal 'thinking steps' in advanced models).
• Token-to-Word Ratio: For English, approximately 1 token equals 4 characters or ¾ of a word. This ratio varies significantly across languages (e.g., English: 1 word ≈ 1.3 tokens; Hindi: 1 word ≈ 6.4 tokens).
• Encoding: Different OpenAI models use different encodings for tokenization (e.g., cl100k_base for GPT-4, GPT-3.5-turbo, text-embedding-ada-002).