Abstract: In recent years, large models have become one of the most important tools in human life. As a bridge for communication between humans and large models, prompts play a crucial role. While high-quality prompts can fully unleash the potential of large models, their design requires both specialized skills and substantial resources, leading to the emergence of prompt trading markets and licensing service models. However, treating prompts as commodities presents three main challenges: 1. Once prompt text is leaked, it can be easily copied and disseminated, losing its value. 2. There is a lack of objective standards and pricing systems for prompt quality. 3. Users have difficulty holding providers of false prompts accountable, and the actions of centralized platforms can also affect the rights of providers. To address these challenges, this paper proposes PromptDEX, a blockchain-based service platform for large model prompts. Through a prompt rental mechanism based on smart contracts and service templates built on LangChain, the platform enables direct interaction between providers and demanders, reducing the impact of centralized institutions on participants’ interests and privacy. All transaction records are transparently stored on the blockchain, ensuring security, reliability, and accountability. Additionally, a dynamic pricing mechanism based on demand-side ratings is implemented. Experimental results show that the additional cost incurred by integrating blockchain is negligible, calculated in terms of fractions of a cent. Providers can build API services with only about 10 lines of code, requiring minimal network bandwidth, demonstrating strong feasibility and practicality.

摘要： 近年来，大模型已经成为人类生活的重要工具之一。作为人类与大模型沟通的桥梁，提示词发挥着至关重要的作用。虽然高质量提示词能够充分激发大模型的潜力，但其设计不仅需要专业技能，还需耗费大量资源，这促使提示词交易市场以及授权服务模式的出现。然而，将提示词作为商品存在以下三个问题：1.提示词明文一旦泄露就会被轻易地复制以及传播致使其失去价值。2. 缺乏客观的提示词质量标准和价格体系。3. 用户难以对虚假提示词的提供者追究责任，同时中心化平台的行为亦会影响提供者的权益。针对上述挑战，本文提出了PromptDEX，一种基于区块链的大模型提示词服务平台。基于智能合约的提示词租用机制和基于LangChain的服务模版，使提供者直接与需求方对接，削弱中心化机构对参与者利益和隐私的影响。同时所有交易记录将被公开透明地记录在链上，确保交易流程安全可靠可追责。此外，平台还设计了以需求方评分为依据的动态定价机制。实验结果表明：PromptDEX引入区块链所带来的额外成本开销以角为单位计算，几乎可以忽略不计。提供者仅需约10行代码即可构建的API服务，且对于网络带宽要求极低，具备较强的可行性与实用性。