Jiang Jie talked to Gu Lu and demonstrated the initial idea. We then decided to formulate it. We started to build the prototype and write the doc.

The first viable prototype and the doc are available in less than one month.

We presented every bit to Edward Liu for a deep review. His feedbacks and ideas are quite positive, encouraging, and insightful. Many questions raised later by others, like interoperability between different dex(s) / tokens / contracts, were discussed. In that afternoon, we started to firmly believe this would be a game-changing solution for bitcoin application development. Things which were considered impossible for Layer-1, are now possible with Sensible Contract.

Through an online meeting, we demonstrated our idea, prototype, and solution (known as v0.1.8) to a few senior Bitcoin SV developers, including Edward Liu, cc (Chen Cheng), Wang Yu (show apps) Xiaohui Liu (sCrypt), TshiMing Ho (MetaSV), Fuqiang Wang (Volt), Aaron (BA & nChain), Zheming Lin (Mempool & DotWallet), Li Long. Sensible Contract is explained in detail and the meeting is productive.

Since an alternative implementation involves upgrading PreImage structure (by doing this Sensible Contract becomes 100% L1 gracefully), we propose the method to nChain for review about whether it’s applicable to adopt the change in future node upgrading plan.

To accelerate BSV token standardization process, Long Yun organized a one-day meeting in Zhuhai. Several dev-teams were invited to talk about various Token solutions currently on BSV. Inspirations were brought up and well discussed. Specifically, cc (Chen Cheng) helped us with utxo-based contract splitting. We made a firmly agreed consensus that Sensible Contract is widely applicable and technically reliable, and it could be the cornerstone of the de facto token protocol. We started to work together to integrate Sensible Contract into our projects and build applications on top of it.

With the help from Bitcoin Association, we introduced Sensible Contract to a broader audience (including founders, tech-leaders, and experts from different companies in China) remotely. The audience was surprised about the possibilities that what can be implemented, and had an impression about bitcoin script and its utilization in real-world applications.

The developer of BTP worked pretty close with us for a few weeks, before merging BTP into Sensible Contract. We learned a lot about how to isolate and consolidate different code into a well-designed and organized utxo-set, which is far more efficient and less complicated.

SatoPlay released the first application utilizing Sensible Contract as the underlying technology. The NFTs are issued on Bitcoin SV network as the very first bitcoin script based NFT. 1000+ cards are issued.

MetaCoin is a series of tokens issued by the OpenMetaNetFoundation Ltd, to incentivize users to use MetaID-related applications. MetaCoin is based on Sensible Contract.

Sensible Contract is released on 2021.04.02.

蒋杰与顾露谈及初始的设计并做了最初的概念展示。我们决定开始严谨地梳理相关的工作，并开始实现原型及对应的原理文档。

在不到一个月的时间里，我们完成了第一个 MVP 的实现和对应文档的编写。

我们把所有细节同刘老师 (老刘) 做了面对面的深入沟通，他给予了我们非常积极的反馈，巨大的鼓励和有洞察力的想法。后来被反复考虑的，dex 下不同 token 互通问题，不同体系合约的相互识别问题，在当时都是被老刘首次提出，也是当时探讨的主要关注点。在那天下午，我们开始确信这个方案蕴含的巨大价值，在很多方面，原来被认为是不可能在层一做到的事情，在感应合约下变得成为可能。

通过一次在线会议，我们向若干 Bitcoin SV 高级工程师分享了感应合约的文档 (v0.1.8)，展示了我们的想法，解决方案及原型。具体包括老刘，陈诚 (cc)，王宇 (show apps 技术负责人)，Xiaohui (sCrypt 创始人)，何启明 (MetaSV 创始人)，王福强 (Volt 创始人)，周全 (nChain 技术专家)，林哲明 (Mempool 和打点钱包创始人)，李龙等。我们向大家解释了感应合约的原理和细节，并集中回答了大家的提问。一次非常有成效的沟通。

在我们的方案中，通过升级 PreImage 结构，即可实现无需任何外部条件的比特币上的纯一层智能合约。我们把方案提交给 nChain，希望能了解到，该方案被包含在未来的节点升级中的可能性。如有可能，也希望能了解到 nChain 对完整方案的研究或评议的情况。

出于加速 BSV 应用发展的目的，龙云 (飞龙) 组织和推动了针对 Token 的规范化工作。在他的组织与邀请下，若干关心感应合约的开发团队及个人在当天分别从全国各地赶赴珠海，进行了一天的研究和讨论。针对各类 Token 方案，大家从各自不同的理论及实践角度提出了自己的见解。其中，陈诚 (cc) 在合约拆分上，给了我们非常有力的帮助。在当天晚上，大家对感应合约的广阔适用性及技术可靠性形成了高度的评价。对于共同推动感应合约的发展，使之成为事实上的标准协议，我们达成了相当程度的共识，并开始更紧密地合作，在各自的项目中实现对感应合约的系统化支持，并开始在其上规划和构造全新的项目。

在比特币协会 (Bitcoin Association) 的帮助下，我们远程向更大的受众（包括国内不同行业的企业家和技术专家）介绍了感应合约及其可能被应用的领域。大家对 Bitcoin SV 作为公链的可能性感到非常惊讶，对比特币开发及工程化应用有了新的和具体的认识。他们同时向我们提出了更多的技术角度之外的问题，这些问题深深启发和鼓舞了我们，我们也尽我们所能向他们做了充分的讲解。

BTP 的开发者陈诚 (cc) 在这几周中与我们密切合作，并随后把 BTP 融合入感应合约的技术实现。我们学习到大量的技巧，关于如何把不同的逻辑按照设计好的 utxo 集来组织。这次技术融合，使得感应合约有了进化，变得更加高效和简单。

小聪 (SatoPlay) 发布了基于感应合约的首个产品 - 小聪 NFT 纪念卡组。这一批纪念卡组作为 NFT，以合约的形式运行于比特币网络之上。在发行的前三天，共铸造了 1000+ 的 NFT 纪念卡。

开放元网基金会发布了基于感应合约 FT 方案的 metacoin，用于激励用户使用 MetaID 相关应用，创造 MetaID 交易的通证。这是 Sensible Contract 工程化的重要一步。

感应合约于 2021.04.02 公开发布。