2024.01 The story of UniSat’s indexer

4 min readJan 8, 2024


Leonidas inquired about why the source code of UniSat’s indexer wasn’t initially open nine months ago. At the time of asking, our priority was minimizing risks during the Jubilee upgrade. Now that the upgrade has been successfully completed, we’ve decided to address this question by crafting an essay to provide a more detailed overview of the whole picture.

This encompasses both historical and practical reasons. The confidence of UniSat to deliver products like UniSat Wallet, UniSat Inscribe, UniSat Search, UniSat Marketplace, brc20-swap, and our in-development projects like UniSat for Atomicals, UniSat App, etc., stems from our team’s commitment to providing users with a range of accessible services.

When we were developing support for brc-20 within UniSat, we approached it like any other feature — integrating the corresponding business logic code for brc-20 support into several of our products, submitting, testing, releasing, and deploying. Frankly, we didn’t anticipate it becoming a focal point in the Bitcoin community within a few months, leading to intense and sustained accusations about the centralization of UniSat’s support for brc-20, let alone becoming the foundation of a purported $5 billion valuation.

Since we didn’t initially develop the brc-20 indexer as a standalone product, extracting it from our product code to create a standalone software required significant refactoring. Imagine developing Windows 95 and suddenly being criticized for being too centralized, with the community urging you to extract the core parts into an open-source Linux kernel while ensuring Windows 95 continues to function seamlessly. The complexity of such a task is quite apparent.

Another layer of complexity we face is the use of a heavyweight optimization solution for improving the user experience, involving extensive distributed coordination of various servers. We aspire for the open-source indexer to be a compact, lightweight solution that can run on low-end machines, accessible to all users rather than advanced developers. This necessitates substantial streamlining and optimization of the existing commercial implementation into a standalone, compact indexer that every user can run without a burden.

Open source doesn’t imply evading responsibility; on the contrary, a robust open-source model will serve as the most potent link between UniSat, developers, and users.

We genuinely desire a healthy, open model for brc-20 indexing. Care to guess who stands to benefit the most from such a model? You got it — UniSat. Through developing services related to brc-20, UniSat has gained valuable experience, and we are eager to share these lessons and insights with the community through a healthy, open model, creating numerous opportunities for different teams to build a plethora of services based on brc-20.

At the Ordinals Summit in September last year, we shared a modular architecture based on brc-20 and then implemented a native brc-20 product, brc20-swap, using this framework. Assuming such a healthy, open model existed, we wouldn’t need an extra two months to invent the concepts of black modules and white modules; we could just allow universal withdrawals for all users, showcasing significant trading advantages compared to the existing marketplaces. Teams utilizing this modular approach for advanced applications like lending, stablecoins, etc., could also benefit from this healthy, open model, working more closely with UniSat to rapidly expand various functionalities for brc-20. As Lorenzo mentioned at the Ordinals Summit, since brc-20 is floating above Bitcoin and is separated from Bitcoin’s physical structure, it can easily bridge into different protocols, blockchains, ecosystems, and industries.

With countless modules continuously emerging from different teams, brc-20 will be omnipresent.

Now you understand why UniSat is eagerly anticipating this healthy and open model, right? It’s not just an open-source code repository but an entire set driving brc-20 to become ‘the connector of everything’ through a healthy and open development model.

We understand that the community will need further discussion and time in order to develop a consensus around the brc-20 standard, such as minor improvements like transfer-attack proposal, and major improvements like the module architecture powering brc20-swap. In light of this, we ask the brc-20 community to think about this question: Do we want to be more expansive to push brc-20 to next level, or end up being just thousands of memes that’ll come to pass?

Nevertheless, UniSat continues to uphold our mission of innovation, maintaining consensus and support for compatibility with Ordinals. To us, we value the growth of brc-20 in the long term, above all else. And we also value inputs from our community members and our collaboration partners.

We will invest more energy and focus on realizing the above vision. UniSat will march forward on the path of innovation, never looking back. We believe that, in 2024, with the establishment of the new open model and the active construction by numerous development teams, brc-20 will be ubiquitous, ushering in a vibrant new ecosystem.

UniSat Team