> For the complete documentation index, see [llms.txt](https://pegasys.gitbook.io/pegasys-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://pegasys.gitbook.io/pegasys-docs/technical-details/pegasys-hub.md). # PegaSys Hub The PegaSys Hub is the term used to describe the singleton lightning node that is controlled by the network’s Schnorr\[4] key. Each PegaSys node holds a shard of the network key, and all (Bitcoin and Lightning) transactions done by the system must go through a threshold signature scheme\[5] (TSS). The signature threshold is set to 2f + 1, where f is the number of failures the system can tolerate, to ensure a majority honest approval for every transaction. Once enough nodes have verified and signed the transaction, a single node broadcasts the transaction to the intended recipient. Once signed, each transaction also needs to be added to PegaSys’s internal ledger for the bookkeeping of user funds. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://pegasys.gitbook.io/pegasys-docs/technical-details/pegasys-hub.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.