> For the complete documentation index, see [llms.txt](https://xdocs.ngd.network/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://xdocs.ngd.network/bridge/general/architecture.md).
# Architecture
The bridge is composed of the following key components:
* Smart Contract for Role Management and Verifying Validator Consensus (BridgeManagement)
* Smart Contract for Transferring Assets (TokenBridge)
* Smart Contract for Bridging Messages (MessageBridge)
* Validator Nodes
* One Relayer Node
> Each of the above listed contracts is deployed once per chain.
The smart contracts serve as the foundation for the bridging system. They contain crucial functionality such as role management (BridgeManagement), accepting token transfer requests including locking and unlocking them (BridgeContract) and message sending (MessageBridge).
The validator nodes track incoming bridge requests, validate and sign them off, and then provide the observed request data including their signature to the relayer.
The relayer is a single node that awaits and collects signatures and bridge request data from validator nodes. Once enough signatures have been collected for passing verification on the destination chain's BridgeManagement, it invokes the corresponding bridge contract to finalize the bridge request. Depending on the type and data of the request, the sent message is persisted, or tokens are distributed or are made available for claiming.
The architecture of the bridge is illustrated in the following image:
---
# 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://xdocs.ngd.network/bridge/general/architecture.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.