# Filters Once incoming blocks are condensed into enriched events, Brist matches these events with user-defined filters before funneling them into the designated output channels. Filters can be stacked, with AND logic applying to the filters in a series. Currently, Brist supports two kinds of filters (with more on the way!): ### Wallet Filters Wallet filters match the sending and/or receiving addresses of events. Wallet filters can be used to, for example: * Create an alert whenever a certain wallet makes a trade, or receives an asset * Create an alert when a certain smart contract (e.g. OpenSea, a Uniswap pool) is interacted with, by entering the contract address in the "To" section ### Token/NFT Filters Token/NFT filters match the smart contract that facilitated a transfer. You can use Token/NFT filters to match with a specific NFT collection (e.g. Bored Ape Yacht Club) or ERC-20 token (e.g. USDC). To create a Token/NFT filter, you just need to indicate the contract address underlying the asset; you can find this information easily on Etherscan, OpenSea, Coingecko, and a variety of other services. We will be enabling token/NFT searches in the near future, so you won't have to know the contract address to create a filter. --- # Agent Instructions: 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: ``` GET https://docs.usebrist.com/fundamentals/filters.md?ask= ``` The question should be specific, self-contained, and written in natural language. 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.