> For the complete documentation index, see [llms.txt](https://docs.jentis.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.jentis.com/use-cases-and-tutorials/transaction-deduplication-function/filtering-data.md). # Filtering Data Our objective is to confirm whether a conversion happened before sending the signal and parameters to a network. To achieve this, we need a unique identifier for that conversion, which is usually the transaction\_id for transaction-based conversions. In this guide, we will use a common example of an ecommerce store where the conversion is a purchase, and each purchase has a unique ID that is submitted to our data layer. Before delving into the process of "how", let us first briefly discuss the "why" aspect of it. Some marketing tools lack the capability of deduplication within their internal processes, which means that the tracking system has to filter out duplicate signals. This usually happens during page reloads, such as when you close the website app on your smartphone after making a purchase and then reopen the same app. This results in the recent page being reloaded and unintentionally sending a redundant conversion signal. To filter out such signals before sending the conversion, we can implement a short routine. --- # 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://docs.jentis.com/use-cases-and-tutorials/transaction-deduplication-function/filtering-data.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.