# SourceFile ### Introduction Files in FlatRedBall can support "external" or "source" files. A source file is a file which must be processed before it can be used by FlatRedBall. Source files enable using files created by 3rd-party applications to be used in FlatRedBall. For example, the source file functionality would allow you to use a .psd file (Photoshop file) as a texture file. However, for a source file to be usable, a specific program (which is often referred to as a "builder") must exist to convert the source file to a file format which is understood by FlatRedBall. For example if the source file were a .psd file, then the destination might be a .png, and a PSD to PNG builder would be needed. ### Source files require builders Glue must be told how to convert a source file to the file type that Glue understands. To do this builders must be set up. To set up a builder, see the [File Build Tool](/flatredball/glue-reference/files/file-build-tool.md) page.. --- # 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.flatredball.com/flatredball/glue-reference/files/glue-reference-sourcefile.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.