# How a file is read Reading a spreadsheet and reading a contract are not the same job, so SnoutData does not decide for you. Right after you add a file, you choose how it gets read, and each option tells you **where your data goes** before you pick it. That is a fact about the route, not a reassurance: the option you choose determines which machines see the content. ## The four options They are listed in escalation order. Start at the top and move down only if you need to. ### 1. The parsers, on this computer The default. Structured files (CSV, TSV, JSON, NDJSON, logs) are read locally by code. **Where the data goes:** nowhere. It stays on this computer. No model is involved at any point. This is the fastest option and it costs nothing. ### 2. A model on this computer For documents the parsers cannot handle, such as a PDF of prose. A local model reads them on your own hardware. **Where the data goes:** nowhere. It stays on this computer. The model is downloaded on demand the first time you choose this option. ### 3. Our AI SnoutData's managed gateway, metered against your plan. Use this when the local model is not good enough for a document and you would rather not run one yourself. **Where the data goes:** the content reaches a model through our gateway, so that it can be read. ### 4. A model of your own Your own API key and your own provider. **Where the data goes:** straight from this computer to that provider. It does not pass through SnoutData's servers, and the billing relationship is between you and them. ## A file is not handed over whole When a model does read something, it is not given the entire file. **A table** has a regular shape, so SnoutData samples it: the header, the first rows and the last rows. The model is asked *how to read this table*, and then the parser reads every row that way. A one-gigabyte export costs a single call, and only a few dozen rows are ever exposed. **A document** has no such regularity, so it is read in windows, in as many passes as it takes. There is no length at which a file is refused for being too long. ## When a read fails A failure is reported, and the flow does not quietly fall back to a different reader. Two different things are kept apart: - **The reader could not run at all** (for example, the local model is not installed). The run stops. - **The reader could not read this particular file.** That file is named and skipped, and the run continues with the others.