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How do I turn a CSV file into a REST API?

Quick answer

Upload your CSV file to SheetZAPI. The first row becomes your field names, every subsequent row becomes a JSON object, and your data is immediately available via a REST API with filtering, sorting, pagination, and Redis caching. It takes under 60 seconds and requires no code.

CSV as an API data source

CSV is the most portable data format — exported from every database, spreadsheet, and SaaS tool. SheetZAPI treats an uploaded CSV exactly like a live Google Sheet: header row maps to field names, values are type-cast automatically, and the full REST interface (GET, POST, PATCH, DELETE, aggregations, filtering) is available immediately.

CSV format requirements

The file must be UTF-8 encoded with a comma delimiter. The first row must contain column headers with no blank cells. SheetZAPI handles quoted fields, embedded commas, and multi-line values. Numeric strings are cast to numbers. Columns named 'true', 'false', 'yes', 'no' (case-insensitive) are cast to booleans. Maximum file size is 50MB.

Querying CSV data via REST

All SheetZAPI query parameters work on CSV data: ?_filter=country:eq:US, ?_sort=revenue, ?_search=acme, ?_fields=name,email,plan, ?_limit=100&_offset=0. Aggregation endpoints (/agg/sum?column=revenue, /agg/count) work on the full dataset without downloading it. Results are cached in Redis after the first request.

Keeping CSV data fresh

Re-upload a new CSV at any time to replace the dataset. Your API URL and key remain unchanged. Alternatively, use the POST /rows endpoint to add new rows programmatically, or PATCH /rows/:id to update individual rows. This lets you treat the uploaded CSV as a persistent, editable dataset rather than a static snapshot.

Frequently asked questions

How do I make a REST API from a CSV file?

Upload your CSV to SheetZAPI. Your data is instantly available as a REST API with filtering, sorting, and caching. No database or backend code required.

Can I query a CSV file via URL without building a backend?

Yes. SheetZAPI exposes your CSV as a REST endpoint with URL-based filtering and sorting. No backend, no parsing code, no infrastructure to manage.

How do I update CSV data via API?

POST to /rows to add rows, PATCH /rows/:id to update, DELETE /rows/:id to remove, or re-upload a new CSV to replace everything. Your API URL stays the same.

Is there a size limit for CSV uploads?

SheetZAPI accepts CSV files up to 50MB. For larger datasets, Google Sheets (up to 10 million cells) is a better source to connect rather than upload.

Turn your CSV into a live REST API

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