Spreadsheet Automation & AI Workflows
Arte Sheets AI Assistant File Attachments: Safe .xlsx/.csv/.tsv/.txt Excerpts & Size Limits
Attach .xlsx, .csv, .tsv, or .txt reference files (up to 2 MB) to the Arte Sheets AI Assistant: understand isolated Web Worker parsing, zero macro/formula execution, and excerpt row/byte caps.
How isolated Web Worker parsing inspects reference files safely without executing macros or formulas!
When you attach a file in the Arte Sheets AI Assistant (available on eligible accounts with a verified email and metered monthly credits), the browser validates that the filename ends in .xlsx, .csv, .tsv, or .txt and does not exceed 2 MB (2,097,152 bytes), then parses it inside a dedicated Web Worker with a 15-second timeout — completely isolated from grid rendering and without ever executing embedded spreadsheet formulas or macros!
For .xlsx workbooks, the worker first validates the ZIP archive header (at most 500 entries and 20 MB uncompressed total), then extracts plain-text cell values across at most the first 3 worksheets, up to 100 rows by 12 columns per sheet (300 characters per cell) and at most 150 row lines total. The worker caps the preview at 12,000 characters, and the request builder trims the attached excerpt to at most 7,000 UTF-8 bytes so the entire request context stays within 23,000 bytes (alongside your active selection).
| Attachment Guardrail in Arte Sheets | Enforced Limit | Practical Workflow Tip |
|---|---|---|
| Supported File Types & Raw Upload Size | .xlsx, .csv, .tsv, .txt <= 2 MB (2,097,152 bytes) | Export narrow summary extracts rather than multi-megabyte raw dumps |
| .xlsx Archive & Sheet Window | <= 500 ZIP entries, <= 20 MB uncompressed, first 3 sheets | Place reference tables on Sheets 1–3 in columns A:L (<= 12 cols) |
| .xlsx Row & Line Excerpt Window | <= 100 rows/sheet, <= 150 lines total, <= 300 chars/cell | Keep lookup headers and key rows within rows 1–100 |
| Prompt Excerpt & Total Context Payload | <= 12,000 chars worker preview; <= 7,000 UTF-8 bytes sent (<= 23 KB total) | Expand the attached preview card in the dialog to inspect exact extracted text |
Attachment Upload Eligibility & .xlsx Row-Coverage Audit Formula
Checks whether a candidate reference file’s extension (B2), byte size (B3 <= 2,097,152), sheet index (B4 <= 3), row count (B5 <= 100), and column count (B6 <= 12) fit cleanly inside the AI Assistant’s full .xlsx excerpt window without truncation.
=IF(OR(AND(LOWER(TRIM(B2 & "")) <> "xlsx", LOWER(TRIM(B2 & "")) <> "csv", LOWER(TRIM(B2 & "")) <> "tsv", LOWER(TRIM(B2 & "")) <> "txt"), B3 <= 0, B3 > 2097152), "Rejected: Must Be .xlsx/.csv/.tsv/.txt <= 2 MB", IF(AND(LOWER(TRIM(B2 & "")) = "xlsx", OR(B4 > 3, B5 > 100, B6 > 12)), "Accepted as Partial Excerpt (First 3 Sheets, 100x12 Cells, <=7 KB Sent)", "Accepted: Full Table Fits Within Worker Excerpt Window"))Percentage of .xlsx Sheet Rows Captured in the First-Sheet 100-Row Excerpt
Computes ROUND(100 * MIN(B5, 100) / B5, 1) so analysts see what share of a single-sheet .xlsx export is visible to the assistant before trimming.
=IF(B5 <= 0, "Invalid Row Count", ROUND(100 * MIN(B5, 100) / B5, 1))Try the example
Use the original values or change them to test your understanding.