mcp-spreadsheet

mcp-spreadsheet

Hand your AI assistant a spreadsheet and talk to it. Point it at any .xlsx, .xlsm, .xlsb, .xls, .ods, .csv or .tsv file on your machine and ask what is in it, filter it, compute a new column, or save it in another format. It handles the messy parts of real files for you: it guesses which row holds the headers, sniffs whether a CSV is separated by commas, semicolons or tabs, keeps quoted commas and newlines intact, reads numbers out of $1,250.00 style text, and reports per-column types and empty counts. It never edits your original file: every write goes to a new path unless you explicitly choose overwrite. Nothing leaves the machine, and there is no API key to get.

Read, query and extend real spreadsheets from chat without ever touching the original file.

60-second install

npm publish for @theluckystrike/mcp-spreadsheet is pending. Until then, the .mcpb one-click bundle or a clone+buildis the working path -- both are verified below.

One-click (.mcpb): download spreadsheet.mcpb from the latest release and double-click it in Claude Desktop:https://github.com/theluckystrike/mcp-servers/releases/latest

Claude Desktop (claude_desktop_config.json):

{
  "mcpServers": {
    "spreadsheet": {
      "command": "npx",
      "args": ["-y", "@theluckystrike/mcp-spreadsheet"]
    }
  }
}

Claude Code:

claude mcp add spreadsheet -- npx -y @theluckystrike/mcp-spreadsheet

Cursor (.cursor/mcp.json):

{
  "mcpServers": {
    "spreadsheet": {
      "command": "npx",
      "args": ["-y", "@theluckystrike/mcp-spreadsheet"]
    }
  }
}

The npx form above starts working the moment the package is published. Until then, use the .mcpb bundle above, orbuild from source with exactly these three commands:

git clone https://github.com/theluckystrike/mcp-servers.git && cd mcp-servers
npm install
npm run build -w packages/mcp-license -w servers/spreadsheet

Then point your client's command at node with one arg: the absolute path to servers/spreadsheet/dist/index.js.

To run in Pro mode set MCP_LICENSE_KEY in the same config block, or call license_activate once with your key.

Tools

Resource template: sheet://<path> returns the sheet_info summary for that file.

What you can say

Worked example

From docs/USER_VALUE_R2.md, a 400-row fixture with a title row and a blank row above the real header(row 3), sheets Sales / Reps / Notes, prices stored as strings like "1,516.16". One call, groundtruth confirmed against the generator: Turing 650, Hopper 567, Linus T 551, Lovelace 486, Liskov 290.

You: Which rep sold the most units in the North region? Top 5 with totals.

  sheet_query {
    path: "/Users/you/sales.xlsx", sheet: "Sales",
    where: "[Region] = \"North\"",
    group_by: ["Rep"],
    aggregate: [{ col: "Units", fn: "sum", as: "total_units" }],
    sort: { col: "total_units", dir: "desc" },
    limit: 5
  }

Assistant: Query: where [Region] = "North"; group by Rep; sum Units as total_units;
sort total_units desc; limit 5
5 groups from 102 of 400 rows, showing 5

Alan Turing     650
Grace Hopper    567
Linus T         551
Ada Lovelace    486
Barbara Liskov  290

The response now echoes the exact query it ran (the Query: line) before the numbers, so a filter youdid not ask for -- an accidental AND [Status] = "Closed", say -- is visible instead of silentlynarrowing the answer.

A second example, adding a column and saving without touching the source:

You: Add a Revenue column and save it as a CSV next to the original.

  sheet_add_column {
    path: "/Users/you/sales.xlsx", sheet: "Sales",
    name: "Revenue", formula: "[Units] * [Unit Price]",
    out_path: "/Users/you/sales.csv"
  }

Assistant: Wrote 400 rows (401 lines with header) to sales.csv.
Revenue = Units * Unit Price on every row, total 10,142,542.04.
Source file untouched.

The where and formula language

A small expression language, parsed and evaluated directly. There is no eval and no code execution: a bare word is always a column name, never a JavaScript value.

• Columns: [Unit Price] for names with spaces, Qty otherwise. Lookup is case insensitive.
• Comparisons: = != > >= < <= contains startswith endswith
• Logic: AND OR NOT and parentheses. AND binds tighter than OR.
• Arithmetic in formulas: + - * % / with the usual precedence.
• Strings: 'single' or "double" quotes; double a quote to escape it.

[Qty] >= 5 AND ([Status] = "open" OR [Region] contains "north")
[Amount] > 1000 AND NOT [Customer] startswith 'Test'

Formula example for sheet_add_column: [Qty] * [Unit Price].

Text comparisons ignore case and surrounding whitespace. Values like $1,250.00, 1 250, and 12% compare as numbers, so [Amount] > 1000 works on a column your spreadsheet stored as text.

Free vs Pro

Over a free read limit the tool still does the work and returns the part it is allowed to return (the first 5,000 rows), with a note saying what was left out. Over the free write limit nothing at all is written: a partial file that looks complete is worse than no file, so the tool refuses, tells you the row count and the cap, and suggests a free workaround (filter the rows down first, or write in 500-row batches). Nothing fails silently.

Get Pro

$19 one-time for this server, $39 for every server, lifetime: https://mcp.zovo.one/buy/spreadsheet

How it stores data

This server keeps no database of its own -- it reads and writes the spreadsheet files you point it at,directly on your disk, and nothing else. Every write (sheet_write, sheet_add_column, sheet_convertin overwrite mode) goes to a temporary file in the same directory first, then is renamed into place, soan interrupted write leaves either the untouched original or the complete new file, never a truncatedone. Because there is no shared state file, there is no advisory lock to take: two calls writing to twodifferent output paths cannot collide, and a call to overwrite the same file twice in a row is simplytwo writes in sequence. To back up your data, back up the spreadsheet files themselves -- there isnothing else to copy.

Limits and honest caveats

• Free reads cap at 5,000 rows and 5 MB; free writes cap at 500 rows per file and refuse rather thantruncate -- you get an error naming the row count and the cap, never a shorter file that lookscomplete.
• The hard ceiling is 50 MB regardless of tier; a file over that is refused outright with a clear messagerather than risking memory exhaustion.
• The where/formula language is intentionally small: no regular expressions, no custom functions,no cross-sheet references in a single formula. It covers comparisons, boolean logic and arithmetic,nothing more.
• sheet_info's header-row guess is a heuristic (looks for the first row with lower emptiness and highertext density than the rows above it). It handles a title row and a blank row above the header; it isnot proof against every layout, and you can always confirm what it picked before querying.

Troubleshooting

• npx hangs or fails to find the package: npm publish for this package is pending. Use the .mcpbbundle or the clone-and-build path above until it lands.
• Using the .mcpb bundle: it installs into Claude Desktop directly; there is no separate configstep.
• Using the clone path: the server binary is servers/spreadsheet/dist/index.js afternpm run build. Point your client's command at node with that absolute path as the only argument.
• Node version: requires Node >= 18. Check with node -v.
• "Path does not exist": the message includes the resolved absolute path (with ~ expanded) -- checkit against where the file actually lives, especially inside a sandboxed or containerized client.
• A write is refused with a row-count message: you hit the free 500-row write cap. Filter the datadown with sheet_query first, write in batches, or activate Pro.
• Nothing shows up / silent failures: logs go to stderr only, never stdout. In Claude Desktop checkSettings -> Developer -> the server's log file; in Claude Code check the terminal or --mcp-debug.

Safety

• Paths that do not exist are refused with the resolved path in the message; ~ is expanded.
• Files over 50 MB are refused with a clear message rather than exhausting memory.
• sheet_add_column and sheet_convert write to a new file and refuse to clobber an existing one unless you pass out_path yourself.
• sheet_write with mode: "new_file" refuses to write over an existing file. Only mode: "overwrite" replaces file contents.
• Output files are written to a temporary name and renamed into place, so an interrupted write cannot truncate a file.

Privacy

All data stays local. Files are read from and written to your own disk, license keys are verified offline with an embedded public key, and the server makes no network requests at all.

Pairs with

• mcp-time-tracker -- export a CSV with export_csv, then query and reshape it here.
• mcp-invoice -- pull line items out of a spreadsheet before turning them into an invoice.
• mcp-price-tracker -- analyze exported price history as a sheet.
• office-suite -- all four servers behind one install, one config entry.
• Guide: Ask questions about an Excel or CSV file from Cursor or Claude

FAQ

Does it handle a spreadsheet with a title row above the headers?Yes. sheet_info guesses the header row and reports which row it picked, so an export with a title lineand a blank line above the real headers opens correctly without you specifying anything.

Can it group and sum, or does it only filter?It groups. sheet_query takes group_by plus aggregate with sum, count, avg, min or max, and can sortby an aggregate alias, so top-N-by-category questions are a single call.

Will it overwrite my original file?No, not unless you explicitly pass an output path that points at the source. sheet_add_column andsheet_convert write a new file next to the original by default.

What happens on the free tier with a file bigger than the limit?Reads return the first 5,000 rows with a note naming what was omitted. Writes over 500 rows are refusedoutright rather than producing a truncated file, and the message tells you the row count, the cap and afree way round.

Is my data sent anywhere?No. The server runs locally on your machine and reads your files directly. It makes no network requests,and it stores nothing of its own beyond the files you ask it to write.

Built by theluckystrike. Support: [email protected]