CSV drop columns

csv-drop-columns · version 1.0.0 · CSV & tables · free, no key needed

Drop named CSV columns and keep the remaining columns in original header order.

Use when you need to: csv drop columns · drop csv columns · remove csv columns.

Supported

• csv drop columns
• drop csv columns
• remove csv columns

Not supported

• rename columns
• reorder remaining columns
• fuzzy header matching
• drop rows
• read files
• fetch urls

Behavior

• columns is a unique non-empty list of existing header names to remove.
• At least one header must remain; remaining columns stay in original header order.
• Cell strings of kept columns are preserved without trimming, case folding, or type coercion.
• An empty document without a header is rejected; a header-only document drops columns and keeps zero data rows.
• The first output header name may not begin with U+FEFF because it is ambiguous with a CSV byte-order mark.

Input

• csv (string, required): max length 256000
• columns (array of string, required): min items 1; max items 256; each min length 1

Output

• csv (string, required)

Limits

• max input bytes: 256000
• max data rows: 5000
• max columns: 256
• max header name bytes: 256
• max dropped columns: 256
• max output bytes: 256000

Example

Request input:

{
  "csv": "id,name,secret,note\n1,Ada,hidden,\"hello, world\"\n",
  "columns": [
    "secret"
  ]
}

Response:

{
  "result": {
    "csv": "id,name,note\n1,Ada,\"hello, world\"\n"
  }
}

How to call it

MCP

Connect https://computefirst.net/mcp (setup), then call execute with:

{
  "id": "csv-drop-columns",
  "version": "1.0.0",
  "input": {
    "csv": "id,name,secret,note\n1,Ada,hidden,\"hello, world\"\n",
    "columns": [
      "secret"
    ]
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/csv-drop-columns/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"csv":"id,name,secret,note\n1,Ada,hidden,\"hello, world\"\n","columns":["secret"]}'

The machine-readable contract is at /v1/tools/csv-drop-columns/versions/1.0.0.

CLI

node cli.mjs run csv-drop-columns 1.0.0 --input input.json --base-url https://computefirst.net

Get the client at /clients/cli/.

Related tools

• CSV dedupe: Remove duplicate CSV data rows while preserving the first occurrence.
• CSV fill defaults: Replace empty cells in named CSV columns with exact default strings.
• CSV filter empty: Keep or drop CSV rows whose named column is the empty string.
• CSV group count: Count CSV rows by exact named-column tuples in first-seen order.
• CSV merge columns: Join named CSV columns with an exact separator into one column.
• CSV rename columns: Rename CSV headers by an exact from/to mapping, preserving row cells and column order.