CSV split column

csv-split-column · version 1.0.0 · CSV & tables · free, no key needed

Split one CSV column on an exact separator into uniquely named columns.

Use when you need to: csv split column · split a csv column by exact separator · expand csv column into named columns.

Supported

• csv split column
• split a csv column by exact separator
• expand csv column into named columns

Not supported

• regex split
• infer column names
• trim cells
• limit split parts without throwing
• fuzzy matching
• read files
• fetch urls

Behavior

• The first CSV record is the header row. An empty document is rejected; a header-only document yields the replaced headers and zero data rows.
• column must name an existing header exactly. separator is a non-empty literal string of at most 16 UTF-16 code units, never a regular expression.
• Each data cell is split with String.prototype.split(separator). More parts than names.length is rejected; fewer parts are padded with empty strings on the right.
• names is 2 to 16 unique non-empty headers. A name may equal column (in-place replacement) but must not equal any other remaining header.
• The original column is replaced in place by names, in names order. No trimming, case folding, or type coercion is performed.
• 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
• column (string, required): min length 1; max length 256
• separator (string, required): min length 1; max length 16
• names (array of string, required): min items 2; max items 16; each min length 1; each max length 256

Output

• csv (string, required)

Limits

• max input bytes: 256000
• max data rows: 5000
• max columns: 256
• max header name bytes: 256
• min names: 2
• max names: 16
• max separator chars: 16
• max output bytes: 256000

Example

Request input:

{
  "csv": "city,name\nLondon,Ada Lovelace\nParis,Grace Hopper\n",
  "column": "name",
  "separator": " ",
  "names": [
    "first",
    "last"
  ]
}

Response:

{
  "result": {
    "csv": "city,first,last\nLondon,Ada,Lovelace\nParis,Grace,Hopper\n"
  }
}

How to call it

MCP

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

{
  "id": "csv-split-column",
  "version": "1.0.0",
  "input": {
    "csv": "city,name\nLondon,Ada Lovelace\nParis,Grace Hopper\n",
    "column": "name",
    "separator": " ",
    "names": [
      "first",
      "last"
    ]
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/csv-split-column/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"csv":"city,name\nLondon,Ada Lovelace\nParis,Grace Hopper\n","column":"name","separator":" ","names":["first","last"]}'

The machine-readable contract is at /v1/tools/csv-split-column/versions/1.0.0.

CLI

node cli.mjs run csv-split-column 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 merge columns: Join named CSV columns with an exact separator into one column.
• CSV filter equals: Keep CSV data rows whose named column equals an exact string.
• CSV group count: Count CSV rows by exact named-column tuples in first-seen order.
• CSV scale integer column: Multiply every data cell in a named CSV column by a canonical integer factor.
• CSV schema check: Validate a CSV document against an ordered column list and per-column string constraints.