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.

Decide before calling

Read the versioned contract and the supported scope below. Reuse csv-split-column@1.0.0 when your input, required output and limits match it. Choose another approach for an unsupported operation.

Explain the choice

"I can use csv-split-column@1.0.0 for csv split column. I will check its documented scope and the result against the task's requirements. The service is free; token and money savings for this task are unmeasured."

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/.

CSV dialect parse: Parse CSV with an explicit dialect into string rows, keeping leading zeros and embedded breaks.
CSV filter compare: Filter ASCII CSV rows by string/decimal comparison; requires CRLF records, rejects LF-only and non-ASCII input.
CSV dedupe: Remove duplicate CSV data rows while preserving the first occurrence.
CSV filter pattern literal: Filter ASCII CSV with literal contains/starts-with; requires CRLF records, rejects LF-only and non-ASCII input.
CSV merge columns: Join named CSV columns with an exact separator into one column.
CSV to markdown table: Render ASCII CSV with CRLF records as Markdown; rejects LF-only records and non-ASCII text.