CSV distinct values

csv-distinct-values · version 1.0.0 · CSV & tables · free, no key needed

List distinct exact values of one CSV column in first-seen order.

Use when you need to: csv distinct values · unique csv column values · distinct column.

Decide before calling

Read the versioned contract and the supported scope below. Reuse csv-distinct-values@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-distinct-values@1.0.0 for csv distinct values. 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 distinct values
• unique csv column values
• distinct column

Not supported

• sort
• case fold
• trim
• numeric unique

Behavior

• The first CSV record is the header row.
• Duplicate and empty header names are rejected.
• column is an exact header name.
• values lists first-seen exact cell strings from that column, including empty string if present.
• No trimming, case folding, type coercion, or other normalization is performed.
• A header-only or empty-data document yields values [].
• An empty document with a column request is invalid.

Input

• csv (string, required): max length 256000
• column (string, required): min length 1; max length 256

Output

• values (array of string, required)
• rows_in (integer, required)
• distinct (integer, required)

Limits

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

Example

Request input:

{
  "csv": "k\na\nb\na\n",
  "column": "k"
}

Response:

{
  "result": {
    "values": [
      "a",
      "b"
    ],
    "rows_in": 3,
    "distinct": 2
  }
}

How to call it

MCP

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

{
  "id": "csv-distinct-values",
  "version": "1.0.0",
  "input": {
    "csv": "k\na\nb\na\n",
    "column": "k"
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/csv-distinct-values/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"csv":"k\na\nb\na\n","column":"k"}'

The machine-readable contract is at /v1/tools/csv-distinct-values/versions/1.0.0.

CLI

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

Get the client at /clients/cli/.

Related tools

• Table count distinct check: Check a claimed COUNT(DISTINCT) and optional distinct-value list over JSON rows; returns the first mismatch.
• CSV abs integer column: Replace every data cell in a named CSV column with the absolute value of a canonical integer.
• CSV clamp integer column: Clamp every data cell in a named CSV column to optional canonical integer min and max bounds.
• CSV filter compare: Filter ASCII CSV rows by string/decimal comparison; requires CRLF records, rejects LF-only and non-ASCII input.
• CSV filter equals: Keep CSV data rows whose named column equals an exact string.
• CSV filter pattern literal: Filter ASCII CSV with literal contains/starts-with; requires CRLF records, rejects LF-only and non-ASCII input.