CSV slice rows

csv-slice-rows · version 1.0.0 · CSV & tables · free, no key needed

Take a contiguous window of CSV data rows by offset and limit, keeping the header.

Use when you need to: csv slice rows · slice csv rows · csv row window.

Supported

• csv slice rows
• slice csv rows
• csv row window

Not supported

• negative indexes
• wrap-around slicing
• sample random rows
• filter by key
• read files
• fetch urls

Behavior

• offset and limit are JSON integers with Number.isInteger; each is between 0 and 5000 inclusive.
• Data rows are sliced as the half-open interval [offset, offset + limit) without wrapping or negative-from-end indexes.
• If offset is past the last data row, the header is kept and zero data rows are returned.
• An empty document without a header is rejected; a header-only document returns the header and rows_out 0 for any valid offset and limit.
• Cell strings are preserved without trimming, case folding, or type coercion.
• 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
• offset (integer, required): min 0; max 5000
• limit (integer, required): min 0; max 5000

Output

• csv (string, required)
• rows_in (integer, required): min 0
• rows_out (integer, required): min 0

Limits

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

Example

Request input:

{
  "csv": "id,name\n1,Ada\n2,Lin\n3,Zoe\n",
  "offset": 1,
  "limit": 1
}

Response:

{
  "result": {
    "csv": "id,name\n2,Lin\n",
    "rows_in": 3,
    "rows_out": 1
  }
}

How to call it

MCP

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

{
  "id": "csv-slice-rows",
  "version": "1.0.0",
  "input": {
    "csv": "id,name\n1,Ada\n2,Lin\n3,Zoe\n",
    "offset": 1,
    "limit": 1
  }
}

HTTP (no key)

curl -X POST https://computefirst.net/v1/tools/csv-slice-rows/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"csv":"id,name\n1,Ada\n2,Lin\n3,Zoe\n","offset":1,"limit":1}'

The machine-readable contract is at /v1/tools/csv-slice-rows/versions/1.0.0.

CLI

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

Get the client at /clients/cli/.

Related tools

• CSV add row number: Prepend a 1-based row_number column of canonical integer strings.
• CSV row diff: Compare two CSV documents with identical headers by unique key tuples and report added, removed, and changed rows.
• CSV anti join: Keep left CSV rows whose exact key tuples do not appear in the right document.
• CSV concat: Concatenate CSV documents that share identical headers, preserving document and row order.
• CSV dedupe: Remove duplicate CSV data rows while preserving the first occurrence.
• CSV group count: Count CSV rows by exact named-column tuples in first-seen order.