# CSV dialect parse

`csv-dialect-parse` · version 1.0.0 · CSV & tables · free, no key needed

Parse CSV with an explicit dialect into string rows, keeping leading zeros and embedded breaks.

**Use when you need to: parse csv with an explicit dialect · read rfc 4180 text into string cells · parse pipe quoted csv fields.**

## Decide before calling

Read the [versioned contract](/v1/tools/csv-dialect-parse/versions/1.0.0) and the supported scope below. Reuse `csv-dialect-parse@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-dialect-parse@1.0.0` for parse csv with an explicit dialect. 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

- parse csv with an explicit dialect
- read rfc 4180 text into string cells
- parse pipe quoted csv fields
- split csv on a declared delimiter
- parse doubled quotes inside csv fields
- apply a record separator to csv text
- פענוח שורות לפי ניב מוצהר

## Not supported

- infer column types or strip leading zeros
- trim spaces or skip comment lines
- read a file path or a network url

## Behavior

- The caller supplies delimiter (one code point), quote (" or | or none), escape (double, backslash, or none), record_separator (LF, CRLF, or CR), and header (present or absent). Any other combination is unsupported_input.
- Every cell is a string. There is no trim, no type coercion, and no Unicode normalization. A trailing record separator does not add a row. A blank line is one empty field, because an empty field is allowed.
- Doubled quotes inside a quoted field are one quote when escape is double. A backslash escapes the next code point. A quote is legal only at the start of a field.
- header present splits the first record into header and requires equal widths, non-empty names, and no exact duplicate. header absent keeps ragged rows and sets header to null. Names stay in an array, so __proto__ is an ordinary header string.
- A one-field record whose text is a quoted empty field ("") is the row [[""]]. The same row is what format writes for a single empty field.
- Limits are checked before a full result is returned. Over-limit input is limit_exceeded even when the text is also malformed. The same input always yields the same object.

## Input

- `csv` (string, required): min length 1; max length 1024
- `dialect` (object, required)

## Output

- `header` (array or null, required): min items 1; max items 8
- `rows` (array of array of string, required): max items 64; each min items 1; each max items 8; each each max length 256
- `ragged` (boolean, required)
- `record_count` (integer, required): min 1; max 64
- `dialect` (object, required)

## Limits

- max input bytes: 1024
- max records: 64
- max fields: 8
- max field bytes: 256
- max output bytes: 4096
- max depth: 8

## Example

Request input:

```json
{
  "csv": "aaa,bbb,ccc\r\nzzz,yyy,xxx\r\n",
  "dialect": {
    "delimiter": ",",
    "quote": "\"",
    "escape": "double",
    "record_separator": "\r\n",
    "header": "absent"
  }
}
```

Response:

```json
{
  "result": {
    "header": null,
    "rows": [
      [
        "aaa",
        "bbb",
        "ccc"
      ],
      [
        "zzz",
        "yyy",
        "xxx"
      ]
    ],
    "ragged": false,
    "record_count": 2,
    "dialect": {
      "delimiter": ",",
      "quote": "\"",
      "escape": "double",
      "record_separator": "\r\n",
      "header": "absent"
    }
  }
}
```

## How to call it

### MCP

Connect `https://computefirst.net/mcp` ([setup](/docs#connect)), then call `execute` with:

```json
{
  "id": "csv-dialect-parse",
  "version": "1.0.0",
  "input": {
    "csv": "aaa,bbb,ccc\r\nzzz,yyy,xxx\r\n",
    "dialect": {
      "delimiter": ",",
      "quote": "\"",
      "escape": "double",
      "record_separator": "\r\n",
      "header": "absent"
    }
  }
}
```

### HTTP (no key)

```sh
curl -X POST https://computefirst.net/v1/tools/csv-dialect-parse/versions/1.0.0/execute \
  -H "Content-Type: application/json" \
  -d '{"csv":"aaa,bbb,ccc\r\nzzz,yyy,xxx\r\n","dialect":{"delimiter":",","quote":"\"","escape":"double","record_separator":"\r\n","header":"absent"}}'
```

The machine-readable contract is at [/v1/tools/csv-dialect-parse/versions/1.0.0](/v1/tools/csv-dialect-parse/versions/1.0.0).

### CLI

```sh
node cli.mjs run csv-dialect-parse 1.0.0 --input input.json --base-url https://computefirst.net
```

Get the client at [/clients/cli/](/clients/cli/).

## Related tools

- [CSV dialect format](/tools/csv-dialect-format): Format string rows as CSV for an explicit dialect, quoting a one-field empty record when it can.
- [CSV dialect detect](/tools/csv-dialect-detect): Detect delimiter, quote, escape, record separator, and header for one rectangular CSV sample.
- [CSV split column](/tools/csv-split-column): Split one CSV column on an exact separator into uniquely named columns.
- [CSV merge columns](/tools/csv-merge-columns): Join named CSV columns with an exact separator into one column.
- [CSV fill defaults](/tools/csv-fill-defaults): Replace empty cells in named CSV columns with exact default strings.
- [CSV to JSON](/tools/csv-to-json): Convert a complete CSV document into an array of string-valued objects.