REST API · v1

Use the FileToolz text tools from your own code.

Word and character counting, case conversion, and CSV conversion over plain HTTP. Keys are issued only to signed-in accounts, so every call runs as a real user.

Get an API key Browse endpoints

Every endpoint requires an API key. Keys belong to a FileToolz account and are created while signed in on the API keys page. Requests without a valid key get 401 invalid_api_key.

Quick start

Three steps, no SDK required.

Sign in or create a FileToolz account.
Open API keys and create a key. It is shown once — store it somewhere safe.
Send it on every request as Authorization: Bearer <key>.

curl https://api.filetoolz.online/v1/word-count \
  -H "Authorization: Bearer ftz_your_key_here" \
  -H "Content-Type: application/json" \
  -d '{"text":"Count the words in this sentence."}'

{
  "ok": true,
  "data": {
    "characters": 33,
    "charactersWithoutSpaces": 27,
    "words": 6,
    "lines": 1,
    "paragraphs": 1
  }
}

Authentication

Send the key either way; both are accepted.

Header	Example
Authorization	`Authorization: Bearer ftz_…`
x-api-key	`x-api-key: ftz_…`

Keys are stored hashed. Only a SHA-256 hash is kept in the database, so a key cannot be read back or recovered — if you lose one, revoke it and create another. Revoking takes effect on the next request.

Endpoints

Base URL https://api.filetoolz.online/v1. All responses are JSON with an ok flag; everything is POST apart from the health check. POST bodies accept JSON, or raw text/plain for the single-field endpoints.

GET /v1/health

Confirms a key works and returns the account it belongs to. Nothing is stored or changed.

curl https://api.filetoolz.online/v1/health \
  -H "Authorization: Bearer ftz_your_key_here"

POST /v1/word-count

Counts characters, characters without spaces, words, lines and paragraphs. Words are split on whitespace; blank lines count as paragraphs separators, not paragraphs.

curl https://api.filetoolz.online/v1/word-count \
  -H "Authorization: Bearer ftz_your_key_here" \
  -H "Content-Type: application/json" \
  -d '{"text":"Hello there."}'

POST /v1/case-convert

Converts text to another case. Modes: upper, lower, title, sentence, slug. Defaults to upper.

curl https://api.filetoolz.online/v1/case-convert \
  -H "Authorization: Bearer ftz_your_key_here" \
  -H "Content-Type: application/json" \
  -d '{"text":"hello world","case":"title"}'

POST /v1/text-to-csv

Turns plain text into CSV. One line becomes one row; fields split on whitespace by default, or on the single character you pass as inputSeparator. Fields containing the output separator, quotes or newlines are quoted per RFC 4180.

curl https://api.filetoolz.online/v1/text-to-csv \
  -H "Authorization: Bearer ftz_your_key_here" \
  -H "Content-Type: application/json" \
  -d '{"text":"a b c\nd e f","columns":["one","two","three"]}'

POST /v1/csv-to-text

Parses CSV (quoted fields, doubled quotes, CRLF, newlines inside quotes) into tab-separated text, or into records with "format":"json".

curl https://api.filetoolz.online/v1/csv-to-text \
  -H "Authorization: Bearer ftz_your_key_here" \
  -H "Content-Type: application/json" \
  -d '{"text":"name,role\n\"Doe, Jane\",\"writer\"","format":"json","header":true}'

Parameters

Endpoint	Field	Meaning
word-count	text	Required. Up to 200,000 characters.
case-convert	text, case	Required text; optional mode, default upper.
text-to-csv	inputSeparator	whitespace (default), tab, or a single character.
text-to-csv	separator	Output column separator, default a comma.
text-to-csv	columns	Optional array of header names.
text-to-csv	eol	Row ending, \r\n (default) or \n.
csv-to-text	delimiter	Input delimiter, default a comma.
csv-to-text	outputSeparator	tab (default) or a single character.
csv-to-text	format, header	text (default) or json; header uses row 1 as keys.

Errors

Failures use the same envelope, with ok: false and a machine-readable code.

{
  "ok": false,
  "error": {
    "code": "invalid_api_key",
    "message": "That API key is not valid or has been revoked."
  }
}

Status	Code	When
400	missing_field / invalid_field	A required field is missing or has the wrong type.
400	invalid_json	The JSON body could not be parsed.
400	empty_text	CSV input contained no data.
401	missing_api_key	No key was sent.
401	invalid_api_key	The key is unknown or has been revoked.
405	method_not_allowed	Wrong HTTP method for the endpoint.
413	payload_too_large / text_too_large	Body over 1 MB, or text over 200,000 characters.
502	auth_upstream_error	Key verification was temporarily unavailable.

Need a tool that is not here yet? The file conversions (PDF, Word, images) still run in the browser at simtools.filetoolz.online.