API

Base URL: https://spincrus.uz/api. All endpoints accept and return JSON. Send your key in the x-api-key header. Without a key you get 100 calls per day per tool from one IP address.

Authentication & limits

Plan	Daily calls	Burst	How to get
Free	100 per tool	10 req/s	No key needed
Pro	50,000	10 req/s	Subscribe, then claim your key in the app or by email

Every response carries x-ratelimit-limit and x-ratelimit-remaining. Over the limit → HTTP 429 with an upgrade link.

Endpoints

GET /v1/tools — list tools with their input schema.

`POST /v1/tools/cron-expression-explainer`

Paste any cron expression and get a plain-English explanation instantly. Supports ranges, steps, lists and @daily/@hourly aliases.

Field	Type	Required
`expression`	string	yes

curl -X POST https://spincrus.uz/api/v1/tools/cron-expression-explainer -H "content-type: application/json" -d '{"expression":"0 9 * * 1-5"}'

Response:

{
  "ok": true,
  "result": {
    "expression": "0 9 * * 1-5",
    "description": "At 09:00 on Monday through Friday.",
    "fields": {
      "minute": "0",
      "hour": "9",
      "dayOfMonth": "*",
      "month": "*",
      "dayOfWeek": "1-5"
    }
  }
}

`POST /v1/tools/readability-checker`

Free readability score calculator: Flesch Reading Ease, Flesch-Kincaid grade, Gunning Fog and ARI, plus word count and reading time.

Field	Type	Required
`text`	text	yes

curl -X POST https://spincrus.uz/api/v1/tools/readability-checker -H "content-type: application/json" -d '{"text":"The quick brown fox jumps over the lazy dog. It was a sunny day and everyone was happy."}'

Response:

{
  "ok": true,
  "result": {
    "words": 18,
    "sentences": 2,
    "syllables": 24,
    "characters": 68,
    "complexWords": 1,
    "avgWordsPerSentence": 9,
    "readingTimeSec": 5,
    "fleschReadingEase": 84.9,
    "fleschKincaidGrade": 3.7,
    "gunningFog": 5.8,
    "automatedReadabilityIndex": 0.9,
    "level": "Easy (6th grade)"
  }
}

`POST /v1/tools/json-to-csv`

Convert JSON arrays to CSV online. Nested objects are flattened with dot notation, quotes are escaped correctly, works with large files.

Field	Type	Required
`json`	json	yes
`delimiter`	string	no

curl -X POST https://spincrus.uz/api/v1/tools/json-to-csv -H "content-type: application/json" -d '{"json":"[{\"id\":1,\"user\":{\"name\":\"Ada\"}},{\"id\":2,\"user\":{\"name\":\"Linus\"}}]"}'

Response:

{
  "ok": true,
  "result": {
    "csv": "id,user.name\n1,Ada\n2,Linus",
    "rows": 2,
    "columns": [
      "id",
      "user.name"
    ]
  }
}

Errors

400 invalid input (message in error), 401 bad key, 404 unknown tool, 429 limit reached, 500 our fault — retry.