curl --request POST \
  --url https://api.iotools.cloud/v1/tool/regex-explainer \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "pattern": "^\\d{3}-\\d{4}$",
  "flagGlobal": "",
  "flagIgnoreCase": "",
  "flagMultiline": "",
  "flagDotAll": "",
  "flagUnicode": ""
}
'

{
  "tool": "regex-explainer",
  "tool_version": "1.0.1",
  "outputs": {
    "summary": "Matches the start of the string, then any digit (0–9) — exactly 3 times, then the character \"-\", then any digit (0–9) — exactly 4 times, then the end of the string.",
    "breakdown": [
      {
        "token": "^",
        "kind": "Anchor",
        "meaning": "The start of the string"
      },
      {
        "token": "\\d{3}",
        "kind": "Quantified character shorthand",
        "meaning": "Any digit (0–9) — exactly 3 times"
      },
      {
        "token": "-",
        "kind": "Literal character",
        "meaning": "The character \"-\""
      },
      {
        "token": "\\d{4}",
        "kind": "Quantified character shorthand",
        "meaning": "Any digit (0–9) — exactly 4 times"
      },
      {
        "token": "$",
        "kind": "Anchor",
        "meaning": "The end of the string"
      }
    ]
  },
  "credits_used": 3,
  "credits_remaining": null
}