CorrectICS API

Validate and inspect .ics (iCalendar) files using simple HTTP endpoints. You can self-host the documentation via the OpenAPI spec or start with the examples below.

Base URL: https://api.correctics.com

Download OpenAPI 3.0 Spec Try the Web Tool

Quickstart

curl -X POST https://api.correctics.com/api/validate \
  -H "Authorization: Bearer <API_KEY>" \
+  -H "Content-Type: text/calendar" \
  --data-binary @calendar.ics

const body = /* string or Buffer of file contents */ '';

const res = await fetch('https://api.correctics.com/api/validate', {
  method: 'POST',
  headers: {
    'Content-Type': 'text/calendar',
    'Authorization': 'Bearer <API_KEY>',
  },
  body,
});
const data = await res.json();

import requests
headers = {
  'Content-Type': 'text/calendar',
    'Authorization': 'Bearer <API_KEY>',
}
data = open('calendar.ics','rb').read()
r = requests.post('https://api.correctics.com/api/validate', data=data, headers=headers)
print(r.json())

Common behaviour

• Free tier rate limit: 5 requests/minute per IP, enforced via Durable Object.
• All responses include X-Request-Id — reference it if you contact support.
• Validation failures return HTTP 422 with stage, errors[], and warnings[].
• Rate limit breaches return HTTP 429 with Retry-After, X-RateLimit-Limit, and X-RateLimit-Remaining.
• ICS payloads are processed in memory and not persisted; logs only retain request metadata.

POST /api/validate

Validate a single ICS payload supplied as text/calendar or text/plain, or upload via multipart/form-data using a file field. Add query params or headers to enable autofix behaviour.

curl -X POST https://api.correctics.com/api/validate \
  -H "Content-Type: text/plain" \
  --data-binary @calendar.ics

{
  "ok": true,
  "stage": "rules",
  "policy": "rfc",
  "errors": [],
  "warnings": []
}

{
  "ok": false,
  "stage": "rules",
  "policy": "rfc",
  "errors": [
    { "code": "RFC.EVENT.DTSTART_MISSING", "severity": "fatal", "message": "VEVENT is missing DTSTART" }
  ],
  "warnings": []
}

POST /api/validate-bulk

Validate multiple ICS files by uploading a ZIP archive. The same query params/headers as the single endpoint apply to every file.

• Maximum 50 files per archive.
• Maximum 5 MiB total uncompressed size.
• Only entries ending in .ics are processed (others ignored).

zip calendars.zip a.ics b.ics
curl -X POST https://api.correctics.com/api/validate-bulk \
  -H "Content-Type: application/zip" \
  --data-binary @calendars.zip

The response aggregates per-file results:

{
  "ok": false,
  "stage": "bulk",
  "counts": { "total": 2, "ok": 1, "failed": 1 },
  "files": [
    { "name": "a.ics", "status": 200, "result": { "ok": true, "errors": [] } },
    { "name": "b.ics", "status": 422, "result": { "ok": false, "errors": [{ "code": "RFC.VERSION.MISSING" }] } }
  ]
}

Error reference

Engineering notes

Short notes on iCalendar edge cases, RFC interpretation, and real-world calendar interoperability.

View notes

Next steps

Higher plan limits, API keys, and webhook integrations are on the roadmap. Submit issues and requests on the repo for updates or drop us a note via the contact form.

OpenAPI (machine-readable): /docs/openapi.yaml