YJTOON API: Rate Limits, Fair Use, and How to Stay Inside Them

YJTOON is free and unauthenticated. To keep it that way, we apply a small set of rate limits based on source IP and User-Agent. This post explains exactly what they are and how to design around them.

Limits in numbers

• 60 requests per minute per IP for the /api/ routes.
• 600 requests per hour per IP overall (covers all endpoints).
• No daily quota. Above the hour ceiling you get a soft 429 for the rest of the hour.

The 429 response

429 bodies are JSON with error, retry_after_seconds, and a request_id for support. Always log the request id if you open a ticket.

Patterns that work

• Cache aggressively. Most YJTOON data changes monthly at most.
• Use the static /static-data/ files for cold paths (one GET, no rate limit).
• Set a User-Agent that includes a contact URL. We whitelist known good agents on request.

What we do not do

• We do not require API keys.
• We do not log request bodies, only metadata.
• We do not serve ads or trackers.

If you hit a wall, open an issue with the request_id from the 429. Most limits can be lifted for a known agent within a day.