Messenger error 613: API calls exceeded the rate limit

Code 613 with subcode 2534040 is the Messenger Platform's explicit per-API throttle: "Calls to this api have exceeded the rate limit," with Meta's remedy stated just as plainly, "your app has reached the rate limit. Pause API calls and try again later." It is the subcoded, Messenger-specific sibling of the bare 613, and in the current error-codes table it is listed in the context of the Instagram and Messenger messaging APIs, where per-second and per-Page ceilings are documented individually.

The ceilings that matter: the Send API accepts 300 calls per second per Page for messages containing text, links, reactions and stickers, but only 10 per second for audio or video content; the conversations API allows 2 calls per second per Page; private replies to post comments are capped at 750 calls per hour. Meta also documents that an app "may be rate limited if too many messages are being sent to a single thread," a per-conversation throttle with no published number, which is the one that catches bots streaming long answers as many rapid messages to one person.

Handling is the standard discipline: pause, back off with jitter, resume slowly. What distinguishes 2534040 from the app-wide code 4 is scope, other Pages and other endpoints keep working, so your limiter should isolate the affected Page or endpoint rather than halting globally.

{
  "error": {
    "message": "(#613) Calls to this api have exceeded the rate limit.",
    "type": "OAuthException",
    "code": 613,
    "error_subcode": 2534040,
    "fbtrace_id": "BLBz/WZt8dN"
  }
}

Encode the documented ceilings as constants in one shared limiter and keep a comfortable margin, 80% is a good line, since your clock and Meta's never quite agree. Give media its own budget. Treat the single-thread throttle as a UX hint: users prefer one coherent message to a burst anyway. All numbers are tabulated with sources in the Messenger limits reference; symptom-first debugging is in the troubleshooting guide.