PromoClock API: Claude peak hours

A free JSON API that tells you whether Claude is in peak hours right now, when session limits drain faster, and when that changes next. Status lines, shell prompts, menu bar apps and bots use it.

GET https://promoclock.co/api/status

No key, no account. Free for non-commercial use under the API terms.

PromoClock started as a live clock for Claude's peak hours. The site at promoclock.co has since grown into a hub for AI tool deals, and its source is no longer public. This repository holds what you need for the API: documentation, terms, the endpoint's code and its contract tests.

Quick start

curl -s -A "my-app/1.0 (+https://github.com/me/my-app)" https://promoclock.co/api/status | jq -r '"\(.emoji) \(.label)"'

🟢 Off-Peak — Normal Speed

Response

{
  "status": "off_peak",
  "isPeak": false,
  "isOffPeak": true,
  "isWeekend": false,
  "sessionLimitSpeed": "normal",
  "emoji": "🟢",
  "label": "Off-Peak — Normal Speed",
  "peakHours": "Weekdays 1pm–7pm UTC / 6:00 AM–12:00 PM PDT",
  "nextChange": "2026-10-21T13:00:00.000Z",
  "minutesUntilChange": 192,
  "timestamp": "2026-10-21T09:47:27.373Z",
  "utcHour": 9,
  "utcDay": 3,
  "note": "No known end date for peak hours adjustment. Weekly limits unchanged."
}

Field names and types are stable, and the contract tests guard them. The text in label, peakHours and note may change, so don't parse it; use the boolean and date fields instead.

Peak hours

• Peak hours run on weekdays (Monday to Friday) from 13:00 to 19:00 UTC. That is 6 AM–12 PM in Pacific daylight time and 5 AM–11 AM in Pacific standard time.
• All other hours, and all of Saturday and Sunday, are off-peak.
• This window was announced on March 27, 2026. If it changes, the API follows and peakHours shows the new window.

Caching and limits

• CORS is open (Access-Control-Allow-Origin: *), so browser apps can call the API directly.
• Caching: responses may come from Cloudflare's cache and can be up to 60 seconds old, but never from before the last status change. Cache-Control says how long each response stays fresh.
• Polling: ask at most once a minute per device. Better still, schedule the next request for nextChange.
• Rate limit: 60 requests per minute per IP address. Above that the API answers 429 Too Many Requests with a Retry-After header and {"error": "Too many requests", "retryAfter": <seconds>}.
• User-Agent: send your app's name, version and a link, for example my-app/1.2 (+https://github.com/me/my-app).

Examples

zsh prompt

Shows 🔴 or 🟢 on the right of your prompt and asks the API at most once a minute.

# ~/.zshrc
zmodload zsh/datetime zsh/stat
claude_status() {
  local cache=${TMPDIR:-/tmp}/claude-status
  local -a mtime
  zstat -A mtime +mtime -- $cache 2>/dev/null
  if (( EPOCHSECONDS - ${mtime[1]:-0} >= 60 )); then
    curl -sf -m 3 -A "zsh-prompt/1.0 (+https://promoclock.co)" https://promoclock.co/api/status |
      python3 -c 'import sys,json; print(json.load(sys.stdin)["emoji"])' >| $cache 2>/dev/null ||
      print '⏳' >| $cache
  fi
  print -rn -- "$(<$cache)"
}
setopt PROMPT_SUBST
RPROMPT='$(claude_status)'

JavaScript (Node.js 18+)

const res = await fetch("https://promoclock.co/api/status", {
  headers: { "User-Agent": "my-app/1.0 (+https://github.com/me/my-app)" },
});
if (!res.ok) throw new Error(`PromoClock API: HTTP ${res.status}`);
const s = await res.json();
console.log(`${s.emoji} ${s.label} · changes in ${s.minutesUntilChange} min`);

// Ask again when the status flips, not on a short timer.
const nextCheckInMs = Math.max(Date.parse(s.nextChange) - Date.now(), 60_000);

In a browser, leave out the User-Agent header; the browser sends its own.

Python

import json
import urllib.request

req = urllib.request.Request(
    "https://promoclock.co/api/status",
    headers={"User-Agent": "my-app/1.0 (+https://github.com/me/my-app)"},
)
with urllib.request.urlopen(req, timeout=5) as r:
    s = json.load(r)

print(s["emoji"], s["label"], f"· changes in {s['minutesUntilChange']} min")

Terms of use

The API is free for non-commercial use under the API terms. In short:

• Credit PromoClock with a link to https://promoclock.co wherever you show the data. If there is no room on screen, put the credit in your README or About screen.
• Commercial use needs written permission. Email [email protected] or contact @onursendere on X.
• Send a User-Agent with your app's name and a link, and ask at most once a minute.

PromoClock is independent and not affiliated with Anthropic. Don't present the data as official Anthropic information.

Used by

Open-source projects that call the API, as of October 2026:

If your project follows the terms, open a pull request to add it here.

What's in this repository

To run the contract tests (Node.js 22.12+):

npm install
npm test

By default the tests call the live API. To test a local copy instead, start it with npm run serve (needs PHP 8) and run:

API_BASE_URL=http://127.0.0.1:8000 npm test

License

The code in this repository is source-available under a non-commercial, no-derivatives license; see LICENSE. Use of the API is covered by the API terms.

Built by Onur Şendere · Digiwings