Cloudflare API Timeout: Fix 524, 522, and Gateway Timeout Errors

Understanding Cloudflare API Timeout Errors

Cloudflare sits between your clients and your origin server as a reverse proxy. When a timeout occurs, the error can originate from three distinct layers: (1) the network path between the client and Cloudflare's edge, (2) the proxy connection between Cloudflare and your origin, or (3) the Cloudflare API itself (api.cloudflare.com) when you are programmatically managing your zone. Each layer produces a different HTTP status code and requires a different fix.

The Four Timeout Error Codes You Will Encounter

524 — A Timeout Occurred

Error 524
A timeout occurred
cloudflare-nginx

Cloudflare successfully opened a TCP connection to your origin but did not receive a complete HTTP response within the proxy read timeout (100 seconds on Free/Pro/Business; configurable on Enterprise). The origin is alive and reachable but is processing too slowly.

522 — Connection Timed Out

Error 522
Connection timed out
cloudflare-nginx

Cloudflare could not complete the TCP three-way handshake with your origin within 15 seconds. Common causes: the origin IP has changed, a firewall or security group is blocking Cloudflare's IP ranges, or the origin process is down.

504 — Gateway Timeout This is the generic HTTP/1.1 version you may see from upstream proxies or load balancers sitting in front of your application. Diagnosis steps are the same as for 524.

Client Timeout Hitting api.cloudflare.com When you are calling https://api.cloudflare.com/client/v4/... from automation and your HTTP client times out, the causes differ: extremely large paginated responses, network path congestion, or incorrectly configured client-side timeout values.

Step 1: Identify Which Layer Is Timing Out

Open your browser developer tools or run curl -v and capture the full response headers. The cf-ray header confirms Cloudflare processed the request. The HTTP status code tells you which layer failed.

curl -v -o /dev/null -s -w "%{http_code} %{time_total}s\n" https://your-domain.com/slow-endpoint

If you see 524 in the response body and a cf-ray header, Cloudflare reached your origin but it timed out — jump to Step 3.

If you see 522, your origin was not reachable at all — jump to Step 4.

If curl itself hangs and you are calling api.cloudflare.com, jump to Step 5.

Step 2: Check the Cloudflare Error Log and Origin Access Logs

In the Cloudflare dashboard, navigate to Analytics → Traffic and filter by the time window. Look for a spike in 5xx errors. Simultaneously check your origin's access log:

# Nginx
tail -n 200 /var/log/nginx/access.log | grep ' 52[24] '

# Apache
tail -n 200 /var/log/apache2/access.log | awk '$9 >= 524'

# Node.js / PM2
pm2 logs --lines 100 | grep -i timeout

If the request never appears in your origin log, the connection is failing before it reaches your application (522 scenario). If it appears and shows a long response time, the origin is the bottleneck (524 scenario).

Step 3: Fix 524 — Origin Is Too Slow

3a. Profile the slow endpoint

Use curl with time breakdown flags to isolate where time is spent:

curl -w "\nDNS: %{time_namelookup}s\nConnect: %{time_connect}s\nTLS: %{time_appconnect}s\nTTFB: %{time_starttransfer}s\nTotal: %{time_total}s\n" \
  -o /dev/null -s https://your-origin-ip/slow-endpoint

If time_starttransfer is > 5 seconds, the bottleneck is server-side processing.

3b. Add a database slow-query log

-- PostgreSQL: enable slow query logging
ALTER SYSTEM SET log_min_duration_statement = '1000'; -- log queries > 1s
SELECT pg_reload_conf();

-- MySQL / MariaDB
SET GLOBAL slow_query_log = 'ON';
SET GLOBAL long_query_time = 1;

3c. Async pattern — return 202 immediately

If the operation genuinely takes more than 30 seconds (report generation, bulk export, ML inference), refactor the endpoint to enqueue work and return a job ID:

# Flask example
@app.route('/api/v1/export', methods=['POST'])
def start_export():
    job_id = queue.enqueue(run_export, request.json)
    return jsonify({'job_id': job_id, 'status': 'queued'}), 202

@app.route('/api/v1/export/<job_id>', methods=['GET'])
def poll_export(job_id):
    job = queue.fetch_job(job_id)
    return jsonify({'status': job.get_status(), 'result': job.result})

3d. Enterprise — increase proxy timeout

If you are on Enterprise, open a support ticket or use the Cloudflare API to set a custom read timeout on a specific route via a Ruleset rule. Free/Pro/Business zones are fixed at 100 seconds.

Step 4: Fix 522 — Origin Unreachable

4a. Verify Cloudflare can reach your origin IP

Cloudflare publishes its egress IP ranges. Your origin firewall must allow inbound traffic from these ranges on port 80 and 443.

# Download Cloudflare's current IP ranges
curl -s https://www.cloudflare.com/ips-v4 > cf_ipv4.txt
curl -s https://www.cloudflare.com/ips-v6 > cf_ipv6.txt

# Check if your origin is currently blocking them (run from a Cloudflare IP or use a VPN)
nc -zv your-origin-ip 443

4b. Update your AWS security group (example)

# Add all Cloudflare IPv4 ranges to your security group
while IFS= read -r cidr; do
  aws ec2 authorize-security-group-ingress \
    --group-id sg-0123456789abcdef0 \
    --protocol tcp --port 443 \
    --cidr "$cidr"
done < cf_ipv4.txt

4c. Confirm DNS A record matches your real origin IP

# Check what IP Cloudflare's DNS is returning (orange-cloud)
dig +short your-domain.com

# Check what IP is stored in Cloudflare DNS records via API
curl -s -X GET "https://api.cloudflare.com/client/v4/zones/ZONE_ID/dns_records?type=A&name=your-domain.com" \
  -H "Authorization: Bearer YOUR_API_TOKEN" \
  -H "Content-Type: application/json" | jq '.result[].content'

If the IP returned does not match your origin, update the A record.

Step 5: Fix Client Timeouts Against api.cloudflare.com

If your automation or CI pipeline is timing out while calling the Cloudflare API directly:

5a. Check rate limit headers

Cloudflare API enforces rate limits (1200 requests per 5 minutes per user globally). Exceeding this returns 429 Too Many Requests — some HTTP clients interpret a stalled 429 response as a timeout.

curl -s -I -X GET "https://api.cloudflare.com/client/v4/zones" \
  -H "Authorization: Bearer YOUR_API_TOKEN" | grep -i 'x-ratelimit\|retry-after'

5b. Implement exponential back-off

import time, requests

def cf_api_get(url, token, max_retries=5):
    for attempt in range(max_retries):
        try:
            resp = requests.get(
                url,
                headers={'Authorization': f'Bearer {token}'},
                timeout=30  # always set an explicit client timeout
            )
            if resp.status_code == 429:
                wait = int(resp.headers.get('Retry-After', 2 ** attempt))
                time.sleep(wait)
                continue
            resp.raise_for_status()
            return resp.json()
        except requests.exceptions.Timeout:
            if attempt == max_retries - 1:
                raise
            time.sleep(2 ** attempt)

5c. Paginate large list responses

Large zones with thousands of DNS records, firewall rules, or cache rules can produce slow list-API responses. Always paginate:

# Paginate DNS records — page through 100 at a time
PAGE=1
while true; do
  RESULT=$(curl -s "https://api.cloudflare.com/client/v4/zones/ZONE_ID/dns_records?per_page=100&page=$PAGE" \
    -H "Authorization: Bearer $CF_TOKEN")
  TOTAL_PAGES=$(echo "$RESULT" | jq '.result_info.total_pages')
  echo "$RESULT" | jq '.result[]'
  [ "$PAGE" -ge "$TOTAL_PAGES" ] && break
  PAGE=$((PAGE + 1))
done

Step 6: Cloudflare Workers-Specific Timeouts

If you are running logic inside a Cloudflare Worker, you face two hard limits:

• CPU time: 10 ms (Free) / 50 ms (Paid) per request
• Wall-clock time for fetch() subrequests: 30 seconds

If your Worker times out, you will see:

Error 1101: Worker threw an exception

or a 522/524 when the Worker's subrequest to your origin times out.

Move expensive logic to Durable Objects or use Cloudflare Queues to fan out work asynchronously. Always set an AbortController signal on subrequests:

export default {
  async fetch(request, env) {
    const controller = new AbortController();
    const timeoutId = setTimeout(() => controller.abort(), 25000); // 25s safety margin
    try {
      const resp = await fetch('https://your-origin.com/api/data', {
        signal: controller.signal
      });
      return resp;
    } catch (e) {
      if (e.name === 'AbortError') {
        return new Response('Origin timeout', { status: 504 });
      }
      throw e;
    } finally {
      clearTimeout(timeoutId);
    }
  }
};