Reliable webhook forwarding with Additional Endpoints
Last updated October 15, 2025
OutboundSync allows you to forward webhook payloads to Additional Endpoints for flexible integrations. This guide explains how the forwarding process works, how rate limits and payload size issues are handled, and what retry mechanisms are in place.
How It Works
When OutboundSync receives a webhook payload from the connected platform, we:
- Deliver the webhook payload to the primary endpoint (the connected CRM)
- Forward the same payload to any configured Additional Endpoints
- Applies safeguards, including retry logic, random delays, and payload optimization, to ensure successful delivery even when downstream systems enforce strict rate limits or reject oversized requests.
Handling Rate Limits
Some destinations enforce API rate limits that restrict how many requests can be processed within a given time window. When requests exceed this limit, the endpoint returns a 429 Too Many Requests response.
OutboundSync’s Handling:
When OutboundSync receives a 429 Too Many Requests response:
- A random delay between 0 and 300 seconds is added before the first retry for each payload.
- This delay helps distribute retry attempts across time, preventing “retry storms” when many payloads fail simultaneously.
- For example, if 100 payloads are being sent and 10 succeed while 90 return a
429, each of those 90 payloads will get a unique random delay between 0 and 300 seconds (e.g., 20s, 45s, etc.). - This ensures that retries are staggered rather than retried all at once, greatly reducing the chance of hitting the same rate limits again.
- After the random delay, OutboundSync applies exponential backoff retries up to seven times:
| Retry # | Additional Delay (minutes) | Total Delay Formula |
| 1 | 1 | random(0–300s) + 2^(1-1) * 60s |
| 2 | 2 | random(0–300s) + 2^(2-1) * 60s |
| 3 | 4 | random(0–300s) + 2^(3-1) * 60s |
| 4 | 8 | random(0–300s) + 2^(4-1) * 60s |
| 5 | 16 | random(0–300s) + 2^(5-1) * 60s |
| 6 | 30 | random(0–300s) + 2^(6-1) * 60s |
| 7 | 60 | random(0–300s) + 2^(7-1) * 60s |
Formula: TotalDelayForEachRetry = random(0–300s) + 2^(RetryNumber - 1) * 60s
This approach minimizes simultaneous retries and increases the likelihood of eventual success without overwhelming the endpoint.
Handling Payload Size Issues
Some destinations reject payloads that exceed a maximum size (e.g., 100 KB). In these cases, payloads may fail with a Payload Too Large error.
OutboundSync’s Handling:
- On detecting a size-related failure, we automatically optimize and retry the payload by converting all HTML fields into plain text.
- The optimized payload is retried under the same exponential backoff schedule.
Summary
OutboundSync ensures reliable delivery of webhook payloads to Additional Endpoints by:
- Detecting rate limit responses and retrying with exponential backoff (up to 7 times).
- Handling payload size errors by optimizing payloads (HTML → plain text).
This makes forwarding via Additional Endpoints robust even when partner systems enforce strict API limits or size constraints.