Source: ai-research/ghl-2026-05-01/support-solutions-articles-48001212085-how-to-use-webhook-site-to-troubleshoot-your-api-requests.md
The single most useful technique for debugging HighLevel API integrations is to redirect the outbound webhook to webhook.site — a free third-party tool that captures the raw HTTP request (headers, body, method) and shows it in real time. You swap your live API URL for a temporary webhook.site URL, run the real-world flow, inspect the captured payload, then swap back. This works for outbound webhooks from HighLevel, payloads from Zapier or Make hitting HighLevel, and any custom integration in between.
Key Takeaways
- webhook.site instantly generates a unique test URL that captures incoming HTTP requests with headers, body, and method.
- The standard debugging move: swap your real endpoint URL for a webhook.site URL, run the real-world trigger (not the integration’s “test” button), inspect the captured payload, fix mismatches, swap back.
- HighLevel doesn’t directly support Basic or Advanced API debugging — they point you at: the Developer Council Slack (
https://www.gohighlevel.com/dev-slack), the monthly Developer Council Zoom call (second-to-last Friday), and the official docs atmarketplace.gohighlevel.com/docs/. - Always trigger via the real-world action (form submit, automation fire, etc.) rather than the integration tool’s built-in test — many tools send a synthetic test payload that doesn’t match production.
- The captured raw payload is the canonical artifact to share when escalating to your developers or HighLevel support.
When to use webhook.site
- An integration is firing but the destination isn’t receiving expected data — capture the actual outbound payload to see what’s wrong.
- Debugging an automation tool (Zapier, Make/Integromat, n8n) → HighLevel flow when API calls fail and you can’t see the request body.
- Validating webhook payload shape before pointing the integration at your production endpoint.
- Capturing a payload to share with your developer team or HighLevel support when escalating an issue.
The 7-step flow
1. Visit webhook.site
Open https://webhook.site in your browser. A unique test URL is generated automatically (looks like https://webhook.site/<uuid>).
2. Copy the unique testing URL
Click Copy to clipboard next to your unique testing webhook URL on the homepage.
3. Open your custom integration
Go to the integration tool you’re debugging — Zapier, Make, n8n, custom app, etc.
4. Replace the HighLevel API URL with the webhook.site URL
In the action that POSTs to HighLevel, swap the production URL for the webhook.site URL you copied. This is the key move — it diverts the payload to a place you can inspect it.
5. Save your updates
Save the integration. Do not use the integration’s built-in “test” button — built-in tests usually send synthetic payloads that don’t match the real production payload.
Instead: trigger the actual real-world action.
- If the webhook fires on form submission → submit the form for real.
- If the webhook fires on automation → run the automation against a real record.
- If the webhook fires on external action → perform that action.
This gives you the same payload that production sees.
6. Review payload data
Back on webhook.site, you’ll see the captured request in real time:
- Method (GET/POST/PUT/DELETE)
- Headers (Content-Type, Authorization, custom headers)
- Body (the raw JSON/form-encoded payload)
- Query string (if any)
Compare against the HighLevel API docs at marketplace.gohighlevel.com/docs/ to find what’s wrong.
7. Copy the payload
Click Copy in the upper right of the Raw Data input box to copy the entire payload. Save this — it’s the canonical artifact when escalating to your developer team or HighLevel support.
After debugging
When you’ve found and fixed the issue, swap the webhook.site URL back to the real HighLevel API URL. Test once more end-to-end against the real endpoint to confirm the fix.
Where to get help
HighLevel doesn’t currently support or service Basic or Advanced API issues directly. They point developers at:
| Resource | URL | Cadence |
|---|---|---|
| Developer Council Slack | https://www.gohighlevel.com/dev-slack | Real-time |
| Developer Council Zoom | https://www.gohighlevel.com/events | Monthly, second-to-last Friday |
| API Documentation | https://marketplace.gohighlevel.com/docs/ | Living |
| Webhook Logs Dashboard | In-app for marketplace apps — see Webhooks | Per-app |
For marketplace-app-specific issues (auth flow, install events), the Webhook Logs Dashboard inside the developer portal shows delivery attempts, retries, and response codes — that’s the first place to look before reaching for webhook.site.
Common API debugging patterns
| Symptom | First check |
|---|---|
| 401 Unauthorized | Token expired? See OAuth 2.0 for refresh flow. PIT mismatched scope? See Private Integration Tokens. |
| 403 Forbidden | Scope insufficient. Check the scope list in your app config matches what the endpoint requires. |
| 404 Not Found | Endpoint path wrong, or resource ID belongs to a different location/company. |
| 422 Unprocessable Entity | Payload shape doesn’t match docs. Capture it via webhook.site to see what’s actually being sent. |
| 429 Too Many Requests | Hit a rate limit. See API Rate Limits for burst/daily windows. |
| Webhook not firing | Verify the event subscription in app config; check Webhook Logs Dashboard for delivery attempts. |
| Webhook firing but receiver not getting it | Use webhook.site as the receiver to confirm the request leaves HighLevel correctly. |
Try It
- Bookmark
https://webhook.siteand copy a unique test URL the next time you start debugging an integration — make this your reflex. - Use the real-world trigger, never the integration’s test button. Synthetic tests send fake payloads.
- Always copy the captured payload before swapping the URL back — you’ll want it for escalation.
- Join the Developer Council Slack now (before you have an emergency) so you can ask questions in real time when something breaks.
- Add the monthly Developer Council Zoom call to your calendar —
https://www.gohighlevel.com/eventslists upcoming dates. - For marketplace apps, set up logging on your webhook receiver from day one. Pair it with the Webhook Logs Dashboard so you can correlate sender (HighLevel) and receiver (your app) views.
Related
- API Guide
- Webhooks
- OAuth 2.0
- Private Integration Tokens
- API Rate Limits
- API Security
- API Endpoints Overview
Open Questions
- Whether webhook.site URLs can be self-hosted for privacy-sensitive payloads (e.g., webhook-tester open-source equivalent), or whether HighLevel docs cover any internal alternative.
- HighLevel’s planned support model for Advanced API issues — current stance is “we don’t service these directly,” but Slack/Zoom communities are explicitly the substitute.
- Webhook signing/verification — sources don’t fully document how to verify a payload truly came from HighLevel before processing it.