HubSpot · api · fg-0397

HubSpot webhook handler processes the same event twice or in the wrong order

Same objectId and subscriptionType delivered more than once

Verified 2026-10-15 · Confirmed by 0 builders · Trust 50/100

Cause

HubSpot batches up to 100 events per request, treats any response slower than five seconds or any 4xx or 5xx as a failure, and retries up to ten times over 24 hours. It does not guarantee ordering, and duplicates can occur.

Fix

Acknowledge with 200 immediately and process from a queue, dedupe on eventId, and order by occurredAt instead of arrival time.

Apply

app.post('/hubspot', (req, res) => { res.sendStatus(200); for (const e of req.body) queue.add(String(e.eventId), e); });

Affects: HubSpot Webhooks API v3 for legacy public apps, as of 2026-10

Sources

• https://developers.hubspot.com/docs/api-reference/legacy/webhooks/guide

claude mcp add --transport http footgun https://getfootgun.com/api/mcp