LeadCentre Webhook Reference

A post to your webhook URL creates a lead. You decide the field names, and an Admin on the account matches them to LeadCentre fields once, per key. There's no schema to follow beyond the formats below.

It doesn't read, update or delete leads, and it doesn't send anything back out. There are no outbound webhooks and no signed requests.

URL and keys

https://hooks.leadcentre.com/in/YOUR-ACCOUNT-ID?key=YOUR-KEY

• Each account has a key called Default and can add more under Settings > Connections. Each key has its own secret, field matching and test state.
• Send the secret as ?key= in the URL, or in an x-api-key header. If both are present, the URL wins. Use the header where you can, because URLs end up in logs.
• A secret is shown once, when it's created or replaced. LeadCentre keeps only a hash, so it can't be recovered.
• Replace this URL issues a new secret, and the old one stops at once. Field matching is kept. Revoke removes a key, and it isn't offered for Default.
• Only POST is accepted. Each client account on an agency platform has its own URL and keys.

Accepted bodies

• A JSON object: one lead.
• A JSON array of objects: one lead per object, up to 25 per post. Anything past 25 is ignored without an error, and non-object items are skipped, so check the length of results.
• A form post (URL-encoded): one lead.

The format is worked out from the body, so a wrong Content-Type header won't stop a JSON or URL-encoded post. multipart/form-data isn't read. It's refused with a 415 and isn't logged, so it won't show on the matching screen. Files aren't accepted in any format.

Limits

• 64 KB per post.
• 120 a minute per key. Each lead in an array counts separately, so five arrays of 25 reach the limit.
• 200 fields per lead and six levels of nesting. Anything further is dropped.

How fields are named

Nested JSON is flattened into dotted names, with array items numbered from 0:

{"contact": {"phone": "07700900123"}, "answers": [{"text": "Roof"}]}

contact.phone     07700900123
answers.0.text    Roof

Values are trimmed and turned into text. Null and empty values are skipped, so they won't appear on the matching screen until a post has a value for them. Send a test with everything filled in.

Numbered names mean position. If your source sends answers as a list, answers.0.text means whatever comes first. If the order changes, values land in the wrong fields with no error, as the Google Ads guide explains. Prefer named fields where you control the payload.

Test mode

A post is test data if the URL includes test=1, or while the key is listening. Listen for test data lasts 15 minutes, or until Stop listening. Test data is logged, shows on the matching screen and never becomes a lead. That includes a real lead sent while the key is listening, as it isn't kept back for later. The response shows the result test, so your system can tell.

Held posts

A post sent before a key has any matching is held, and shows the result awaiting_mapping. Pressing Save field matching turns held posts into leads, with their original received time. A post that was matched but had no name, phone or email (the result no_contact) is retried the same way, so matching a renamed field recovers it. Each save handles up to 200, oldest first, so save again for a longer backlog. Received posts are deleted after 30 days, so anything still held by then is lost.

Duplicates

Match your own ID to Unique ID. A repeat returns the result duplicate and doesn't create a second lead. Unique IDs apply across your whole account, including other keys, so prefix them if two sources could use the same number. Without a Unique ID, every post makes a new lead.

Responses

A successful post returns one result per lead, in order:

{"ok": true, "results": ["lead", "duplicate"]}

Status	Meaning
200	Received. Each result is lead, duplicate, no_contact, test or awaiting_mapping. Check them, because no_contact also returns 200.
400	Send JSON or a form post. The body was empty, broken JSON, plain text or an array with no objects.
401	Invalid webhook URL or key. It's missing, wrong, replaced or revoked, the account ID is malformed or the account is suspended.
404	Not found. The path isn't /in/YOUR-ACCOUNT-ID.
413	Body too large. Over 64 KB.
415	Multipart form data is not supported. Send JSON or a URL-encoded form (application/x-www-form-urlencoded).
429	Too many requests. Over the limit for this key, so wait and try again.
500	A lead couldn't be saved, and ok is false. Earlier items in the array may have been saved, so retry only with Unique ID matched.

What happens to mapped values

• First name and last name combine into the full name when no full name is matched.
• Emails are lowercased and postcodes uppercased.
• A future or unreadable Date received is ignored, and the lead takes the time it arrived. Send ISO dates such as 2026-11-04T10:30:00Z, because a UK date such as 04/11/2026 can be read as 11 April.
• Lead source defaults to the key's name, so name keys after the source.
• If two fields are matched to the same LeadCentre field, the first with a value wins.
• A lead needs at least a name, phone or email.