Capture leads and subscribers

The request and response contract for POST /leads and POST /subscribe, the two endpoints a tenant's site form posts to.

Mark records a lead or a newsletter signup through two public endpoints: POST /leads and POST /subscribe. Your site keeps its own form, design, and copy — these endpoints are the contract your form's submit handler posts to.

Both endpoints live on the API host (for example https://api.mark.lifewithdata.org) and take a JSON body over HTTPS. Life With Data gives you the key value below; it identifies your workspace and is safe to include in client-side code.

Before you integrate

Your public form key. Every request body includes key, the value Life With Data gave you for your workspace.
Your site's domain on the allowlist. Requests from a browser must come from an origin Life With Data has added to your workspace. An origin that isn't allowed gets refused.
A consent checkbox. Both endpoints require an explicit consent acknowledgment before they record anything.

POST /leads

Call this when a visitor submits your lead form.

POST /leads
Content-Type: application/json

Field	Type	Required	Notes
`key`	string	Yes	Your public form key.
`email`	string	Yes	The visitor's email.
`consent`	`true`	Yes	Must be exactly `true`.
`consentVersion`	string	Yes	The version of the consent text you showed.
`pageUrl`	string	Yes	The page the form was on, including any `utm_*` query parameters.
`renderedAt`	number	Yes	Unix time in milliseconds when the form first rendered. Used to reject a submit that happens too fast to be human.
`name`	string	No
`phone`	string	No
`message`	string	No	The visitor's message.
`personaId`	string	No	An id from your Mark workspace, if your form asks which persona the visitor matches.
`answers`	object	No	Any other named field on your form: a flat object of strings, numbers, or booleans, up to 40 keys.
`referrer`	string	No	`document.referrer` at submit time.
`distinctId`	string	No	Your analytics visitor id, if you have one.
`fbclid`, `gclid`	string	No	Ad click ids from the page URL.
`honeypot`	string	No	Leave any hidden honeypot input empty; a filled value marks the submission as a bot.

A successful submission returns:

{ "leadId": "..." }

Show your own thank-you message — Mark doesn't redirect anywhere. If the same email submits again while their lead is still new, Mark attaches the new message to that same lead instead of creating a second one.

Call this for a newsletter or marketing-only signup, where you don't want a sales lead created. It takes the same fields as POST /leads except phone, message, personaId, and answers, and returns:

{ "contactId": "..." }

Responses

Status	Meaning
`201`	Recorded. The body has `leadId` or `contactId`.
`200` with an empty body	The submission looked automated (a filled honeypot or an impossibly fast submit) and nothing was recorded.
`400`	The body is missing a required field, `consent` isn't `true`, or `answers` doesn't fit the shape above.
`403`	The request's origin isn't on your workspace's allowlist.
`404`	The `key` doesn't match a workspace.
`429`	Too many requests from the same address; try again shortly.

Example

curl -X POST https://api.mark.lifewithdata.org/leads \
  -H "Content-Type: application/json" \
  -d '{
    "key": "your-public-form-key",
    "email": "visitor@example.com",
    "message": "Interested in a quote",
    "consent": true,
    "consentVersion": "1.0",
    "pageUrl": "https://your-site.com/contact?utm_source=instagram",
    "renderedAt": 1735000000000
  }'

Before you integrate

POST /leads

POST /subscribe

Responses

Example

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