Identify users

POST https://datafa.st/api/v1/identify

Link a DataFast visitor to a known user and store profile metadata.

Request

Authentication

df_ website API key for one website.
dft_ account token with identify:write. Pass websiteId as a query parameter.

Body parameters

Field	Type	Required	Description
`user_id`	string	Yes	Stable user ID. Non-empty, max 255 characters.
`datafast_visitor_id`	string	Yes	DataFast visitor UUID from the browser cookie or client SDK. Used to attach server-side events to a visitor journey.
`Any other top-level field`	any	No	Stored inside profile metadata. Example: send `email: "jane@example.com"`, `plan: "pro"`, `company: "Acme"`, `role: "admin"`, or `signup_source: "invite"`.

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Response

Returns a JSON object with status and endpoint-specific fields.

Response fields

Field	Type	Description
`status`	string	`success`.
`data.message`	string	Human-readable confirmation or status message for the operation.
`data.profileId`	string	ObjectId of the Identify profile created or found by DataFast. Profile ObjectId when a profile exists or is created.

Errors

Common errors include 400 for invalid input, 401 for missing or invalid tokens, 403 for missing permission or suspended tracking, 404 for missing resources, and 500 for server errors.

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curl -X POST "https://datafa.st/api/v1/identify" \ -H "Authorization: Bearer df_xxx" \ -H "Content-Type: application/json" \ -d '{"user_id":"user_123","datafast_visitor_id":"a3ab2331-989f-4cfa-91c6-2461c9e3c6bd","email":"jane@example.com","plan":"pro"}'