Upload a contact list as a LinkedIn Matched Audience via the Streaming API

Steps

1. Create a DMP segment via POST /v2/dmpSegments with segmentType set to 'FILE' and a name; note the returned segment ID.
2. Use the Streaming API endpoint to send hashed user records — SHA-256 hash email addresses in lowercase before sending; include additional identifiers (first name, last name, company) to improve match rates.
3. POST batches of hashed records to the streaming endpoint associated with your segment ID; the Streaming API supports real-time incremental additions and removals without replacing the entire list.
4. Monitor the segment's size via GET /v2/dmpSegments/{id}; audience size will only be visible in Campaign Manager once the segment reaches LinkedIn's minimum threshold.
5. Attach the audience to a campaign by referencing the segment ID in the campaign's targetingCriteria under the matched audience targeting facet.
6. Note that the static CSV upload endpoint (POST /media/upload for DMP segment list creation) was sunset in September 2025; use only the Streaming API for new integrations.