When possible, use the Promoted SDKs directly instead of the APIs. The Delivery and Metrics APIs use Protobuf schemas. See the Promoted Protobuf Schema Github Repo for detailed and exact technical API documentation for Delivery and Metrics.

API	Description	Where to use?
Delivery API	Matches content to the requesting user.	Instead of calling the API directly, use the server-side SDKs.
Metrics API	Used to log records to Promoted.	In your proxy FE logging call, send batches of log records to Metrics API.
Content API	Sending Content and User data asynchronously.	After database writes (change data capture) At the end of your mutate API calls Batch cron

API Interface

The easiest way to send messages to Promoted APIs is to send JSON over HTTP. The API servers convert the JSON to a Protocol buffer representation. Some services support sending Protocol buffer bytes to reduce latencies.