Introduction

Usage based billing using ingested events

Usage Based Billing is an advanced feature enabling you to charge customers based on their real-time application usage.

Overview

Solifyn has a powerful Usage Based Billing infrastructure that allows you to charge your customers based on the usage of your application.

This is done by ingesting events from your application, creating Meters to represent that usage, and then adding metered prices to Products to charge for it.

Concepts

Events

Events are the core of Usage Based Billing. They represent a single unit of consumption or usage done by a customer in your application. Typical examples of events include:

• A customer consumed AI LLM tokens
• A customer streamed minutes of video
• A customer made an API request

Events are sent to Solifyn using the Events Ingestion API and are stored in our database. An event consists of the following fields:

• event_id: A unique identifier for the event to ensure idempotency.
• customer_id: The Solifyn customer ID associated with the usage event.
• event_name: The string identifier matching a configured meter’s event name (e.g. api.request).
• value: An optional numeric value representing the quantity of consumption (defaults to 1).
• metadata: A JSON object containing custom key-value pairs used for filters or advanced aggregation.
• timestamp: An optional ISO 8601 string representing when the event occurred.

Here is an example of a Solifyn event payload:

{
  "event_id": "evt_9Y3kP4qR7tU1vW2xZ5aB6c",
  "customer_id": "cus_8n7m6l5k4j3h2g1f0e9d8c",
  "event_name": "api.request",
  "value": 1,
  "metadata": {
    "region": "asia-southeast-1",
    "plan": "enterprise"
  },
  "timestamp": "2026-05-23T10:00:00.000Z"
}

Meters

Meters are there to filter and aggregate the events that are ingested. Said another way, this is how you define what usage you want to charge for, based on the events you send to Solifyn. For example:

• AI usage meter, which filters the events with the name ai_usage and sums the total_tokens field.
• Video streaming meter, which filters the events with the name video_streamed and sums the duration field.
• File upload meter, which filters the events with the name file_uploaded and sums the size field.

You can create and manage your meters from the dashboard. Solifyn is then able to compute the usage over time, both globally and per customer.

Metered Price

A metered price is a price that is based on the usage of a meter, which is computed by filtering aggregating the events that are ingested. This is how you charge your customers for the usage of your application.

Quickstart

Get up and running in 5 minutes

1. Create a Meter

   Meters consist of filters and an aggregation function. The filter is used to filter the events that should be included in the meter and the aggregation function is used to compute the usage.

   
2. Add metered price to a Product

   To enable usage based billing for a Product, you need to add a metered price to the Product. Metered prices are only applicable to Subscription Products.

   
3. Ingest Events

   Now you’re ready to ingest events from your application. Sending events which match the meter’s filter will increment the meter’s usage for the customer.