Credit usage
This page explains how Dagster+ counts credits for common operations, including the difference between metadata updates and materializations.
What consumes credits
| Operation | Credit cost |
|---|---|
| An asset materialization backed by a step execution (per partition) | 1 credit |
| An observable source asset execution | 1 credit |
| An asset materialization reported from a sensor (no step execution) | 0 credits |
Adding a dynamic partition via context.instance.add_dynamic_partitions() | 0 credits (metadata only) |
| Asset observations | 0 credits |
| Asset checks | 0 credits |
| Sensor evaluations | 0 credits |
Materializations with and without step execution
Credits are only charged for materializations that involve a step execution — that is, when Dagster actually runs compute to produce an asset. If a sensor reports that an asset was materialized by an external system (using context.log_for_asset(...) or by yielding AssetMaterialization events), no step is executed and no credit is consumed.
This means you can use sensors to track the state of externally-produced assets in the Dagster UI without incurring credit usage. If you want Dagster to perform compute itself (transformations, loading, etc.), that step execution costs 1 credit per partition.
Sensors and asset checks
Sensor evaluations and asset check executions do not consume credits, regardless of how frequently they run or how many assets they target.
Dynamic partitions and observable source assets
Adding new partitions through context.instance.add_dynamic_partitions() is a metadata update. It does not consume credits regardless of how many partitions are added. The materializations of downstream assets that fill in those new partitions are what generate credit usage.
For example, suppose you use an observable source asset to detect new files (e.g., from Snowpipe) and add them as dynamic partitions. If the observable source asset discovers 500 new files:
- The discovery run costs 1 credit (the observable source asset execution itself).
- Adding the 500 partitions costs 0 credits.
- Materializing a downstream asset across all 500 new partitions costs 500 credits (1 per partition).
- Each additional downstream asset that processes those partitions incurs its own per-partition credit cost.
Reporting events from external systems
If you only need to record metadata about work that happened outside Dagster, report it as an asset observation rather than a materialization. Observations don't count against credit usage.