Learn about Dagster's core concepts and how to use them in your data platform.

Software-defined assets#

An asset is an object in persistent storage, such as a table, file, or persisted machine learning model. A software-defined asset is a Dagster object that couples an asset to the function and upstream assets used to produce its contents.


Ops are the core unit of computation in Dagster. They typically perform relatively simple tasks, such as executing a database query or sending a Slack message.


A graph is a set of interconnected ops or sub-graphs. While individual ops typically perform simple tasks, ops can be assembled into a graph to accomplish complex tasks.


Jobs are the main unit of execution and monitoring in Dagster. The core of a job is a graph of ops connected via data dependencies.

Schedules and sensors#

Schedules launch runs on a fixed interval, while sensors allow you to do so based on an external state change.

Partitions and backfills#

A software-defined asset or job can represent a collection of partitions that can be tracked and executed independently.

I/O management#

IO Managers are user-provided objects that store asset and op outputs and load them as inputs to downstream assets and ops.


Dagster provides a configuration system that allows you to document, schematize, and error-check your configuration.

Code locations#

A code location is a collection of Dagster definitions, including assets, jobs, schedules, sensors, and resources. Dagster tools like Dagit and the Dagster CLI use code locations to load your code.

Learn more about code locations.


Resources enable you to separate logic from external dependencies, making developing and testing possible in multiple environments.

Learn more about resources.


Dagit is a web-based interface for viewing and interacting with Dagster objects.

Learn more about Dagit.

GraphQL API#

The GraphQL API allows you to interact programmatically with Dagster.

Dagster types#

The Dagster type system provides gradual, opt-in typing for the inputs and outputs of assets and ops.

Learn more about Dagster types.


A rich, extensible logging system, Dagster's built-in logger tracks all execution events. Loggers can also be customized to fit your infrastructure.


Dagster enables you to build testable and maintainable data applications. It provides ways to allow you unit-test your data applications, separate business logic from environments, and set explicit expectations on uncontrollable inputs.

Learn more about testing.