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Aspect Build Systems

The end-to-end Bazel experience that developers actually want to use.

Aspect is a build system based on Bazel.

The aspect CLI is a drop-in replacement for the bazel CLI that comes with Bazel. We also provide Bazel “rules” to integrate tightly with language ecosystems.

Aspect provides a simpler, intutive experience for developers new to Bazel, adds the power tools that make advanced users more productive and the customizability your DevInfra team needs to support your organization.

Customize Bazel for your organization

Every organization has a different engineering culture and developer stack. Bazel was designed for Google’s workflows, not yours. Aspect’s plugin system allows you to fit Bazel into your team’s development process, with custom commands, behaviors, and integrations.

People working together on software

Your Developer Infrastructure team can write your own plugins using our SDK which execute directly from your repository. A vibrant ecosystem of plugins will grow which accelerates your Bazel migration.

In the following example, the error message from a badly written genrule was confusing, so a plugin was written to provide more help:

Some other uses of plugins include:

Read more in the plugins documentation


When running in an interactive terminal, aspect gives helpful prompts to fix mistakes in how you run the tool, your Bazel configuration, or your code.

In this example, the Bazel configuration didn’t allow a dependency because the visibility attribute needed adjustment, so the user is prompted if they’d like the source files edited:

Some other examples of interactivity:

When run outside an interactive terminal, such as on CI, the prompts are instead printed for developers to copy-paste to their machine.

Bazel Rules

We are experts in Bazel rules. In addition to being the maintainers of rules_nodejs and rules_python under the bazelbuild GitHub org, Aspect hosts our own next-generation rulesets. See the pinned repositories on our GitHub homepage:

Expert help is a click away

Our Bazel documentation site, makes it easy to search for the missing documentation across all Bazel rulesets.

aspect is sponsored by Aspect Development, a Bazel consulting company. If your organization needs more help to make your Bazel migration a success, come find us at

Open source and no lock-in

You can rely on aspect to power your developer experience workflows.

It is a superset of what Bazel provides, so you can always go back to running bazel commands.

In fact, it includes bazelisk which is the recommended version manager from the Bazel team.

It is open-source, and free for use by individuals, non-profits, and small businesses. Companies with more than 250 employees can contact us at for a license quote.


Using a package manager

Coming soon

Manual installation

Download a binary from our GitHub Releases page and put it in your PATH.

On MacOS you can bypass the “Unknown Developer” dialog by running

xattr -c $(which aspect)

before launching aspect.

User Manuals

The commands are documented under aspect.