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

To use Aspect CLI in an existing Bazel workspace, run:

printf '%s\n%s' "aspect-build/9.9.9-aspect_0_11_0" "$(cat .bazelversion)" >.bazelversion

A simpler, intuitive experience for developers new to Bazel

Power tools that make advanced users more productive

Customizability your DevEx team needs to support your organization

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

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Helpful prompts fix errors when running in an interactive terminal

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Power your developer experience workflows

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Fit Bazel into your team’s development process, with custom commands, behaviors, and integrations

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Open source

Free for use by individuals, non-profits, and small businesses

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

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

Aspect Workflows

Aspect Workflows integrates Bazel with your CI/CD workflow using your existing CI platform.

Aspect Workflows supports Buildkite, CircleCI, and GitHub Actions.

Aspect Workflows is a fully-managed offering. We operate the services, tune infrastructure configurations, and ensure CI stays fast and cloud costs are minimized.

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Configure Bazel with CI specific flags

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Detect and report on non-determinism that causes cache misses

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Reduce datacenter costs by scaling down unneeded replicas off-peak

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Reduce developer queue times by scaling up in anticipation of peak load

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Avoid slow builds by keeping CI workers warm

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.

Aspect’s high performance custom rulesets

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  • rules_py - Bazel rules for running Python tools and building Python projects

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  • bazel-lib - Common useful rules & functions for writing custom build rules with Starlark

Aspect maintains some of Bazel's most popular core rulesets

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Our engineers have contributed to other projects in the Bazelbuild

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Expert help is a click away

Aspect Development, our professional services division, is here to help make your Bazel migration a success. Come find us at

The CLI makes it easy for developers to diagnose their broken build by asking for help directly within their terminal session.