How to use external AXL modules

MODULE.aspect at your repo root declares external AXL module dependencies — analogous to MODULE.bazel for Bazel deps. Once declared, modules are loadable in any .axl file in the repo.

Declaring a dependency

Use axl_archive_dep to pull in a module from an archive URL:

MODULE.aspect

axl_archive_dep(
    name = "aspect_rules_lint",
    urls = ["https://github.com/aspect-build/rules_lint/archive/65525d871f677071877d3ea1ec096499ff7dd147.tar.gz"],
    integrity = "sha512-TGcxutWr8FwxrK3G+uthbEpuYM2oOVpHPOvaVPzLLuHkfPY0jn/GWFp9myQeFzDFsRZ4ilT0jAWfGZhTk/nesQ==",
    strip_prefix = "rules_lint-65525d871f677071877d3ea1ec096499ff7dd147",
    auto_use_tasks = True,
    dev = True,
)

Parameters:

Parameter	Description
`name`	The module name used in `load()` statements as `@name`
`urls`	List of archive URLs (first reachable URL is used)
`integrity`	SHA-512 checksum in subresource integrity format for reproducibility
`strip_prefix`	Directory prefix to strip from the archive (usually `repo-commitsha`)
`auto_use_tasks`	If `True`, all tasks exported by the module are automatically registered as CLI commands — no explicit `load()` in your `.axl` files needed
`dev`	If `True`, the module is only active during local development, not in CI environments that set `ASPECT_DEV=false`

Loading from a module

After declaring a dependency, use load() to import specific symbols:

.aspect/config.axl

load("@aspect_rules_lint//lint.axl", "LintTrait")

def config(ctx: ConfigContext):
    ctx.traits[LintTrait].aspects = ["//tools/lint:my_linter"]

load() path forms:

"@module_name//path/to/file.axl" — file inside a declared external module
"@aspect//traits.axl" — built-in Aspect library (always available, no declaration needed)
"./relative.axl" — relative to the current file
"path/from/repo/root.axl" — absolute from the workspace root (no leading ./)

Built-in `@aspect` library

The @aspect module is always available without a MODULE.aspect declaration. It exports the built-in traits, features, and utilities used throughout the config examples in these docs:

load("@aspect//traits.axl", "BazelTrait")
load("@aspect//feature/artifacts.axl", "ArtifactUpload")
load("@aspect//format.axl", "format")

​Declaring a dependency

​Loading from a module

​Built-in @aspect library

Declaring a dependency

Loading from a module

Built-in `@aspect` library