dependsOn declares that a course or section has a prerequisite. It’s the only thing tying material together into a graph, rather than a flat pile of pages.

Format

Each entry is a dot-separated reference:

<theme.id>.<course.id>              # depends on an entire course
<theme.id>.<course.id>.<section.id> # depends on one specific section

For example, a section titled “Arrays” that depends on the functions_python section of the procedural course in the software_architecture_and_design theme:

name: Arrays
dependsOn: [software_architecture_and_design.procedural.functions_python]

dependsOn can be set at course level (the whole course depends on something) or section level (just this section does). Leave it as an empty list (dependsOn: []) if there’s no prerequisite.

Note: references are resolved by matching theme.id/course.id/section.id alone — the identifiers need to be unique within the material repos configured together in one deployment, not just within their own repo. If a Gutenberg instance pulls in multiple material repos and two of them happen to reuse the same theme or course id, a dependsOn reference could resolve against the wrong one. Keep ids repo-unique if your deployment combines more than one material repo.

What it drives

  • The dependency diagram (/material/.../diagram) draws an edge from each course/section to everything it depends on, so learners (and authors) can see the prerequisite graph at a glance.
  • Dependency-based navigation: previous/next links can be derived from the dependency graph, and can appear alongside course- or event-authored ordering rather than only as a fallback — see Material Navigation for how the sources interact.
  • Prerequisite hints shown to learners on course/section pages.

Ordering vs. dependency

dependsOn is about conceptual prerequisites, not the order sections are taught in — that’s what Course Tracks’ files: field is for. A course’s files: list is the authored teaching order; dependsOn is the (potentially cross-course, cross-theme) prerequisite graph. The two often agree but don’t have to — a section can be taught in a fixed track order while also declaring a dependency on something from a completely different theme.