Skip to main content



OSO tracks the dependency graph among projects in a collection or ecosystem. A dependency is a software package, module, or project that another project requires to function properly. Conversely, a dependent is a project that includes a specific package as its dependency. These metrics can highlight the usefulness of a given open source software project to other projects in the ecosystem.


These metrics are currently in development.

Direct vs. Indirect Dependents

Dependents can be categorized as:

  • Direct Dependents: Projects that directly include the parent package in their list of dependencies.
  • Indirect Dependents: Projects that rely on the parent package through an intermediary package. For example, if Package A depends on Package B, and Package B relies on Package C, then Package A is an indirect dependent of Package C.

Developer Dependencies

Many package managers, such as npm and Crates, distinguish between production code dependencies and developer dependencies that are only needed for local development and testing.

Below is an example of an npm package.json file with developer dependencies:

"name": "my_package",
"version": "1.0.0",
"dependencies": {
"my_dep": "^1.0.0",
"another_dep": "~2.2.0"
"devDependencies" : {
"my_test_framework": "^3.1.0",
"another_dev_dep": "1.0.0 - 1.2.0"

Constraints on Dependency Analysis

For Open Source Observer, we've set the following constraints for our dependency analysis:

  1. Only direct dependents are considered, excluding indirect ones.
  2. Dependency analysis is restricted to specific collections or the union of specific collection sets. This ensures a more manageable indexing process and a clearer understanding of critical package relationships within an ecosystem.

Without such constraints, certain packages might appear as indirect dependents or dependencies for a vast majority of open source projects.


Note: This is a hypothetical example. Real-world examples based on actual dependency graphs will be added soon.

Consider a collection of "Ethereum Developer Tools" with projects like ethers and wagmi and another collection called "Optimism Applications" with projects like velodrome-finance and zora. If velodrome-finance depends on ethers, and zora depends on both ethers and wagmi, then ethers has two dependents, and wagmi has one.

Ecosystems: Ethereum Developer Tools & Optimism Applications
|----> Project: ethers
| |
| |----> Dependent: velodrome-finance
| |----> Dependent: zora
|----> Project: wagmi
|----> Dependent: zora

Dependent Metrics

In addition to mapping projects and their dependents, we also capture the following data about a project's dependents:

Current Dependents

Count of dependent projects as of the most recent indexing run. These may also be referred to as "downstream dependencies" or "reverse dependencies".

Current Dependencies

Count of dependencies as of the most recent indexing run. These may also be referred to as "upstream dependencies".

Active Developer Dependents

Count of active developers of all dependent projects in the same collection.

Active User Dependents

Count of active users of all dependent projects in the same collection.

Fees Dependents

Total sequencer fees of all dependent projects in the same collection.

To contribute new metrics, please see our guide here