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Yarn

Yarn is an open-source JavaScript package manager and project manager originally created at Facebook in 2016 and now developed as a fully independent community project (Yarn Berry, currently v4) on github.com/yarnpkg/berry. Yarn was the first package manager designed around workspaces and introduced Plug'n'Play (a node_modules-free module resolution strategy), Zero-Installs (committable caches for instant clones), Constraints (a cross-workspace policy DSL), and a rich protocol system covering npm, git, github, file, link, portal, patch, exec, and workspace dependencies. It is distributed via Corepack and licensed under BSD-2-Clause.

human only

Limited machine-readable signal and partial portal coverage — documentation a human can read, but little a machine or agent can consume without scraping.

Kin Score

API Evangelist profiles Yarn the way a machine reads it — 35 machine-readable artifacts across 10 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.

Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — Yarn scores 35.3/100 (thin), with a separate agent-readiness read of 0/100 (human only). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.

Kin Score

This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.

Kin Score Kin Score How this is scored →
scored 2026-07-27 · rubric v0.5
Composite quality — 35.3/100 · thin
Contract Quality 8.0 / 25
Developer Ergonomics 7.0 / 20
Commercial Clarity 0.0 / 20
Operational Transparency 2.7 / 13
Governance 8.8 / 12
Discoverability 8.8 / 10
Agent readiness — 0/100 · human only
Machine-Readable Contract 0 / 18
Agentic Access Contract 0 / 15
MCP Server 0 / 12
Machine-Readable Auth 0 / 10
Idempotency 0 / 9
Stable Error Semantics 0 / 8
Request/Response Examples 0 / 7
Rate-Limit Signaling 0 / 7
Typed Event Surface 0 / 6
Agent Skills 0 / 5
Well-Known Catalog 0 / 4
Consent & Bot Identity 0 / 3

How we profile Yarn

Each block below is one kind of artifact we hold for Yarn. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.

APIs 10

Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.

Individual APIs this provider publishes, each with its own machine-readable definition.

Yarn CLI

The Yarn command-line interface — `yarn` — provides install, add, remove, up, run, exec, dlx, info, why, pack, rebuild, dedupe, node, bin, search, upgrade-interactive, and stage...

Yarn Workspaces

Yarn was the first package manager built specifically around workspaces. `yarn workspace`, `yarn workspaces foreach`, `yarn workspaces focus`, and `yarn workspaces list` provide...

Yarn Plug'n'Play

Plug'n'Play (PnP) is Yarn's alternative to the traditional node_modules folder. Yarn generates a single `.pnp.cjs` file containing the exact dependency tree which Node.js consul...

Yarn Zero-Installs

Zero-Installs commit Yarn's package cache (`.yarn/cache`) into the repository alongside the `.pnp.cjs` file. Clones of the repository can start working immediately without runni...

Yarn Constraints

Yarn Constraints let you declare cross-workspace rules — required fields in `package.json`, forbidden dependencies, version pinning, and consistency requirements — using a JavaS...

Yarn Protocols

Yarn supports a rich set of dependency protocols beyond `npm:` semver — `git:`, `github:`, `file:`, `link:`, `portal:`, `patch:`, `exec:`, `workspace:`, and `http(s):`. Protocol...

Yarn Plugin API

Yarn ships with a full plugin API exposed by `@yarnpkg/core`. Plugins can register commands, resolvers, fetchers, linkers, and lifecycle hooks. Plugins are installed with `yarn ...

Yarn Version (Release Workflow)

Yarn provides a release-workflow primitive for monorepos. Contributors declare per-workspace version bumps as deferred decisions (`yarn version check --interactive`) and the pro...

Yarn Patch

First-class dependency patching — `yarn patch ` extracts a temporary editable copy of a dependency and `yarn patch-commit` saves the resulting diff as a `patch:` protoc...

Yarn DLX

The yarn dlx command runs a package in an isolated temporary environment without permanently installing it. Yarn's equivalent of npx, used for one-shot tools, code generators, a...

Scroll within the panel for all 10 ·

Features 21

The notable capabilities this provider advertises, captured as structured features so they can be searched and compared instead of read one landing page at a time.

Notable capabilities this provider offers.

Yarn 4 (Berry) — TypeScript rewrite of the Yarn package manager, fully independent open-source project
Workspaces — first-class monorepo support with `yarn workspace`, `yarn workspaces foreach`, and `yarn workspaces focus`
Plug'n'Play (PnP) — node_modules-free dependency resolution via a single `.pnp.cjs` manifest plus a Rust implementation (pnp-rs)
Zero-Installs — commit the cache so clones bootstrap with no `yarn install` step
Constraints — JavaScript and Prolog DSL for cross-workspace policy enforcement
Protocols — npm, git, github, file, link, portal, patch, exec, workspace, and http(s) dependency sources
Plugin system — extensible commands, resolvers, fetchers, and linkers via `@yarnpkg/core`
20+ bundled plugins including plugin-npm, plugin-pnp, plugin-workspace-tools, plugin-constraints, plugin-typescript, and plugin-interactive-tools
First-class dependency patching with yarn patch and yarn patch-commit, no extra tooling required
Yarn dlx — safe ephemeral package execution as a drop-in replacement for npx
Yarn up — project-wide dependency upgrades across all workspaces
Yarn dedupe — collapse overlapping semver ranges into the fewest possible resolutions
Yarn version — release workflow with deferred per-workspace version decisions
Yarn npm publish and yarn npm login for npm registry publishing
Yarn npm audit for vulnerability scanning
Corepack integration — projects pin their Yarn version via the packageManager field in package.json
Yarn set version stable upgrades the per-project Yarn binary
Configuration via .yarnrc.yml with checked-in defaults
Editor SDKs (@yarnpkg/sdks) for VS Code, Vim, and other editors to integrate with PnP
Portable @yarnpkg/shell interpreter so scripts in package.json work identically on every OS
BSD-2-Clause license, governed by a community contributor model independent of any single company

Scroll within the panel for all 21 ·

Semantic Vocabularies 1

JSON-LD contexts give the data shared meaning across APIs. We profile them because semantics are what let a machine reconcile 'customer' here with 'customer' somewhere else.

JSON-LD contexts and semantic vocabularies used across these APIs.

Yarn Pkg Context

29 classes · 10 properties

JSON-LD

Spectral Rules 1

Governance rulesets we run against this provider's specs — the automated checks behind parts of the score. Profiling them makes the quality bar explicit and re-runnable, not a matter of opinion.

Yarn API Rules

5 rules · 3 warnings

SPECTRAL

JSON Schema 1

Standalone JSON Schema definitions describe the data models behind the API. We profile them so the shapes are validatable on their own — useful long after a single request is forgotten.

Standalone JSON Schema definitions for this provider's data models.

Yarn Workspace package.json

23 properties

JSON SCHEMA

Security Posture 1

Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Yarn Pkg Domain Security

TLSv1.2

SECURITY

Resources

Every other property we hold for Yarn — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.

Get Started 2

Portal, sign-up, and the first successful call

Access & Security 1

Authentication, authorization, and security posture

Operate 2

Status, limits, changes, and where to get help

Commercial 1

Pricing, plans, and the legal terms of use

Other 1

Properties that don't map to a standard resource type

← All providers · Data indexed from github.com/api-evangelist/yarn-pkg · machine-readable index on apis.io