Principle:Mlc ai Web llm Dependency Version Pinning

Knowledge Sources	npm package-lock.json Mlc_ai_Web_llm
Domains	Build_System, Package_Management
Last Updated	2026-02-14 22:30 GMT

Overview

Technique for ensuring reproducible builds by recording exact dependency versions and integrity hashes in a lockfile that is committed to version control.

Description

Dependency version pinning solves the problem of non-deterministic builds caused by semver range resolution. When package.json declares a dependency like "loglevel": "^1.9.1", different environments may resolve this to different patch versions depending on when npm install runs. The lockfile eliminates this ambiguity by recording the exact resolved version for every dependency in the tree.

Key properties of lockfile-based pinning:

• Determinism -- Every npm ci invocation produces an identical node_modules/ tree
• Integrity -- SHA-512 hashes verify that downloaded packages have not been tampered with
• Transitivity -- Pins not just direct dependencies but the entire transitive dependency graph
• Auditability -- The full dependency tree is inspectable for security vulnerabilities

Usage

Use dependency version pinning for any project where build reproducibility matters. This is especially critical for:

• CI/CD pipelines -- Ensures builds are identical regardless of when they run
• Security-sensitive projects -- Integrity hashes detect supply chain tampering
• Team development -- All developers work with identical dependency versions
• Production deployments -- The exact tested dependency set is deployed

Theoretical Basis

Lockfile Resolution Algorithm

Pseudo-code logic:

# Abstract lockfile resolution process
for each dependency in package.json:
    resolve semver range to exact version (e.g., "^1.9.1" → "1.9.2")
    compute SHA-512 integrity hash of package tarball
    record (name, version, integrity, resolved_url) in lockfile
    recursively resolve transitive dependencies

npm ci vs npm install

Command	Behavior	Use Case
npm install	Resolves from package.json, may update lockfile	Development: adding/updating dependencies
npm ci	Installs strictly from lockfile, fails on mismatch	CI/CD: deterministic builds

Lockfile Version 3

npm lockfile version 3 (used by web-llm) stores a flat packages map keyed by node_modules/ path. This format:

• Eliminates the nested dependencies structure of earlier versions
• Directly represents the physical layout of node_modules/
• Supports workspaces and package aliases

Related Pages

• Implementation:Mlc_ai_Web_llm_Package_Lock