LinkID – Persistent Identifiers for the Web

LinkID is a persistent identifier system that decouples the identity of a hyperlink from the physical address of its target resource. It solves both Link Rot (broken links) and Content Drift (changed content at same URL).

How It Works

Traditional hyperlinks break when URLs change. LinkID assigns each hyperlink relationship a unique, location-independent identifier (LinkID) that remains valid regardless of where the target resource moves or how its content changes.

Traditional:  Document → URL → Resource (breaks when URL changes)
LinkID:       Document → LinkID → Resolver → Current Resource (always works)

Repository Structure

lid/
├── sdk/              # Client libraries
│   ├── js/           # JavaScript/TypeScript – npm: @linkgenetic/client
│   ├── python/       # Python – pip: linkid-client
│   └── java/         # Java – Maven: org.linkgenetic:linkid-client
├── spec/             # W3C Specification
├── draft/            # IETF Internet-Draft (URI scheme)
├── docs/             # Contributing guidelines, Code of Conduct
└── tests/            # Conformance tests

Quick Start

JavaScript / TypeScript

npm install @linkgenetic/client

import { LinkIDClient } from '@linkgenetic/client';

const client = new LinkIDClient({ resolverUrl: 'https://linkid.io' });
const result = await client.resolve('linkid:7e96f229-21c3-4a3d-a6cf-ef7d8dd70f24');
console.log(result.uri); // current location of the resource

Python

pip install linkid-client

from linkid import LinkIdClient

client = LinkIdClient(resolver="https://linkid.io")
result = client.resolve("linkid:7e96f229-21c3-4a3d-a6cf-ef7d8dd70f24")
print(result.target_uri)  # current location of the resource

Java

<dependency>
    <groupId>org.linkgenetic</groupId>
    <artifactId>linkid-client</artifactId>
    <version>1.0.0</version>
</dependency>

LinkIdClient client = new LinkIdClient("https://linkid.io");
ResolutionResult result = client.resolve("linkid:7e96f229-21c3-4a3d-a6cf-ef7d8dd70f24");
System.out.println(result.getTargetUri());

Use Cases

• Enterprise documents – Embed LinkIDs in PDF, Word, and other documents. Links survive server migrations, domain changes, and content restructuring.
• Web publishing – Replace fragile URLs with persistent LinkIDs. Readers always reach the current version of referenced content.
• Archives and libraries – Maintain long-term reference integrity with time-aware resolution and archived versions.
• QR codes and print media – LinkIDs in printed materials resolve to current resources even years after publication.
• API integrations – Register and manage LinkIDs programmatically via REST API.
• Wikipedia & Wikimedia – Persistent reference identifiers for Wikipedia citations, solving link rot and content drift at scale. See Wikimedia Hackathon 2026 for detailed use cases.

See docs/use-cases/ for the full use case library covering LinkID, LinkManager, and combined deployments across Academia, Libraries, and Government.

Licensing

This project uses a Triple License model:

License	For	Cost
LCL (Community License)	Non-commercial use, evaluation, research	Free
LPIL (Public Interest License)	Universities, libraries, government, NGOs	Free
LEL (Enterprise License)	Commercial use	Contact us

Client SDK libraries are freely usable under LCL. Server-side implementations of the LinkID system are available under LEL or LPIL.

Contributing

We welcome contributions! Please read CONTRIBUTING.md and sign our Contributor License Agreement (CLA) before submitting pull requests.

Contributions are welcome for:

• Client SDK libraries (bug fixes, new language bindings)
• Documentation and translations
• Conformance tests
• Specification editorial improvements

Patent Notice

LinkID technology is protected by patent application CH P220889 and international applications derived therefrom. Use of the client SDK libraries does not require a patent license. For details on patent licensing, see our licensing page.

Specifications

• W3C LinkID Specification
• IETF Internet-Draft: LinkID URI Scheme
• IANA linkid: URI Scheme Registration

Standards Activity

• WICG Proposal: LinkID – Web Incubator Community Group proposal
• TPAC 2025 Breakout Session – LinkID presentation at W3C TPAC 2025, Kobe
• TPAC 2025 Session Proposal – Original session proposal and discussion
• Wikimedia Hackathon 2026 – Improving Wikipedia Reference Integrity with Persistent LinkIDs · Milan, May 1–3 2026 · ⚓ T422252

Why LinkID? The Broken Links Problem

Research shows that link rot is a systemic problem across the Web:

• When Online Content Disappears – Pew Research Center (2024): 38% of web pages from 2013 are no longer accessible

Links

• Link Genetic GmbH – Company website
• LinkManager – AI-powered broken link detection and repair
• LinkID Portal – LinkID management portal
• LinkID Research Publications - Link Genetic Research Publications