# Data Integrity and SSI Types _(@interop/data-integrity-core)_

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> TypeScript types and definitions for the SSI ecosystem - cryptographic keys, DIDs, Verifiable Credentials, zCaps and related concepts.

## Table of Contents

- [Background](#background)
- [Install](#install)
- [Usage](#usage)
- [Contribute](#contribute)
- [License](#license)

## Background

If you're implementing the Verifiable Credential specification in TypeScript,
chances are that you're using a type definition for VerifiableCredentials
and VerifiablePresentations. Many VC-related projects (Sphereon's Veramo, 
LEF's LearnCard, Transmute's Verifiable Data) include the type definitions in
their monorepos.

We saw a niche for a standalone library that exported just the type definitions,
hence this repository.

See [W3C Verifiable Credentials Data Model](https://www.w3.org/TR/vc-data-model/)
specification.

Inspired by / incorporates elements of other VC Typescript libraries:

* https://github.com/Sphereon-Opensource/veramo (`/packages/core/src/types/vc-data-model.ts`)
* https://github.com/transmute-industries/verifiable-data (`/packages/vc.js/src/types/`)
* https://github.com/learningeconomy/LearnCard (`/packages/learn-card-core/src/types/`)
* Existing type definitions in DCC libraries (in `learner-credential-wallet` and others)

## Install

- Node.js 20+ is recommended.

### NPM

To install via NPM:

```
npm install @interop/data-integrity-core
```

### Development

To install locally (for development):

```
git clone https://github.com/interop-alliance/data-integrity-core.git
cd data-integrity-core
npm install
```

## Usage

```ts
import { IVerifiableCredential, IVerifiablePresentation } from '@interop/data-integrity-core'

// for example, in an Express route definition:
const vp = req.body.presentation as IVerifiablePresentation
```

**Import everything from the package root.** The root entry point
(`@interop/data-integrity-core`) re-exports every type, interface, and class
in this package, and is the recommended single import path. The package is
types-only with `"sideEffects": false`, so importing from the root is fully
tree-shakeable.

The subpath exports (`/did`, `/keypair`, `/loader`, `/vcdm`, `/zcap`) are
optional and exist only for narrower imports; each re-exports a subset of what
the root already provides. You never need a subpath to reach a type listed
below.

### Exported Types/Interfaces

* `IVerifiableCredential` and `IVerifiablePresentation`
* `IOpenBadgeCredentialV3` (for OBv3 VCs)
* `IDIDCoreDocument` and its children, `IDIDDocument_v1_0` and `IDIDDocument_v1_1`
* `IKeyPair` key description interface and its children, such as `IVerificationKeyPair2020` and `IKeyAgreementKeyPair2020`
* `AbstractKeyPair` abstract class (IKeyPair + signers, verifiers, and so on)
* `ISigner`
* `IDocumentLoader` and `IRemoteDocument`.
* `IZcap` and related interfaces (`IRootZcap`, `IDelegatedZcap`, `IZcapLike`, and `ICapabilityDelegationProof`)
* `IJWE` and related JOSE types (`IRecipient`, `IEPK`, `IKeyResolver`, `IKeyAgreementKey`, `IHMAC`)
* `IEDVDocument` and related EDV types (`IEncryptedDocument`, `IEDVConfig`, `IEDVChunk`, `IIndexEntry`, `IEDVQuery`)

## Contribute

PRs accepted.

See [CONTRIBUTING.md](CONTRIBUTING.md) -- code style and contribution
conventions.

If editing the Readme, please conform to the
[standard-readme](https://github.com/RichardLitt/standard-readme) specification.

## License

[MIT License](LICENSE.md) © 2026 Interop Alliance.