OID4VC Presentation Exchange Library

A TypeScript library for handling OpenID for Verifiable Credentials (OID4VC) Presentation Exchange operations, providing comprehensive support for Presentation Definitions and Presentation Submissions according to the Presentation Exchange specification.

Features

• Presentation Definition Support: Full implementation of Presentation Definition types and validation
• Presentation Submission Handling: Parse and validate Presentation Submissions from various embed locations
• JSON Path Operations: Utilities for JSON Path validation and extraction
• Type Safety: Complete TypeScript support with comprehensive type definitions
• Multiple Embed Locations: Support for JWT, OIDC, DIDComms, VP, and CHAPI embed locations

Installation

npm install @vecrea/oid4vc-prex

Quick Start

import { PresentationExchange, JsonPathOps } from '@vecrea/oid4vc-prex';

// Parse a Presentation Submission
const jsonString = '{"presentation_submission": {...}}';
const result =
  await PresentationExchange.jsonParse.decodePresentationSubmission(jsonString);

if (result.isSuccess()) {
  const submission = result.value;
  console.log('Submission ID:', submission.id);
} else {
  console.error('Failed to parse:', result.error);
}

// Validate JSON Path
const isValid = JsonPathOps.isValid('$.credential.credentialSubject.id');
console.log('Is valid JSON Path:', isValid);

// Extract data using JSON Path
const jsonData =
  '{"credential": {"credentialSubject": {"id": "did:example:123"}}}';
const extracted = JsonPathOps.getJsonAtPath(
  '$.credential.credentialSubject.id',
  jsonData
);
console.log('Extracted value:', extracted);

API Reference

PresentationExchange

The main entry point for the library.

jsonParse.decodePresentationSubmission(input)

Parses a Presentation Submission from a JSON string or ReadableStream.

Parameters:

• input: string | ReadableStream<Uint8Array> - The JSON input

Returns: Promise<Result<PresentationSubmission>>

Example:

const result =
  await PresentationExchange.jsonParse.decodePresentationSubmission(jsonString);

JsonPathOps

Utility class for JSON Path operations.

JsonPathOps.isValid(path)

Validates if a string is a valid JSON Path.

Parameters:

• path: string - The JSON Path to validate

Returns: boolean

JsonPathOps.getJsonAtPath(jsonPath, jsonString)

Extracts data from JSON using a JSON Path.

Parameters:

• jsonPath: string - The JSON Path expression
• jsonString: string - The JSON string to extract from

Returns: string - The extracted value as a JSON string

Types

The library exports comprehensive TypeScript types for all Presentation Exchange components:

• JSONSchema - JSON Schema type alias for version 7
• Constraints - Constraint definitions for input descriptors
• DescriptorMap - Descriptor mapping specifications
• FieldConstraint - Field-level constraint definitions
• Filter - Filter specifications for credential filtering
• Format - Format definitions for credential formats
• From - Source specification for credentials
• Group - Group definitions for organizing input descriptors
• Id - Identifier types
• InputDescriptor - Input descriptor specifications
• InputDescriptorId - Input descriptor identifier types
• JsonObject - JSON object type definitions
• JsonPath - JSON Path type definitions
• Name - Name type definitions
• NonEmptySet - Non-empty set type definitions
• PresentationDefinition - Core presentation definition structure
• PresentationSubmission - Presentation submission data
• Purpose - Purpose definitions for input descriptors
• Rule - Rule definitions for constraints
• SubmissionRequirement - Submission requirement specifications

Embed Locations

The library supports parsing Presentation Submissions from various embed locations:

• JWT: Embedded in JWT tokens
• OIDC: Embedded in OpenID Connect flows
• DIDComms: Embedded in DID Communication messages
• VP: Embedded in Verifiable Presentations
• CHAPI: Embedded in Credential Handler API responses

Development

Prerequisites

• Node.js 18+
• npm or yarn

Setup

npm install

Build

npm run build

Testing

npm test

Type Checking

npm run typecheck

Linting

npm run lint

License

Licensed under the Apache License, Version 2.0. See the LICENSE file for details.

Contributing

This project follows the Presentation Exchange specification. When contributing, please ensure compliance with the specification and maintain type safety.

Related Links

• Presentation Exchange Specification
• OpenID for Verifiable Credentials