VCX NodeJS Wrapper¶

https://github.com/sktston/vcx-demo-node

This is a NodeJS wrapper for VCX library. VCX is the open-source library on top of Libindy which fully implements the credentials exchange.

Note: This library is currently in experimental state.

Contribution Guide¶

Make sure you have these packages installed:

StandardJS
Typescript
TSLint

Also this has a dependency on: * libvcx debian Because it creates a symlink (/usr/lib/libvcx.so)

Run this commands before submitting your PR:

npm run lint

Documentation:¶

Run these commands:

npm install
npm ci
npm run doc-gen

* A directory will be created locally ./docs which contains an index.html file which can be used to navigate the generated documents.

Run Demo¶

The demo represents example how 2 actors, Alice and Faber institution, exchange credentials.
They may consult Indy blockchain (pool of Indy nodes) to find out certain pieces of information. Faber and Alice are represented by 2 scripts faber.js and alice.js but you could imagine that there's a webserver running code alike what's inside faber.js and there's a perhaps smartphone or laptop running code alike in alice.js.
Faber and Alice in the demo also don't exchange the credentials peer to peer. Instead, the exchange happens through intermediary service represented by Dummy Cloud Agent. The data Alice and Faber are exchanging over Dummy Cloud Agent are however encrypted and cannot be read by the Dummy Cloud Agent. The Dummy Cloud Agent is something like illiterate postman. He'll take a letter from one party and delivers it to the other party. But he's unable to read the messages he's handling.

Pre-requirements¶

Libraries¶

Before you'll be able to run demo, you need to make sure you've compiled - libindy - libvcx - libnullpay - Optionally libindystrgpostgres if you want to run demo with postgres wallet.

Library binaries must be located /usr/local/lib on OSX, /usr/lib on Linux.

Indy pool¶

You'll also have to run pool of Indy nodes on your machine. You can achieve by simply running a docker container which encapsulates multiple interconnected Indy nodes. Instructions here.

Steps to run demo¶

Install NodeJS dependencies
```
npm install
```
Compile LibVCX Wrapper
```
npm run compile
```
Start Dummy Cloud Agent
Run Faber agent, representing an institution
```
npm run demo:faber
```
Give it a few seconds, then run Alice's agent which will connect with Faber's agent
```
npm run demo:alice
```

Demo with Posgres wallet¶

You can also run demo in mode where both Faber and Alice are using Postgres wallets. Follow instructions to compile postgres wallet plugin and startup local postgres docker container.

Once yu have that ready, use these commands to start demo in postgres mode.

npm run demo:faber:pg

npm run demo:alice:pg

Demo with webhook notifications¶

Another feature are webhook notifications. If you run sample webhook notification server by running: npm run demo:notifyserver

This will start new http server on localhost:7209.

Opened port on localhost:7209 will modify Faber and Alice in the demo in following way: They will register their notification webhook in cloud agency. Everytime cloud agent will receive a message on behalf of the owner, it will send notification to webhook url specified in agent configuration. In the case of this demo, it's by default localhost:7209/notifications/faber and localhost:7209/notifications/alice.

Additional Demo¶

Examples of multi-holder implementation by extending the previous faber-alice example are in the demo-multi and demo-webhook directories. In the previous faber-alice example, Faber is implemented to act as the Issuer and Verifier at the same time. In the multi-holder examples, this is divided into Issuer and Verifier respectively. (faber-issuer, faber-verifier)

Both the demo-multi anddemo-webhook examples implement multi-holders, but the difference between the agent message check method is that demo-multi uses the polling method and demo-webhook uses the webhook triggered method.

Before running demo-multi and demo-webhook, dummy cloud agent or vcxnodeagency must be executed first. It is recommended to use 3 terminals for example execution

Terminal-1: ~/demo-webhook/node faber-issuer.js -> copy invitation code
Terminal-2: ~/demo-webhook/node faber-verifier.js -> copy invitation code
Terminal-3: ~/demo-webhook/node alice-multi.js -i 'issuer invitation code' -v 'verifier invitation code' -n <number of alice>

alice-multi.js must provide the corresponding invitation code as a parameter to connect to the faber-issuer and faber-verifier.
-i and -v options
Be careful to wrap it with ' ' when giving invitation code arguments to the shell. for example, node alice-multi.js -v '{"@id":"70d5ed' -v '{"@id":"3a685538-78' -n 16
In the demo-multi example, the invitation code must be given through the -i and -v options, but can be omitted in the demo-webhook example.
In the demo-webhook example, the http server is running on the faber-issuer and faber-verifier, and alice-multi can connect to the server to receive the invitation code.
For example, node alice-multi.js -n 16