Overview

This a PoC for encapsulating HTTP responses on Cardano chain that can be retrieved via cardano-graphql using custom URI cardano+metadata://$TX_ID?network=$NETWORK&key=$METADATUM_LABEL&type=http-response.

type=http-response is an optional parameter that allows the library to parse the metadata JSON object as if it were an actual HTTP response and then, return a mocked axios response (more info here). If it's not parsed, the plain JSON object is returned "as it is" on-chain.

It defaults to use dandelion.link's cardano-graphql deployments that can be overriden passing a valid URL via graphql query string parameter.

I currently have tested using nodejs, but should build and work on browsers 🤷

Build

npm install
npm run build

Usage from React

I've managed to use this library right in the same way than in the examples by from a React app. For that you just need to:

• Install npm package:

npm i @repsistance/cardano-meta-handler

• Snippet:

import cardanoMetaHandler from '@repsistance/cardano-meta-handler'

const uri = "metadata+cardano://2065e342de1748dd69788f71e7816b61b0e93da942a87a5a334d6a9a3defdc2a?network=testnet&key=104116116112&type=http-response"
const request = await cardanoMetaHandler.get(uri);

console.log(request.data);

Run by examples

# get tx metadata as it is on-chain (gzip+base64)
node examples/get-plain-metadata.js

# aplication/pgp-signature example
node examples/get-http-response-metadata.js | jq . 

# aplication/ld+json example
node examples/get-http-response-metadata2.js | jq .

# verify rcmorano's 3D-ADA json-ld response from Cardano chain
node examples/verify-pgp-metadata.js

# build txmetadata object from file:/// uri
node examples/build-txmeta-from-file.js

# build tx metadata object from https:// uri
node examples/build-txmeta-from-weburl.js

Check examples for some comments.