API

Ancon Protocol - Universal Metadata

Author	Rogelio Morrell Caballero
Category	VC, DID, PKI, Cryptography, NFT
Created	2021-08-23

Simple Summary

Enables an IPLD protocol level Metadata and Files smart contract for use with data economy use cases.

Abstract

Ancon delivers an immutable CID reference to a IPLD Node stored as a block in a Cosmos IAVL merkle tree. Similar to Flow Cadence resource oriented language, Ancon Metadata is unique and must be implemented as a store prefix, where any account owns its resources. In our implementation, we defined accounts as a DID method that uses a ethr-did-registry inspired implementation in Cosmos.

API

POST /ancon.v1.metadata.add

ancon.metadata.add(value, [options])

Adds an universal metadata.

Parameters

Metadata

Name	Type	Description
name	string	Identifies the asset to which this metadata represents
description	string	Describes the asset to which this token represents
image	string	A URI pointing to a resource with mime type image/* representing the asset to which this token represents
sources	array of string	Current intellectual property
owner	string	The owner is a DID identifier
parent	string	Transaction block
verifiedCredentialRef	string	Is the verified credential for the metadata
links	array of string	References

Returns

Type	Description
Promise<Response>	An object that contains the CID

example of the returned object:

{
  hash: "QmHash.."
}

Metadata JSON Schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "$id": "https://ancon.dao.pa/v1/protocol/metadata",
  "title": "metadata",
  "description": "Ancon Protocol metadata schema",
  "type": "object",
  "properties": {
      "name": {
          "type": "string",
          "description": "Identifies the asset to which this token represents",
      },
      "description": {
          "type": "string",
          "description": "Describes the asset to which this token represents",
      },
      "image": {
          "type": "string",
          "description": "A URI pointing to a resource with mime type image/* representing the asset to which this token represents.",
      },
      "sources": {
          "type": "array",
          "description": "Current intellectual property",
      },
      "owner": {
          "type": "string",
          "description": "The owner is a DID identifier",
      },
      "parent": {
          "type": "string",
          "description": "Direct ascendant of the current intellectual property",
      },
      "verifiedCredentialRef": {
          "type": "string",
          "description": "Is the verified credential for the metadata",
      },
      "links": {
          "type": "array",
          "description": "Sample of references included in the current intellectual property",
      }
  },
  "required": [ "name", "description", "image", "sources" ]
}

Example

A new NFT token can use Ancon Protocol to store IPLD CID in Metadata to keep it verifiable.

Upload content and stores CID for each content, content needs to be CID or multihash to be verifiable.

Link your content to metadata accordingly and store it in Ancon using AnconJS

const payload = {
  "name": "XDV metadata sample",
  "description": "testing sample",
  "image": "https://explore.ipld.io/#/explore/QmSnuWmxptJZdLJpKRarxBMS2Ju2oANVrgbr2xWbie9b2D",
  "services": ["https://explore.ipld.io/#/explore/",
  "https://explore.ipld.io/#/explore/",
  "https://explore.ipld.io/#/explore/"],
  "links": [
    "QmSnuWmxptJZdLJpKRarxBMS2Ju2oANVrgbr2xWbie9b2D",
    "z8mWaJHXieAVxxLagBpdaNWFEBKVWmMiE",
    "QmdmQXB2mzChmMeKY47C43LxUdg1NDJ5MWcKMKxDu7RgQm",
  ],
};


const res = await ancon.metadata.add(payload)
console.log(`https://gateway.dao.pa/ancon/${res.cid}`)

Mint or anchor your Ancon metadata after its vetted by chain consensus protocol. The metadata is just a link to a gateway and always public.

GET /ancon/{cid}{path}

ancon.metadata.get(hash, [options])

Gets a metadata.

Parameters

File

Name	Type	Description
path	string	Describes the path
cid	multihash	IPLD multihash

Returns

Type	Description
Promise<Response>	An object that contains the data

example of the returned object:

{
  data: "Mksadsoks=="
}