chainpoint-validate-js

A Node.js module for validating Chainpoint blockchain receipts

Installation

$ npm install --save chainpoint-validate

Usage

Use the isValidReceipt function to validate your Chainpoint receipt.

chainpointValidate.isValidReceipt(receipt, confirmAnchor, callback);
/*
  receipt - the receipt to be validated, as a string or JSON
  confirmAnchor - boolean indicating whether you want to confirm the existence of the anchor at its source. True to confirm that the merkle root is stored at the source specified in the anchor object of the receipt (such as in a bitcoin transaction's OP_RETURN value). Will append an 'exists' value to the anchor object in the results when True. False to validate only the receipt content and proof data. 
  callback - This function should expect an error message as its first parameter, and a result object as its second parameter
*/

Example

var chainpointvalidate = require('chainpoint-validate');

var chainpointValidate = new chainpointvalidate();

var validReceipt = {
 "@context": "https://w3id.org/chainpoint/v2",
 "type": "ChainpointSHA256v2",
 "targetHash": "bdf8c9bdf076d6aff0292a1c9448691d2ae283f2ce41b045355e2c8cb8e85ef2",
 "merkleRoot": "51296468ea48ddbcc546abb85b935c73058fd8acdb0b953da6aa1ae966581a7a",
 "proof": [
   {
     "left": "bdf8c9bdf076d6aff0292a1c9448691d2ae283f2ce41b045355e2c8cb8e85ef2"
   },
   {
     "left": "cb0dbbedb5ec5363e39be9fc43f56f321e1572cfcf304d26fc67cb6ea2e49faf"
   },
   {
     "right": "cb0dbbedb5ec5363e39be9fc43f56f321e1572cfcf304d26fc67cb6ea2e49faf"
   }
 ],
 "anchors": [
   {
     "type": "BTCOpReturn",
     "sourceId": "f3be82fe1b5d8f18e009cb9a491781289d2e01678311fe2b2e4e84381aafadee"
   }
 ]
};
var invalidReceipt = "not a receipt";

chainpointValidate.isValidReceipt(validReceipt, true, function (err, result) {
  if(err) {
    // handle this error
  } else {
    // result.isValid will equal true
    // result.anchors will be an array of anchor objects, optionally including
    // an exists parameter, if you configured validation to confirm the anchor as well
  }
});

chainpointValidate.isValidReceipt(invalidReceipt, true, function (err, result) {
  if(err) {
    // handle this error
  } else {
    // result.isValid will equal false
    // result.error will contain a reason why the receipt failed validation
  }
});

Sample Valid Result

{
  isValid: true,
  anchors: [
    {
      type: 'BTCOpReturn',
      sourceId: 'f3be82fe1b5d8f18e009cb9a491781289d2e01678311fe2b2e4e84381aafadee',
      exists: true
    }
  ]
}

When 'confirmAnchor' is set to true, an additional 'exists' value is added indicating the whether or not the data actually exists in the transaction. This function relies on BlockCypher's API which currently rate limits to 3 per second and 200 per hour. Confirmations requested beyond those limits will return false.

Sample Invalid Result

{
  isValid: false,
  error: 'Cannot parse receipt JSON'
}