# Cert Verifier with external explorer APIs

**URL:** <https://community.blockcerts.org/t/cert-verifier-with-external-explorer-apis/2711>\
**Category:** Technical\
**Created:** [January 18, 2021, 12:11pm UTC](https://community.blockcerts.org/t/cert-verifier-with-external-explorer-apis/2711 "2021-01-18T12:11:56Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![danishfastian](https://avatars.discourse-cdn.com/v4/letter/d/85f322/32.png) [@danishfastian](https://community.blockcerts.org/u/danishfastian)\
**Post date:** [January 18, 2021, 12:11pm UTC](https://community.blockcerts.org/t/cert-verifier-with-external-explorer-apis/2711/1 "2021-01-18T12:11:56Z")

</div>

Has anyone tried Cert Verifier JS with options to pass Explorer API implementation as an argument. I can see the documentation however when I tried to pass implementation it gives an error. Below is the code. and error I am getting is “One or more of your custom explorer APIs does not have a parsing function”

```
var myOptions = {
                explorerAPIs:
                [
                    {
                        serviceName: "BlockCypherTest",
                        parsingFunction: function (e) {
                            if (e.confirmations < mr) throw new Yn(Gt, mn("errors", "parseBlockCypherResponse"));
                            const t = Qf(e.received), r = e.outputs, n = r[r.length - 1], i = e.inputs[0].addresses[0];
                            return { remoteHash: oN(n.script, hr.bitcoin.prefixes), issuingAddress: i, time: t, revokedAddresses: r.filter(e => !!e.spent_by).map(e => e.addresses[0]) }
                        },
                        priority: 1,
                        serviceURL:
                        {
                            main: "https://api.blockcypher.com/v1/btc/main/txs/{transaction_id}?limit=500",
                            test: "https://api.blockcypher.com/v1/btc/test3/txs/{transaction_id}?limit=500"
                        }
                    }
                ] 
            };    

            const certificate = new Verifier.Certificate(this.certJSON, myOptions);
```

---

<div class="post-metadata">

**Author:** ![danishfastian](https://avatars.discourse-cdn.com/v4/letter/d/85f322/32.png) [@danishfastian](https://community.blockcerts.org/u/danishfastian)\
**Post date:** [January 24, 2021, 10:24am UTC](https://community.blockcerts.org/t/cert-verifier-with-external-explorer-apis/2711/2 "2021-01-24T10:24:24Z")

</div>

Thanks a lot for fixing the issue.

> <https://github.com/blockchain-certificates/cert-verifier-js/issues/846>
>
> As per my below post I am getting below error when trying to use external API
> https://community.blockcerts.org/t/cert-verifier-with-external-explorer-apis/2711
> Some observations based on debugging:
> Deep copy...