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javascriptjsonpostbitcoinaxios

Broadcasting Raw Transaction on Blockcypher, getting a error on POST request

I have a raw bitcoin transaction, that I would like to broadcast with the Blockcypher API, I'm using axios to send the POST request:

var axios = require('axios')

axios.post('https://api.blockcypher.com/v1/bcy/test/txs/send', {
    "tx": "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"
  })
  .then(function (response) {
    console.log(response);
  })
  .catch(function (response) {
    console.log(response);
  });

I get an error when running this in the terminal: 

{ data: { error: 'Couldn\'t deserialize request: json: cannot unmarshal string into Go value of type pooch.JSONTx' }

Any idea what's wrong with my POST? I tried to post with tx instead of "tx" but it still doesn't work. On the docs, they suggest to do it like this:

var pushtx = {
  tx: "01000000011935b41d12936df99d322ac8972b74ecff7b79408bbccaf1b2eb8015228beac8000000006b483045022100921fc36b911094280f07d8504a80fbab9b823a25f102e2bc69b14bcd369dfc7902200d07067d47f040e724b556e5bc3061af132d5a47bd96e901429d53c41e0f8cca012102152e2bb5b273561ece7bbe8b1df51a4c44f5ab0bc940c105045e2cc77e618044ffffffff0240420f00000000001976a9145fb1af31edd2aa5a2bbaa24f6043d6ec31f7e63288ac20da3c00000000001976a914efec6de6c253e657a9d5506a78ee48d89762fb3188ac00000000"
};

$.post('https://api.blockcypher.com/v1/bcy/test/txs/push', JSON.stringify(pushtx))
  .then(function(d) {console.log(d)});

But when I do that I get the error:

TypeError: undefined is not a function

So I think using axios is easier because I'm at least getting a response from Blockcypher back. Any help would be really appreciated!

Solution

  • Full disclosure: BlockCypher's Developer Advocate here. First, Per Greg's advice in the comments, in the first case, using the /txs/send endpoint we expect a TX Skeleton. This is outlined more clearly in the Creating Transactions section of the docs.

    Using /txs/push should work in your case, although I also got an error. To investigate, I first checked out our /txs/decode endpoint, which is a good first step for debugging, since it will show you how our servers deserialize a raw transaction. You can read more about it here.

    var decodetx = {
  tx: "01000000011935b41d12936df99d322ac8972b74ecff7b79408bbccaf1b2eb8015228beac8000000006b483045022100921fc36b911094280f07d8504a80fbab9b823a25f102e2bc69b14bcd369dfc7902200d07067d47f040e724b556e5bc3061af132d5a47bd96e901429d53c41e0f8cca012102152e2bb5b273561ece7bbe8b1df51a4c44f5ab0bc940c105045e2cc77e618044ffffffff0240420f00000000001976a9145fb1af31edd2aa5a2bbaa24f6043d6ec31f7e63288ac20da3c00000000001976a914efec6de6c253e657a9d5506a78ee48d89762fb3188ac00000000"
};

$.post('https://api.blockcypher.com/v1/bcy/test/txs/decode', JSON.stringify(decode))
  .then(function(d) {console.log(d)});

    This worked for me, returning the decoded (but not pushed!) transaction:

    {
  "block_height": -1,
  "block_index": -1,
  "hash": "4e6dfb1415b4fba5bd257c129847c70fbd4e45e41828079c4a282680528f3a50",
  "addresses": [
    "CEztKBAYNoUEEaPYbkyFeXC5v8Jz9RoZH9",
    "C1rGdt7QEPGiwPMFhNKNhHmyoWpa5X92pn"
  ],
  "total": 4988000,
  "fees": 12000,
  "size": 226,
  "preference": "high",
  "relayed_by": "54.213.170.147, 127.0.0.1",
  "received": "2016-02-17T20:16:43.124983132Z",
  "ver": 1,
  "lock_time": 0,
  "double_spend": false,
  "vin_sz": 1,
  "vout_sz": 2,
  "confirmations": 0,
  "inputs": [
    {
      "prev_hash": "c8ea8b221580ebb2f1cabc8b40797bffec742b97c82a329df96d93121db43519",
      "output_index": 0,
      "script": "483045022100921fc36b911094280f07d8504a80fbab9b823a25f102e2bc69b14bcd369dfc7902200d07067d47f040e724b556e5bc3061af132d5a47bd96e901429d53c41e0f8cca012102152e2bb5b273561ece7bbe8b1df51a4c44f5ab0bc940c105045e2cc77e618044",
      "output_value": 5000000,
      "sequence": 4294967295,
      "addresses": [
        "CEztKBAYNoUEEaPYbkyFeXC5v8Jz9RoZH9"
      ],
      "script_type": "pay-to-pubkey-hash",
      "age": 386562
    }
  ],
  "outputs": [
    {
      "value": 1000000,
      "script": "76a9145fb1af31edd2aa5a2bbaa24f6043d6ec31f7e63288ac",
      "addresses": [
        "C1rGdt7QEPGiwPMFhNKNhHmyoWpa5X92pn"
      ],
      "script_type": "pay-to-pubkey-hash"
    },
    {
      "value": 3988000,
      "script": "76a914efec6de6c253e657a9d5506a78ee48d89762fb3188ac",
      "spent_by": "892fd7b36c1c3a2e5edb9b4a5d4ffd9ba74d78d3acf3b249991bd8d10a287dbd",
      "addresses": [
        "CEztKBAYNoUEEaPYbkyFeXC5v8Jz9RoZH9"
      ],
      "script_type": "pay-to-pubkey-hash"
    }
  ]
}

    Everything looks good here. So I tried to use /txs/push, this time, collecting the error message in the return through a cURL:

    curl -d '{"tx":"01000000011935b41d12936df99d322ac8972b74ecff7b79408bbccaf1b2eb8015228beac8000000006b483045022100921fc36b911094
280f07d8504a80fbab9b823a25f102e2bc69b14bcd369dfc7902200d07067d47f040e724b556e5bc3061af132d5a47bd96e901429d53c41e0f8cca012102152e2bb5b273561ece7bbe8b1d
f51a4c44f5ab0bc940c105045e2cc77e618044ffffffff0240420f00000000001976a9145fb1af31edd2aa5a2bbaa24f6043d6ec31f7e63288ac20da3c00000000001976a914efec6de6c2
53e657a9d5506a78ee48d89762fb3188ac00000000"}' https://api.blockcypher.com/v1/bcy/test/txs/push
{"error": "Error validating transaction: Transaction with hash 4e6dfb1415b4fba5bd257c129847c70fbd4e45e41828079c4a282680528f3a50 already exists.."}

    Sure enough, per that error message, that transaction already exists on our internal testnet, as seen here:

    https://live.blockcypher.com/bcy/tx/4e6dfb1415b4fba5bd257c129847c70fbd4e45e41828079c4a282680528f3a50/

    I think you were trying to push an already-pushed raw transaction. If you want to test transaction creation, I'd recommend generating your own addresses on our testnet here:

    http://dev.blockcypher.com/#generate-address-endpoint

    You can use our faucet to send some coins to those addresses:

    http://dev.blockcypher.com/#testing (or through a web interface here: https://accounts.blockcypher.com/blockcypher-faucet ).

    Then follow the steps outlined in the "Creating Transactions":

    http://dev.blockcypher.com/#creating-transactions

    Hope that helps!