JavaScript quickstart for BigchainDB

‼️ High chance of 🔥 and 😡 ahead if you expect this to be production-ready.

‼️ ONLY (and I mean only) supports BigchainDB Server 0.9

Some naive helpers to get you on your way to making some transactions 💥, if you'd like to use BigchainDB with JavaScript.

Aimed to support usage in browsers or node; if it doesn't, well, I don't know what to say except it's probably you 😏. Use at your own risk 🚀. At least I can tell you it's ES∞+, so you'll probably need a babel here and a bundler there (or use one of the built versions), of which I expect you'll know quite well (otherwise, go check out js-reactor 😉).

Getting started

Srs, just read through index.js and see if you can make any sense of it.

You may also be interested in a long-form example with actual code.

The expected flow for making transactions:

1. Go get yourself some keypairs! Just make a new Keypair() (or a whole bunch of them, nobody's counting 😎).
2. Go get yourself a condition! makeEd25519Condition() should do the trick ✨.
3. Go wrap that condition as an output (don't worry about the why)! makeOutput() no sweat 💪.
4. (Optional) You've got everyting you need, except for an asset. Maybe define one (any JSON-serializable object will do).
5. Time to get on the rocket ship, baby. makeCreateTransaction() your way to lifelong glory and fame 👏!
6. Ok, now you've got a transaction, but we need you to sign (signTransaction()) it cause, you know... cryptography and ¯\_(ツ)_/¯.
7. Alright, sick dude, you've finally got everything you need to POST to a server. Phew 💦. Go fetch() your way to business, start☝️life4evar!

...

Alright, alright, so you've made a couple transactions. Now what? Do I hear you saying "_{Transfer them??}" No problem, brotha, I gotcha covered :neckbeard:.

1. Go get some more outputs (wrapping conditions), maybe based on some new made-up friends (i.e. keypairs).
2. Go make a transfer transaction, using the transaction you want to spend (i.e. you can fulfill) in makeTransferTransaction() ✌️. If you're not sure what any of this means (and you're as confused as I think you are right now), you might wanna go check out this and this and this first.
3. Sign that transaction with signTransaction()!
4. POST to the server, and watch the 💵s drop, man.

Needs for speeds

This implementation plays "safe" by using JS-native (or downgradable) libraries for its crypto-related functions to keep compatabilities with the browser. If that makes you 😒 and you'd rather go :godmode: with some ⚡ ⚡, you can try using some of these to go as fast as a 🚤 --🏄‍♂️ :

• chloride, or its underlying sodium library
• node-sha3 -- MAKE SURE to use steakknife's fork if the FIPS 202 upgrade hasn't been merged (otherwise, you'll run into all kinds of hashing problems)

🚨 WARNING WARNING WARNING 🚨

Crypto-conditions

Make sure you keep using a crypto-conditions implementation that implements the older v1 draft (e.g. five-bells-condition@v3.3.1). BigchainDB Server 0.9 does not implement the newer version of the spec and WILL fail if you to use a newer implementation of crypto-conditions.

SHA3

Make sure to use a SHA3 implementation that has been upgraded as per FIPS 202. Otherwise, the hashes you generate WILL be invalid in the eyes of the BigchainDB Server.

Ed25519

If you do end up replacing tweetnacl with chloride (or any other Ed25519 package), you might want to double check that it gives you a correct public/private (or verifying/signing, if they use that lingo) keypair.

An example BigchainDB Server-generated keypair (encoded in base58):

• Public: "DjPMHDD9JtgypDKY38mPz9f6owjAMAKhLuN1JfRAat8C"
• Private: "7Gf5YRch2hYTyeLxqNLgTY63D9K5QH2UQ7LYFeBGuKvo"

Your package should be able to take in the decoded version of the private key and return you the same public key (once you encode that to base58).

---

Example

OK, OK, I gotcha, you'd rather see some actual code rather than a giant list of steps that don't mean anything. 👇 is for you.

import {
    Ed25519Keypair,
    makeEd25519Condition,
    makeOutput,
    makeCreateTransaction,
    makeTransferTransaction,
    signTransaction,
} from 'js-bigchaindb-quickstart'; // Or however you'd like to import it

/**********************
 * CREATE transaction *
 **********************/
// First, create a keypair for our new friend, Ash (let's be real--who would you rather catch some
// Pokemon: Alice or the Ketchum man himself?)
const ash = new Ed25519Keypair();

console.log(ash.publicKey); // something like "DjPMHDD9JtgypDKY38mPz9f6owjAMAKhLuN1JfRAat8C"
console.log(ash.privateKey); // something like "7Gf5YRch2hYTyeLxqNLgTY63D9K5QH2UQ7LYFeBGuKvo"

// Let's get an output and condition that lets Ash be the recipient of the new asset we're creating
const ashCondition = new makeEd25519Condition(ash.publicKey);
const ashOutput = new makeOutput(ashCondition);

console.log(ashOutput);
/* Something like
{
    "amount": 1,
    "condition": {
        "details": {
            "signature": null,
            "type_id": 4,
            "type": "fulfillment",
            "bitmask": 32,
            "public_key": "DjPMHDD9JtgypDKY38mPz9f6owjAMAKhLuN1JfRAat8C"
        },
        "uri": "cc:4:20:vSfobaaMSP52nxnVkPiLMysCTR-t8JpjbWIdU6SvRYU:96"
    },
    "public_keys": [
        "DjPMHDD9JtgypDKY38mPz9f6owjAMAKhLuN1JfRAat8C"
    ]
}
*/

// Let's make an asset, to pretend this isn't boring.
const pokeAsset = {
    'name': 'Pikachu',
    'trait': 'Will never, ever, EVAARRR leave your back'
};

const noMetadata = null; // Let's ignore that meta-stuff for now

// Now let's go give Ash his beloved Pikachu
const createPokeTx = makeCreateTransaction(pokeAsset, noMetadata, [ashOutput], ash.publicKey);

console.log(createPokeTx);
/* Something like
{
    "id": "38acf7a938a39be335afc8e7300468b981a29813d52938104ba3badfe21470c9",
    "operation": "CREATE",
    "outputs": [
        {
            "amount": 1,
            "condition": {
                "details": {
                    "signature": null,
                    "type_id": 4,
                    "type": "fulfillment",
                    "bitmask": 32,
                    "public_key": "DjPMHDD9JtgypDKY38mPz9f6owjAMAKhLuN1JfRAat8C"
                },
                "uri": "cc:4:20:vSfobaaMSP52nxnVkPiLMysCTR-t8JpjbWIdU6SvRYU:96"
            },
            "public_keys": [
                "DjPMHDD9JtgypDKY38mPz9f6owjAMAKhLuN1JfRAat8C"
            ]
        }
    ],
    "inputs": [
        {
            "fulfillment": null,
            "fulfills": null,
            "owners_before": [
                "DjPMHDD9JtgypDKY38mPz9f6owjAMAKhLuN1JfRAat8C"
            ]
        }
    ],
    "metadata": null,
    "asset": {
        "data": {
            "name": "Pikachu",
            "trait": "Will never, ever, EVAARRR leave your back"
        }
    },
    "version": "0.9"
}
*/

// Let's sign this thing to make it legit! (Let's call Ash the "issuer", but a registered PokeCorp
// could be the one issuing instead)
const signedCreateTx = signTransaction(createPokeTx, ash.privateKey);

console.log(signedPokeTx);
/* Something like
{
    "id": "38acf7a938a39be335afc8e7300468b981a29813d52938104ba3badfe21470c9",
    "operation": "CREATE",
    "outputs": [
        {
            "amount": 1,
            "condition": {
                "details": {
                    "signature": null,
                    "type_id": 4,
                    "type": "fulfillment",
                    "bitmask": 32,
                    "public_key": "DjPMHDD9JtgypDKY38mPz9f6owjAMAKhLuN1JfRAat8C"
                },
                "uri": "cc:4:20:vSfobaaMSP52nxnVkPiLMysCTR-t8JpjbWIdU6SvRYU:96"
            },
            "public_keys": [
                "DjPMHDD9JtgypDKY38mPz9f6owjAMAKhLuN1JfRAat8C"
            ]
        }
    ],
    "inputs": [
        {
            "fulfillment": "cf:4:vSfobaaMSP52nxnVkPiLMysCTR-t8JpjbWIdU6SvRYWj-cp1qb1vsTSt_775cGe-NQFxgyUQvcPx1nWkJRgXhMvTk2vN2QJU_nd2DgeTbIcWBF-8-N1SH2WqQLsXJLcP",
            "fulfills": null,
            "owners_before": [
                "DjPMHDD9JtgypDKY38mPz9f6owjAMAKhLuN1JfRAat8C"
            ]
        }
    ],
    "metadata": null,
    "asset": {
        "data": {
            "name": "Pikachu",
            "trait": "Will never, ever, EVAARRR leave your back"
        }
    },
    "version": "0.9"
}
*/

// Alright, now you've got yourself a valid transaction and you can do some crazy thing like send it
// over to a BigchainDB node. I'll leave that as an exercise for you ;).

/************************
 * TRANSFER transaction *
 ************************/
// Alright, let's get Ash some imaginary friends (remember Brock? Neither do I)
const brock = new Ed25519Keypair(); // public: "H8ZVy61CCKh5VQV9nzzzggNW8e5CyTbSiegpdLqLSmqi", private: "5xoYuPP92pznaGZF9KLsyAdR5C7yDU79of1KA9UK4qKS"

// Let's pretend that, for the sake of this example, Ash can actually part with Pikachu. Let's trade
// Pikachu to Brock (we won't be getting anything back, but if it helps, you can pretend Brock'll
// give Ash some help with his love life).
const brockCondition = new makeEd25519Condition(brock.publicKey);
const brockOutput = new makeOutput(brockCondition);

// Let's create the TRANSFER transaction cementing this trade. We'll use the "unspent" CREATE
// transaction that assigned Pikachu to Ash as an input to this TRANSFER.
// Note that we'll keep ignoring that metadata stuff.
// Also note that we could use either `createPokeTx` (unsigned) or `signedCreateTx` (signed) here
// for the input transaction. Either way, we'll be fulfilling the first (and only) output set in it.
const fulfilledOutputIndex = 0;
const transferPokeTx = makeTransferTransaction(createPokeTx, noMetadata, [brockOutput], fulfilledOutputIndex);

// OK, let's sign this TRANSFER (Ash has to, as he's the one currently in "control" of Pikachu)
const signedTransferTx = signTransaction(transferPokeTx, ash.privateKey);

console.log(signedTransferTx);
/* If everything went well, you should get something like this
{
    "id": "0876962a40479e171135cd92dbae7f0216f2691561b56a579cff631371d4d128",
    "operation": "TRANSFER",
    "outputs": [
        {
            "amount": 1,
            "condition": {
                "details": {
                    "signature": null,
                    "type_id": 4,
                    "type": "fulfillment",
                    "bitmask": 32,
                    "public_key": "H8ZVy61CCKh5VQV9nzzzggNW8e5CyTbSiegpdLqLSmqi"
                },
                "uri": "cc:4:20:76rNv-DAIjZC0-68Gl0KEuDpcJRpCAAQXxvVbTvQAxE:96"
            },
            "public_keys": [
                "H8ZVy61CCKh5VQV9nzzzggNW8e5CyTbSiegpdLqLSmqi"
            ]
        }
    ],
    "inputs": [
        {
            "fulfillment": "cf:4:vSfobaaMSP52nxnVkPiLMysCTR-t8JpjbWIdU6SvRYU8UJKi0Oq7QoCXIHuiWEYzxfgVEYs9HHtDIWBSkq1uvMX6l7VKwUCrK93k6JMNVBA8djOa5UGfDDF49xLVEgQI",
            "fulfills": {
                "output": 0,
                "txid": "38acf7a938a39be335afc8e7300468b981a29813d52938104ba3badfe21470c9"
            },
            "owners_before": [
                "DjPMHDD9JtgypDKY38mPz9f6owjAMAKhLuN1JfRAat8C"
            ]
        }
    ],
    "metadata": null,
    "asset": {
        "id": "38acf7a938a39be335afc8e7300468b981a29813d52938104ba3badfe21470c9"
    },
    "version": "0.9"
}
*/

// Assuming you figured out how to send a transaction to a BigchainDB node, and that the federation
// you sent it to has validated the CREATE transaction you sent, you should now be able to cement
// the TRANSFER of Pikachu to Brock by sending `signedTransferTx` to a node in the same federation.



=========================================================================================================



                  /*************************************************************
                   *                                                           *
                   *                  ~~~   CHALLENGE   ~~~                    *
                   *                                                           *
                   *   So who's making the decentralized version of Pokemon?   *
                   *                    (cause I want in)                      *
                   *                                                           *
                   *************************************************************/