Paydata is the simplest library for building and broadcasting data transactions to the Bitcoin SV blockchain.
Signed transactions include 10 satoshis as developer fee to keep libraries updated and improved.
Post to the blockchain with just 4 lines of code.
Paydata.send({
safe: true,
pay: { key: privateKey },
data: ["0x6d02", "Hello from Paydata"]
});
Post to both memo.sv and other compatible dapps with a single interface.
Create 1satordinals and inscribe onchain
Install both paydata
and bsv2
(Paydata has a peer dependency on bsv2)
npm install @samooth/paydata
and then require it
const paydata = require('@samooth/paydata')
<script src='https://unpkg.com/@samooth/paydata'></script>
or
<script src='https://bsv.direct/lib/paydata.min.js'></script>
Send "Hello from Paydata"
to memo.sv in 5 lines of code.
const privateKey = [YOUR PRIVATE KEY HERE];
paydata.send({
safe: true,
pay: { key: privateKey },
data: ["0x6d02", "Hello from Paydata"]
});
Above code builds an OP_RETURN
transaction with 0x6d02 hello
as push data, and broadcasts it to Bitcoin SV network.
Paydata lets you build a transaction in a declarative manner. Here's an example:
var config = {
safe: true,
feeKb: 50,
pay: {
key: "5JZ4RXH4MoXpaUQMcJHo8DxhZtkf5U5VnYd9zZH8BRKZuAbxZEw",
to: [{
address: "1A2JN4JAUoKCQ5kA4pHhu4qCqma8jZSU81",
value: 1000
}]
},
data: ["0x6d02", "hello from Paydata"]
}
Above config describes a transaction that:
- Posts
"hello from Paydata"
to memo.sv network (See the protocol at https://memo.sv/protocol), - paying the fee of
50
satoshis per kilobyte, - signed with a private key:
5JZ4RXH4MoXpaUQMcJHo8DxhZtkf5U5VnYd9zZH8BRKZuAbxZEw
, - through Bitails endpoint at https://bitails.io
- while tipping the user
1A2JN4JAUoKCQ5kA4pHhu4qCqma8jZSU81
a value of1000
satoshis.
All you need to do to invoke it is call:
paydata.send(config)
Want to instead build a transaction but save it for later or export it? Just call:
paydata.build(config, function(error, tx) {
console.log("Here's the transaction! : ", tx)
})
And that's it! No complex APIs, but you can construct pretty much all kinds of transactions.
Paydata
is powered by bsv, which in turn is a fork of bitcore-lib, which means all the low level transactions are completely robust and secure, since they're being used in production at companies like:
- Moneybutton
- Bitpay
- and more
Paydata
was created in order to make it dead simple to construct OP_RETURN
related transactions, but you can even use it to build regular transactions.
Also Paydata
exposes Paydata.bsv
endpoint which you can use to access the underlying bsv
library. If you need more sophisticated features (in most cases you won't), feel free to use this feature. Best of both worlds!
Paydata is designed with a different philosophy than conventional Bitcoin transaction libraries.
While traditional Bitcoin libraries focus on sending money, Paydata is focused on sending data.
The API is optimized to make this as simple as possible. Paydata library has only two methods:
build
: For building a transaction (but not sending)send
: For sending a transaction
"build" builds a transaction but doesn't broadcast it to the network.
The build()
method takes two arguments:
- A JSON object describing the type of transaction
- A callback function that will be called after building the transaction: The callback function has two arguments. The first is an error object if something fails. The second is the constructed transaction.
The first argument--a declarative JSON object--can contain the following attributes:
-
pay
: For describing everything related to actually sending money (optional) -
data
: For constructingOP_RETURN
data -
network
: Selects the network,main
for Mainnet ortest
for testnet -
safe
: Please set totrue
. This will create a "safe"OP_FALSE OP_RETURN
transaction instead of rawOP_RETURN
. (Learn more) -
opReturn
: Switch OP_RETURN flag to off in case is needed, will removeOP_RETURN
from script. -
tx
: For importing previously "built" transactions (optional) -
feeKb
: Fee per Kb (optional: default is 1) -
lock
: nLocktime (optional: default is 0) -
seq
: nSequence to apply to all utxos (optional: default MAX) -
utxos
: Array of utxos to use as inputs (optional: default queries API), customhashType
,seq
andscript
can be specified per utxo. -
hashType
: Custom SIGHASH flag to apply to all utxos (optional: default isall
)
Instead of just building, you can build AND send. Same syntax as build()
.
The only difference is the callback function.
- build() returns a constructed transaction object through the callback
- send() returns a transaction hash (since it's already been sent)
const tx = {
safe: true,
pay: { key: "5JZ4RXH4MoXpaUQMcJHo8DxhZtkf5U5VnYd9zZH8BRKZuAbxZEw" },
data: ["0x6d02", "hello world"])
}
paydata.send(tx, function(err, res) {
console.log(res)
})
B. Building an UNSIGNED transaction and exporting, and then later importing and sending the transaction in separate steps
// Build and export an unsigned transaction for later usage
var exportedTxHex = "";
const tx = {
safe: true,
data: ["0x6d02", "hello world"]
}
paydata.build(tx, function(err, res) {
exportedTxHex = res.toHex();
})
// Later import exportedTxHex and sign it with privatkey, and broadcast, all in one method:
paydata.send({
tx: exportedTx,
pay: { key: "5JZ4RXH4MoXpaUQMcJHo8DxhZtkf5U5VnYd9zZH8BRKZuAbxZEw" }
}, function(err, hash) {
// hash contains the transaction hash after the broadcast
})
This time since the exported transaction is already signed, no need for additional pay.key
attriute when sending later
// Build and export an unsigned transaction for later usage
var exportedSignedTxHex = "";
const tx = {
safe: true,
pay: { key: "5JZ4RXH4MoXpaUQMcJHo8DxhZtkf5U5VnYd9zZH8BRKZuAbxZEw" },
data: ["0x6d02", "hello world"]
}
paydata.build(tx, function(err, res) {
exportedSignedTxHex = res.toHex();
})
// Later import exportedTxHex and broadcast, all in one method:
paydata.send({
tx: exportedSignedTx,
}, function(err, hash) {
// hash contains the transaction hash after the broadcast
})
The pay
attribute deals with everything related to actually sending money.
key
: Signing with private keyto
: Attaching tips on top of OP_RETURN messages (Normally OP_RETURN transactions don't have a receiver)
When a pay
attribute is present, the build()
call generates a transaction
instead of a script
.
The key
attribute is mandatory. You must specify a private key in order to sign a transaction.
const tx = {
safe: true,
data: ["0x6d02", "hello world"],
pay: { key: "5JZ4RXH4MoXpaUQMcJHo8DxhZtkf5U5VnYd9zZH8BRKZuAbxZEw" }
}
paydata.build(tx, function(err, tx) {
/**
* res contains the generated transaction object
* (a signed transaction, since 'key' is included)
**/
})
The to
attribute is an array of receivers to send the OP_RETURN to. Normally this is left empty because most OP_RETURN
transactions are meant to have no receivers. But you can also send it to multiple users. For example you can use this feature to send tips to one or more people.
- default:
null
- Each item in the
to
array can have 2 attributes:- address: Bitcoin SV address string
- value: number (in satoshi)
const tx = {
safe: true,
pay: {
key: "5JZ4RXH4MoXpaUQMcJHo8DxhZtkf5U5VnYd9zZH8BRKZuAbxZEw",
to: [{
address: "1A2JN4JAUoKCQ5kA4pHhu4qCqma8jZSU81",
value: 500
}, {
address: "1A2JN4JAUoKCQ5kA4pHhu4qCqma8jZSU81",
value: 500
}]
},
data: ["0x6d02", "hello world"]
};
paydata.build(tx, function(err, res) {
/**
* res contains the generated transaction object
* (a signed transaction, since 'key' is included.
* Also, the transaction includes actual coin transfer outputs,
* since the "to" attribute is included)
**/
})
The data
attribute is used to construct human readable/processable data to post to the blockchain.
const tx = {
safe: true,
data: ["0x6d02", "hello world"]
}
daydata.build(tx, function(err, tx) {
/**
* res contains the generated transaction object, powered by bsv
* You can check it out at https://bsv.direct/docs/bsv.js/tx.html
* Some available methods you can call on the tx object are:
* 1. tx.toHex() => Export as string
* 2. tx.toJSON() => Inspect the transaction as JSON object
**/
});
NOTE: Each item in the data
array can either be:
- a regular string
- a hex string
- Binary data (Buffer in node.js, and ArrayBuffer in browser)
To use hex string, simply prefix the string with "0x".
To use Buffer types, just pass the Buffer (or ArrayBuffer) object as push data.
To use an opcode, pass an object {op: [OPCODE]}
(You can see the OPCODE list here)
In above example, we can see that the first item is "0x6d02"
. Paydata will automatically recognize this as a hex string and interpret as a hex string (while discarding the 0x prefix before the interpretation)
In Node.js (Buffer)
const tx = {
safe: true,
data: ["0x6d02", Buffer.from("Abc"), "hello world"]
}
paydata.build(tx, function(err, tx) {
/**
* res contains the generated transaction object, powered by bsv
* You can check it out at https://github.com/samooth/bsv/blob/master/lib/transaction/transaction.js
* Some available methods you can call on the tx object are:
* 1. tx.toHex() => Export as string
* 2. tx.toJSON() => Inspect the transaction as JSON object
**/
});
In Browser, building OP_RETURN from input[type=file]
(ArrayBuffer)
document.querySelector("input[type=file]").onchange = function(e) {
// get file type
var filetype = e.target.files[0].type
var reader = new FileReader();
// Listen to file load event (Will call the actual load below)
reader.addEventListener('load', function(event) {
// ArrayBuffer
var ab = event.target.result
paydata.build({
data: [ "19HxigV4QyBv3tHpQVcUEQyq1pzZVdoAut", ab, filetype ]
}, function(err, res) {
console.log("built transaction = ", res)
})
})
// Read file content as "ArrayBuffer"
reader.readAsArrayBuffer(e.target.files[0]);
}
This is useful if you want to export a transaction and later recover it. By default transaction returned is in BSV format.
const tx = {
data: "6a04366430320b68656c6c6f20776f726c64"
}
paydata.build(tx, function(err, tx) {
/**
* res contains the generated transaction object, powered by bsv
* You can check it out at https://github.com/samooth/bsv/blob/master/lib/transaction/transaction.js
* Some available methods you can call on the tx object are:
* 1. tx.toHex() => Export as string
* 2. tx.toJSON() => Inspect the transaction as JSON object
**/
});
The network
can be 'main' for Mainnet or 'test' for Testnet
The api
attribute is used to manually set the JSON-RPC endpoint you wish to broadcast through.
- default:
woc
( options: bitails, woc, electrumx )
const tx = {
api: "bitails",
safe: true,
pay: {
key: "5JZ4RXH4MoXpaUQMcJHo8DxhZtkf5U5VnYd9zZH8BRKZuAbxZEw",
},
data: ["0x6d02", "hello world"]
};
paydata.build(tx, function(err, res) {
/**
* res contains the generated transaction object
* (a signed transaction, since 'key' is included)
**/
})
The feeKb
attribute is used to specify the transaction fee per kilobyte in satoshis.
- default:
1
const tx = {
safe: true,
feeKb: 50,
pay: {
key: "5JZ4RXH4MoXpaUQMcJHo8DxhZtkf5U5VnYd9zZH8BRKZuAbxZEw",
},
data: ["0x6d02", "hello world"]
}
paydata.build(tx, function(err, res) {
/**
* res contains the generated transaction object
* (a signed transaction, since 'key' is included)
**/
})
Sometimes you want more fine-grained control over which UTXOs to use for a transaction.
Paydata enables to specify an array of utxos to be spent, an even include the locking script.
Use with boolean option useAllUtxos
set to true
let lockScript = Script.fromAsmString("OP_TRUE OP_RETURN ...");
const tx = {
safe: true,
useAllUtxos: true,
utxos:[
{ tx_hash:"83a884fe039114150e79fb5326a0a3c3e75895b728d74b4c4aa93bb782850ca2", tx_pos:0, value: 1 },
{ txid:"83a884fe039114150e79fb5326a0a3c3e75895b728d74b4c4aa93bb782850ca2", vout:1, satoshis: 1 },
{ txid:"83a884fe039114150e79fb5326a0a3c3e75895b728d74b4c4aa93bb782850ca2", vout:1, satoshis: 1, script: lockingScript },
],
pay: {
key: "5JZ4RXH4MoXpaUQMcJHo8DxhZtkf5U5VnYd9zZH8BRKZuAbxZEw",
}
},
data: ["0x6d02", "hello world"]
}
Paydata.build(tx, function(err, tx) {
/**
* res contains the generated transaction object
* (a signed transaction, since 'key' is included)
**/
})
You may want to import a previously exported transaction. This is when you use the tx
attribute.
paydata.build({
tx: "01000000014182e9844c2979d973d3e82c55d57e1a971ed2e5473557ce0414864612911aa5010000006b48304502210098f8f32cd532bc73eef1e01c3d359caf0a7aa8f3dc1eebb8011d80810c9dbe66022054c6b23d5bd9573a1e6135c39dcc31a65cab91f3b3db781995e824614e24bad9412102d024c1861ccc655ce3395bc4d8a0bdcfb929ffcd9d1a8c81d8c6fa1dfb9bd70cffffffff020000000000000000106a026d020b68656c6c6f20776f726c64c2ff0000000000001976a9142a3a6886d98776d0197611e5328ba8806c3739db88ac00000000"
}, function(err, tx) {
// 'tx' is a transaction object
})
You can export an unsigned transaction, and later import and sign it to create a signed transaction, simply by supporting a pay.key
attribute.
// import an unsigned transaction and sign it
paydata.build({
tx: "01000000014182e9844c2979d973d3e82c55d57e1a971ed2e5473557ce0414864612911aa5010000006b48304502210098f8f32cd532bc73eef1e01c3d359caf0a7aa8f3dc1eebb8011d80810c9dbe66022054c6b23d5bd9573a1e6135c39dcc31a65cab91f3b3db781995e824614e24bad9412102d024c1861ccc655ce3395bc4d8a0bdcfb929ffcd9d1a8c81d8c6fa1dfb9bd70cffffffff020000000000000000106a026d020b68656c6c6f20776f726c64c2ff0000000000001976a9142a3a6886d98776d0197611e5328ba8806c3739db88ac00000000",
pay: {
key: "5JZ4RXH4MoXpaUQMcJHo8DxhZtkf5U5VnYd9zZH8BRKZuAbxZEw"
}
}, function(err, tx) {
// 'tx' is a signed transaction object
})
Notice how in addition to the tx
attribute we've added the pay.key
attribute. This will import the unsigned transaction and sign it.
If you already have a signed transaction object, you can simply send it away without any additional steps.
paydata.send({
tx: "01000000014182e9844c2979d973d3e82c55d57e1a971ed2e5473557ce0414864612911aa5010000006b48304502210098f8f32cd532bc73eef1e01c3d359caf0a7aa8f3dc1eebb8011d80810c9dbe66022054c6b23d5bd9573a1e6135c39dcc31a65cab91f3b3db781995e824614e24bad9412102d024c1861ccc655ce3395bc4d8a0bdcfb929ffcd9d1a8c81d8c6fa1dfb9bd70cffffffff020000000000000000106a026d020b68656c6c6f20776f726c64c2ff0000000000001976a9142a3a6886d98776d0197611e5328ba8806c3739db88ac00000000"
}, function(err, hash) {
// 'hash' is the transaction hash
})
In case of several outputs to be needed use nData option instead of data.
const tx = { nData:[ [ "ThisIsOutputNumber 0" ], [ "ThisIsOutputNumber 1" ] ]}
To add some satoshis to all outputs produced by nData, the option dataSats
must be used to specify the amount.
Paydata enables customizing nLocktime and nSequence by using the arguments lock
and seq
-
lock
: Specify nLock time for tx -
seq
: Specify nSequence for input(s), can be specified per utxo or as general option to apply to all inputs
Create custom signature types using option hashType
either as general option or as per each utxo on the utxos
option
The possible signature types are:
all
single
none
all|any
single|any
none|any
Paydata depends on two powerful libraries for low level stuff.
- bsv: https://github.com/samooth/bsv
- explorer wrapper: https://github.com/samooth/explorer
While Paydata is designed to be the simplest possible way to write data to the blockchain, you may want to sometimes access the low level libraries that power Paydata.
Paydata exposes additional endpoints so you can simply access these libraries without having to install or include any additional libraries.
This endpoint exposes the bsv library object. Basically by referncing bsv
you have access to the entire bsv library.
const bsv = paydata.bsv
const { PrivKey, Address } = bsv
const privateKey = new PrivKey.fromRandom();
const address = Address.fromPrivKey(privateKey);
console.log(address.toString())
This endpoint is used to access the explorer library.
Using this endpoint you can connect to a public API endpoint to let you make various direct API function calls such as utxos(<address>)
, etc. (Basically it instantiates and returns the Explorer
object from https://github.com/samooth/explorer)
paydata.connect([network],[params])
If you leave the network
part out, it will automatically connect to mainnet
params = { api: 'woc'||'bitails'||'electrumx' }
default API: [bitails] https://docs.bitails.io woc: WhatsOnChain
let explorer = paydata.connect()
explorer.utxos("14xMz8rKm4L83RuZdmsHXD2jvENZbv72vR", function(err, utxos) {
if (err) {
console.log("Error: ", err)
} else {
console.log(utxos)
}
})
paydata.connect('main',{api:"woc"}).utxos("14xMz8rKm4L83RuZdmsHXD2jvENZbv72vR", function(err, utxos) {
if (err) {
console.log("Error: ", err)
} else {
console.log(utxos)
}
});