Koinos Library for Javascript and Typescript. It can be used in node and browsers.
Install the package from NPM
npm install koilibYou can also load it directly to the browser by downloading the bunble file located at dist/koinos.min.js, or its non-minified version dist/koinos.js (useful for debugging).
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<title>My App</title>
<script src="koinos.min.js"></script>
<script>
(async () => {
const provider = new Provider(["http://api.koinos.io:8080"]);
const signer = Signer.fromSeed("my seed");
signer.provider = provider;
const koinContract = new Contract({
id: "19JntSm8pSNETT9aHTwAUHC5RMoaSmgZPJ",
abi: utils.Krc20Abi,
provider,
signer,
});
const koin = koinContract.functions;
// Get balance
const { result } = await koin.balanceOf({
owner: signer.getAddress(),
});
console.log(balance.result);
})();
</script>
</head>
<body></body>
</html>With Typescript import the library
import { Signer, Contract, Provider, Serializer, utils } from "koilib";With Javascript import the library with require
const { Signer, Contract, Provider, Serializer, utils } = require("koilib");There are 4 principal classes:
- Signer: Class containing the private key. It is used to sign.
- Provider: Class to connect with the RPC node.
- Contract: Class defining the contract to interact with.
- Serializer: Class with the protocol buffers definitions to serialize/deserialize data types.
The following code shows how to sign a transaction, broadcast a transaction, and read contracts.
(async () => {
// define signer, provider, and contract
const provider = new Provider(["http://api.koinos.io:8080"]);
const signer = Signer.fromSeed("my seed");
signer.provider = provider;
const koinContract = new Contract({
id: "19JntSm8pSNETT9aHTwAUHC5RMoaSmgZPJ",
abi: utils.Krc20Abi,
provider,
signer,
});
const koin = koinContract.functions;
// optional: preformat input/output
koinContract.abi.methods.balanceOf.preformatInput = (owner) => ({ owner });
koinContract.abi.methods.balanceOf.preformatOutput = (res) =>
utils.formatUnits(res.value, 8);
koinContract.abi.methods.transfer.preformatInput = (input) => ({
from: signer.getAddress(),
to: input.to,
value: utils.parseUnits(input.value, 8),
});
// Transfer
const { transaction } = await koin.transfer({
to: "172AB1FgCsYrRAW5cwQ8KjadgxofvgPFd6",
value: "10.0001",
});
console.log(`Transaction id ${transaction.id} submitted`);
// wait to be mined
const blockNumber = await transaction.wait();
console.log(`Transaction mined. Block number: ${blockNumber}`);
// read the balance
const { result } = await koin.balanceOf(signer.getAddress());
console.log(balance.result);
})();It's also possible to upload contracts. First, follow the instructions in koinos-cdt to compile the contracts as wasm files. Then you can use koilib to deploy them.
(async () => {
// define signer, provider and bytecode
const provider = new Provider(["http://api.koinos.io:8080"]);
const signer = Signer.fromSeed("my seed");
signer.provider = provider;
const bytecode = fs.readFileSync("my_contract.wasm");
// create contract and deploy
const contract = new Contract({ signer, provider, bytecode });
const { transaction } = await contract.deploy();
// wait to be mined
const blockNumber = await transaction.wait();
console.log(`Contract uploaded in block number ${blockNumber}`);
})();ABIs are composed of 2 elements: methods and types.
- The methods define the names of the entries of the smart contract, the corresponding endpoints and the name of the types used.
- The types all the description to serialize and deserialize using proto buffers.
To generate the types is necessary to use the dependency protobufjs. The following example shows how to generate the protobuf descriptor from a .proto file.
const fs = require("fs");
const pbjs = require("protobufjs/cli/pbjs");
pbjs.main(["--target", "json", "./token.proto"], (err, output) => {
if (err) throw err;
fs.writeFileSync("./token-proto.json", output);
});Then this descriptor can be loaded to define the ABI:
const tokenJson = require("./token-proto.json");
const abiToken = {
methods: {
balanceOf: {
entryPoint: 0x15619248,
inputs: "balance_of_arguments",
outputs: "balance_of_result",
readOnly: true,
defaultOutput: { value: "0" },
},
transfer: {
entryPoint: 0x62efa292,
inputs: "transfer_arguments",
outputs: "transfer_result",
},
mint: {
entryPoint: 0xc2f82bdc,
inputs: "mint_argumnets",
outputs: "mint_result",
},
},
types: tokenJson,
};Note that this example uses "defaultOutput" for the method "balanceOf". This is used when the smart contract returns an empty response (for instance when there are no balance records for a specific address) and you require a default output in such cases.
-
Can this library be used to create smart contracts?
No. You need to install koinos-cdt for this purpose.
-
Can this library be used to deploy smart contracts?
Yes. If you already have the contract compiled as a .wasm file you can use the Contract class to load the bytecode and deploy it.
-
Can this library be used to create the ABI for any smart contract?
For the ABI you need the .proto file and the library protobufjs. Then follow the format for the ABI as described in the previous section. It's important to note that this ABI is not the same ABI used in koinos-cli. In particular, descriptors use different format (koilib using json format, cli using binary format).
-
Can this library be used to interact with smart contracts?
Yes. You can use it to call readOnly functions, or send transactions to the contract by calling write functions.
The complete documentation can be found at https://joticajulian.github.io/koilib/
MIT License
Copyright (c) 2021 Julián González
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.