MeshKoios Provider
Distributed & open-source public API query layer for Cardano
Koios provides a query layer which allows your app to access information stored on the blockchain.
Get started:
import { KoiosProvider } from "@meshsdk/core";
const provider = new KoiosProvider(
'preprod', // "api" | "preview" | "preprod" | "guild"
'<Your-API-Key>',
);Get your API key from Koios User Profile page.
Get data from URL
You can fetch any data from the blockchain by providing the URL path.
await provider.get('/addresses/addr_test1qpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0uafhxhu32dys6pvn6wlw8dav6cmp4pmtv7cc3yel9uu0nq93swx9/transactions')Fetch Account Info
Obtain information about a specific stake account.
await provider.fetchAccountInfo('stake_test1uzw5mnt7g4xjgdqkfa80hrk7kdvds6sa4k0vvgjvlj7w8eskffj2n')Fetch Address Assets
Fetch assets from an address.
await provider.fetchAddressAssets(
'addr_test1qpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0uafhxhu32dys6pvn6wlw8dav6cmp4pmtv7cc3yel9uu0nq93swx9'
);Fetch Address UTxOs
Fetch UTxOs from address
await provider.fetchAddressAssets(
'addr_test1qpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0uafhxhu32dys6pvn6wlw8dav6cmp4pmtv7cc3yel9uu0nq93swx9'
);Fetch assets from address
Fetch assets given an address
await provider.fetchAddressAssets(
'addr_test1qpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0uafhxhu32dys6pvn6wlw8dav6cmp4pmtv7cc3yel9uu0nq93swx9',
);Fetch Address UTxOs
Fetch UTxOs controlled by an address.
await provider.fetchAddressUTxOs('addr_test1qpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0uafhxhu32dys6pvn6wlw8dav6cmp4pmtv7cc3yel9uu0nq93swx9')Optionally, you can filter UTXOs containing a particular asset by providing asset, where it is the concatenation of policy ID and asset.
await fetchAddressUTxOs(address: string, asset?: string)Fetch Asset Addresses
Fetch a list of a addresses containing a specific asset where it is the concatenation of policy ID and asset.
await provider.fetchAssetAddresses('d9312da562da182b02322fd8acb536f37eb9d29fba7c49dc172555274d657368546f6b656e')Fetch Asset Metadata
Fetch the asset metadata by providing asset's unit, which is the concatenation of policy ID and asset name in hex.
await provider.fetchAssetMetadata('d9312da562da182b02322fd8acb536f37eb9d29fba7c49dc172555274d657368546f6b656e')Fetch Block Info
Fetch block infomation. You can get the hash from fetchTxInfo().
await provider.fetchBlockInfo('79f60880b097ec7dabb81f75f0b52fedf5e922d4f779a11c0c432dcf22c56089')Fetch Collection Assets
Fetch a list of assets belonging to a collection by providing its Policy ID.
await provider.fetchCollectionAssets('d9312da562da182b02322fd8acb536f37eb9d29fba7c49dc17255527')The API will return a list of assets and a cursor next. If the cursor is not null, you can use it to fetch the next page of results. Here is an example of the response.
{
"assets": [
{
"unit": "d9312da562da182b02322fd8acb536f37eb9d29fba7c49dc17255527",
"quantity": "1"
},
],
"next": 2
}The fetchCollectionAssets function also accepts an optional cursor parameter to fetch the next page of results. The default value is 1.
await fetchCollectionAssets(
policyId: string,
cursor = 1
)Fetch Handle Address
ADA Handle allows users to use a human-readable "Handle" to associate an address.
Each Handle is a unique NFT, minted and issued on the Cardano blockchain. These NFTs act as unique identifiers for the UTXO that they reside in.
We can resolve the handle's address with fetchHandleAddress.
// Handle: `meshsdk`
await provider.fetchHandleAddress('meshsdk')Fetch Handle
ADA Handle allows users to use a human-readable "Handle" to associate an address.
Each Handle is a unique NFT, minted and issued on the Cardano blockchain. These NFTs act as unique identifiers for the UTXO that they reside in.
ADA Handle also released a CIP68 handle and this function will fetch the metadata of the handle.
// Handle: `meshsdk`
await provider.fetchHandle('meshsdk')Fetch Protocol Parameters
Fetch the latest protocol parameters.
await provider.fetchProtocolParameters()Optionally, you can provide an epoch number to fetch the protocol parameters of that epoch.
Fetch Transaction Info
Fetch transaction infomation. Only confirmed transaction can be retrieved.
await provider.fetchTxInfo('f4ec9833a3bf95403d395f699bc564938f3419537e7fb5084425d3838a4b6159')Fetch UTxOs
Get UTxOs for a given hash.
await provider.fetchUTxOs('dfd2a2616e6154a092807b1ceebb9ddcadc0f22cf5c8e0e6b0757815083ccb70')Optionally, you can specify the index of the index output.
await provider.fetchUTxOs('hash_here', 0)Fetch Proposal Info
Get information for a given governance proposal, identified by the txHash and proposal index
await provider.fetchGovernanceProposal('372d688faa77e146798b581b322c0f2981a9023764736ade5d12e0e4e796af8c', 0)Submit Transaction
Submit a serialized transaction to the network.
await provider.submitTx(signedTx);On Transaction Confirmed
Allow you to listen to a transaction confirmation. Upon confirmation, the callback will be called.
const tx = new Transaction({ initiator: wallet });
tx.sendLovelace('addr_test1vpvx0sacufuypa2k4sngk7q40zc5c4npl337uusdh64kv0c7e4cxr', '5000000');
const unsignedTx = await tx.build();
const signedTx = await wallet.signTx(unsignedTx);
const txHash = await wallet.submitTx(signedTx);
provider.onTxConfirmed(txHash, () => {
// Transaction confirmed
});