QueryAssetRates

QueryAssetRates retrieves the exchange rate between a tap asset and BTC for a specified transaction type, subject asset, and payment asset. The asset rate represents the number of tap asset units per BTC.

Source: priceoraclerpc/price_oracle.proto

gRPC

rpc QueryAssetRates (QueryAssetRatesRequest) returns (QueryAssetRatesResponse);

REST

HTTP Method	Path
GET	/v1/taproot-assets/rfq/priceoracle/assetrates

Code Samples

gRPC

Javascript

const fs = require('fs');
const grpc = require('@grpc/grpc-js');
const protoLoader = require('@grpc/proto-loader');

const GRPC_HOST = 'localhost:10029'
const MACAROON_PATH = 'TAPROOT-ASSETS_DIR/regtest/taproot-assets.macaroon'
const TLS_PATH = 'TAPROOT-ASSETS_DIR/tls.cert'

const loaderOptions = {
  keepCase: true,
  longs: String,
  enums: String,
  defaults: true,
  oneofs: true,
};
const packageDefinition = protoLoader.loadSync('priceoraclerpc/price_oracle.proto', loaderOptions);
const priceoraclerpc = grpc.loadPackageDefinition(packageDefinition).priceoraclerpc;
process.env.GRPC_SSL_CIPHER_SUITES = 'HIGH+ECDSA';
const tlsCert = fs.readFileSync(TLS_PATH);
const sslCreds = grpc.credentials.createSsl(tlsCert);
const macaroon = fs.readFileSync(MACAROON_PATH).toString('hex');
const macaroonCreds = grpc.credentials.createFromMetadataGenerator(function(args, callback) {
  let metadata = new grpc.Metadata();
  metadata.add('macaroon', macaroon);
  callback(null, metadata);
});
let creds = grpc.credentials.combineChannelCredentials(sslCreds, macaroonCreds);
let client = new priceoraclerpc.PriceOracle(GRPC_HOST, creds);
let request = {
  transaction_type: <TransactionType>,
  subject_asset: <AssetSpecifier>,
  subject_asset_max_amount: <uint64>,
  payment_asset: <AssetSpecifier>,
  payment_asset_max_amount: <uint64>,
  asset_rates_hint: <AssetRates>,
};
client.queryAssetRates(request, function(err, response) {
  console.log(response);
});
// Console output:
//  {
//    "ok": <QueryAssetRatesOkResponse>,
//    "error": <QueryAssetRatesErrResponse>,
//  }

Python

import codecs, grpc, os
# Generate the following 2 modules by compiling the priceoraclerpc/price_oracle.proto with the grpcio-tools.
# See https://github.com/lightningnetwork/lnd/blob/master/docs/grpc/python.md for instructions.
import price_oracle_pb2 as priceoraclerpc, price_oracle_pb2_grpc as price_oraclestub

GRPC_HOST = 'localhost:10029'
MACAROON_PATH = 'TAPROOT-ASSETS_DIR/regtest/taproot-assets.macaroon'
TLS_PATH = 'TAPROOT-ASSETS_DIR/tls.cert'

# create macaroon credentials
macaroon = codecs.encode(open(MACAROON_PATH, 'rb').read(), 'hex')
def metadata_callback(context, callback):
  callback([('macaroon', macaroon)], None)
auth_creds = grpc.metadata_call_credentials(metadata_callback)
# create SSL credentials
os.environ['GRPC_SSL_CIPHER_SUITES'] = 'HIGH+ECDSA'
cert = open(TLS_PATH, 'rb').read()
ssl_creds = grpc.ssl_channel_credentials(cert)
# combine macaroon and SSL credentials
combined_creds = grpc.composite_channel_credentials(ssl_creds, auth_creds)
# make the request
channel = grpc.secure_channel(GRPC_HOST, combined_creds)
stub = price_oraclestub.PriceOracleStub(channel)
request = priceoraclerpc.QueryAssetRatesRequest(
  transaction_type=<TransactionType>,
  subject_asset=<AssetSpecifier>,
  subject_asset_max_amount=<uint64>,
  payment_asset=<AssetSpecifier>,
  payment_asset_max_amount=<uint64>,
  asset_rates_hint=<AssetRates>,
)
response = stub.QueryAssetRates(request)
print(response)
# {
#    "ok": <QueryAssetRatesOkResponse>,
#    "error": <QueryAssetRatesErrResponse>,
# }

REST

Javascript

const fs = require('fs');
const request = require('request');

const REST_HOST = 'localhost:8089'
const MACAROON_PATH = 'TAPROOT-ASSETS_DIR/regtest/taproot-assets.macaroon'

let options = {
  url: `https://${REST_HOST}/v1/taproot-assets/rfq/priceoracle/assetrates`,
  // Work-around for self-signed certificates.
  rejectUnauthorized: false,
  json: true,
  headers: {
    'Grpc-Metadata-macaroon': fs.readFileSync(MACAROON_PATH).toString('hex'),
  },
}
request.get(options, function(error, response, body) {
  console.log(body);
});
// Console output:
//  {
//    "ok": <object>, // <QueryAssetRatesOkResponse> 
//    "error": <object>, // <QueryAssetRatesErrResponse> 
//  }

Python

import base64, codecs, json, requests

REST_HOST = 'localhost:8089'
MACAROON_PATH = 'TAPROOT-ASSETS_DIR/regtest/taproot-assets.macaroon'
TLS_PATH = 'TAPROOT-ASSETS_DIR/tls.cert'

url = f'https://{REST_HOST}/v1/taproot-assets/rfq/priceoracle/assetrates'
macaroon = codecs.encode(open(MACAROON_PATH, 'rb').read(), 'hex')
headers = {'Grpc-Metadata-macaroon': macaroon}
r = requests.get(url, headers=headers, verify=TLS_PATH)
print(r.json())
# {
#    "ok": <QueryAssetRatesOkResponse>,
#    "error": <QueryAssetRatesErrResponse>,
# }

Shell

# There is no CLI command for this RPC

Messages

priceoraclerpc.QueryAssetRatesRequest

Source: priceoraclerpc/price_oracle.proto

Field	gRPC Type	REST Type	REST Placement
transaction_type transaction_type indicates whether the transaction is a purchase or a sale. Nested REST Parameters transaction_type: string in query	TransactionType	object	query
subject_asset subject_asset is the asset to be priced for purchase or sale. Nested REST Parameters subject_asset.asset_id: string in query subject_asset.group_key_str: string in query subject_asset.asset_id_str: string in query subject_asset.group_key: string in query	AssetSpecifier	object	query
subject_asset_max_amount subject_asset_max_amount is the maximum amount of the subject asset that could be involved in the transaction.	uint64	string	query
payment_asset payment_asset is the asset used for purchasing or receiving from a sale. NOTE: An asset ID of all zeros indicates that the payment asset is BTC. In this case, the asset rate will be given as milli-satoshi per asset unit Nested REST Parameters payment_asset.group_key_str: string in query payment_asset.asset_id: string in query payment_asset.group_key: string in query payment_asset.asset_id_str: string in query	AssetSpecifier	object	query
payment_asset_max_amount payment_asset_max_amount is the maximum amount of the payment asset that could be involved in the transaction. This field is optional. If set to zero, it is considered unset.	uint64	string	query
asset_rates_hint asset_rates_hint is an optional suggestion of asset rates for the transaction, intended to provide guidance on expected pricing. Nested REST Parameters asset_rates_hint.paymentAssetRate.scale: integer in query asset_rates_hint.expiry_timestamp: string in query asset_rates_hint.subjectAssetRate.coefficient: string in query asset_rates_hint.subjectAssetRate.scale: integer in query asset_rates_hint.paymentAssetRate.coefficient: string in query	AssetRates	object	query

priceoraclerpc.QueryAssetRatesResponse

Source: priceoraclerpc/price_oracle.proto

Field	gRPC Type	REST Type
ok ok is the successful response to the query.	QueryAssetRatesOkResponse	object
error error is the error response to the query.	QueryAssetRatesErrResponse	object

Nested Messages

priceoraclerpc.AssetRates

Field	gRPC Type	REST Type
subjectAssetRate subjectAssetRate is the number of subject asset units per BTC represented as a fixed-point number. This field is also commonly referred to as the subject asset to BTC (conversion) rate. When the subject asset is BTC, this field should be set to 100 billion, as one BTC is equivalent to 100 billion msats.	FixedPoint	object
paymentAssetRate paymentAssetRate is the number of payment asset units per BTC represented as a fixed-point number. This field is also commonly referred to as the payment asset to BTC (conversion) rate. When the payment asset is BTC, this field should be set to 100 billion, as one BTC is equivalent to 100 billion msats.	FixedPoint	object
expiry_timestamp expiry_timestamp is the Unix timestamp in seconds after which the asset rates are no longer valid.	uint64	string

priceoraclerpc.AssetSpecifier

Field	gRPC Type	REST Type
asset_id The 32-byte asset ID specified as raw bytes (gRPC only).	bytes	string
asset_id_str The 32-byte asset ID encoded as a hex string (use this for REST).	string	string
group_key The 32-byte asset group key specified as raw bytes (gRPC only).	bytes	string
group_key_str The 32-byte asset group key encoded as hex string (use this for REST).	string	string

priceoraclerpc.FixedPoint

Field	gRPC Type	REST Type
coefficient The coefficient is the fractional value scaled-up as an integer. This integer is represented as a string as it may be too large to fit in a uint64.	string	string
scale The scale is the component that determines how many decimal places the coefficient should be divided by to obtain the fractional value.	uint32	integer

priceoraclerpc.QueryAssetRatesErrResponse

Field	gRPC Type	REST Type
message error is the error message.	string	string
code code is the error code.	uint32	integer

priceoraclerpc.QueryAssetRatesOkResponse

Field	gRPC Type	REST Type
asset_rates asset_rates is the asset exchange rates for the transaction.	AssetRates	object

Enums

priceoraclerpc.TransactionType

Name	Number
PURCHASE PURCHASE indicates a purchase transaction.	0
SALE SALE indicates a sale transaction.	1