examples/ether-price-getter

Ether Price Quotation Service

Overview

This module utilizes curl and the Coinmarketcap API to allow the query of the latest Ether (ETH) price relative to some 120 currencies. The service requires a valid Coinmarketcap API key, which is freely available with registration. The query function wraps this API call: https://coinmarketcap.com/api/documentation/v1/#operation/getV2CryptocurrencyQuotesLatest:

ether_price_getter(api_key: String, currency_symbol: String)

which expects the [Coinmarketcap API key] and the three letter currency symbol, e.g.:

call ether_price_getter ether_price_getter  ["32fd4c0f-59cf-4182-8f22-d4083df0a738", "EUR"]

Please note that you need to supply a valid Coinmarketcap API key and that the free account limits the number of conversions to one. The result from the Fluence service call is the raw json string, e.g.:

result: String("{\"status\":{\"timestamp\":\"2021-02-22T20:47:59.960Z\",\"error_code\":0,\"error_message\":null,\"elapsed\":225,\"credit_count\":1,\"notice\":null},\"data\":{\"ETH\":{\"id\":1027,\"name\":\"Ethereum\",\"symbol\":\"ETH\",\"slug\":\"ethereum\",\"num_market_pairs\":5986,\"date_added\":\"2015-08-07T00:00:00.000Z\",\"tags\":[\"mineable\",\"pow\",\"smart-contracts\",\"coinbase-ventures-portfolio\",\"three-arrows-capital-portfolio\",\"polychain-capital-portfolio\"],\"max_supply\":null,\"circulating_supply\":114779907.124,\"total_supply\":114779907.124,\"is_active\":1,\"platform\":null,\"cmc_rank\":2,\"is_fiat\":0,\"last_updated\":\"2021-02-22T20:46:06.000Z\",\"quote\":{\"EUR\":{\"price\":1464.4187545109621,\"volume_24h\":34069036322.326084,\"percent_change_1h\":3.41360427,\"percent_change_24h\":-10.32669439,\"percent_change_7d\":-3.70439114,\"percent_change_30d\":41.39754247,\"market_cap\":168085848633.412,\"last_updated\":\"2021-02-22T20:47:05.000Z\"}}}}}")

Where to Find The Service

The service is discoverable at Fluence, e.g., https://dash.fluence.dev/blueprint/a7959f53-a70b-4183-83e0-649f4f91160c, and ready for use.

How to Build The Service

machine setup instructions

In the eth-price-getter dir,

# if needed
chmod +x .build.sh

./build.sh

That compiles both the curl and the price getter code and places the resulting wasm code into the artifacts dir. For local testing run fce-repl Config.toml to initiate the repl:

fce-repl Config.toml
Welcome to the FCE REPL (version 0.1.33)
app service was created with service id = b0cc4d0d-fb3e-49e1-8532-54d77e03cdaa
elapsed time 82.757883ms

1> interface
Loaded modules interface:

curl_adapter:
  fn curl_request(url: String) -> String

ether_price_getter:
  fn ether_price_getter(api_key: String, currency_symbol: String) -> String

2> call ether_price_getter ether_price_getter ["35fd4b0e-56cf-4182-8f22-d4095cf0a738", "EUR"]
INFO: Running "/usr/bin/curl -H X-CMC_PRO_API_KEY: 35fd4b0e-56cf-4182-8f22-d4095cf0a738 -H Accept: application/json -d symbol=ETH&convert=EUR -G https://pro-api.coinmarketcap.com/v1/cryptocurrency/quotes/latest" ...
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   868    0   868    0     0   2755      0 --:--:-- --:--:-- --:--:--  2755
result: String("{\"status\":{\"timestamp\":\"2021-02-22T21:06:42.598Z\",\"error_code\":0,\"error_message\":null,\"elapsed\":18,\"credit_count\":1,\"notice\":null},\"data\":{\"ETH\":{\"id\":1027,\"name\":\"Ethereum\",\"symbol\":\"ETH\",\"slug\":\"ethereum\",\"num_market_pairs\":5986,\"date_added\":\"2015-08-07T00:00:00.000Z\",\"tags\":[\"mineable\",\"pow\",\"smart-contracts\",\"coinbase-ventures-portfolio\",\"three-arrows-capital-portfolio\",\"polychain-capital-portfolio\"],\"max_supply\":null,\"circulating_supply\":114779907.124,\"total_supply\":114779907.124,\"is_active\":1,\"platform\":null,\"cmc_rank\":2,\"is_fiat\":0,\"last_updated\":\"2021-02-22T21:05:03.000Z\",\"quote\":{\"EUR\":{\"price\":1459.5551152082585,\"volume_24h\":33903071552.817226,\"percent_change_1h\":2.64386327,\"percent_change_24h\":-10.46990835,\"percent_change_7d\":-4.37412016,\"percent_change_30d\":41.26794407,\"market_cap\":167527600565.963,\"last_updated\":\"2021-02-22T21:06:05.000Z\"}}}}}")
 elapsed time: 323.584665ms

3>

Calling interface lists both the curl_adapter and ether_price_getter interfaces. Calling the ether_price_getter service function with the API key and conversion currency symbol, "35fd4b0e-56cf-4182-8f22-d4095cf0a738", "EUR", yields the raw json string result expected.

How to Deploy The Service

ToDo: fldist installation instructions

If you don't have a seed ready to use:

fldist create_keypair
{
  id: '12D3KooWQy61BZ4P1DeJzhvsQ76uQAQc7N8tDk6NDz5BFnnhwuPP',
  privKey: 'CAESYI9nA79xXH9yYeuU4UDPiaa7C84U0OKnihdSkSdbMOIV4RtA5l9dooR41cO8lCz3okYpEboK6maL7yk1ABgCvrLhG0DmX12ihHjVw7yULPeiRikRugrqZovvKTUAGAK+sg==',
  pubKey: 'CAESIOEbQOZfXaKEeNXDvJQs96JGKRG6Cupmi+8pNQAYAr6y',
  seed: 'AenQdfKCRrh1sajNFkKKV1iojgVnLWyatdaqwzEMopje'
}

which yields a fresh keypair and derived seed and allows us to create a new service. The fldist new_service is a convenience method that takes care the module uploads to the node, the creation of the blueprint, and finally, the instantiation of the services.

fldist new_service --env testnet -n "Ether Price Getter" -s AenQdfKCRrh1sajNFkKKV1iojgVnLWyatdaqwzEMopje --ms artifacts/curl_adapter.wasm:curl_cfg.json artifacts/ether_price_getter.wasm:ether_price_getter_cfg.json

specifies that we are creating a new service comprised of two modules, the curl_adapter module and the ether_price_getter module, and generates the confirmation with service id:

client seed: AenQdfKCRrh1sajNFkKKV1iojgVnLWyatdaqwzEMopje
client peerId: 12D3KooWQy61BZ4P1DeJzhvsQ76uQAQc7N8tDk6NDz5BFnnhwuPP
node peerId: 12D3KooWBUJifCTgaxAUrcM9JysqCcS4CS8tiYH5hExbdWCAoNwb
uploading blueprint Ether Price Getter to node 12D3KooWBUJifCTgaxAUrcM9JysqCcS4CS8tiYH5hExbdWCAoNwb via client 12D3KooWQy61BZ4P1DeJzhvsQ76uQAQc7N8tDk6NDz5BFnnhwuPP
creating service a7959f53-a70b-4183-83e0-649f4f91160c
service id: 9840c6be-11c8-47e2-98e0-88d758b5a456
service created successfully

We can now discover the service on the Fluence dashboard and put it to use. Whether we want to write a frontend application or use the fldist tool to execute the remote service, we need an AIR script. Using the prepared AIR script for which you need to supply your own API key:

fldist run_air  -p get_eth_price.clj -d '{"service":"9840c6be-11c8-47e2-98e0-88d758b5a456"}'

client seed: 6w6j5yiPU7pMj86XSoLwesoSxhM2fzNNKF6DDtqm3WCH
client peerId: 12D3KooWAwwuy9mz1w14JhznVo1cA4UKtvVv1Gy4EKRywVRwKQ1w
node peerId: 12D3KooWBUJifCTgaxAUrcM9JysqCcS4CS8tiYH5hExbdWCAoNwb
Particle id: 9eb6c275-8f1a-4bae-b457-747546b3daaf. Waiting for results... Press Ctrl+C to stop the script.
===================
[
  "{\"status\":{\"timestamp\":\"2021-02-24T07:11:26.493Z\",\"error_code\":0,\"error_message\":null,\"elapsed\":14,\"credit_count\":1,\"notice\":null},\"data\":{\"ETH\":{\"id\":1027,\"name\":\"Ethereum\",\"symbol\":\"ETH\",\"slug\":\"ethereum\",\"num_market_pairs\":6018,\"date_added\":\"2015-08-07T00:00:00.000Z\",\"tags\":[\"mineable\",\"pow\",\"smart-contracts\",\"coinbase-ventures-portfolio\",\"three-arrows-capital-portfolio\",\"polychain-capital-portfolio\"],\"max_supply\":null,\"circulating_supply\":114799158.0615,\"total_supply\":114799158.0615,\"is_active\":1,\"platform\":null,\"cmc_rank\":2,\"is_fiat\":0,\"last_updated\":\"2021-02-24T07:10:03.000Z\",\"quote\":{\"EUR\":{\"price\":1338.6331723430615,\"volume_24h\":40823704838.16298,\"percent_change_1h\":-1.44088165,\"percent_change_24h\":-0.24837544,\"percent_change_7d\":-8.52364557,\"percent_change_30d\":13.62330192,\"market_cap\":153673961138.17825,\"last_updated\":\"2021-02-24T07:11:06.000Z\"}}}}}"
]
[
  [
    {
      peer_pk: '12D3KooWBUJifCTgaxAUrcM9JysqCcS4CS8tiYH5hExbdWCAoNwb',
      service_id: '9840c6be-11c8-47e2-98e0-88d758b5a456',
      function_name: 'ether_price_getter',
      json_path: ''
    }
  ]
]
===================

yields the expected raw pricing response. Please note that with the free account, only one currency conversion target can be supplied per query.