added oracle example and ergonomic WASI guest HTTP client crate #4
Conversation
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@macovedj is investigating what we need to change for the data structure JSON that is written to the chain as the result. We need to change the output of the component to match the schema expected by the contract. Or create a new contract. |
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For output format, check out https://github.com/Lay3rLabs/lay3r-contracts/pull/41 The result is parsed as |
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| ## Deploy | ||
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| Upload the compiled Wasm component to the Wasmatic node. |
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Note: we will want some cli tool to make this easier. This bash, json, curl stuff is a pain to work with.
This should be completed as part of Lay3rLabs/avs-toolkit#17 and then added here
cc @ueco-jb
oracle-example/src/lib.rs
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| #[derive(Serialize, Debug)] | ||
| #[serde(rename_all = "camelCase")] | ||
| struct Price { |
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The result expected by the oracle contract is just the price field as a string. (you can use f32::to_string())
You can make this field and print it for nice debug logs. (I think it is cool to show println!() works, but I guess devs won't have access to logs)
But for the Result, use:
struct Result {
price: String,
}
let result = Result { price: calc_prices.btcusd.avg_last_hour.price.to_string() };And of course json-encode as now
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@ethanfrey Just to confirm, price would be the latest BTCUSD or one of the trailing averages?
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Just pushed, as average price over the past minute.
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Actually, probably better over the past hour average price. Due to the frequency of polling.
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I thought my code sample clarified. calc_prices.btcusd.avg_last_hour.price.to_string()
yes, the rolling average over the last hour.
this actually needs some overhaul in average calculation to make it "blockchain safe", but we can start with this for now and get things running
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Sorry missed that in your example.
| @@ -39,7 +39,7 @@ async fn get_avg_btc(reactor: Reactor) -> Result<Vec<u8>, String> { | |||
| history.record_latest_price(now, price)?; | |||
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| // calculate average prices | |||
| let avg_last_minute = history.average(now - 60); | |||
| let avg_last_minute = history.average(now - 3600); | |||
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Uh, I agree with the change, but shouldn't you change the name of the variable as well?
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Oops, yeah. I'll fix.
Incorporating feedback from Lay3rLabs/avs-toolkit#22
Simplified the ergonomic HTTP guest crate down to the bare minimum for the hackathon. Imports the latest version of
wstdcrate but only uses its public functions / types that work for the async runtime. Unfortunately, the rest ofwstdis not usable yet. So I wrote a simplified HTTP client from scratch here that should be good enough for now.The example Oracle operates as a task queue trigger application. When triggered,
makes an outbound HTTP request to CoinGecko API with the a provided
API_KEYenv var.The app stores the
BTCUSDprice history in the file system. Completes with writing to the chainthe resulting current price and averages over the past minute and hour. But still requires testing additional testing.
Closes https://github.com/Lay3rLabs/wasmatic/issues/8
Closes #1
Closes Lay3rLabs/avs-toolkit#22
More docs and guiding through the Wasmatic deployment process can be added to follow up PRs or this one. Just wanted to get the code up for review ASAP.