18 releases (10 stable)
3.0.0-beta.0 | Dec 27, 2021 |
---|---|
2.2.0 | Aug 6, 2021 |
2.1.0 | Jun 29, 2021 |
1.2.4 | Mar 17, 2021 |
1.1.0 | Jul 31, 2020 |
#3 in #terra
1,008 downloads per month
Used in 18 crates
(17 directly)
13KB
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Terra Bindings for CosmWasm
This crate provides Terra-specific bindings to enable your CosmWasm smart contracts to interact with the Terra blockchain by exposing messages and queriers that can be emitted and used from within your contract.
Installation
Add the following to your smart contract's Cargo.toml
:
[dependencies]
terra-cosmwasm = { version = "2.2" }
Contents
Currently, the Terra bindings include:
- Query support for:
- Market
- swap rate between 2 currencies at market price
- Treasury
- current tax cap for a denomination
- current tax rate
- Oracle
- exchange rates for the given base_denom / quote_denoms
- Market
- Messages
MsgSwap
MsgSwapSend
Usage
Querying
In order to use the query functions enabled by the bindings, create a TerraQuerier
instance within your contract logic -- in either init()
, handle()
, or query()
entrypoints. You can access all the enabled queries through this object.
// src/contract.rs
use cosmwasm_std::Coin;
use terra_cosmwasm::{ TerraQuerier, SwapResponse, TaxRateResponse, TaxCapResponse, ExchangeRatesResponse };
...
// handler
pub fn try_something<S: Storage, A: Api, Q: Querier>(
deps: &mut Extern<S, A, Q>,
env: Env,
offer: &Coin
) -> StdResult<HandleResponse> {
let querier = TerraQuerier::new(&deps.querier);
let swap_rate: SwapResponse = querier.query_swap(offer.clone(), "uusd")?;
let tax_cap: TaxCapResponse = querier.query_tax_cap("usdr")?;
let tax_rate: TaxRateResponse = querier.query_tax_rate()?;
let exchange_rates: ExchangeRatesResponse = querier.query_exchange_rates("uusd", vec!["uluna", "ukrw"])?;
...
}
Creating Messages
NOTE: The Terra bindings do not cover messages that have already been implemented by the CosmWasm team, such as staking-related messages and fundamental ones like MsgSend
.
You may want your contract to perform messages such as MsgSwap
and MsgSwapSend
operations at the end of its execution. To do this, create a message using the predefined functions:
create_swap_msg
create_swap_send_msg
And add it to the vector ofmessages
in yourHandleResponse
before you returnOk
.
use cosmwasm_std::CosmosMsg;
use terra_cosmwasm::{create_swap_msg, TerraMsgWrapper};
...
pub fn try_something<S: Storage, A: Api, Q: Querier>(
deps: &mut Extern<S, A, Q>,
env: Env,
offer: &Coin
) -> StdResult<HandleResponse<TerraMsgWrapper>> {
...
let msg: CosmosMsg<TerraMsgWrapper> = create_swap_msg(contract_addr, offer_coin, ask_denom);
let res = HandleResponse {
messages: vec![msg],
log: vec![],
data: None
};
Ok(res)
}
Dependencies
~3.5–5.5MB
~114K SLoC