ethers_middleware/gas_oracle/
blocknative.rs

1use super::{from_gwei_f64, GasCategory, GasOracle, GasOracleError, Result, GWEI_TO_WEI_U256};
2use async_trait::async_trait;
3use ethers_core::types::U256;
4use reqwest::{header::AUTHORIZATION, Client};
5use serde::Deserialize;
6use std::collections::HashMap;
7use url::Url;
8
9const URL: &str = "https://api.blocknative.com/gasprices/blockprices";
10
11/// A client over HTTP for the [BlockNative](https://www.blocknative.com/gas-estimator) gas tracker API
12/// that implements the `GasOracle` trait.
13#[derive(Clone, Debug)]
14#[must_use]
15pub struct BlockNative {
16    client: Client,
17    url: Url,
18    api_key: Option<String>,
19    gas_category: GasCategory,
20}
21
22#[derive(Clone, Debug, Deserialize, PartialEq)]
23#[serde(rename_all = "camelCase")]
24pub struct Response {
25    pub system: String,
26    pub network: String,
27    pub unit: String,
28    pub max_price: u64,
29    pub block_prices: Vec<BlockPrice>,
30    pub estimated_base_fees: Option<Vec<HashMap<String, Vec<BaseFeeEstimate>>>>,
31}
32
33#[derive(Clone, Debug, Deserialize, PartialEq)]
34#[serde(rename_all = "camelCase")]
35pub struct BlockPrice {
36    pub block_number: u64,
37    pub estimated_transaction_count: u64,
38    pub base_fee_per_gas: f64,
39    pub estimated_prices: Vec<GasEstimate>,
40}
41
42#[derive(Clone, Copy, Debug, Deserialize, PartialEq)]
43#[serde(rename_all = "camelCase")]
44pub struct GasEstimate {
45    pub confidence: u64,
46    pub price: u64,
47    pub max_priority_fee_per_gas: f64,
48    pub max_fee_per_gas: f64,
49}
50
51#[derive(Clone, Copy, Debug, Deserialize, PartialEq)]
52#[serde(rename_all = "camelCase")]
53pub struct BaseFeeEstimate {
54    pub confidence: u64,
55    pub base_fee: f64,
56}
57
58impl Response {
59    #[inline]
60    pub fn estimate_from_category(&self, gas_category: &GasCategory) -> Result<GasEstimate> {
61        let confidence = gas_category_to_confidence(gas_category);
62        let price = self
63            .block_prices
64            .first()
65            .ok_or(GasOracleError::InvalidResponse)?
66            .estimated_prices
67            .iter()
68            .find(|p| p.confidence == confidence)
69            .ok_or(GasOracleError::GasCategoryNotSupported)?;
70        Ok(*price)
71    }
72}
73
74impl Default for BlockNative {
75    fn default() -> Self {
76        Self::new(None)
77    }
78}
79
80#[cfg_attr(target_arch = "wasm32", async_trait(?Send))]
81#[cfg_attr(not(target_arch = "wasm32"), async_trait)]
82impl GasOracle for BlockNative {
83    async fn fetch(&self) -> Result<U256> {
84        let estimate = self.query().await?.estimate_from_category(&self.gas_category)?;
85        Ok(U256::from(estimate.price) * GWEI_TO_WEI_U256)
86    }
87
88    async fn estimate_eip1559_fees(&self) -> Result<(U256, U256)> {
89        let estimate = self.query().await?.estimate_from_category(&self.gas_category)?;
90        let max = from_gwei_f64(estimate.max_fee_per_gas);
91        let prio = from_gwei_f64(estimate.max_priority_fee_per_gas);
92        Ok((max, prio))
93    }
94}
95
96impl BlockNative {
97    /// Creates a new [BlockNative](https://www.blocknative.com/gas-estimator) gas oracle.
98    pub fn new(api_key: Option<String>) -> Self {
99        Self::with_client(Client::new(), api_key)
100    }
101
102    /// Same as [`Self::new`] but with a custom [`Client`].
103    pub fn with_client(client: Client, api_key: Option<String>) -> Self {
104        let url = Url::parse(URL).unwrap();
105        Self { client, api_key, url, gas_category: GasCategory::Standard }
106    }
107
108    /// Sets the gas price category to be used when fetching the gas price.
109    pub fn category(mut self, gas_category: GasCategory) -> Self {
110        self.gas_category = gas_category;
111        self
112    }
113
114    /// Perform a request to the gas price API and deserialize the response.
115    pub async fn query(&self) -> Result<Response, GasOracleError> {
116        let mut request = self.client.get(self.url.clone());
117        if let Some(api_key) = self.api_key.as_ref() {
118            request = request.header(AUTHORIZATION, api_key);
119        }
120        let response = request.send().await?.error_for_status()?.json().await?;
121        Ok(response)
122    }
123}
124
125#[inline]
126fn gas_category_to_confidence(gas_category: &GasCategory) -> u64 {
127    match gas_category {
128        GasCategory::SafeLow => 80,
129        GasCategory::Standard => 90,
130        GasCategory::Fast => 95,
131        GasCategory::Fastest => 99,
132    }
133}
ethers_middleware/gas_oracle/blocknative.rs

ethers_middleware/gas_oracle/
blocknative.rs
