feat: add blockscout-chains crate

libs/Cargo.toml

@@ -2,6 +2,7 @@
 resolver = "2"
 members = [
     "blockscout-auth",
+    "blockscout-chains",
     "blockscout-client/crate",
     "blockscout-db",
     "endpoints/swagger",

libs/blockscout-chains/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "blockscout-chains"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+anyhow = "1"
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1"
+reqwest = { version = "0.12", features = ["json"] }
+reqwest-middleware = "0.3"
+reqwest-retry = "0.6"
+
+[dev-dependencies]
+tokio = { version = "1.0", features = ["macros"] }

libs/blockscout-chains/src/lib.rs

@@ -0,0 +1,58 @@
+use reqwest_middleware::ClientBuilder;
+use reqwest_retry::{policies::ExponentialBackoff, RetryTransientMiddleware};
+use serde::Deserialize;
+use std::collections::HashMap;
+
+const CHAINS_URL: &str = "https://chains.blockscout.com/api/chains";
+
+pub async fn get_blockscout_chains() -> anyhow::Result<BlockscoutChains> {
+    let max_retries = 3;
+    let retry_policy = ExponentialBackoff::builder().build_with_max_retries(max_retries);
+    let client = ClientBuilder::new(reqwest::Client::new())
+        .with(RetryTransientMiddleware::new_with_policy(retry_policy))
+        .build();
+    let res = client.get(CHAINS_URL).send().await?;
+    let chains: BlockscoutChains = res.json().await?;
+    Ok(chains)
+}
+
+pub type BlockscoutChains = HashMap<i64, BlockscoutChainData>;
+
+#[derive(Deserialize, Debug)]
+#[serde(rename_all = "camelCase")]
+pub struct BlockscoutChainData {
+    pub name: String,
+    pub description: String,
+    pub ecosystem: Ecosystem,
+    pub is_testnet: Option<bool>,
+    pub layer: Option<u8>,
+    pub rollup_type: Option<String>,
+    pub website: String,
+    pub explorers: Vec<ExplorerConfig>,
+    pub logo: String,
+}
+
+#[derive(Deserialize, Debug)]
+#[serde(untagged)]
+pub enum Ecosystem {
+    Single(String),
+    Multiple(Vec<String>),
+}
+
+#[derive(Deserialize, Debug)]
+#[serde(rename_all = "camelCase")]
+pub struct ExplorerConfig {
+    pub url: String,
+    pub hosted_by: String,
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[tokio::test]
+    async fn test_get_blockscout_chains() {
+        let chains = get_blockscout_chains().await.unwrap();
+        assert!(!chains.is_empty());
+    }
+}