allow missing params in requests

README.md

@@ -91,6 +91,8 @@ Check that the websocket is working:
 ```
 $ websocat ws://127.0.0.1:8544
 
+{"jsonrpc":"2.0","method":"web3_clientVersion","id":1}
+
 {"jsonrpc": "2.0", "id": 1, "method": "eth_subscribe", "params": ["newHeads"]}
 
 {"jsonrpc": "2.0", "id": 1, "method": "eth_subscribe", "params": ["newPendingTransactions"]}

config/development_polygon.toml

@@ -11,6 +11,8 @@ db_url = "mysql://root:[email protected]:13306/dev_web3_proxy"
 deposit_factory_contract = "0x4e3BC2054788De923A04936C6ADdB99A05B0Ea36"
 deposit_topic = "0x45fdc265dc29885b9a485766b03e70978440d38c7c328ee0a14fa40c76c6af54"
 
+free_subscriptions = true
+
 # a timeseries database is optional. it is used for making pretty graphs
 influxdb_host = "http://127.0.0.1:18086"
 influxdb_org = "dev_org"

web3_proxy/src/jsonrpc.rs

@@ -6,6 +6,7 @@ use axum::response::Response;
 use derive_more::From;
 use serde::de::{self, Deserializer, MapAccess, SeqAccess, Visitor};
 use serde::{Deserialize, Serialize};
+use serde_inline_default::serde_inline_default;
 use serde_json::json;
 use serde_json::value::{to_raw_value, RawValue};
 use std::borrow::Cow;
@@ -19,13 +20,14 @@ pub trait JsonRpcResultData = serde::Serialize + serde::de::DeserializeOwned + f
 
 // TODO: &str here instead of String should save a lot of allocations
 // TODO: generic type for params?
+#[serde_inline_default]
 #[derive(Clone, Deserialize, Serialize)]
 pub struct JsonRpcRequest {
     pub jsonrpc: String,
     /// id could be a stricter type, but many rpcs do things against the spec
     pub id: Box<RawValue>,
     pub method: String,
-    /// TODO: skip serializing if serde_json::Value::Null
+    #[serde_inline_default(serde_json::Value::Null)]
     pub params: serde_json::Value,
 }