diff --git a/src/main/kotlin/io/emeraldpay/dshackle/reader/JsonRpcReader.kt b/src/main/kotlin/io/emeraldpay/dshackle/reader/JsonRpcReader.kt
new file mode 100644
index 00000000..00017c7e
--- /dev/null
+++ b/src/main/kotlin/io/emeraldpay/dshackle/reader/JsonRpcReader.kt
@@ -0,0 +1,6 @@
+package io.emeraldpay.dshackle.reader
+
+import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
+import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
+
+typealias JsonRpcReader = Reader<JsonRpcRequest, JsonRpcResponse>
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/startup/ConfiguredUpstreams.kt b/src/main/kotlin/io/emeraldpay/dshackle/startup/ConfiguredUpstreams.kt
index dafb8f84..d612bfab 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/startup/ConfiguredUpstreams.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/startup/ConfiguredUpstreams.kt
@@ -22,7 +22,7 @@ import io.emeraldpay.dshackle.Chain
 import io.emeraldpay.dshackle.FileResolver
 import io.emeraldpay.dshackle.Global
 import io.emeraldpay.dshackle.config.UpstreamsConfig
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.*
 import io.emeraldpay.dshackle.upstream.bitcoin.BitcoinRpcHead
 import io.emeraldpay.dshackle.upstream.bitcoin.BitcoinRpcUpstream
@@ -41,8 +41,6 @@ import io.emeraldpay.dshackle.upstream.forkchoice.ForkChoice
 import io.emeraldpay.dshackle.upstream.forkchoice.MostWorkForkChoice
 import io.emeraldpay.dshackle.upstream.forkchoice.NoChoiceWithPriorityForkChoice
 import io.emeraldpay.dshackle.upstream.grpc.GrpcUpstreams
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 import org.slf4j.LoggerFactory
 import org.springframework.boot.ApplicationArguments
 import org.springframework.boot.ApplicationRunner
@@ -226,7 +224,7 @@ open class ConfiguredUpstreams(
             log.warn("Upstream doesn't have API configuration")
             return null
         }
-        val directApi: Reader<JsonRpcRequest, JsonRpcResponse> = httpFactory.create(config.id, chain)
+        val directApi: JsonRpcReader = httpFactory.create(config.id, chain)
         val esplora = conn.esplora?.let { endpoint ->
             val tls = endpoint.tls?.let { tls ->
                 tls.ca?.let { ca ->
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/HttpFactory.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/HttpFactory.kt
index ea6359b7..e0257d49 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/HttpFactory.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/HttpFactory.kt
@@ -1,10 +1,8 @@
 package io.emeraldpay.dshackle.upstream
 
 import io.emeraldpay.dshackle.Chain
-import io.emeraldpay.dshackle.reader.Reader
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 
 interface HttpFactory {
-    fun create(id: String?, chain: Chain): Reader<JsonRpcRequest, JsonRpcResponse>
+    fun create(id: String?, chain: Chain): JsonRpcReader
 }
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/HttpRpcFactory.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/HttpRpcFactory.kt
index a0f97c8c..b5116c8c 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/HttpRpcFactory.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/HttpRpcFactory.kt
@@ -2,10 +2,8 @@ package io.emeraldpay.dshackle.upstream
 
 import io.emeraldpay.dshackle.Chain
 import io.emeraldpay.dshackle.config.AuthConfig
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcHttpClient
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 import io.emeraldpay.dshackle.upstream.rpcclient.RpcMetrics
 import io.micrometer.core.instrument.Counter
 import io.micrometer.core.instrument.Metrics
@@ -17,7 +15,7 @@ open class HttpRpcFactory(
     private val basicAuth: AuthConfig.ClientBasicAuth?,
     private val tls: ByteArray?
 ) : HttpFactory {
-    override fun create(id: String?, chain: Chain): Reader<JsonRpcRequest, JsonRpcResponse> {
+    override fun create(id: String?, chain: Chain): JsonRpcReader {
         val metricsTags = listOf(
             // "unknown" is not supposed to happen
             Tag.of("upstream", id ?: "unknown"),
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/Multistream.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/Multistream.kt
index 9c655c26..b1343232 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/Multistream.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/Multistream.kt
@@ -20,12 +20,10 @@ import io.emeraldpay.dshackle.Chain
 import io.emeraldpay.dshackle.cache.Caches
 import io.emeraldpay.dshackle.cache.CachesEnabled
 import io.emeraldpay.dshackle.config.UpstreamsConfig
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.startup.UpstreamChangeEvent
 import io.emeraldpay.dshackle.upstream.calls.AggregatedCallMethods
 import io.emeraldpay.dshackle.upstream.calls.CallMethods
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 import io.micrometer.core.instrument.Gauge
 import io.micrometer.core.instrument.Meter
 import io.micrometer.core.instrument.Metrics
@@ -175,9 +173,9 @@ abstract class Multistream(
     /**
      * Finds an API that leverages caches and other optimizations/transformations of the request.
      */
-    abstract fun getRoutedApi(localEnabled: Boolean): Mono<Reader<JsonRpcRequest, JsonRpcResponse>>
+    abstract fun getRoutedApi(localEnabled: Boolean): Mono<JsonRpcReader>
 
-    override fun getApi(): Reader<JsonRpcRequest, JsonRpcResponse> {
+    override fun getApi(): JsonRpcReader {
         throw NotImplementedError("Immediate direct API is not implemented for Aggregated Upstream")
     }
 
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/Upstream.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/Upstream.kt
index e8de7910..3685bbf9 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/Upstream.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/Upstream.kt
@@ -17,10 +17,8 @@
 package io.emeraldpay.dshackle.upstream
 
 import io.emeraldpay.dshackle.config.UpstreamsConfig
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.calls.CallMethods
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 import reactor.core.publisher.Flux
 
 interface Upstream {
@@ -28,7 +26,7 @@ interface Upstream {
     fun getStatus(): UpstreamAvailability
     fun observeStatus(): Flux<UpstreamAvailability>
     fun getHead(): Head
-    fun getApi(): Reader<JsonRpcRequest, JsonRpcResponse>
+    fun getApi(): JsonRpcReader
     fun getOptions(): UpstreamsConfig.Options
     fun getRole(): UpstreamsConfig.UpstreamRole
     fun setLag(lag: Long)
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinMultistream.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinMultistream.kt
index 0400debd..afa793fb 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinMultistream.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinMultistream.kt
@@ -18,13 +18,11 @@ package io.emeraldpay.dshackle.upstream.bitcoin
 import io.emeraldpay.dshackle.Chain
 import io.emeraldpay.dshackle.cache.Caches
 import io.emeraldpay.dshackle.config.UpstreamsConfig
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.*
 import io.emeraldpay.dshackle.upstream.Lifecycle
 import io.emeraldpay.dshackle.upstream.calls.DefaultBitcoinMethods
 import io.emeraldpay.dshackle.upstream.forkchoice.MostWorkForkChoice
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 import org.slf4j.LoggerFactory
 import reactor.core.publisher.Mono
 
@@ -98,7 +96,7 @@ open class BitcoinMultistream(
     /**
      * Finds an API that executed directly on a remote.
      */
-    open fun getDirectApi(matcher: Selector.Matcher): Mono<Reader<JsonRpcRequest, JsonRpcResponse>> {
+    open fun getDirectApi(matcher: Selector.Matcher): Mono<JsonRpcReader> {
         val apis = getApiSource(matcher)
         apis.request(1)
         return Mono.from(apis)
@@ -106,7 +104,7 @@ open class BitcoinMultistream(
             .switchIfEmpty(Mono.error(Exception("No API available for $chain")))
     }
 
-    override fun getRoutedApi(localEnabled: Boolean): Mono<Reader<JsonRpcRequest, JsonRpcResponse>> {
+    override fun getRoutedApi(localEnabled: Boolean): Mono<JsonRpcReader> {
         return Mono.just(callRouter)
     }
 
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinRpcHead.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinRpcHead.kt
index 5c018104..ecd994af 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinRpcHead.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinRpcHead.kt
@@ -16,7 +16,7 @@
 package io.emeraldpay.dshackle.upstream.bitcoin
 
 import io.emeraldpay.dshackle.Defaults
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.AbstractHead
 import io.emeraldpay.dshackle.upstream.Head
 import io.emeraldpay.dshackle.upstream.Lifecycle
@@ -33,7 +33,7 @@ import java.time.Duration
 import java.util.concurrent.Executors
 
 class BitcoinRpcHead(
-    private val api: Reader<JsonRpcRequest, JsonRpcResponse>,
+    private val api: JsonRpcReader,
     private val extractBlock: ExtractBlock,
     private val interval: Duration = Duration.ofSeconds(15)
 ) : Head, AbstractHead(MostWorkForkChoice(), awaitHeadTimeoutMs = 1200_000), Lifecycle {
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinRpcUpstream.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinRpcUpstream.kt
index 2f500bf8..8d6802ab 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinRpcUpstream.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinRpcUpstream.kt
@@ -17,7 +17,7 @@ package io.emeraldpay.dshackle.upstream.bitcoin
 
 import io.emeraldpay.dshackle.Chain
 import io.emeraldpay.dshackle.config.UpstreamsConfig
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.startup.QuorumForLabels
 import io.emeraldpay.dshackle.upstream.Capability
 import io.emeraldpay.dshackle.upstream.Head
@@ -25,15 +25,13 @@ import io.emeraldpay.dshackle.upstream.Lifecycle
 import io.emeraldpay.dshackle.upstream.Upstream
 import io.emeraldpay.dshackle.upstream.UpstreamAvailability
 import io.emeraldpay.dshackle.upstream.calls.CallMethods
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 import org.slf4j.LoggerFactory
 import reactor.core.Disposable
 
 open class BitcoinRpcUpstream(
     id: String,
     chain: Chain,
-    private val directApi: Reader<JsonRpcRequest, JsonRpcResponse>,
+    private val directApi: JsonRpcReader,
     private val head: Head,
     options: UpstreamsConfig.Options,
     role: UpstreamsConfig.UpstreamRole,
@@ -65,7 +63,7 @@ open class BitcoinRpcUpstream(
         return head
     }
 
-    override fun getApi(): Reader<JsonRpcRequest, JsonRpcResponse> {
+    override fun getApi(): JsonRpcReader {
         return directApi
     }
 
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinUpstreamValidator.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinUpstreamValidator.kt
index 6fd2a32e..7909be7d 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinUpstreamValidator.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinUpstreamValidator.kt
@@ -16,7 +16,7 @@
 package io.emeraldpay.dshackle.upstream.bitcoin
 
 import io.emeraldpay.dshackle.config.UpstreamsConfig
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.UpstreamAvailability
 import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
 import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
@@ -29,7 +29,7 @@ import java.time.Duration
 import java.util.concurrent.Executors
 
 class BitcoinUpstreamValidator(
-    private val api: Reader<JsonRpcRequest, JsonRpcResponse>,
+    private val api: JsonRpcReader,
     private val options: UpstreamsConfig.Options
 ) {
 
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinZMQHead.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinZMQHead.kt
index 07ed5837..c8b22608 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinZMQHead.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinZMQHead.kt
@@ -2,7 +2,7 @@ package io.emeraldpay.dshackle.upstream.bitcoin
 
 import io.emeraldpay.dshackle.Defaults
 import io.emeraldpay.dshackle.data.BlockContainer
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.AbstractHead
 import io.emeraldpay.dshackle.upstream.Head
 import io.emeraldpay.dshackle.upstream.Lifecycle
@@ -19,7 +19,7 @@ import java.time.Duration
 
 class BitcoinZMQHead(
     private val server: ZMQServer,
-    private val api: Reader<JsonRpcRequest, JsonRpcResponse>,
+    private val api: JsonRpcReader,
     private val extractBlock: ExtractBlock,
 ) : Head, AbstractHead(MostWorkForkChoice(), awaitHeadTimeoutMs = 1200_000), Lifecycle {
 
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/LocalCallRouter.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/LocalCallRouter.kt
index f1abee27..74574fa9 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/LocalCallRouter.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/LocalCallRouter.kt
@@ -17,7 +17,7 @@ package io.emeraldpay.dshackle.upstream.bitcoin
 
 import io.emeraldpay.dshackle.Global
 import io.emeraldpay.dshackle.SilentException
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.bitcoin.data.RpcUnspent
 import io.emeraldpay.dshackle.upstream.bitcoin.data.SimpleUnspent
 import io.emeraldpay.dshackle.upstream.calls.CallMethods
@@ -39,7 +39,7 @@ import reactor.core.publisher.Mono
 class LocalCallRouter(
     private val methods: CallMethods,
     private val reader: BitcoinReader,
-) : Reader<JsonRpcRequest, JsonRpcResponse> {
+) : JsonRpcReader {
 
     companion object {
         private val log = LoggerFactory.getLogger(LocalCallRouter::class.java)
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/DefaultEthereumHead.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/DefaultEthereumHead.kt
index c9af6626..0afda6be 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/DefaultEthereumHead.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/DefaultEthereumHead.kt
@@ -17,13 +17,12 @@ package io.emeraldpay.dshackle.upstream.ethereum
 
 import io.emeraldpay.dshackle.Defaults
 import io.emeraldpay.dshackle.data.BlockContainer
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.AbstractHead
 import io.emeraldpay.dshackle.upstream.BlockValidator
 import io.emeraldpay.dshackle.upstream.Head
 import io.emeraldpay.dshackle.upstream.forkchoice.ForkChoice
 import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 import io.emeraldpay.etherjar.hex.HexQuantity
 import org.slf4j.LoggerFactory
 import reactor.core.publisher.Mono
@@ -38,7 +37,7 @@ open class DefaultEthereumHead(
         private val log = LoggerFactory.getLogger(DefaultEthereumHead::class.java)
     }
 
-    fun getLatestBlock(api: Reader<JsonRpcRequest, JsonRpcResponse>): Mono<BlockContainer> {
+    fun getLatestBlock(api: JsonRpcReader): Mono<BlockContainer> {
         return api.read(JsonRpcRequest("eth_blockNumber", emptyList()))
             .subscribeOn(EthereumRpcHead.scheduler)
             .timeout(Defaults.timeout, Mono.error(Exception("Block number not received")))
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumMultistream.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumMultistream.kt
index 60df1920..a5a47f50 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumMultistream.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumMultistream.kt
@@ -20,7 +20,7 @@ import io.emeraldpay.api.proto.BlockchainOuterClass
 import io.emeraldpay.dshackle.Chain
 import io.emeraldpay.dshackle.cache.Caches
 import io.emeraldpay.dshackle.config.UpstreamsConfig
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.*
 import io.emeraldpay.dshackle.upstream.Lifecycle
 import io.emeraldpay.dshackle.upstream.ethereum.subscribe.AggregatedPendingTxes
@@ -28,8 +28,6 @@ import io.emeraldpay.dshackle.upstream.ethereum.subscribe.NoPendingTxes
 import io.emeraldpay.dshackle.upstream.ethereum.subscribe.PendingTxesSource
 import io.emeraldpay.dshackle.upstream.forkchoice.MostWorkForkChoice
 import io.emeraldpay.dshackle.upstream.grpc.GrpcUpstream
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 import org.slf4j.LoggerFactory
 import org.springframework.util.ConcurrentReferenceHashMap
 import reactor.core.publisher.Flux
@@ -179,7 +177,7 @@ open class EthereumMultistream(
         return subscribe
     }
 
-    override fun getRoutedApi(localEnabled: Boolean): Mono<Reader<JsonRpcRequest, JsonRpcResponse>> {
+    override fun getRoutedApi(localEnabled: Boolean): Mono<JsonRpcReader> {
         return Mono.just(LocalCallRouter(reader, getMethods(), getHead(), localEnabled))
     }
 
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumRpcHead.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumRpcHead.kt
index 16331153..464179c8 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumRpcHead.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumRpcHead.kt
@@ -16,12 +16,10 @@
  */
 package io.emeraldpay.dshackle.upstream.ethereum
 
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.BlockValidator
 import io.emeraldpay.dshackle.upstream.Lifecycle
 import io.emeraldpay.dshackle.upstream.forkchoice.ForkChoice
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 import org.slf4j.LoggerFactory
 import org.springframework.scheduling.concurrent.CustomizableThreadFactory
 import reactor.core.Disposable
@@ -31,7 +29,7 @@ import java.time.Duration
 import java.util.concurrent.Executors
 
 class EthereumRpcHead(
-    private val api: Reader<JsonRpcRequest, JsonRpcResponse>,
+    private val api: JsonRpcReader,
     forkChoice: ForkChoice,
     upstreamId: String,
     blockValidator: BlockValidator,
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumRpcUpstream.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumRpcUpstream.kt
index c1dac856..d3a4b426 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumRpcUpstream.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumRpcUpstream.kt
@@ -20,7 +20,7 @@ import io.emeraldpay.dshackle.Chain
 import io.emeraldpay.dshackle.cache.Caches
 import io.emeraldpay.dshackle.cache.CachesEnabled
 import io.emeraldpay.dshackle.config.UpstreamsConfig
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.startup.QuorumForLabels
 import io.emeraldpay.dshackle.upstream.Head
 import io.emeraldpay.dshackle.upstream.Upstream
@@ -28,8 +28,6 @@ import io.emeraldpay.dshackle.upstream.UpstreamAvailability
 import io.emeraldpay.dshackle.upstream.calls.CallMethods
 import io.emeraldpay.dshackle.upstream.ethereum.connectors.ConnectorFactory
 import io.emeraldpay.dshackle.upstream.ethereum.connectors.EthereumConnector
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 import org.slf4j.LoggerFactory
 import org.springframework.context.Lifecycle
 import reactor.core.Disposable
@@ -88,7 +86,7 @@ open class EthereumRpcUpstream(
         return connector.isRunning()
     }
 
-    override fun getApi(): Reader<JsonRpcRequest, JsonRpcResponse> {
+    override fun getApi(): JsonRpcReader {
         return connector.getApi()
     }
 
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumWsHead.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumWsHead.kt
index 640f1492..16e4636a 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumWsHead.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumWsHead.kt
@@ -20,7 +20,7 @@ import io.emeraldpay.dshackle.Defaults
 import io.emeraldpay.dshackle.Global
 import io.emeraldpay.dshackle.SilentException
 import io.emeraldpay.dshackle.data.BlockContainer
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.BlockValidator
 import io.emeraldpay.dshackle.upstream.Lifecycle
 import io.emeraldpay.dshackle.upstream.forkchoice.ForkChoice
@@ -40,7 +40,7 @@ class EthereumWsHead(
     upstreamId: String,
     forkChoice: ForkChoice,
     blockValidator: BlockValidator,
-    private val api: Reader<JsonRpcRequest, JsonRpcResponse>,
+    private val api: JsonRpcReader,
     private val wsSubscriptions: WsSubscriptions,
 ) : DefaultEthereumHead(upstreamId, forkChoice, blockValidator), Lifecycle {
 
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/LocalCallRouter.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/LocalCallRouter.kt
index 48da7ed4..b75923d6 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/LocalCallRouter.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/LocalCallRouter.kt
@@ -17,7 +17,7 @@ package io.emeraldpay.dshackle.upstream.ethereum
 
 import io.emeraldpay.dshackle.data.BlockId
 import io.emeraldpay.dshackle.data.TxId
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.Head
 import io.emeraldpay.dshackle.upstream.calls.CallMethods
 import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
@@ -41,7 +41,7 @@ class LocalCallRouter(
     private val methods: CallMethods,
     private val head: Head,
     private val localEnabled: Boolean
-) : Reader<JsonRpcRequest, JsonRpcResponse> {
+) : JsonRpcReader {
 
     companion object {
         private val log = LoggerFactory.getLogger(LocalCallRouter::class.java)
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/connectors/EthereumConnector.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/connectors/EthereumConnector.kt
index 74acddda..722c5b98 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/connectors/EthereumConnector.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/connectors/EthereumConnector.kt
@@ -1,16 +1,14 @@
 package io.emeraldpay.dshackle.upstream.ethereum.connectors
 
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.Head
 import io.emeraldpay.dshackle.upstream.Lifecycle
 import io.emeraldpay.dshackle.upstream.ethereum.EthereumIngressSubscription
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 
 interface EthereumConnector : Lifecycle {
     fun getHead(): Head
 
-    fun getApi(): Reader<JsonRpcRequest, JsonRpcResponse>
+    fun getApi(): JsonRpcReader
 
     fun getIngressSubscription(): EthereumIngressSubscription
 }
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/connectors/EthereumRpcConnector.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/connectors/EthereumRpcConnector.kt
index 15d95a8c..6af81f16 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/connectors/EthereumRpcConnector.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/connectors/EthereumRpcConnector.kt
@@ -2,7 +2,7 @@ package io.emeraldpay.dshackle.upstream.ethereum.connectors
 
 import io.emeraldpay.dshackle.cache.Caches
 import io.emeraldpay.dshackle.cache.CachesEnabled
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.BlockValidator
 import io.emeraldpay.dshackle.upstream.Head
 import io.emeraldpay.dshackle.upstream.Lifecycle
@@ -10,13 +10,11 @@ import io.emeraldpay.dshackle.upstream.MergedHead
 import io.emeraldpay.dshackle.upstream.ethereum.*
 import io.emeraldpay.dshackle.upstream.forkchoice.AlwaysForkChoice
 import io.emeraldpay.dshackle.upstream.forkchoice.ForkChoice
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 import org.slf4j.LoggerFactory
 import java.time.Duration
 
 class EthereumRpcConnector(
-    private val directReader: Reader<JsonRpcRequest, JsonRpcResponse>,
+    private val directReader: JsonRpcReader,
     wsFactory: EthereumWsFactory?,
     id: String,
     forkChoice: ForkChoice,
@@ -72,7 +70,7 @@ class EthereumRpcConnector(
         conn?.close()
     }
 
-    override fun getApi(): Reader<JsonRpcRequest, JsonRpcResponse> {
+    override fun getApi(): JsonRpcReader {
         return directReader
     }
 
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/connectors/EthereumWsConnector.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/connectors/EthereumWsConnector.kt
index ab4d18da..bc6bc41f 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/connectors/EthereumWsConnector.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/connectors/EthereumWsConnector.kt
@@ -1,14 +1,12 @@
 package io.emeraldpay.dshackle.upstream.ethereum.connectors
 
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.BlockValidator
 import io.emeraldpay.dshackle.upstream.DefaultUpstream
 import io.emeraldpay.dshackle.upstream.Head
 import io.emeraldpay.dshackle.upstream.ethereum.*
 import io.emeraldpay.dshackle.upstream.ethereum.subscribe.EthereumWsIngressSubscription
 import io.emeraldpay.dshackle.upstream.forkchoice.ForkChoice
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcWsClient
 
 class EthereumWsConnector(
@@ -18,7 +16,7 @@ class EthereumWsConnector(
     blockValidator: BlockValidator
 ) : EthereumConnector {
     private val conn: WsConnectionImpl
-    private val api: Reader<JsonRpcRequest, JsonRpcResponse>
+    private val api: JsonRpcReader
     private val head: EthereumWsHead
     private val subscriptions: EthereumIngressSubscription
 
@@ -44,7 +42,7 @@ class EthereumWsConnector(
         head.stop()
     }
 
-    override fun getApi(): Reader<JsonRpcRequest, JsonRpcResponse> {
+    override fun getApi(): JsonRpcReader {
         return api
     }
 
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum_pos/EthereumPosMultiStream.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum_pos/EthereumPosMultiStream.kt
index ad473770..53f116b5 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum_pos/EthereumPosMultiStream.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum_pos/EthereumPosMultiStream.kt
@@ -20,15 +20,13 @@ import io.emeraldpay.api.proto.BlockchainOuterClass
 import io.emeraldpay.dshackle.Chain
 import io.emeraldpay.dshackle.cache.Caches
 import io.emeraldpay.dshackle.config.UpstreamsConfig
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.*
 import io.emeraldpay.dshackle.upstream.ethereum.subscribe.AggregatedPendingTxes
 import io.emeraldpay.dshackle.upstream.ethereum.subscribe.NoPendingTxes
 import io.emeraldpay.dshackle.upstream.ethereum.subscribe.PendingTxesSource
 import io.emeraldpay.dshackle.upstream.forkchoice.PriorityForkChoice
 import io.emeraldpay.dshackle.upstream.grpc.GrpcUpstream
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 import org.slf4j.LoggerFactory
 import org.springframework.util.ConcurrentReferenceHashMap
 import reactor.core.publisher.Flux
@@ -149,7 +147,7 @@ open class EthereumPosMultiStream(
         return this as T
     }
 
-    override fun getRoutedApi(localEnabled: Boolean): Mono<Reader<JsonRpcRequest, JsonRpcResponse>> {
+    override fun getRoutedApi(localEnabled: Boolean): Mono<JsonRpcReader> {
         return Mono.just(LocalCallRouter(reader, getMethods(), getHead(), localEnabled))
     }
 
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum_pos/EthereumPosRpcUpstream.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum_pos/EthereumPosRpcUpstream.kt
index cf34f76b..390ff7f9 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum_pos/EthereumPosRpcUpstream.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum_pos/EthereumPosRpcUpstream.kt
@@ -20,7 +20,7 @@ import io.emeraldpay.dshackle.Chain
 import io.emeraldpay.dshackle.cache.Caches
 import io.emeraldpay.dshackle.cache.CachesEnabled
 import io.emeraldpay.dshackle.config.UpstreamsConfig
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.startup.QuorumForLabels
 import io.emeraldpay.dshackle.upstream.Head
 import io.emeraldpay.dshackle.upstream.Lifecycle
@@ -29,8 +29,6 @@ import io.emeraldpay.dshackle.upstream.UpstreamAvailability
 import io.emeraldpay.dshackle.upstream.calls.CallMethods
 import io.emeraldpay.dshackle.upstream.ethereum.connectors.ConnectorFactory
 import io.emeraldpay.dshackle.upstream.ethereum.connectors.EthereumConnector
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
-import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 import org.slf4j.LoggerFactory
 import reactor.core.Disposable
 
@@ -83,7 +81,7 @@ open class EthereumPosRpcUpstream(
         return connector.isRunning()
     }
 
-    override fun getApi(): Reader<JsonRpcRequest, JsonRpcResponse> {
+    override fun getApi(): JsonRpcReader {
         return connector.getApi()
     }
 
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/BitcoinGrpcUpstream.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/BitcoinGrpcUpstream.kt
index 6237777c..b0acf871 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/BitcoinGrpcUpstream.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/BitcoinGrpcUpstream.kt
@@ -22,7 +22,7 @@ import io.emeraldpay.dshackle.Defaults
 import io.emeraldpay.dshackle.config.UpstreamsConfig
 import io.emeraldpay.dshackle.data.BlockContainer
 import io.emeraldpay.dshackle.data.BlockId
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.Capability
 import io.emeraldpay.dshackle.upstream.Head
 import io.emeraldpay.dshackle.upstream.Lifecycle
@@ -66,7 +66,7 @@ class BitcoinGrpcUpstream(
     }
 
     private val extractBlock = ExtractBlock()
-    private val defaultReader: Reader<JsonRpcRequest, JsonRpcResponse> = client.getReader()
+    private val defaultReader: JsonRpcReader = client.getReader()
     private val blockConverter: Function<BlockchainOuterClass.ChainHead, BlockContainer> = Function { value ->
         val block = BlockContainer(
             value.height,
@@ -112,7 +112,7 @@ class BitcoinGrpcUpstream(
         return grpcHead
     }
 
-    override fun getApi(): Reader<JsonRpcRequest, JsonRpcResponse> {
+    override fun getApi(): JsonRpcReader {
         return defaultReader
     }
 
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/EthereumGrpcUpstream.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/EthereumGrpcUpstream.kt
index 8006e078..96250ac6 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/EthereumGrpcUpstream.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/EthereumGrpcUpstream.kt
@@ -23,7 +23,7 @@ import io.emeraldpay.dshackle.Defaults
 import io.emeraldpay.dshackle.config.UpstreamsConfig
 import io.emeraldpay.dshackle.data.BlockContainer
 import io.emeraldpay.dshackle.data.BlockId
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.startup.QuorumForLabels
 import io.emeraldpay.dshackle.upstream.Capability
 import io.emeraldpay.dshackle.upstream.Head
@@ -107,7 +107,7 @@ open class EthereumGrpcUpstream(
     private val grpcHead = GrpcHead(chain, this, remote, blockConverter, reloadBlock, MostWorkForkChoice())
     private var capabilities: Set<Capability> = emptySet()
 
-    private val defaultReader: Reader<JsonRpcRequest, JsonRpcResponse> = client.getReader()
+    private val defaultReader: JsonRpcReader = client.getReader()
     var timeout = Defaults.timeout
     private val ethereumSubscriptions = EthereumDshackleIngressSubscription(chain, remote)
 
@@ -162,7 +162,7 @@ open class EthereumGrpcUpstream(
         return grpcHead
     }
 
-    override fun getApi(): Reader<JsonRpcRequest, JsonRpcResponse> {
+    override fun getApi(): JsonRpcReader {
         return defaultReader
     }
 
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/EthereumPosGrpcUpstream.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/EthereumPosGrpcUpstream.kt
index 75f456ba..c7c4c9c5 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/EthereumPosGrpcUpstream.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/EthereumPosGrpcUpstream.kt
@@ -23,7 +23,7 @@ import io.emeraldpay.dshackle.Defaults
 import io.emeraldpay.dshackle.config.UpstreamsConfig
 import io.emeraldpay.dshackle.data.BlockContainer
 import io.emeraldpay.dshackle.data.BlockId
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.startup.QuorumForLabels
 import io.emeraldpay.dshackle.upstream.Capability
 import io.emeraldpay.dshackle.upstream.Head
@@ -107,7 +107,7 @@ open class EthereumPosGrpcUpstream(
     private val grpcHead = GrpcHead(chain, this, remote, blockConverter, reloadBlock, NoChoiceWithPriorityForkChoice(nodeRating, parentId))
     private var capabilities: Set<Capability> = emptySet()
 
-    private val defaultReader: Reader<JsonRpcRequest, JsonRpcResponse> = client.getReader()
+    private val defaultReader: JsonRpcReader = client.getReader()
     var timeout = Defaults.timeout
     private val ethereumSubscriptions = EthereumDshackleIngressSubscription(chain, remote)
 
@@ -162,7 +162,7 @@ open class EthereumPosGrpcUpstream(
         return grpcHead
     }
 
-    override fun getApi(): Reader<JsonRpcRequest, JsonRpcResponse> {
+    override fun getApi(): JsonRpcReader {
         return defaultReader
     }
 
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/JsonRpcGrpcClient.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/JsonRpcGrpcClient.kt
index b525b1c2..8faf70aa 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/JsonRpcGrpcClient.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/JsonRpcGrpcClient.kt
@@ -21,7 +21,7 @@ import io.emeraldpay.api.proto.BlockchainOuterClass.NativeCallReplySignature
 import io.emeraldpay.api.proto.ReactorBlockchainGrpc
 import io.emeraldpay.dshackle.Chain
 import io.emeraldpay.dshackle.Global
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.signature.ResponseSigner
 import io.emeraldpay.etherjar.rpc.RpcException
 import io.emeraldpay.etherjar.rpc.RpcResponseError
@@ -41,7 +41,7 @@ class JsonRpcGrpcClient(
         private val log = LoggerFactory.getLogger(JsonRpcGrpcClient::class.java)
     }
 
-    fun getReader(): Reader<JsonRpcRequest, JsonRpcResponse> {
+    fun getReader(): JsonRpcReader {
         return Executor(stub, chain, metrics)
     }
 
@@ -49,7 +49,7 @@ class JsonRpcGrpcClient(
         private val stub: ReactorBlockchainGrpc.ReactorBlockchainStub,
         private val chain: Chain,
         private val metrics: RpcMetrics?
-    ) : Reader<JsonRpcRequest, JsonRpcResponse> {
+    ) : JsonRpcReader {
 
         override fun read(key: JsonRpcRequest): Mono<JsonRpcResponse> {
             val timer = StopWatch()
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/JsonRpcHttpClient.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/JsonRpcHttpClient.kt
index 154ea0c4..93b0cebf 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/JsonRpcHttpClient.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/JsonRpcHttpClient.kt
@@ -16,7 +16,7 @@
 package io.emeraldpay.dshackle.upstream.rpcclient
 
 import io.emeraldpay.dshackle.config.AuthConfig
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.etherjar.rpc.RpcException
 import io.emeraldpay.etherjar.rpc.RpcResponseError
 import io.netty.buffer.Unpooled
@@ -48,7 +48,7 @@ class JsonRpcHttpClient(
     private val metrics: RpcMetrics,
     basicAuth: AuthConfig.ClientBasicAuth? = null,
     tlsCAAuth: ByteArray? = null
-) : Reader<JsonRpcRequest, JsonRpcResponse> {
+) : JsonRpcReader {
 
     companion object {
         private val log = LoggerFactory.getLogger(JsonRpcHttpClient::class.java)
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/JsonRpcSwitchClient.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/JsonRpcSwitchClient.kt
index 82ab68cd..c9b57de5 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/JsonRpcSwitchClient.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/JsonRpcSwitchClient.kt
@@ -1,6 +1,6 @@
 package io.emeraldpay.dshackle.upstream.rpcclient
 
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import org.slf4j.LoggerFactory
 import reactor.core.publisher.Mono
 
@@ -9,9 +9,9 @@ import reactor.core.publisher.Mono
  * It always calls the Primary reader, and if it fails or produces an empty result, then it calls the Secondary reader.
  */
 class JsonRpcSwitchClient(
-    private val primary: Reader<JsonRpcRequest, JsonRpcResponse>,
-    private val secondary: Reader<JsonRpcRequest, JsonRpcResponse>,
-) : Reader<JsonRpcRequest, JsonRpcResponse> {
+    private val primary: JsonRpcReader,
+    private val secondary: JsonRpcReader,
+) : JsonRpcReader {
 
     companion object {
         private val log = LoggerFactory.getLogger(JsonRpcSwitchClient::class.java)
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/JsonRpcWsClient.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/JsonRpcWsClient.kt
index a286d7f3..bd60dd49 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/JsonRpcWsClient.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/rpcclient/JsonRpcWsClient.kt
@@ -15,14 +15,14 @@
  */
 package io.emeraldpay.dshackle.upstream.rpcclient
 
-import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.reader.JsonRpcReader
 import io.emeraldpay.dshackle.upstream.ethereum.WsConnectionImpl
 import io.emeraldpay.etherjar.rpc.RpcResponseError
 import reactor.core.publisher.Mono
 
 class JsonRpcWsClient(
     private val ws: WsConnectionImpl
-) : Reader<JsonRpcRequest, JsonRpcResponse> {
+) : JsonRpcReader {
 
     override fun read(key: JsonRpcRequest): Mono<JsonRpcResponse> {
         if (!ws.isConnected) {