diff --git a/build.gradle b/build.gradle
index 03cc3cb6..d9363198 100644
--- a/build.gradle
+++ b/build.gradle
@@ -289,3 +289,6 @@ detekt {
 tasks.withType(Detekt).configureEach {
     jvmTarget = "13"
 }
+
+// formats code for each build
+tasks.findByName("ktlintCheck").dependsOn("ktlintFormat")
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/config/context/MultistreamsConfig.kt b/src/main/kotlin/io/emeraldpay/dshackle/config/context/MultistreamsConfig.kt
index 7ffdd93d..cfa80f3a 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/config/context/MultistreamsConfig.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/config/context/MultistreamsConfig.kt
@@ -1,6 +1,7 @@
 package io.emeraldpay.dshackle.config.context
 
 import io.emeraldpay.dshackle.cache.CachesFactory
+import io.emeraldpay.dshackle.upstream.CallTargetsHolder
 import io.emeraldpay.dshackle.upstream.Multistream
 import io.emeraldpay.dshackle.upstream.bitcoin.BitcoinMultistream
 import io.emeraldpay.dshackle.upstream.ethereum.EthereumMultistream
@@ -13,13 +14,31 @@ import org.springframework.context.annotation.Configuration
 @Configuration
 class MultistreamsConfig {
     @Bean
-    fun allMultistreams(cachesFactory: CachesFactory): List<Multistream> {
+    fun allMultistreams(
+        cachesFactory: CachesFactory,
+        callTargetsHolder: CallTargetsHolder
+    ): List<Multistream> {
         return Chain.values()
             .mapNotNull { chain ->
                 when (BlockchainType.from(chain)) {
-                    BlockchainType.EVM_POS -> EthereumPosMultiStream(chain, ArrayList(), cachesFactory.getCaches(chain))
-                    BlockchainType.EVM_POW -> EthereumMultistream(chain, ArrayList(), cachesFactory.getCaches(chain))
-                    BlockchainType.BITCOIN -> BitcoinMultistream(chain, ArrayList(), cachesFactory.getCaches(chain))
+                    BlockchainType.EVM_POS -> EthereumPosMultiStream(
+                        chain,
+                        ArrayList(),
+                        cachesFactory.getCaches(chain),
+                        callTargetsHolder
+                    )
+                    BlockchainType.EVM_POW -> EthereumMultistream(
+                        chain,
+                        ArrayList(),
+                        cachesFactory.getCaches(chain),
+                        callTargetsHolder
+                    )
+                    BlockchainType.BITCOIN -> BitcoinMultistream(
+                        chain,
+                        ArrayList(),
+                        cachesFactory.getCaches(chain),
+                        callTargetsHolder
+                    )
                     else -> null
                 }
             }
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/startup/ConfiguredUpstreams.kt b/src/main/kotlin/io/emeraldpay/dshackle/startup/ConfiguredUpstreams.kt
index 3a86c6ac..8fc7e036 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/startup/ConfiguredUpstreams.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/startup/ConfiguredUpstreams.kt
@@ -21,13 +21,7 @@ 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.upstream.BlockValidator
-import io.emeraldpay.dshackle.upstream.CurrentMultistreamHolder
-import io.emeraldpay.dshackle.upstream.Head
-import io.emeraldpay.dshackle.upstream.HttpRpcFactory
-import io.emeraldpay.dshackle.upstream.MergedHead
-import io.emeraldpay.dshackle.upstream.Selector
-import io.emeraldpay.dshackle.upstream.Upstream
+import io.emeraldpay.dshackle.upstream.*
 import io.emeraldpay.dshackle.upstream.bitcoin.BitcoinRpcHead
 import io.emeraldpay.dshackle.upstream.bitcoin.BitcoinRpcUpstream
 import io.emeraldpay.dshackle.upstream.bitcoin.BitcoinZMQHead
@@ -50,19 +44,20 @@ import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcResponse
 import io.emeraldpay.grpc.BlockchainType
 import io.emeraldpay.grpc.Chain
 import org.slf4j.LoggerFactory
-import org.springframework.beans.factory.annotation.Autowired
-import org.springframework.stereotype.Repository
+import org.springframework.context.ApplicationEventPublisher
+import org.springframework.stereotype.Component
 import java.net.URI
 import java.util.concurrent.atomic.AtomicInteger
 import java.util.function.Function
 import javax.annotation.PostConstruct
 import kotlin.math.abs
 
-@Repository
+@Component
 open class ConfiguredUpstreams(
-    @Autowired private val currentUpstreams: CurrentMultistreamHolder,
-    @Autowired private val fileResolver: FileResolver,
-    @Autowired private val config: UpstreamsConfig
+    private val fileResolver: FileResolver,
+    private val config: UpstreamsConfig,
+    private val callTargets: CallTargetsHolder,
+    private val eventPublisher: ApplicationEventPublisher
 ) {
 
     private val log = LoggerFactory.getLogger(ConfiguredUpstreams::class.java)
@@ -115,7 +110,8 @@ open class ConfiguredUpstreams(
                     }
                 }
                 upstream?.let {
-                    currentUpstreams.update(UpstreamChange(chain, upstream, UpstreamChange.ChangeType.ADDED))
+                    val event = UpstreamChangeEvent(chain, upstream, UpstreamChangeEvent.ChangeType.ADDED)
+                    eventPublisher.publishEvent(event)
                 }
             }
         }
@@ -150,7 +146,7 @@ open class ConfiguredUpstreams(
     fun buildMethods(config: UpstreamsConfig.Upstream<*>, chain: Chain): CallMethods {
         return if (config.methods != null) {
             ManagedCallMethods(
-                currentUpstreams.getDefaultMethods(chain),
+                callTargets.getDefaultMethods(chain),
                 config.methods!!.enabled.map { it.name }.toSet(),
                 config.methods!!.disabled.map { it.name }.toSet()
             ).also {
@@ -164,7 +160,7 @@ open class ConfiguredUpstreams(
                 }
             }
         } else {
-            currentUpstreams.getDefaultMethods(chain)
+            callTargets.getDefaultMethods(chain)
         }
     }
 
@@ -315,7 +311,7 @@ open class ConfiguredUpstreams(
             .doOnNext {
                 log.info("Chain ${it.chain} ${it.type} through gRPC at ${endpoint.host}:${endpoint.port}. With caps: ${it.upstream.getCapabilities()}")
             }
-            .subscribe(currentUpstreams::update)
+            .subscribe(eventPublisher::publishEvent)
     }
 
     private fun buildHttpFactory(conn: UpstreamsConfig.RpcConnection, urls: ArrayList<URI>? = null): HttpRpcFactory? {
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/startup/UpstreamChange.kt b/src/main/kotlin/io/emeraldpay/dshackle/startup/UpstreamChangeEvent.kt
similarity index 98%
rename from src/main/kotlin/io/emeraldpay/dshackle/startup/UpstreamChange.kt
rename to src/main/kotlin/io/emeraldpay/dshackle/startup/UpstreamChangeEvent.kt
index 213e55a1..34bcc8bf 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/startup/UpstreamChange.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/startup/UpstreamChangeEvent.kt
@@ -24,7 +24,7 @@ import io.emeraldpay.grpc.Chain
 /**
  * An update event to the list of currently available upstreams.
  */
-class UpstreamChange(
+class UpstreamChangeEvent(
     /**
      * Target blockchain
      */
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/CallTargetsHolder.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/CallTargetsHolder.kt
new file mode 100644
index 00000000..2ad03f39
--- /dev/null
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/CallTargetsHolder.kt
@@ -0,0 +1,29 @@
+package io.emeraldpay.dshackle.upstream
+
+import io.emeraldpay.dshackle.upstream.calls.CallMethods
+import io.emeraldpay.dshackle.upstream.calls.DefaultBitcoinMethods
+import io.emeraldpay.dshackle.upstream.calls.DefaultEthereumMethods
+import io.emeraldpay.grpc.BlockchainType
+import io.emeraldpay.grpc.Chain
+import org.springframework.stereotype.Component
+import java.util.HashMap
+
+@Component
+class CallTargetsHolder {
+    private val callTargets = HashMap<Chain, CallMethods>()
+
+    fun getDefaultMethods(chain: Chain): CallMethods {
+        return callTargets[chain] ?: return setupDefaultMethods(chain)
+    }
+
+    private fun setupDefaultMethods(chain: Chain): CallMethods {
+        val created = when (BlockchainType.from(chain)) {
+            BlockchainType.EVM_POW -> DefaultEthereumMethods(chain)
+            BlockchainType.BITCOIN -> DefaultBitcoinMethods()
+            BlockchainType.EVM_POS -> DefaultEthereumMethods(chain)
+            else -> throw IllegalStateException("Unsupported chain: $chain")
+        }
+        callTargets[chain] = created
+        return created
+    }
+}
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/CurrentMultistreamHolder.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/CurrentMultistreamHolder.kt
index 2de935f6..0402c727 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/CurrentMultistreamHolder.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/CurrentMultistreamHolder.kt
@@ -16,15 +16,6 @@
  */
 package io.emeraldpay.dshackle.upstream
 
-import io.emeraldpay.dshackle.cache.CachesEnabled
-import io.emeraldpay.dshackle.startup.UpstreamChange
-import io.emeraldpay.dshackle.upstream.bitcoin.BitcoinUpstream
-import io.emeraldpay.dshackle.upstream.calls.CallMethods
-import io.emeraldpay.dshackle.upstream.calls.DefaultBitcoinMethods
-import io.emeraldpay.dshackle.upstream.calls.DefaultEthereumMethods
-import io.emeraldpay.dshackle.upstream.ethereum.EthereumPosUpstream
-import io.emeraldpay.dshackle.upstream.ethereum.EthereumUpstream
-import io.emeraldpay.grpc.BlockchainType
 import io.emeraldpay.grpc.Chain
 import org.slf4j.LoggerFactory
 import org.springframework.stereotype.Component
@@ -49,61 +40,8 @@ open class CurrentMultistreamHolder(
     private val chainsBus = Sinks.many()
         .multicast()
         .directBestEffort<Chain>()
-    private val callTargets = HashMap<Chain, CallMethods>()
     private val updateLock = ReentrantLock()
 
-    fun update(change: UpstreamChange) {
-        updateLock.withLock {
-            log.debug("Upstream update: ${change.type} ${change.chain} via ${change.upstream.getId()}")
-            val chain = change.chain
-            try {
-                when (BlockchainType.from(chain)) {
-                    BlockchainType.EVM_POW -> {
-                        val up = change.upstream.cast(EthereumUpstream::class.java)
-                        val current = chainMapping.getValue(chain)
-                        processUpdate(change, up, current)
-                    }
-
-                    BlockchainType.EVM_POS -> {
-                        val up = change.upstream.cast(EthereumPosUpstream::class.java)
-                        val current = chainMapping.getValue(chain)
-                        processUpdate(change, up, current)
-                    }
-
-                    BlockchainType.BITCOIN -> {
-                        val up = change.upstream.cast(BitcoinUpstream::class.java)
-                        val current = chainMapping.getValue(chain)
-                        processUpdate(change, up, current)
-                    }
-
-                    else -> {
-                        log.error("Update for unsupported chain: $chain")
-                    }
-                }
-            } catch (e: Throwable) {
-                log.error("Failed to update upstream", e)
-            }
-        }
-    }
-
-    fun processUpdate(change: UpstreamChange, up: Upstream, current: Multistream) {
-        val chain = change.chain
-        if (change.type == UpstreamChange.ChangeType.REMOVED) {
-            current.removeUpstream(up.getId())
-            log.info("Upstream ${change.upstream.getId()} with chain $chain has been removed")
-        } else {
-            if (up is CachesEnabled) {
-                up.setCaches(current.caches)
-            }
-            current.addUpstream(up)
-
-            if (!callTargets.containsKey(chain)) {
-                setupDefaultMethods(chain)
-            }
-            log.info("Upstream ${change.upstream.getId()} with chain $chain has been added")
-        }
-    }
-
     override fun getUpstream(chain: Chain): Multistream? {
         return chainMapping[chain]
     }
@@ -122,23 +60,8 @@ open class CurrentMultistreamHolder(
         )
     }
 
-    override fun getDefaultMethods(chain: Chain): CallMethods {
-        return callTargets[chain] ?: return setupDefaultMethods(chain)
-    }
-
-    fun setupDefaultMethods(chain: Chain): CallMethods {
-        val created = when (BlockchainType.from(chain)) {
-            BlockchainType.EVM_POW -> DefaultEthereumMethods(chain)
-            BlockchainType.BITCOIN -> DefaultBitcoinMethods()
-            BlockchainType.EVM_POS -> DefaultEthereumMethods(chain)
-            else -> throw IllegalStateException("Unsupported chain: $chain")
-        }
-        callTargets[chain] = created
-        return created
-    }
-
     override fun isAvailable(chain: Chain): Boolean {
-        return chainMapping.containsKey(chain) && callTargets.containsKey(chain)
+        return chainMapping.getValue(chain).isAvailable()
     }
 
     @PreDestroy
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/Multistream.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/Multistream.kt
index c04dd9e0..80e19481 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/Multistream.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/Multistream.kt
@@ -17,8 +17,10 @@
 package io.emeraldpay.dshackle.upstream
 
 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.startup.UpstreamChangeEvent
 import io.emeraldpay.dshackle.upstream.calls.AggregatedCallMethods
 import io.emeraldpay.dshackle.upstream.calls.CallMethods
 import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
@@ -30,6 +32,7 @@ import org.apache.commons.collections4.Factory
 import org.apache.commons.collections4.FunctorException
 import org.slf4j.LoggerFactory
 import org.springframework.context.Lifecycle
+import org.springframework.context.event.EventListener
 import reactor.core.Disposable
 import reactor.core.publisher.Flux
 import reactor.core.publisher.Mono
@@ -48,7 +51,8 @@ abstract class Multistream(
     val chain: Chain,
     private val upstreams: MutableList<Upstream>,
     val caches: Caches,
-    val postprocessor: RequestPostprocessor
+    val postprocessor: RequestPostprocessor,
+    val callTargetsHolder: CallTargetsHolder
 ) : Upstream, Lifecycle {
 
     companion object {
@@ -316,6 +320,23 @@ abstract class Multistream(
         log.info("State of ${chain.chainCode}: height=${height ?: '?'}, status=[$statuses], lag=[$lag], weak=[$weak]")
     }
 
+    @EventListener
+    fun onUpstreamChange(event: UpstreamChangeEvent) {
+        val chain = event.chain
+        if (this.chain == chain) {
+            if (event.type == UpstreamChangeEvent.ChangeType.REMOVED) {
+                removeUpstream(event.upstream.getId())
+                log.info("Upstream ${event.upstream.getId()} with chain $chain has been removed")
+            } else {
+                if (event.upstream is CachesEnabled) {
+                    event.upstream.setCaches(caches)
+                }
+                addUpstream(event.upstream)
+                log.info("Upstream ${event.upstream.getId()} with chain $chain has been added")
+            }
+        }
+    }
+
     // --------------------------------------------------------------------------------------------------------
 
     class UpstreamStatus(val upstream: Upstream, val status: UpstreamAvailability, val ts: Instant = Instant.now())
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/MultistreamHolder.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/MultistreamHolder.kt
index 852ffdee..6e1c4ab0 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/MultistreamHolder.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/MultistreamHolder.kt
@@ -16,7 +16,6 @@
  */
 package io.emeraldpay.dshackle.upstream
 
-import io.emeraldpay.dshackle.upstream.calls.CallMethods
 import io.emeraldpay.grpc.Chain
 import reactor.core.publisher.Flux
 
@@ -27,6 +26,5 @@ interface MultistreamHolder {
     fun getUpstream(chain: Chain): Multistream?
     fun getAvailable(): List<Chain>
     fun observeChains(): Flux<Chain>
-    fun getDefaultMethods(chain: Chain): CallMethods
     fun isAvailable(chain: Chain): Boolean
 }
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 d72a3fb5..14ebfda0 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinMultistream.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/bitcoin/BitcoinMultistream.kt
@@ -18,14 +18,7 @@ package io.emeraldpay.dshackle.upstream.bitcoin
 import io.emeraldpay.dshackle.cache.Caches
 import io.emeraldpay.dshackle.config.UpstreamsConfig
 import io.emeraldpay.dshackle.reader.Reader
-import io.emeraldpay.dshackle.upstream.ChainFees
-import io.emeraldpay.dshackle.upstream.EmptyHead
-import io.emeraldpay.dshackle.upstream.Head
-import io.emeraldpay.dshackle.upstream.MergedHead
-import io.emeraldpay.dshackle.upstream.Multistream
-import io.emeraldpay.dshackle.upstream.RequestPostprocessor
-import io.emeraldpay.dshackle.upstream.Selector
-import io.emeraldpay.dshackle.upstream.Upstream
+import io.emeraldpay.dshackle.upstream.*
 import io.emeraldpay.dshackle.upstream.calls.DefaultBitcoinMethods
 import io.emeraldpay.dshackle.upstream.forkchoice.MostWorkForkChoice
 import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
@@ -39,8 +32,9 @@ import reactor.core.publisher.Mono
 open class BitcoinMultistream(
     chain: Chain,
     private val sourceUpstreams: MutableList<BitcoinUpstream>,
-    caches: Caches
-) : Multistream(chain, sourceUpstreams as MutableList<Upstream>, caches, RequestPostprocessor.Empty()), Lifecycle {
+    caches: Caches,
+    callTargetsHolder: CallTargetsHolder
+) : Multistream(chain, sourceUpstreams as MutableList<Upstream>, caches, RequestPostprocessor.Empty(), callTargetsHolder), Lifecycle {
 
     companion object {
         private val log = LoggerFactory.getLogger(BitcoinMultistream::class.java)
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 259e88a6..e2fb57f5 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumMultistream.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/ethereum/EthereumMultistream.kt
@@ -20,13 +20,7 @@ import io.emeraldpay.api.proto.BlockchainOuterClass
 import io.emeraldpay.dshackle.cache.Caches
 import io.emeraldpay.dshackle.config.UpstreamsConfig
 import io.emeraldpay.dshackle.reader.Reader
-import io.emeraldpay.dshackle.upstream.ChainFees
-import io.emeraldpay.dshackle.upstream.EmptyHead
-import io.emeraldpay.dshackle.upstream.Head
-import io.emeraldpay.dshackle.upstream.MergedHead
-import io.emeraldpay.dshackle.upstream.Multistream
-import io.emeraldpay.dshackle.upstream.Selector
-import io.emeraldpay.dshackle.upstream.Upstream
+import io.emeraldpay.dshackle.upstream.*
 import io.emeraldpay.dshackle.upstream.forkchoice.MostWorkForkChoice
 import io.emeraldpay.dshackle.upstream.grpc.GrpcUpstream
 import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
@@ -42,8 +36,9 @@ import reactor.core.publisher.Mono
 open class EthereumMultistream(
     chain: Chain,
     val upstreams: MutableList<EthereumUpstream>,
-    caches: Caches
-) : Multistream(chain, upstreams as MutableList<Upstream>, caches, CacheRequested(caches)), EthereumLikeMultistream {
+    caches: Caches,
+    callTargetsHolder: CallTargetsHolder
+) : Multistream(chain, upstreams as MutableList<Upstream>, caches, CacheRequested(caches), callTargetsHolder), EthereumLikeMultistream {
 
     companion object {
         private val log = LoggerFactory.getLogger(EthereumMultistream::class.java)
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 cd872db7..3e93a81a 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
@@ -20,13 +20,7 @@ import io.emeraldpay.api.proto.BlockchainOuterClass
 import io.emeraldpay.dshackle.cache.Caches
 import io.emeraldpay.dshackle.config.UpstreamsConfig
 import io.emeraldpay.dshackle.reader.Reader
-import io.emeraldpay.dshackle.upstream.ChainFees
-import io.emeraldpay.dshackle.upstream.EmptyHead
-import io.emeraldpay.dshackle.upstream.Head
-import io.emeraldpay.dshackle.upstream.MergedHead
-import io.emeraldpay.dshackle.upstream.Multistream
-import io.emeraldpay.dshackle.upstream.Selector
-import io.emeraldpay.dshackle.upstream.Upstream
+import io.emeraldpay.dshackle.upstream.*
 import io.emeraldpay.dshackle.upstream.forkchoice.PriorityForkChoice
 import io.emeraldpay.dshackle.upstream.grpc.GrpcUpstream
 import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
@@ -42,8 +36,9 @@ import reactor.core.publisher.Mono
 open class EthereumPosMultiStream(
     chain: Chain,
     val upstreams: MutableList<EthereumPosUpstream>,
-    caches: Caches
-) : Multistream(chain, upstreams as MutableList<Upstream>, caches, CacheRequested(caches)), EthereumLikeMultistream {
+    caches: Caches,
+    callTargetsHolder: CallTargetsHolder
+) : Multistream(chain, upstreams as MutableList<Upstream>, caches, CacheRequested(caches), callTargetsHolder), EthereumLikeMultistream {
 
     companion object {
         private val log = LoggerFactory.getLogger(EthereumPosMultiStream::class.java)
diff --git a/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/GrpcUpstreams.kt b/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/GrpcUpstreams.kt
index c92fd624..f74cb62c 100644
--- a/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/GrpcUpstreams.kt
+++ b/src/main/kotlin/io/emeraldpay/dshackle/upstream/grpc/GrpcUpstreams.kt
@@ -22,7 +22,7 @@ import io.emeraldpay.dshackle.Defaults
 import io.emeraldpay.dshackle.FileResolver
 import io.emeraldpay.dshackle.config.AuthConfig
 import io.emeraldpay.dshackle.config.UpstreamsConfig
-import io.emeraldpay.dshackle.startup.UpstreamChange
+import io.emeraldpay.dshackle.startup.UpstreamChangeEvent
 import io.emeraldpay.dshackle.upstream.DefaultUpstream
 import io.emeraldpay.dshackle.upstream.UpstreamAvailability
 import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcGrpcClient
@@ -69,7 +69,7 @@ class GrpcUpstreams(
     private val known = HashMap<Chain, DefaultUpstream>()
     private val lock = ReentrantLock()
 
-    fun start(): Flux<UpstreamChange> {
+    fun start(): Flux<UpstreamChangeEvent> {
         val channel: ManagedChannelBuilder<*> = if (auth != null && StringUtils.isNotEmpty(auth.ca)) {
             NettyChannelBuilder.forAddress(host, port)
                 // some messages are very large. many of them in megabytes, some even in gigabytes (ex. ETH Traces)
@@ -122,7 +122,7 @@ class GrpcUpstreams(
         return updates
     }
 
-    fun processDescription(value: BlockchainOuterClass.DescribeResponse): Flux<UpstreamChange> {
+    fun processDescription(value: BlockchainOuterClass.DescribeResponse): Flux<UpstreamChangeEvent> {
         val current = value.chainsList.filter {
             Chain.byId(it.chain.number) != Chain.UNSPECIFIED
         }.mapNotNull { chainDetails ->
@@ -138,14 +138,14 @@ class GrpcUpstreams(
         }
 
         val added = current.filter {
-            it.type == UpstreamChange.ChangeType.ADDED
+            it.type == UpstreamChangeEvent.ChangeType.ADDED
         }
 
         val removed = known.filterNot { kv ->
             val stillCurrent = current.any { c -> c.chain == kv.key }
             stillCurrent
         }.map {
-            UpstreamChange(it.key, known.remove(it.key)!!, UpstreamChange.ChangeType.REMOVED)
+            UpstreamChangeEvent(it.key, known.remove(it.key)!!, UpstreamChangeEvent.ChangeType.REMOVED)
         }
         return Flux.fromIterable(removed + added)
     }
@@ -172,7 +172,7 @@ class GrpcUpstreams(
         return sslContext.build()
     }
 
-    fun getOrCreate(chain: Chain): UpstreamChange {
+    fun getOrCreate(chain: Chain): UpstreamChangeEvent {
         val metricsTags = listOf(
             Tag.of("upstream", id),
             Tag.of("chain", chain.chainCode)
@@ -202,7 +202,7 @@ class GrpcUpstreams(
         }
     }
 
-    fun getOrCreateEthereum(chain: Chain, metrics: RpcMetrics): UpstreamChange {
+    fun getOrCreateEthereum(chain: Chain, metrics: RpcMetrics): UpstreamChangeEvent {
         lock.withLock {
             val current = known[chain]
             return if (current == null) {
@@ -211,14 +211,14 @@ class GrpcUpstreams(
                 created.timeout = this.timeout
                 known[chain] = created
                 created.start()
-                UpstreamChange(chain, created, UpstreamChange.ChangeType.ADDED)
+                UpstreamChangeEvent(chain, created, UpstreamChangeEvent.ChangeType.ADDED)
             } else {
-                UpstreamChange(chain, current, UpstreamChange.ChangeType.REVALIDATED)
+                UpstreamChangeEvent(chain, current, UpstreamChangeEvent.ChangeType.REVALIDATED)
             }
         }
     }
 
-    fun getOrCreateEthereumPos(chain: Chain, metrics: RpcMetrics): UpstreamChange {
+    fun getOrCreateEthereumPos(chain: Chain, metrics: RpcMetrics): UpstreamChangeEvent {
         lock.withLock {
             val current = known[chain]
             return if (current == null) {
@@ -227,14 +227,14 @@ class GrpcUpstreams(
                 created.timeout = this.timeout
                 known[chain] = created
                 created.start()
-                UpstreamChange(chain, created, UpstreamChange.ChangeType.ADDED)
+                UpstreamChangeEvent(chain, created, UpstreamChangeEvent.ChangeType.ADDED)
             } else {
-                UpstreamChange(chain, current, UpstreamChange.ChangeType.REVALIDATED)
+                UpstreamChangeEvent(chain, current, UpstreamChangeEvent.ChangeType.REVALIDATED)
             }
         }
     }
 
-    fun getOrCreateBitcoin(chain: Chain, metrics: RpcMetrics): UpstreamChange {
+    fun getOrCreateBitcoin(chain: Chain, metrics: RpcMetrics): UpstreamChangeEvent {
         lock.withLock {
             val current = known[chain]
             return if (current == null) {
@@ -243,9 +243,9 @@ class GrpcUpstreams(
                 created.timeout = this.timeout
                 known[chain] = created
                 created.start()
-                UpstreamChange(chain, created, UpstreamChange.ChangeType.ADDED)
+                UpstreamChangeEvent(chain, created, UpstreamChangeEvent.ChangeType.ADDED)
             } else {
-                UpstreamChange(chain, current, UpstreamChange.ChangeType.REVALIDATED)
+                UpstreamChangeEvent(chain, current, UpstreamChangeEvent.ChangeType.REVALIDATED)
             }
         }
     }
diff --git a/src/test/groovy/io/emeraldpay/dshackle/startup/ConfiguredUpstreamsSpec.groovy b/src/test/groovy/io/emeraldpay/dshackle/startup/ConfiguredUpstreamsSpec.groovy
index 4e6f6eea..f799729d 100644
--- a/src/test/groovy/io/emeraldpay/dshackle/startup/ConfiguredUpstreamsSpec.groovy
+++ b/src/test/groovy/io/emeraldpay/dshackle/startup/ConfiguredUpstreamsSpec.groovy
@@ -4,21 +4,24 @@ import io.emeraldpay.dshackle.FileResolver
 import io.emeraldpay.dshackle.cache.CachesFactory
 import io.emeraldpay.dshackle.config.UpstreamsConfig
 import io.emeraldpay.dshackle.quorum.NonEmptyQuorum
+import io.emeraldpay.dshackle.upstream.CallTargetsHolder
 import io.emeraldpay.dshackle.upstream.CurrentMultistreamHolder
 import io.emeraldpay.dshackle.upstream.calls.DefaultEthereumMethods
 import io.emeraldpay.dshackle.upstream.calls.ManagedCallMethods
 import io.emeraldpay.grpc.Chain
+import org.springframework.context.ApplicationEventPublisher
 import spock.lang.Specification
 
 class ConfiguredUpstreamsSpec extends Specification {
 
     def "Applied  quorum to extra methods"() {
         setup:
-        def currentUpstreams = Mock(CurrentMultistreamHolder) {
-            _ * getDefaultMethods(Chain.ETHEREUM) >> new DefaultEthereumMethods(Chain.ETHEREUM)
-        }
+        def callTargetsHolder = new CallTargetsHolder()
         def configurer = new ConfiguredUpstreams(
-                currentUpstreams, Stub(FileResolver), Stub(UpstreamsConfig)
+                Stub(FileResolver),
+                Stub(UpstreamsConfig),
+                callTargetsHolder,
+                Mock(ApplicationEventPublisher)
         )
         def methods = new UpstreamsConfig.Methods(
                 [
@@ -38,11 +41,12 @@ class ConfiguredUpstreamsSpec extends Specification {
 
     def "Got static response from extra methods"() {
         setup:
-        def currentUpstreams = Mock(CurrentMultistreamHolder) {
-            _ * getDefaultMethods(Chain.ETHEREUM) >> new DefaultEthereumMethods(Chain.ETHEREUM)
-        }
+        def callTargetsHolder = new CallTargetsHolder()
         def configurer = new ConfiguredUpstreams(
-                currentUpstreams, Stub(FileResolver), Stub(UpstreamsConfig)
+                Stub(FileResolver),
+                Stub(UpstreamsConfig),
+                callTargetsHolder,
+                Mock(ApplicationEventPublisher)
         )
         def methods = new UpstreamsConfig.Methods(
                 [
@@ -61,7 +65,12 @@ class ConfiguredUpstreamsSpec extends Specification {
 
     def "Calculate node-id"() {
         setup:
-        def configurer = new ConfiguredUpstreams(Stub(CurrentMultistreamHolder), Stub(FileResolver), Stub(UpstreamsConfig)
+        def callTargetsHolder = new CallTargetsHolder()
+        def configurer = new ConfiguredUpstreams(
+                Stub(FileResolver),
+                Stub(UpstreamsConfig),
+                callTargetsHolder,
+                Mock(ApplicationEventPublisher)
         )
         expect:
         configurer.getHash(node, src) == expected
@@ -75,7 +84,12 @@ class ConfiguredUpstreamsSpec extends Specification {
 
     def "Calculate node-id conflicting results"() {
         setup:
-        def configurer = new ConfiguredUpstreams(Stub(CurrentMultistreamHolder), Stub(FileResolver), Stub(UpstreamsConfig)
+        def callTargetsHolder = new CallTargetsHolder()
+        def configurer = new ConfiguredUpstreams(
+                Stub(FileResolver),
+                Stub(UpstreamsConfig),
+                callTargetsHolder,
+                Mock(ApplicationEventPublisher)
         )
         when:
         def h1 = configurer.getHash(null, "hohoho")
diff --git a/src/test/groovy/io/emeraldpay/dshackle/test/MultistreamHolderMock.groovy b/src/test/groovy/io/emeraldpay/dshackle/test/MultistreamHolderMock.groovy
index 660b7611..9e34c546 100644
--- a/src/test/groovy/io/emeraldpay/dshackle/test/MultistreamHolderMock.groovy
+++ b/src/test/groovy/io/emeraldpay/dshackle/test/MultistreamHolderMock.groovy
@@ -50,7 +50,7 @@ class MultistreamHolderMock implements MultistreamHolder {
                 if (up instanceof EthereumPosMultiStream) {
                     upstreams[chain] = up
                 } else if (up instanceof EthereumPosRpcUpstream) {
-                    upstreams[chain] = new EthereumPosMultiStream(chain, [up as EthereumPosRpcUpstream], Caches.default())
+                    upstreams[chain] = new EthereumPosMultiStream(chain, [up as EthereumPosRpcUpstream], Caches.default(), TestingCommons.callTargetsHolder)
                 } else {
                     throw new IllegalArgumentException("Unsupported upstream type ${up.class}")
                 }
@@ -59,7 +59,7 @@ class MultistreamHolderMock implements MultistreamHolder {
                 if (up instanceof BitcoinMultistream) {
                     upstreams[chain] = up
                 } else if (up instanceof BitcoinRpcUpstream) {
-                    upstreams[chain] = new BitcoinMultistream(chain, [up as BitcoinRpcUpstream], Caches.default())
+                    upstreams[chain] = new BitcoinMultistream(chain, [up as BitcoinRpcUpstream], Caches.default(), TestingCommons.callTargetsHolder)
                 } else {
                     throw new IllegalArgumentException("Unsupported upstream type ${up.class}")
                 }
@@ -86,15 +86,6 @@ class MultistreamHolderMock implements MultistreamHolder {
         return Flux.fromIterable(getAvailable())
     }
 
-    @Override
-    DefaultEthereumMethods getDefaultMethods(@NotNull Chain chain) {
-        if (target[chain] == null) {
-            DefaultEthereumMethods targets = new DefaultEthereumMethods(chain)
-            target[chain] = targets
-        }
-        return target[chain]
-    }
-
     @Override
     boolean isAvailable(@NotNull Chain chain) {
         return upstreams.containsKey(chain)
@@ -107,7 +98,7 @@ class MultistreamHolderMock implements MultistreamHolder {
         Head customHead = null
 
         EthereumMultistreamMock(@NotNull Chain chain, @NotNull List<EthereumPosRpcUpstream> upstreams, @NotNull Caches caches) {
-            super(chain, upstreams, caches)
+            super(chain, upstreams, caches, TestingCommons.callTargetsHolder)
         }
 
         EthereumMultistreamMock(@NotNull Chain chain, @NotNull List<EthereumPosRpcUpstream> upstreams) {
diff --git a/src/test/groovy/io/emeraldpay/dshackle/test/TestingCommons.groovy b/src/test/groovy/io/emeraldpay/dshackle/test/TestingCommons.groovy
index 6ad08167..f2c640d7 100644
--- a/src/test/groovy/io/emeraldpay/dshackle/test/TestingCommons.groovy
+++ b/src/test/groovy/io/emeraldpay/dshackle/test/TestingCommons.groovy
@@ -24,8 +24,10 @@ import io.emeraldpay.dshackle.data.BlockContainer
 import io.emeraldpay.dshackle.data.BlockId
 import io.emeraldpay.dshackle.reader.EmptyReader
 import io.emeraldpay.dshackle.reader.Reader
+import io.emeraldpay.dshackle.upstream.CallTargetsHolder
 import io.emeraldpay.dshackle.upstream.Multistream
 import io.emeraldpay.dshackle.upstream.calls.DirectCallMethods
+import io.emeraldpay.dshackle.upstream.ethereum.EthereumMultistream
 import io.emeraldpay.dshackle.upstream.ethereum.EthereumPosMultiStream
 import io.emeraldpay.dshackle.upstream.ethereum.EthereumPosUpstream
 import io.emeraldpay.dshackle.upstream.rpcclient.JsonRpcRequest
@@ -78,7 +80,7 @@ class TestingCommons {
     }
 
     static Multistream multistream(EthereumPosRpcUpstreamMock up) {
-        return new EthereumPosMultiStream(Chain.ETHEREUM, [up], Caches.default()).tap {
+        return new EthereumPosMultiStream(Chain.ETHEREUM, [up], Caches.default(), callTargetsHolder).tap {
             start()
         }
     }
@@ -94,12 +96,16 @@ class TestingCommons {
     static List<Multistream> defaultMultistreams() {
         return [
                 multistreamWithoutUpstreams(Chain.ETHEREUM),
-                multistreamWithoutUpstreams(Chain.ETHEREUM_CLASSIC)
+                multistreamClassicWithoutUpstreams(Chain.ETHEREUM_CLASSIC)
         ]
     }
 
     static Multistream multistreamWithoutUpstreams(Chain chain) {
-        return new EthereumPosMultiStream(chain, [], emptyCaches().getCaches(chain))
+        return new EthereumPosMultiStream(chain, [], emptyCaches().getCaches(chain), callTargetsHolder)
+    }
+
+    static Multistream multistreamClassicWithoutUpstreams(Chain chain) {
+        return new EthereumMultistream(chain, [], emptyCaches().getCaches(chain), callTargetsHolder)
     }
 
     static FileResolver fileResolver() {
@@ -138,4 +144,6 @@ class TestingCommons {
     }
 
     static MeterRegistry meterRegistry = new LoggingMeterRegistry()
+
+    static CallTargetsHolder callTargetsHolder = new CallTargetsHolder()
 }
diff --git a/src/test/groovy/io/emeraldpay/dshackle/upstream/CurrentMultistreamHolderSpec.groovy b/src/test/groovy/io/emeraldpay/dshackle/upstream/CurrentMultistreamHolderSpec.groovy
index 0ec23584..4e488e9d 100644
--- a/src/test/groovy/io/emeraldpay/dshackle/upstream/CurrentMultistreamHolderSpec.groovy
+++ b/src/test/groovy/io/emeraldpay/dshackle/upstream/CurrentMultistreamHolderSpec.groovy
@@ -15,7 +15,7 @@
  */
 package io.emeraldpay.dshackle.upstream
 
-import io.emeraldpay.dshackle.startup.UpstreamChange
+import io.emeraldpay.dshackle.startup.UpstreamChangeEvent
 import io.emeraldpay.dshackle.test.EthereumPosRpcUpstreamMock
 import io.emeraldpay.dshackle.test.EthereumRpcUpstreamMock
 import io.emeraldpay.dshackle.test.TestingCommons
@@ -29,7 +29,7 @@ class CurrentMultistreamHolderSpec extends Specification {
         def current = new CurrentMultistreamHolder(TestingCommons.defaultMultistreams())
         def up = new EthereumPosRpcUpstreamMock("test", Chain.ETHEREUM, TestingCommons.api())
         when:
-        current.update(new UpstreamChange(Chain.ETHEREUM, up, UpstreamChange.ChangeType.ADDED))
+        current.getUpstream(Chain.ETHEREUM).onUpstreamChange(new UpstreamChangeEvent(Chain.ETHEREUM, up, UpstreamChangeEvent.ChangeType.ADDED))
         then:
         current.getAvailable() == [Chain.ETHEREUM]
         current.getUpstream(Chain.ETHEREUM).getAll()[0] == up
@@ -42,9 +42,10 @@ class CurrentMultistreamHolderSpec extends Specification {
         def up2 = new EthereumRpcUpstreamMock("test2", Chain.ETHEREUM_CLASSIC, TestingCommons.api())
         def up3 = new EthereumPosRpcUpstreamMock("test3", Chain.ETHEREUM, TestingCommons.api())
         when:
-        current.update(new UpstreamChange(Chain.ETHEREUM, up1, UpstreamChange.ChangeType.ADDED))
-        current.update(new UpstreamChange(Chain.ETHEREUM_CLASSIC, up2, UpstreamChange.ChangeType.ADDED))
-        current.update(new UpstreamChange(Chain.ETHEREUM, up3, UpstreamChange.ChangeType.ADDED))
+        current.getUpstream(Chain.ETHEREUM).onUpstreamChange(new UpstreamChangeEvent(Chain.ETHEREUM, up1, UpstreamChangeEvent.ChangeType.ADDED))
+        current.getUpstream(Chain.ETHEREUM_CLASSIC).onUpstreamChange(new UpstreamChangeEvent(Chain.ETHEREUM_CLASSIC, up2, UpstreamChangeEvent.ChangeType.ADDED))
+        current.getUpstream(Chain.ETHEREUM).onUpstreamChange(new UpstreamChangeEvent(Chain.ETHEREUM, up3, UpstreamChangeEvent.ChangeType.ADDED))
+        current.getUpstream(Chain.ETHEREUM_CLASSIC).onUpstreamChange(new UpstreamChangeEvent(Chain.ETHEREUM, up3, UpstreamChangeEvent.ChangeType.ADDED))
         then:
         current.getAvailable().toSet() == [Chain.ETHEREUM, Chain.ETHEREUM_CLASSIC].toSet()
         current.getUpstream(Chain.ETHEREUM).getAll().toSet() == [up1, up3].toSet()
@@ -59,10 +60,10 @@ class CurrentMultistreamHolderSpec extends Specification {
         def up3 = new EthereumPosRpcUpstreamMock("test3", Chain.ETHEREUM, TestingCommons.api())
         def up1_del = new EthereumPosRpcUpstreamMock("test1", Chain.ETHEREUM, TestingCommons.api())
         when:
-        current.update(new UpstreamChange(Chain.ETHEREUM, up1, UpstreamChange.ChangeType.ADDED))
-        current.update(new UpstreamChange(Chain.ETHEREUM_CLASSIC, up2, UpstreamChange.ChangeType.ADDED))
-        current.update(new UpstreamChange(Chain.ETHEREUM, up3, UpstreamChange.ChangeType.ADDED))
-        current.update(new UpstreamChange(Chain.ETHEREUM, up1_del, UpstreamChange.ChangeType.REMOVED))
+        current.getUpstream(Chain.ETHEREUM).onUpstreamChange(new UpstreamChangeEvent(Chain.ETHEREUM, up1, UpstreamChangeEvent.ChangeType.ADDED))
+        current.getUpstream(Chain.ETHEREUM_CLASSIC).onUpstreamChange(new UpstreamChangeEvent(Chain.ETHEREUM_CLASSIC, up2, UpstreamChangeEvent.ChangeType.ADDED))
+        current.getUpstream(Chain.ETHEREUM).onUpstreamChange(new UpstreamChangeEvent(Chain.ETHEREUM, up3, UpstreamChangeEvent.ChangeType.ADDED))
+        current.getUpstream(Chain.ETHEREUM).onUpstreamChange(new UpstreamChangeEvent(Chain.ETHEREUM, up1_del, UpstreamChangeEvent.ChangeType.REMOVED))
         then:
         current.getAvailable().toSet() == [Chain.ETHEREUM, Chain.ETHEREUM_CLASSIC].toSet()
         current.getUpstream(Chain.ETHEREUM).getAll().toSet() == [up3].toSet()
@@ -80,7 +81,7 @@ class CurrentMultistreamHolderSpec extends Specification {
         !act
 
         when:
-        current.update(new UpstreamChange(Chain.ETHEREUM, up1, UpstreamChange.ChangeType.ADDED))
+        current.getUpstream(Chain.ETHEREUM).onUpstreamChange(new UpstreamChangeEvent(Chain.ETHEREUM, up1, UpstreamChangeEvent.ChangeType.ADDED))
         act = current.isAvailable(Chain.ETHEREUM)
 
         then:
diff --git a/src/test/groovy/io/emeraldpay/dshackle/upstream/MultistreamSpec.groovy b/src/test/groovy/io/emeraldpay/dshackle/upstream/MultistreamSpec.groovy
index 8a28f4b3..b432bcb8 100644
--- a/src/test/groovy/io/emeraldpay/dshackle/upstream/MultistreamSpec.groovy
+++ b/src/test/groovy/io/emeraldpay/dshackle/upstream/MultistreamSpec.groovy
@@ -50,7 +50,7 @@ class MultistreamSpec extends Specification {
         setup:
         def up1 = new EthereumPosRpcUpstreamMock("test1", Chain.ETHEREUM, TestingCommons.api(), new DirectCallMethods(["eth_test1", "eth_test2"]))
         def up2 = new EthereumPosRpcUpstreamMock("test1", Chain.ETHEREUM, TestingCommons.api(), new DirectCallMethods(["eth_test2", "eth_test3"]))
-        def aggr = new EthereumPosMultiStream(Chain.ETHEREUM, [up1, up2], Caches.default())
+        def aggr = new EthereumPosMultiStream(Chain.ETHEREUM, [up1, up2], Caches.default(), TestingCommons.callTargetsHolder)
         when:
         aggr.onUpstreamsUpdated()
         def act = aggr.getMethods()
@@ -206,7 +206,7 @@ class MultistreamSpec extends Specification {
         def up1 = TestingCommons.upstream("test-1", "internal")
         def up2 = TestingCommons.upstream("test-2", "external")
         def up3 = TestingCommons.upstream("test-3", "external")
-        def multistream = new EthereumPosMultiStream(Chain.ETHEREUM, [up1, up2, up3], Caches.default())
+        def multistream = new EthereumPosMultiStream(Chain.ETHEREUM, [up1, up2, up3], Caches.default(), TestingCommons.callTargetsHolder)
 
         expect:
         multistream.getHead(new Selector.LabelMatcher("provider", ["internal"])).is(up1.ethereumHeadMock)
@@ -345,7 +345,7 @@ class MultistreamSpec extends Specification {
     class TestMultistream extends Multistream {
 
         TestMultistream(List<Upstream> upstreams, @NotNull RequestPostprocessor postprocessor) {
-            super(Chain.ETHEREUM, upstreams, Caches.default(), postprocessor)
+            super(Chain.ETHEREUM, upstreams, Caches.default(), postprocessor, TestingCommons.callTargetsHolder)
         }
 
         @Override
@@ -386,7 +386,7 @@ class MultistreamSpec extends Specification {
     class TestEthereumPosMultistream extends EthereumPosMultiStream {
 
         TestEthereumPosMultistream(@NotNull Chain chain, @NotNull List<EthereumPosUpstream> upstreams, @NotNull Caches caches) {
-            super(chain, upstreams, caches)
+            super(chain, upstreams, caches, TestingCommons.callTargetsHolder)
         }
 
         @Override