diff --git a/testing/simple-upstream/settings.gradle b/testing/simple-upstream/settings.gradle
index 262005ff..faa039c6 100644
--- a/testing/simple-upstream/settings.gradle
+++ b/testing/simple-upstream/settings.gradle
@@ -1 +1 @@
-rootProject.name = 'dschackle-testing-simple-upstream'
\ No newline at end of file
+rootProject.name = 'dshackle-testing-simple-upstream'
\ No newline at end of file
diff --git a/testing/trial/README.adoc b/testing/trial/README.adoc
new file mode 100644
index 00000000..80d35c4b
--- /dev/null
+++ b/testing/trial/README.adoc
@@ -0,0 +1,8 @@
+= Actual Tests
+
+Expects running _Simple Upstream_ and _Testing Dshackle_.
+
+.Run from current directory
+----
+./gradlew check
+----
\ No newline at end of file
diff --git a/testing/trial/build.gradle b/testing/trial/build.gradle
new file mode 100644
index 00000000..6c7bc8d8
--- /dev/null
+++ b/testing/trial/build.gradle
@@ -0,0 +1,23 @@
+plugins {
+    id 'java'
+    id 'groovy'
+    id 'idea'
+}
+
+repositories {
+    mavenLocal()
+    mavenCentral()
+}
+
+dependencies {
+    implementation "org.apache.httpcomponents:httpclient:4.5.12"
+    implementation "org.codehaus.groovy:groovy:3.0.4"
+    implementation "com.fasterxml.jackson.core:jackson-core:2.9.8"
+    implementation "com.fasterxml.jackson.core:jackson-databind:2.9.8"
+
+    testImplementation "org.spockframework:spock-core:2.0-M3-groovy-3.0"
+}
+
+test {
+    useJUnitPlatform()
+}
\ No newline at end of file
diff --git a/testing/trial/gradle/wrapper/gradle-wrapper.jar b/testing/trial/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 00000000..62d4c053
Binary files /dev/null and b/testing/trial/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/testing/trial/gradle/wrapper/gradle-wrapper.properties b/testing/trial/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 00000000..bb8b2fc2
--- /dev/null
+++ b/testing/trial/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.5.1-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/testing/trial/gradlew b/testing/trial/gradlew
new file mode 100755
index 00000000..fbd7c515
--- /dev/null
+++ b/testing/trial/gradlew
@@ -0,0 +1,185 @@
+#!/usr/bin/env sh
+
+#
+# Copyright 2015 the original author or authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#      https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+##############################################################################
+##
+##  Gradle start up script for UN*X
+##
+##############################################################################
+
+# Attempt to set APP_HOME
+# Resolve links: $0 may be a link
+PRG="$0"
+# Need this for relative symlinks.
+while [ -h "$PRG" ] ; do
+    ls=`ls -ld "$PRG"`
+    link=`expr "$ls" : '.*-> \(.*\)$'`
+    if expr "$link" : '/.*' > /dev/null; then
+        PRG="$link"
+    else
+        PRG=`dirname "$PRG"`"/$link"
+    fi
+done
+SAVED="`pwd`"
+cd "`dirname \"$PRG\"`/" >/dev/null
+APP_HOME="`pwd -P`"
+cd "$SAVED" >/dev/null
+
+APP_NAME="Gradle"
+APP_BASE_NAME=`basename "$0"`
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Use the maximum available, or set MAX_FD != -1 to use that value.
+MAX_FD="maximum"
+
+warn () {
+    echo "$*"
+}
+
+die () {
+    echo
+    echo "$*"
+    echo
+    exit 1
+}
+
+# OS specific support (must be 'true' or 'false').
+cygwin=false
+msys=false
+darwin=false
+nonstop=false
+case "`uname`" in
+  CYGWIN* )
+    cygwin=true
+    ;;
+  Darwin* )
+    darwin=true
+    ;;
+  MINGW* )
+    msys=true
+    ;;
+  NONSTOP* )
+    nonstop=true
+    ;;
+esac
+
+CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
+
+
+# Determine the Java command to use to start the JVM.
+if [ -n "$JAVA_HOME" ] ; then
+    if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
+        # IBM's JDK on AIX uses strange locations for the executables
+        JAVACMD="$JAVA_HOME/jre/sh/java"
+    else
+        JAVACMD="$JAVA_HOME/bin/java"
+    fi
+    if [ ! -x "$JAVACMD" ] ; then
+        die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+    fi
+else
+    JAVACMD="java"
+    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+
+Please set the JAVA_HOME variable in your environment to match the
+location of your Java installation."
+fi
+
+# Increase the maximum file descriptors if we can.
+if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
+    MAX_FD_LIMIT=`ulimit -H -n`
+    if [ $? -eq 0 ] ; then
+        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
+            MAX_FD="$MAX_FD_LIMIT"
+        fi
+        ulimit -n $MAX_FD
+        if [ $? -ne 0 ] ; then
+            warn "Could not set maximum file descriptor limit: $MAX_FD"
+        fi
+    else
+        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
+    fi
+fi
+
+# For Darwin, add options to specify how the application appears in the dock
+if $darwin; then
+    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
+fi
+
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
+    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
+    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
+    
+    JAVACMD=`cygpath --unix "$JAVACMD"`
+
+    # We build the pattern for arguments to be converted via cygpath
+    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
+    SEP=""
+    for dir in $ROOTDIRSRAW ; do
+        ROOTDIRS="$ROOTDIRS$SEP$dir"
+        SEP="|"
+    done
+    OURCYGPATTERN="(^($ROOTDIRS))"
+    # Add a user-defined pattern to the cygpath arguments
+    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
+        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
+    fi
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    i=0
+    for arg in "$@" ; do
+        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
+        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
+
+        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
+            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
+        else
+            eval `echo args$i`="\"$arg\""
+        fi
+        i=`expr $i + 1`
+    done
+    case $i in
+        0) set -- ;;
+        1) set -- "$args0" ;;
+        2) set -- "$args0" "$args1" ;;
+        3) set -- "$args0" "$args1" "$args2" ;;
+        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
+        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
+        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
+        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
+        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
+        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+    esac
+fi
+
+# Escape application args
+save () {
+    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
+    echo " "
+}
+APP_ARGS=`save "$@"`
+
+# Collect all arguments for the java command, following the shell quoting and substitution rules
+eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+
+exec "$JAVACMD" "$@"
diff --git a/testing/trial/gradlew.bat b/testing/trial/gradlew.bat
new file mode 100644
index 00000000..5093609d
--- /dev/null
+++ b/testing/trial/gradlew.bat
@@ -0,0 +1,104 @@
+@rem
+@rem Copyright 2015 the original author or authors.
+@rem
+@rem Licensed under the Apache License, Version 2.0 (the "License");
+@rem you may not use this file except in compliance with the License.
+@rem You may obtain a copy of the License at
+@rem
+@rem      https://www.apache.org/licenses/LICENSE-2.0
+@rem
+@rem Unless required by applicable law or agreed to in writing, software
+@rem distributed under the License is distributed on an "AS IS" BASIS,
+@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+@rem See the License for the specific language governing permissions and
+@rem limitations under the License.
+@rem
+
+@if "%DEBUG%" == "" @echo off
+@rem ##########################################################################
+@rem
+@rem  Gradle startup script for Windows
+@rem
+@rem ##########################################################################
+
+@rem Set local scope for the variables with windows NT shell
+if "%OS%"=="Windows_NT" setlocal
+
+set DIRNAME=%~dp0
+if "%DIRNAME%" == "" set DIRNAME=.
+set APP_BASE_NAME=%~n0
+set APP_HOME=%DIRNAME%
+
+@rem Resolve any "." and ".." in APP_HOME to make it shorter.
+for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi
+
+@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m"
+
+@rem Find java.exe
+if defined JAVA_HOME goto findJavaFromJavaHome
+
+set JAVA_EXE=java.exe
+%JAVA_EXE% -version >NUL 2>&1
+if "%ERRORLEVEL%" == "0" goto init
+
+echo.
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:findJavaFromJavaHome
+set JAVA_HOME=%JAVA_HOME:"=%
+set JAVA_EXE=%JAVA_HOME%/bin/java.exe
+
+if exist "%JAVA_EXE%" goto init
+
+echo.
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
+echo.
+echo Please set the JAVA_HOME variable in your environment to match the
+echo location of your Java installation.
+
+goto fail
+
+:init
+@rem Get command-line arguments, handling Windows variants
+
+if not "%OS%" == "Windows_NT" goto win9xME_args
+
+:win9xME_args
+@rem Slurp the command line arguments.
+set CMD_LINE_ARGS=
+set _SKIP=2
+
+:win9xME_args_slurp
+if "x%~1" == "x" goto execute
+
+set CMD_LINE_ARGS=%*
+
+:execute
+@rem Setup the command line
+
+set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
+
+
+@rem Execute Gradle
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %CMD_LINE_ARGS%
+
+:end
+@rem End local scope for the variables with windows NT shell
+if "%ERRORLEVEL%"=="0" goto mainEnd
+
+:fail
+rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
+rem the _cmd.exe /c_ return code!
+if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
+exit /b 1
+
+:mainEnd
+if "%OS%"=="Windows_NT" endlocal
+
+:omega
diff --git a/testing/trial/settings.gradle b/testing/trial/settings.gradle
new file mode 100644
index 00000000..e27e091c
--- /dev/null
+++ b/testing/trial/settings.gradle
@@ -0,0 +1 @@
+rootProject.name = 'dshackle-testing-trial'
\ No newline at end of file
diff --git a/testing/trial/src/main/groovy/io/emeraldpay/dshackle/testing/trial/Debugger.groovy b/testing/trial/src/main/groovy/io/emeraldpay/dshackle/testing/trial/Debugger.groovy
new file mode 100644
index 00000000..fe8dc620
--- /dev/null
+++ b/testing/trial/src/main/groovy/io/emeraldpay/dshackle/testing/trial/Debugger.groovy
@@ -0,0 +1,20 @@
+package io.emeraldpay.dshackle.testing.trial
+
+class Debugger {
+
+    public static enabled = true
+
+    static void showOut(String json) {
+        if (!enabled) {
+            return
+        }
+        println(">> $json")
+    }
+
+    static void showIn(String json) {
+        if (!enabled) {
+            return
+        }
+        println("<< $json")
+    }
+}
diff --git a/testing/trial/src/main/groovy/io/emeraldpay/dshackle/testing/trial/ProxyClient.groovy b/testing/trial/src/main/groovy/io/emeraldpay/dshackle/testing/trial/ProxyClient.groovy
new file mode 100644
index 00000000..a6c4a1a2
--- /dev/null
+++ b/testing/trial/src/main/groovy/io/emeraldpay/dshackle/testing/trial/ProxyClient.groovy
@@ -0,0 +1,63 @@
+package io.emeraldpay.dshackle.testing.trial
+
+import com.fasterxml.jackson.databind.ObjectMapper
+import org.apache.commons.codec.binary.Hex
+import org.apache.http.HttpHeaders
+import org.apache.http.client.HttpClient
+import org.apache.http.client.methods.CloseableHttpResponse
+import org.apache.http.client.methods.HttpPost
+import org.apache.http.entity.ContentType
+import org.apache.http.entity.StringEntity
+import org.apache.http.impl.client.CloseableHttpClient
+import org.apache.http.impl.client.HttpClientBuilder
+import org.apache.http.impl.client.HttpClients
+
+class ProxyClient {
+
+    private int sequence = 0;
+
+    private String url
+    private ObjectMapper objectMapper
+
+    ProxyClient(String url) {
+        this.url = url
+        this.objectMapper = new ObjectMapper()
+    }
+
+    static ProxyClient forPrefix(String prefix) {
+        return new ProxyClient("http://127.0.0.1:18080/$prefix")
+    }
+
+    Map<String, Object> execute(String method, List<Object> params) {
+        return execute(sequence++, method, params)
+    }
+
+    Map<String, Object> execute(Object id, String method, List<Object> params) {
+        Map jsonData = [
+                id     : id,
+                jsonrpc: "2.0",
+                method : method,
+                params : params
+        ]
+        String reqJson = objectMapper.writeValueAsString(jsonData)
+        Debugger.showOut(reqJson)
+        CloseableHttpClient httpClient = null
+        try {
+            httpClient = HttpClients.createDefault()
+            def request = new HttpPost(url)
+            request.setEntity(new StringEntity(reqJson, ContentType.APPLICATION_JSON))
+            CloseableHttpResponse response = httpClient.execute(request)
+            if (response.getStatusLine().statusCode != 200) {
+                throw new IllegalStateException("Non-ok status: " + response.getStatusLine().statusCode)
+            }
+            String respJson = response.entity.content.text
+            Debugger.showIn(respJson)
+            return objectMapper.readerFor(Map).readValue(respJson)
+        } finally {
+            httpClient?.close()
+        }
+
+        return [error: "NOT EXECUTED"]
+    }
+
+}
diff --git a/testing/trial/src/test/groovy/io/emeraldpay/dshackle/testing/trial/proxy/GivesErrorSpec.groovy b/testing/trial/src/test/groovy/io/emeraldpay/dshackle/testing/trial/proxy/GivesErrorSpec.groovy
new file mode 100644
index 00000000..88a56ea7
--- /dev/null
+++ b/testing/trial/src/test/groovy/io/emeraldpay/dshackle/testing/trial/proxy/GivesErrorSpec.groovy
@@ -0,0 +1,37 @@
+package io.emeraldpay.dshackle.testing.trial.proxy
+
+import io.emeraldpay.dshackle.testing.trial.ProxyClient
+import spock.lang.Specification
+
+class GivesErrorSpec extends Specification {
+
+    def client = ProxyClient.forPrefix("eth")
+
+    def "Gives error message"() {
+        // issue #42
+        when:
+        def act = client.execute("eth_call", [[to: "0x542156d51D10Db5acCB99f9Db7e7C91B74E80a2c"]])
+        then:
+        act.result == null
+        act.error != null
+        with(act.error) {
+            code == -32015
+            message == "VM execution error."
+        }
+    }
+
+    def "Gives error data"() {
+        // issue #42
+        when:
+        def act = client.execute("eth_call", [[to: "0x8ee2a5aca4f88cb8c757b8593d0734855dcc0eba"]])
+        then:
+        act.result == null
+        act.error != null
+        with(act.error) {
+            code == -32015
+            message == "VM execution error."
+            data == "revert: SafeMath: division by zero"
+        }
+    }
+
+}
diff --git a/testing/trial/src/test/groovy/io/emeraldpay/dshackle/testing/trial/proxy/HardcodedCallsSpec.groovy b/testing/trial/src/test/groovy/io/emeraldpay/dshackle/testing/trial/proxy/HardcodedCallsSpec.groovy
new file mode 100644
index 00000000..b2c033e3
--- /dev/null
+++ b/testing/trial/src/test/groovy/io/emeraldpay/dshackle/testing/trial/proxy/HardcodedCallsSpec.groovy
@@ -0,0 +1,34 @@
+package io.emeraldpay.dshackle.testing.trial.proxy
+
+import io.emeraldpay.dshackle.testing.trial.ProxyClient
+import spock.lang.Specification
+
+class HardcodedCallsSpec extends Specification {
+
+    def client = ProxyClient.forPrefix("eth")
+
+    def "get syncing"() {
+        when:
+        def act = client.execute("eth_syncing", [])
+        then:
+        act.result == false
+        act.error == null
+    }
+
+    def "get network version"() {
+        when:
+        def act = client.execute("net_version", [])
+        then:
+        act.result == 1
+        act.error == null
+    }
+
+    def "get peer count"() {
+        when:
+        def act = client.execute("net_peerCount", [])
+        then:
+        act.result == "0x2a"
+        act.error == null
+    }
+
+}
diff --git a/testing/trial/src/test/groovy/io/emeraldpay/dshackle/testing/trial/proxy/StandardCallsSpec.groovy b/testing/trial/src/test/groovy/io/emeraldpay/dshackle/testing/trial/proxy/StandardCallsSpec.groovy
new file mode 100644
index 00000000..76c0d528
--- /dev/null
+++ b/testing/trial/src/test/groovy/io/emeraldpay/dshackle/testing/trial/proxy/StandardCallsSpec.groovy
@@ -0,0 +1,51 @@
+package io.emeraldpay.dshackle.testing.trial.proxy
+
+import io.emeraldpay.dshackle.testing.trial.ProxyClient
+import spock.lang.Specification
+
+class StandardCallsSpec extends Specification {
+
+    def client = ProxyClient.forPrefix("eth")
+
+    def "get height"() {
+        when:
+        def act = client.execute("eth_blockNumber", [])
+        then:
+        act.result == "0x100001"
+        act.error == null
+    }
+
+    def "get block"() {
+        when:
+        def act = client.execute("eth_getBlockByNumber", ["0x100001", false])
+        then:
+        act.result != null
+        with(act.result) {
+            number == "0x100001"
+            hash == "0x18c68d9ba58772a4409d65d61891b25db03a105a7769ae08ef2cff697921b446"
+            transactions == [
+                    "0x146b8f4b6300c73bb7476359b9f1c5ee3f686a86b2aa673552cf0f9de9a42e77",
+                    "0xe589a39acea3091b584b650158d08b159aa07e97b8e8cddb8f81cb606e13382e"
+            ]
+        }
+        act.error == null
+    }
+
+    def "get block with txes"() {
+        when:
+        def act = client.execute("eth_getBlockByNumber", ["0x100001", true])
+        then:
+        act.result != null
+        with(act.result) {
+            number == "0x100001"
+            hash == "0x18c68d9ba58772a4409d65d61891b25db03a105a7769ae08ef2cff697921b446"
+            transactions.size() == 2
+            transactions[0] instanceof Map
+            transactions[1] instanceof Map
+            with(transactions.find { it.hash == "0x146b8f4b6300c73bb7476359b9f1c5ee3f686a86b2aa673552cf0f9de9a42e77" }) {
+                from == "0x2a65aca4d5fc5b5c859090a6c34d164135398226"
+            }
+        }
+        act.error == null
+    }
+}