diff --git a/.gitignore b/.gitignore
index bce2f67..d7c8359 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,6 @@
+##############################
+## Swift and macOS
+##############################
 Packages
 .build
 xcuserdata
@@ -5,3 +8,72 @@ Catbird.xcodeproj
 DerivedData/
 .DS_Store
 .swiftpm
+
+##############################
+## Java
+##############################
+.mtj.tmp/
+*.class
+*.jar
+*.war
+*.ear
+*.nar
+hs_err_pid*
+
+##############################
+## Maven
+##############################
+target/
+pom.xml.tag
+pom.xml.releaseBackup
+pom.xml.versionsBackup
+pom.xml.next
+pom.xml.bak
+release.properties
+dependency-reduced-pom.xml
+buildNumber.properties
+.mvn/timing.properties
+.mvn/wrapper/maven-wrapper.jar
+
+##############################
+## Gradle
+##############################
+bin/
+build/
+.gradle
+.gradletasknamecache
+gradle-app.setting
+!gradle-wrapper.jar
+
+##############################
+## IntelliJ
+##############################
+out/
+.idea/
+.idea_modules/
+*.iml
+*.ipr
+*.iws
+
+##############################
+## Eclipse
+##############################
+.settings/
+bin/
+tmp/
+.metadata
+.classpath
+.project
+*.tmp
+*.bak
+*.swp
+*~.nib
+local.properties
+.loadpath
+.factorypath
+
+##############################
+## Visual Studio Code
+##############################
+.vscode/
+.code-workspace
diff --git a/catbird-api/build.gradle b/catbird-api/build.gradle
new file mode 100644
index 0000000..cece448
--- /dev/null
+++ b/catbird-api/build.gradle
@@ -0,0 +1,21 @@
+plugins {
+    id 'java'
+    id 'org.jetbrains.kotlin.jvm' version '1.4.0'
+    id 'org.jetbrains.kotlin.plugin.serialization' version '1.4.10'
+}
+
+apply plugin: 'kotlinx-serialization'
+
+group 'com.redmadrobot'
+version '1.0-SNAPSHOT'
+
+repositories {
+    mavenCentral()
+}
+
+dependencies {
+    implementation 'org.jetbrains.kotlin:kotlin-stdlib'
+    implementation 'org.jetbrains.kotlinx:kotlinx-serialization-core:1.0.0-RC'
+    implementation 'com.google.code.gson:gson:2.8.6'
+    testCompile group: 'junit', name: 'junit', version: '4.12'
+}
diff --git a/catbird-api/gradle.properties b/catbird-api/gradle.properties
new file mode 100644
index 0000000..29e08e8
--- /dev/null
+++ b/catbird-api/gradle.properties
@@ -0,0 +1 @@
+kotlin.code.style=official
\ No newline at end of file
diff --git a/catbird-api/gradle/wrapper/gradle-wrapper.jar b/catbird-api/gradle/wrapper/gradle-wrapper.jar
new file mode 100644
index 0000000..62d4c05
Binary files /dev/null and b/catbird-api/gradle/wrapper/gradle-wrapper.jar differ
diff --git a/catbird-api/gradle/wrapper/gradle-wrapper.properties b/catbird-api/gradle/wrapper/gradle-wrapper.properties
new file mode 100644
index 0000000..a4b4429
--- /dev/null
+++ b/catbird-api/gradle/wrapper/gradle-wrapper.properties
@@ -0,0 +1,5 @@
+distributionBase=GRADLE_USER_HOME
+distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-6.3-bin.zip
+zipStoreBase=GRADLE_USER_HOME
+zipStorePath=wrapper/dists
diff --git a/catbird-api/gradlew b/catbird-api/gradlew
new file mode 100755
index 0000000..fbd7c51
--- /dev/null
+++ b/catbird-api/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/catbird-api/gradlew.bat b/catbird-api/gradlew.bat
new file mode 100644
index 0000000..a9f778a
--- /dev/null
+++ b/catbird-api/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/catbird-api/settings.gradle b/catbird-api/settings.gradle
new file mode 100644
index 0000000..75a4657
--- /dev/null
+++ b/catbird-api/settings.gradle
@@ -0,0 +1,2 @@
+rootProject.name = 'catbird-api'
+
diff --git a/catbird-api/src/main/kotlin/Catbird.kt b/catbird-api/src/main/kotlin/Catbird.kt
new file mode 100644
index 0000000..b2a85b8
--- /dev/null
+++ b/catbird-api/src/main/kotlin/Catbird.kt
@@ -0,0 +1,48 @@
+import java.io.OutputStreamWriter
+import java.net.HttpURLConnection
+import java.net.URL
+
+class Catbird(
+    var url: URL = URL(LOCAL_HOST),
+    var encoder: JsonEncoder = JsonEncoder()
+) {
+    companion object {
+        const val LOCAL_HOST = "http://127.0.0.1:8080"
+        const val ACTION_PATH = "/catbird/api/mocks"
+    }
+
+    fun update(mock: CatbirdMock) {
+        perform(CatbirdAction.Update(mock.pattern, mock.response))
+    }
+
+    fun remove(mock: CatbirdMock) {
+        perform(CatbirdAction.Remove(mock.pattern))
+    }
+
+    fun removeAll() {
+        perform(CatbirdAction.RemoveAll())
+    }
+
+    fun perform(action: CatbirdAction) {
+        val body = encoder.encode(action)
+        val url = this.url.toURI().resolve(ACTION_PATH).toURL();
+        post(url, body)
+    }
+
+    private fun post(url: URL, body: String) {
+        with(url.openConnection() as HttpURLConnection) {
+            requestMethod = "POST"
+            doOutput = true
+            setRequestProperty("Content-Type", "application/json")
+
+            OutputStreamWriter(outputStream).use {
+                it.write(body)
+                it.flush()
+            }
+
+            inputStream.bufferedReader().use {
+                print(it.readText())
+            }
+        }
+    }
+}
diff --git a/catbird-api/src/main/kotlin/CatbirdAction.kt b/catbird-api/src/main/kotlin/CatbirdAction.kt
new file mode 100644
index 0000000..b5e59c8
--- /dev/null
+++ b/catbird-api/src/main/kotlin/CatbirdAction.kt
@@ -0,0 +1,26 @@
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+sealed class CatbirdAction(val type: Type) {
+    @Serializable
+    enum class Type {
+        @SerialName("update") UPDATE,
+        @SerialName("remove") REMOVE,
+        @SerialName("removeAll") REMOVE_ALL
+    }
+
+    @Serializable
+    data class Update(
+        val pattern: RequestPattern,
+        val response: ResponseMock
+    ): CatbirdAction(Type.UPDATE)
+
+    @Serializable
+    data class Remove(
+        val pattern: RequestPattern
+    ): CatbirdAction(Type.REMOVE)
+
+    @Serializable
+    class RemoveAll: CatbirdAction(Type.REMOVE_ALL)
+}
diff --git a/catbird-api/src/main/kotlin/CatbirdMock.kt b/catbird-api/src/main/kotlin/CatbirdMock.kt
new file mode 100644
index 0000000..13de8fc
--- /dev/null
+++ b/catbird-api/src/main/kotlin/CatbirdMock.kt
@@ -0,0 +1,4 @@
+interface CatbirdMock {
+    val pattern: RequestPattern
+    val response: ResponseMock
+}
\ No newline at end of file
diff --git a/catbird-api/src/main/kotlin/JsonEncoder.kt b/catbird-api/src/main/kotlin/JsonEncoder.kt
new file mode 100644
index 0000000..f82dd1d
--- /dev/null
+++ b/catbird-api/src/main/kotlin/JsonEncoder.kt
@@ -0,0 +1,12 @@
+import kotlinx.serialization.encodeToString
+import kotlinx.serialization.json.*
+
+class JsonEncoder(prettyPrint: Boolean = false) {
+    val json = Json {
+        this.prettyPrint = prettyPrint
+        this.classDiscriminator = "_type"
+    }
+
+    inline fun <reified T> encode(value: T): String =
+        json.encodeToString(value)
+}
diff --git a/catbird-api/src/main/kotlin/PatternMatch.kt b/catbird-api/src/main/kotlin/PatternMatch.kt
new file mode 100644
index 0000000..efbced2
--- /dev/null
+++ b/catbird-api/src/main/kotlin/PatternMatch.kt
@@ -0,0 +1,30 @@
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class PatternMatch(
+    val kind: Kind = Kind.EQUAL,
+    val value: String
+) {
+    @Serializable
+    enum class Kind {
+        @SerialName("equal") EQUAL,
+        @SerialName("wildcard") WILDCARD,
+        @SerialName("regexp") REGEXP
+    }
+
+    companion object {
+        @JvmStatic
+        fun equal(value: String) =
+            PatternMatch(Kind.EQUAL, value)
+
+        @JvmStatic
+        fun wildcard(value: String) =
+            PatternMatch(Kind.WILDCARD, value)
+
+        @JvmStatic
+        fun regexp(value: String) =
+            PatternMatch(Kind.REGEXP, value)
+    }
+}
+
diff --git a/catbird-api/src/main/kotlin/RequestPattern.kt b/catbird-api/src/main/kotlin/RequestPattern.kt
new file mode 100644
index 0000000..62a5a7d
--- /dev/null
+++ b/catbird-api/src/main/kotlin/RequestPattern.kt
@@ -0,0 +1,20 @@
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class RequestPattern(
+    var method: String = "GET",
+    var url: PatternMatch = PatternMatch(value = ""),
+    var headers: MutableMap<String, PatternMatch> = mutableMapOf()
+) {
+    fun setPath(string: String) {
+        url = PatternMatch(value = string)
+    }
+
+    fun setHeader(name: String, value: String) {
+        headers[name] = PatternMatch(value = value)
+    }
+
+    fun setCookie(value: String) {
+        setHeader("Cookie", value)
+    }
+}
\ No newline at end of file
diff --git a/catbird-api/src/main/kotlin/ResponseMock.kt b/catbird-api/src/main/kotlin/ResponseMock.kt
new file mode 100644
index 0000000..9598c04
--- /dev/null
+++ b/catbird-api/src/main/kotlin/ResponseMock.kt
@@ -0,0 +1,31 @@
+import kotlinx.serialization.Serializable
+import java.nio.file.Files
+import java.nio.file.Paths
+import java.util.Base64
+
+@Serializable
+data class ResponseMock(
+    var status: Int = 200,
+    var headers: MutableMap<String, String> = mutableMapOf(),
+    var body: String? = null,
+    var limit: Int? = null,
+    var delay: Int? = null,
+) {
+    fun setHeader(name: String, value: String) {
+        headers[name] = value
+    }
+
+    fun setCookie(value: String) {
+        setHeader("Set-Cookie", value)
+    }
+
+    fun setFile(path: String) {
+        val fileBytes = Files.readAllBytes(Paths.get(path))
+        val encodedBytes = Base64.getEncoder().encode(fileBytes)
+        body = String(encodedBytes)
+    }
+
+    fun setString(string: String) {
+        body = Base64.getEncoder().encodeToString(string.toByteArray())
+    }
+}
\ No newline at end of file
diff --git a/catbird-api/src/test/kotlin/CatbirdActionTest.kt b/catbird-api/src/test/kotlin/CatbirdActionTest.kt
new file mode 100644
index 0000000..3719ad8
--- /dev/null
+++ b/catbird-api/src/test/kotlin/CatbirdActionTest.kt
@@ -0,0 +1,71 @@
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class CatbirdActionTest {
+    private val encoder = JsonEncoder(prettyPrint = true)
+
+    @Test
+    fun `encode update action`() {
+        val pattern = RequestPattern()
+        val response = ResponseMock()
+        val action = CatbirdAction.Update(pattern, response)
+        val actual = encoder.encode(action)
+        var expected = """
+        {
+            "type": "update",
+            "pattern": {
+                "method": "GET",
+                "url": {
+                    "kind": "equal",
+                    "value": ""
+                },
+                "headers": {
+                }
+            },
+            "response": {
+                "status": 200,
+                "headers": {
+                },
+                "body": null,
+                "limit": null,
+                "delay": null
+            }
+        }
+        """.trimIndent()
+        assertEquals(expected, actual)
+    }
+
+    @Test
+    fun `encode remove action`() {
+        val pattern = RequestPattern()
+        val action = CatbirdAction.Remove(pattern)
+        val actual = encoder.encode(action)
+        var expected = """
+        {
+            "type": "remove",
+            "pattern": {
+                "method": "GET",
+                "url": {
+                    "kind": "equal",
+                    "value": ""
+                },
+                "headers": {
+                }
+            }
+        }
+        """.trimIndent()
+        assertEquals(expected, actual)
+    }
+
+    @Test
+    fun `encode remove all action`() {
+        val action = CatbirdAction.RemoveAll()
+        val actual = encoder.encode(action)
+        var expected = """
+        {
+            "type": "removeAll"
+        }
+        """.trimIndent()
+        assertEquals(expected, actual)
+    }
+}
diff --git a/catbird-api/src/test/kotlin/PatternMatchTest.kt b/catbird-api/src/test/kotlin/PatternMatchTest.kt
new file mode 100644
index 0000000..3362f75
--- /dev/null
+++ b/catbird-api/src/test/kotlin/PatternMatchTest.kt
@@ -0,0 +1,60 @@
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class PatternMatchTest {
+    private val encoder = JsonEncoder(prettyPrint = true)
+
+    @Test
+    fun `default kind equal`() {
+        val pattern = PatternMatch(value = "accounts")
+        assertEquals(PatternMatch.Kind.EQUAL, pattern.kind)
+    }
+
+    @Test
+    fun `encode equal to json`() {
+        val pattern = PatternMatch(
+            PatternMatch.Kind.EQUAL,
+            "accounts"
+        )
+        val actual = encoder.encode(pattern)
+        var expected = """
+        {
+            "kind": "equal",
+            "value": "accounts"
+        }
+        """.trimIndent()
+        assertEquals(expected, actual)
+    }
+
+    @Test
+    fun `encode wildcard to json`() {
+        val pattern = PatternMatch(
+            PatternMatch.Kind.WILDCARD,
+            "accounts"
+        )
+        val actual = encoder.encode(pattern)
+        var expected = """
+        {
+            "kind": "wildcard",
+            "value": "accounts"
+        }
+        """.trimIndent()
+        assertEquals(expected, actual)
+    }
+
+    @Test
+    fun `encode regexp to json`() {
+        val pattern = PatternMatch(
+            PatternMatch.Kind.REGEXP,
+            "accounts"
+        )
+        val actual = encoder.encode(pattern)
+        var expected = """
+        {
+            "kind": "regexp",
+            "value": "accounts"
+        }
+        """.trimIndent()
+        assertEquals(expected, actual)
+    }
+}
\ No newline at end of file
diff --git a/catbird-api/src/test/kotlin/RequestPatternTest.kt b/catbird-api/src/test/kotlin/RequestPatternTest.kt
new file mode 100644
index 0000000..b5f61f4
--- /dev/null
+++ b/catbird-api/src/test/kotlin/RequestPatternTest.kt
@@ -0,0 +1,83 @@
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class RequestPatternTest {
+    private val encoder = JsonEncoder(prettyPrint = true)
+
+    @Test
+    fun `default values`() {
+        val actual = RequestPattern()
+        val expected = RequestPattern(
+            method = "GET",
+            url = PatternMatch.equal(""),
+            headers = mutableMapOf()
+        )
+        assertEquals(expected, actual)
+    }
+
+    @Test
+    fun `set header`() {
+        val request = RequestPattern()
+        request.setHeader("a", "b")
+        request.setHeader("1", "2")
+        val actual = request.headers
+        val expected = mapOf(
+            "a" to PatternMatch.equal("b"),
+            "1" to PatternMatch.equal("2")
+        )
+        assertEquals(expected, actual)
+    }
+
+    @Test
+    fun `set cookie`() {
+        val request = RequestPattern()
+        request.setCookie("x")
+        val actual = request.headers
+        val expected = mapOf("Cookie" to PatternMatch.equal("x"))
+        assertEquals(expected, actual)
+    }
+
+    @Test
+    fun `encode with default values`() {
+        val request = RequestPattern()
+        val actual = encoder.encode(request)
+        val expected = """
+        {
+            "method": "GET",
+            "url": {
+                "kind": "equal",
+                "value": ""
+            },
+            "headers": {
+            }
+        }
+        """.trimIndent()
+        assertEquals(expected, actual)
+    }
+
+    @Test
+    fun `encode with all values`() {
+        val request = RequestPattern(
+            method = "POST",
+            url = PatternMatch(value = "/accounts"),
+            headers = mutableMapOf("z" to PatternMatch.wildcard("*"))
+        )
+        val actual = encoder.encode(request)
+        val expected = """
+        {
+            "method": "POST",
+            "url": {
+                "kind": "equal",
+                "value": "/accounts"
+            },
+            "headers": {
+                "z": {
+                    "kind": "wildcard",
+                    "value": "*"
+                }
+            }
+        }
+        """.trimIndent()
+        assertEquals(expected, actual)
+    }
+}
\ No newline at end of file
diff --git a/catbird-api/src/test/kotlin/ResponseMockTest.kt b/catbird-api/src/test/kotlin/ResponseMockTest.kt
new file mode 100644
index 0000000..46b25be
--- /dev/null
+++ b/catbird-api/src/test/kotlin/ResponseMockTest.kt
@@ -0,0 +1,75 @@
+import org.junit.Assert.assertEquals
+import org.junit.Test
+
+class ResponseMockTest {
+    private val encoder = JsonEncoder(prettyPrint = true)
+
+    @Test
+    fun `default values`() {
+        val actual = ResponseMock()
+        val expected = ResponseMock(
+            status = 200,
+            headers = mutableMapOf(),
+            body = null,
+            limit = null,
+            delay = null
+        )
+        assertEquals(expected, actual)
+    }
+
+    @Test
+    fun `set header`() {
+        val response = ResponseMock()
+        response.setHeader("a", "b")
+        response.setHeader("1", "2")
+        assertEquals(mapOf("a" to "b", "1" to "2"), response.headers)
+    }
+
+    @Test
+    fun `set cookie`() {
+        val response = ResponseMock()
+        response.setCookie("x")
+        assertEquals(mapOf("Set-Cookie" to "x"), response.headers)
+    }
+
+    @Test
+    fun `encode with default values`() {
+        val response = ResponseMock()
+        val actual = encoder.encode(response)
+        val expected = """
+        {
+            "status": 200,
+            "headers": {
+            },
+            "body": null,
+            "limit": null,
+            "delay": null
+        }
+        """.trimIndent()
+        assertEquals(expected, actual)
+    }
+
+    @Test
+    fun `encode with all values`() {
+        val response = ResponseMock(
+            status = 500,
+            headers = mutableMapOf("x" to "y"),
+            body = "hello",
+            limit = 1,
+            delay = 4
+        )
+        val actual = encoder.encode(response)
+        val expected = """
+        {
+            "status": 500,
+            "headers": {
+                "x": "y"
+            },
+            "body": "hello",
+            "limit": 1,
+            "delay": 4
+        }
+        """.trimIndent()
+        assertEquals(expected, actual)
+    }
+}
\ No newline at end of file