diff --git a/src/main/java/dan200/computercraft/core/apis/IAPIEnvironment.java b/src/main/java/dan200/computercraft/core/apis/IAPIEnvironment.java
index 25960c580..1f6ffe08a 100644
--- a/src/main/java/dan200/computercraft/core/apis/IAPIEnvironment.java
+++ b/src/main/java/dan200/computercraft/core/apis/IAPIEnvironment.java
@@ -62,6 +62,7 @@ interface IPeripheralChangeListener
     @Nullable
     IPeripheral getPeripheral( ComputerSide side );
 
+    @Nullable
     String getLabel();
 
     void setLabel( @Nullable String label );
diff --git a/src/test/java/dan200/computercraft/core/apis/AsyncRunner.kt b/src/test/java/dan200/computercraft/core/apis/AsyncRunner.kt
new file mode 100644
index 000000000..936fb6c62
--- /dev/null
+++ b/src/test/java/dan200/computercraft/core/apis/AsyncRunner.kt
@@ -0,0 +1,121 @@
+package dan200.computercraft.core.apis
+
+import dan200.computercraft.ComputerCraft
+import dan200.computercraft.api.lua.ILuaAPI
+import dan200.computercraft.api.lua.MethodResult
+import dan200.computercraft.api.peripheral.IPeripheral
+import dan200.computercraft.api.peripheral.IWorkMonitor
+import dan200.computercraft.core.computer.BasicEnvironment
+import dan200.computercraft.core.computer.ComputerSide
+import dan200.computercraft.core.computer.IComputerEnvironment
+import dan200.computercraft.core.filesystem.FileSystem
+import dan200.computercraft.core.terminal.Terminal
+import dan200.computercraft.core.tracking.TrackingField
+import kotlinx.coroutines.channels.Channel
+import kotlinx.coroutines.runBlocking
+import kotlinx.coroutines.withTimeout
+import kotlin.time.Duration
+import kotlin.time.ExperimentalTime
+import kotlin.time.seconds
+
+
+abstract class NullApiEnvironment : IAPIEnvironment {
+    private val computerEnv = BasicEnvironment()
+
+    override fun getComputerID(): Int = 0
+    override fun getComputerEnvironment(): IComputerEnvironment = computerEnv
+    override fun getMainThreadMonitor(): IWorkMonitor = throw IllegalStateException("Work monitor not available")
+    override fun getTerminal(): Terminal = throw IllegalStateException("Terminal not available")
+    override fun getFileSystem(): FileSystem = throw IllegalStateException("Terminal not available")
+    override fun shutdown() {}
+    override fun reboot() {}
+    override fun setOutput(side: ComputerSide?, output: Int) {}
+    override fun getOutput(side: ComputerSide?): Int = 0
+    override fun getInput(side: ComputerSide?): Int = 0
+    override fun setBundledOutput(side: ComputerSide?, output: Int) {}
+    override fun getBundledOutput(side: ComputerSide?): Int = 0
+    override fun getBundledInput(side: ComputerSide?): Int = 0
+    override fun setPeripheralChangeListener(listener: IAPIEnvironment.IPeripheralChangeListener?) {}
+    override fun getPeripheral(side: ComputerSide?): IPeripheral? = null
+    override fun getLabel(): String? = null
+    override fun setLabel(label: String?) {}
+    override fun startTimer(ticks: Long): Int = 0
+    override fun cancelTimer(id: Int) {}
+    override fun addTrackingChange(field: TrackingField, change: Long) {}
+}
+
+class EventResult(val name: String, val args: Array<Any?>)
+
+class AsyncRunner : NullApiEnvironment() {
+    private val eventStream: Channel<Array<Any?>> = Channel(Int.MAX_VALUE)
+    private val apis: MutableList<ILuaAPI> = mutableListOf()
+
+    override fun queueEvent(event: String?, vararg args: Any?) {
+        ComputerCraft.log.debug("Queue event $event ${args.contentToString()}")
+        if (!eventStream.offer(arrayOf(event, *args))) {
+            throw IllegalStateException("Queue is full")
+        }
+    }
+
+    override fun shutdown() {
+        super.shutdown()
+        eventStream.close()
+        apis.forEach { it.shutdown() }
+    }
+
+    fun <T : ILuaAPI> addApi(api: T): T {
+        apis.add(api)
+        api.startup()
+        return api
+    }
+
+    suspend fun resultOf(toRun: MethodResult): Array<Any?> {
+        var running = toRun
+        while (running.callback != null) running = runOnce(running)
+        return running.result ?: empty
+    }
+
+    private suspend fun runOnce(obj: MethodResult): MethodResult {
+        val callback = obj.callback ?: throw NullPointerException("Callback cannot be null")
+
+        val result = obj.result
+        val filter: String? = if (result.isNullOrEmpty() || result[0] !is String) {
+            null
+        } else {
+            result[0] as String
+        }
+
+        return callback.resume(pullEventImpl(filter))
+    }
+
+    private suspend fun pullEventImpl(filter: String?): Array<Any?> {
+        for (event in eventStream) {
+            ComputerCraft.log.debug("Pulled event ${event.contentToString()}")
+            val eventName = event[0] as String
+            if (filter == null || eventName == filter || eventName == "terminate") return event
+        }
+
+        throw IllegalStateException("No more events")
+    }
+
+    suspend fun pullEvent(filter: String? = null): EventResult {
+        val result = pullEventImpl(filter)
+        return EventResult(result[0] as String, result.copyOfRange(1, result.size))
+    }
+
+    companion object {
+        private val empty: Array<Any?> = arrayOf()
+
+        @OptIn(ExperimentalTime::class)
+        fun runTest(timeout: Duration = 5.seconds, fn: suspend AsyncRunner.() -> Unit) {
+            runBlocking {
+                val runner = AsyncRunner()
+                try {
+                    withTimeout(timeout) { fn(runner) }
+                } finally {
+                    runner.shutdown()
+                }
+            }
+        }
+    }
+}
diff --git a/src/test/java/dan200/computercraft/core/apis/http/options/TestHttpApi.kt b/src/test/java/dan200/computercraft/core/apis/http/options/TestHttpApi.kt
new file mode 100644
index 000000000..206924cc0
--- /dev/null
+++ b/src/test/java/dan200/computercraft/core/apis/http/options/TestHttpApi.kt
@@ -0,0 +1,51 @@
+package dan200.computercraft.core.apis.http.options
+
+import dan200.computercraft.ComputerCraft
+import dan200.computercraft.core.apis.AsyncRunner
+import dan200.computercraft.core.apis.HTTPAPI
+import org.junit.jupiter.api.AfterAll
+import org.junit.jupiter.api.Assertions.assertArrayEquals
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.BeforeAll
+import org.junit.jupiter.api.Disabled
+import org.junit.jupiter.api.Test
+import java.util.*
+
+@Disabled("Requires some setup locally.")
+class TestHttpApi {
+    companion object {
+        private const val WS_ADDRESS = "ws://127.0.0.1:8080"
+
+        @JvmStatic
+        @BeforeAll
+        fun before() {
+            ComputerCraft.httpRules = listOf(AddressRule.parse("*", null, Action.ALLOW.toPartial()))
+        }
+
+        @JvmStatic
+        @AfterAll
+        fun after() {
+            ComputerCraft.httpRules = Collections.unmodifiableList(
+                listOf(
+                    AddressRule.parse("\$private", null, Action.DENY.toPartial()),
+                    AddressRule.parse("*", null, Action.ALLOW.toPartial())
+                )
+            )
+        }
+    }
+
+    @Test
+    fun `Connects to websocket`() {
+        AsyncRunner.runTest {
+            val httpApi = addApi(HTTPAPI(this))
+
+            val result = httpApi.websocket(WS_ADDRESS, Optional.empty())
+            assertArrayEquals(arrayOf(true), result, "Should have created websocket")
+
+            val event = pullEvent()
+            assertEquals("websocket_success", event.name) {
+                "Websocket failed to connect: ${event.args.contentToString()}"
+            }
+        }
+    }
+}