Merge branch 'master' into dbus

lib/src/main/java/org/asamk/signal/manager/Manager.java

@@ -2028,6 +2028,9 @@ public class Manager implements Closeable {
             try {
                 action.execute(this);
             } catch (Throwable e) {
+                if (e instanceof AssertionError && e.getCause() instanceof InterruptedException) {
+                    Thread.currentThread().interrupt();
+                }
                 logger.warn("Message action failed.", e);
             }
         }
@@ -2074,7 +2077,7 @@ public class Manager implements Closeable {
             boolean returnOnTimeout,
             boolean ignoreAttachments,
             ReceiveMessageHandler handler
-    ) throws IOException {
+    ) throws IOException, InterruptedException {
         retryFailedReceivedMessages(handler, ignoreAttachments);
 
         Set<HandleAction> queuedActions = null;
@@ -2110,6 +2113,9 @@ public class Manager implements Closeable {
                             try {
                                 action.execute(this);
                             } catch (Throwable e) {
+                                if (e instanceof AssertionError && e.getCause() instanceof InterruptedException) {
+                                    Thread.currentThread().interrupt();
+                                }
                                 logger.warn("Message action failed.", e);
                             }
                         }
@@ -2120,6 +2126,12 @@ public class Manager implements Closeable {
                     // Continue to wait another timeout for new messages
                     continue;
                 }
+            } catch (AssertionError e) {
+                if (e.getCause() instanceof InterruptedException) {
+                    throw (InterruptedException) e.getCause();
+                } else {
+                    throw e;
+                }
             } catch (TimeoutException e) {
                 if (returnOnTimeout) return;
                 continue;
@@ -2153,6 +2165,9 @@ public class Manager implements Closeable {
                         try {
                             action.execute(this);
                         } catch (Throwable e) {
+                            if (e instanceof AssertionError && e.getCause() instanceof InterruptedException) {
+                                Thread.currentThread().interrupt();
+                            }
                             logger.warn("Message action failed.", e);
                         }
                     }
@@ -2549,6 +2564,9 @@ public class Manager implements Closeable {
             avatarStore.storeProfileAvatar(address,
                     outputStream -> retrieveProfileAvatar(avatarPath, profileKey, outputStream));
         } catch (Throwable e) {
+            if (e instanceof AssertionError && e.getCause() instanceof InterruptedException) {
+                Thread.currentThread().interrupt();
+            }
             logger.warn("Failed to download profile avatar, ignoring: {}", e.getMessage());
         }
     }

man/signal-cli.1.adoc

@@ -162,7 +162,7 @@ Send a message to another user or group.
 RECIPIENT::
 Specify the recipients’ phone number.
 
-*-g* GROUP, *--group* GROUP::
+*-g* GROUP, *--group-id* GROUP::
 Specify the recipient group ID in base64 encoding.
 
 *-m* MESSAGE, *--message* MESSAGE::
@@ -174,7 +174,7 @@ Add one or more files as attachment.
 *--note-to-self*::
 Send the message to self without notification.
 
-*-e*, *--endsession*::
+*-e*, *--end-session*::
 Clear session state and send end session message.
 
 === sendReaction
@@ -184,7 +184,7 @@ Send reaction to a previously received or sent message.
 RECIPIENT::
 Specify the recipients’ phone number.
 
-*-g* GROUP, *--group* GROUP::
+*-g* GROUP, *--group-id* GROUP::
 Specify the recipient group ID in base64 encoding.
 
 *-e* EMOJI, *--emoji* EMOJI::
@@ -207,7 +207,7 @@ Indicator will be shown for 15seconds unless a typing STOP message is sent first
 RECIPIENT::
 Specify the recipients’ phone number.
 
-*-g* GROUP, *--group* GROUP::
+*-g* GROUP, *--group-id* GROUP::
 Specify the recipient group ID in base64 encoding.
 
 *-s*, *--stop*::
@@ -220,7 +220,7 @@ Remotely delete a previously sent message.
 RECIPIENT::
 Specify the recipients’ phone number.
 
-*-g* GROUP, *--group* GROUP::
+*-g* GROUP, *--group-id* GROUP::
 Specify the recipient group ID in base64 encoding.
 
 *-t* TIMESTAMP, *--target-timestamp* TIMESTAMP::
@@ -250,7 +250,7 @@ The invitation link URI (starts with `https://signal.group/#`)
 Create or update a group.
 If the user is a pending member, this command will accept the group invitation.
 
-*-g* GROUP, *--group* GROUP::
+*-g* GROUP, *--group-id* GROUP::
 Specify the recipient group ID in base64 encoding.
 If not specified, a new group with a new random ID is generated.
 
@@ -296,7 +296,7 @@ To disable expiration set expiration time to 0.
 Send a quit group message to all group members and remove self from member list.
 If the user is a pending member, this command will decline the group invitation.
 
-*-g* GROUP, *--group* GROUP::
+*-g* GROUP, *--group-id* GROUP::
 Specify the recipient group ID in base64 encoding.
 
 *--delete*::
@@ -385,7 +385,7 @@ This change is only local but can be synchronized to other devices by using `sen
 [CONTACT [CONTACT ...]]::
 Specify the phone numbers of contacts that should be blocked.
 
-*-g* [GROUP [GROUP ...]], *--group* [GROUP [GROUP ...]]::
+*-g* [GROUP [GROUP ...]], *--group-id* [GROUP [GROUP ...]]::
 Specify the group IDs that should be blocked in base64 encoding.
 
 === unblock
@@ -396,7 +396,7 @@ This change is only local but can be synchronized to other devices by using `sen
 [CONTACT [CONTACT ...]]::
 Specify the phone numbers of contacts that should be unblocked.
 
-*-g* [GROUP [GROUP ...]], *--group* [GROUP [GROUP ...]]::
+*-g* [GROUP [GROUP ...]], *--group-id* [GROUP [GROUP ...]]::
 Specify the group IDs that should be unblocked in base64 encoding.
 
 === sendContacts

src/main/java/org/asamk/signal/App.java

@@ -92,7 +92,7 @@ public class App {
     public void init() throws CommandException {
         var outputType = ns.<OutputType>get("output");
         var outputWriter = outputType == OutputType.JSON
-                ? new JsonWriter(System.out)
+                ? new JsonWriterImpl(System.out)
                 : new PlainTextWriterImpl(System.out);
 
         var commandKey = ns.getString("command");

src/main/java/org/asamk/signal/GroupLinkState.java

@@ -1,35 +0,0 @@
-package org.asamk.signal;
-
-public enum GroupLinkState {
-    ENABLED {
-        @Override
-        public String toString() {
-            return "enabled";
-        }
-    },
-    ENABLED_WITH_APPROVAL {
-        @Override
-        public String toString() {
-            return "enabled-with-approval";
-        }
-    },
-    DISABLED {
-        @Override
-        public String toString() {
-            return "disabled";
-        }
-    };
-
-    public org.asamk.signal.manager.groups.GroupLinkState toLinkState() {
-        switch (this) {
-            case ENABLED:
-                return org.asamk.signal.manager.groups.GroupLinkState.ENABLED;
-            case ENABLED_WITH_APPROVAL:
-                return org.asamk.signal.manager.groups.GroupLinkState.ENABLED_WITH_APPROVAL;
-            case DISABLED:
-                return org.asamk.signal.manager.groups.GroupLinkState.DISABLED;
-            default:
-                throw new AssertionError();
-        }
-    }
-}

src/main/java/org/asamk/signal/GroupPermission.java

@@ -1,27 +0,0 @@
-package org.asamk.signal;
-
-public enum GroupPermission {
-    EVERY_MEMBER {
-        @Override
-        public String toString() {
-            return "every-member";
-        }
-    },
-    ONLY_ADMINS {
-        @Override
-        public String toString() {
-            return "only-admins";
-        }
-    };
-
-    public org.asamk.signal.manager.groups.GroupPermission toManager() {
-        switch (this) {
-            case EVERY_MEMBER:
-                return org.asamk.signal.manager.groups.GroupPermission.EVERY_MEMBER;
-            case ONLY_ADMINS:
-                return org.asamk.signal.manager.groups.GroupPermission.ONLY_ADMINS;
-            default:
-                throw new AssertionError();
-        }
-    }
-}

src/main/java/org/asamk/signal/JsonWriter.java

@@ -1,43 +1,6 @@
 package org.asamk.signal;
 
-import com.fasterxml.jackson.annotation.JsonAutoDetect;
+public interface JsonWriter extends OutputWriter {
-import com.fasterxml.jackson.annotation.PropertyAccessor;
-import com.fasterxml.jackson.core.JsonGenerator;
-import com.fasterxml.jackson.core.JsonProcessingException;
-import com.fasterxml.jackson.databind.ObjectMapper;
 
-import java.io.BufferedWriter;
+    void write(final Object object);
-import java.io.IOException;
-import java.io.OutputStream;
-import java.io.OutputStreamWriter;
-import java.io.Writer;
-import java.nio.charset.StandardCharsets;
-
-public class JsonWriter implements OutputWriter {
-
-    private final Writer writer;
-    private final ObjectMapper objectMapper;
-
-    public JsonWriter(final OutputStream outputStream) {
-        this.writer = new BufferedWriter(new OutputStreamWriter(outputStream, StandardCharsets.UTF_8));
-
-        objectMapper = new ObjectMapper();
-        objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.PUBLIC_ONLY);
-        objectMapper.disable(JsonGenerator.Feature.AUTO_CLOSE_TARGET);
-    }
-
-    public void write(final Object object) {
-        try {
-            try {
-                objectMapper.writeValue(writer, object);
-            } catch (JsonProcessingException e) {
-                // Some issue with json serialization, probably caused by a bug
-                throw new AssertionError(e);
-            }
-            writer.write(System.lineSeparator());
-            writer.flush();
-        } catch (IOException e) {
-            throw new AssertionError(e);
-        }
-    }
 }

src/main/java/org/asamk/signal/JsonWriterImpl.java

@@ -0,0 +1,40 @@
+package org.asamk.signal;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+
+import org.asamk.signal.util.Util;
+
+import java.io.BufferedWriter;
+import java.io.IOException;
+import java.io.OutputStream;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
+import java.nio.charset.StandardCharsets;
+
+public class JsonWriterImpl implements JsonWriter {
+
+    private final Writer writer;
+    private final ObjectMapper objectMapper;
+
+    public JsonWriterImpl(final OutputStream outputStream) {
+        this.writer = new BufferedWriter(new OutputStreamWriter(outputStream, StandardCharsets.UTF_8));
+
+        objectMapper = Util.createJsonObjectMapper();
+    }
+
+    public synchronized void write(final Object object) {
+        try {
+            try {
+                objectMapper.writeValue(writer, object);
+            } catch (JsonProcessingException e) {
+                // Some issue with json serialization, probably caused by a bug
+                throw new AssertionError(e);
+            }
+            writer.write(System.lineSeparator());
+            writer.flush();
+        } catch (IOException e) {
+            throw new AssertionError(e);
+        }
+    }
+}

src/main/java/org/asamk/signal/commands/AddDeviceCommand.java

@@ -17,7 +17,7 @@ import java.io.IOException;
 import java.net.URI;
 import java.net.URISyntaxException;
 
-public class AddDeviceCommand implements LocalCommand {
+public class AddDeviceCommand implements JsonRpcLocalCommand {
 
     private final static Logger logger = LoggerFactory.getLogger(AddDeviceCommand.class);
 

src/main/java/org/asamk/signal/commands/BlockCommand.java

@@ -15,14 +15,14 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.whispersystems.signalservice.api.util.InvalidNumberException;
 
-public class BlockCommand implements LocalCommand {
+public class BlockCommand implements JsonRpcLocalCommand {
 
     private final static Logger logger = LoggerFactory.getLogger(BlockCommand.class);
 
     public static void attachToSubparser(final Subparser subparser) {
         subparser.help("Block the given contacts or groups (no messages will be received)");
         subparser.addArgument("contact").help("Contact number").nargs("*");
-        subparser.addArgument("-g", "--group").help("Group ID").nargs("*");
+        subparser.addArgument("-g", "--group-id", "--group").help("Group ID").nargs("*");
     }
 
     public BlockCommand(final OutputWriter outputWriter) {
@@ -40,8 +40,8 @@ public class BlockCommand implements LocalCommand {
             }
         }
 
-        if (ns.<String>getList("group") != null) {
+        if (ns.<String>getList("group-id") != null) {
-            for (var groupIdString : ns.<String>getList("group")) {
+            for (var groupIdString : ns.<String>getList("group-id")) {
                 try {
                     var groupId = Util.decodeGroupId(groupIdString);
                     m.setGroupBlocked(groupId, true);

src/main/java/org/asamk/signal/commands/Commands.java

@@ -16,6 +16,7 @@ public class Commands {
         addCommand("block", BlockCommand::new, BlockCommand::attachToSubparser);
         addCommand("daemon", DaemonCommand::new, DaemonCommand::attachToSubparser);
         addCommand("getUserStatus", GetUserStatusCommand::new, GetUserStatusCommand::attachToSubparser);
+        addCommand("jsonRpc", JsonRpcDispatcherCommand::new, JsonRpcDispatcherCommand::attachToSubparser);
         addCommand("link", LinkCommand::new, LinkCommand::attachToSubparser);
         addCommand("listContacts", ListContactsCommand::new, ListContactsCommand::attachToSubparser);
         addCommand("listDevices", ListDevicesCommand::new, ListDevicesCommand::attachToSubparser);
@@ -43,6 +44,7 @@ public class Commands {
         addCommand("updateProfile", UpdateProfileCommand::new, UpdateProfileCommand::attachToSubparser);
         addCommand("uploadStickerPack", UploadStickerPackCommand::new, UploadStickerPackCommand::attachToSubparser);
         addCommand("verify", VerifyCommand::new, VerifyCommand::attachToSubparser);
+        addCommand("version", VersionCommand::new, null);
     }
 
     public static Map<String, SubparserAttacher> getCommandSubparserAttachers() {
@@ -60,7 +62,9 @@ public class Commands {
             String name, CommandConstructor commandConstructor, SubparserAttacher subparserAttacher
     ) {
         commands.put(name, commandConstructor);
-        commandSubparserAttacher.put(name, subparserAttacher);
+        if (subparserAttacher != null) {
+            commandSubparserAttacher.put(name, subparserAttacher);
+        }
     }
 
     private interface CommandConstructor {

src/main/java/org/asamk/signal/commands/DaemonCommand.java

@@ -128,14 +128,17 @@ public class DaemonCommand implements MultiLocalCommand {
         logger.info("Exported dbus object: " + objectPath);
 
         final var thread = new Thread(() -> {
-            while (true) {
+            while (!Thread.interrupted()) {
                 try {
                     final var receiveMessageHandler = outputWriter instanceof JsonWriter
                             ? new JsonDbusReceiveMessageHandler(m, (JsonWriter) outputWriter, conn, objectPath)
                             : new DbusReceiveMessageHandler(m, (PlainTextWriter) outputWriter, conn, objectPath);
                     m.receiveMessages(1, TimeUnit.HOURS, false, ignoreAttachments, receiveMessageHandler);
+                    break;
                 } catch (IOException e) {
                     logger.warn("Receiving messages failed, retrying", e);
+                } catch (InterruptedException ignored) {
+                    break;
                 }
             }
         });

src/main/java/org/asamk/signal/commands/GetUserStatusCommand.java

@@ -4,9 +4,8 @@ import net.sourceforge.argparse4j.inf.Namespace;
 import net.sourceforge.argparse4j.inf.Subparser;
 
 import org.asamk.signal.JsonWriter;
-import org.asamk.signal.OutputType;
 import org.asamk.signal.OutputWriter;
-import org.asamk.signal.PlainTextWriterImpl;
+import org.asamk.signal.PlainTextWriter;
 import org.asamk.signal.commands.exceptions.CommandException;
 import org.asamk.signal.commands.exceptions.IOErrorException;
 import org.asamk.signal.manager.Manager;
@@ -16,10 +15,9 @@ import org.slf4j.LoggerFactory;
 import java.io.IOException;
 import java.util.HashSet;
 import java.util.Map;
-import java.util.Set;
 import java.util.stream.Collectors;
 
-public class GetUserStatusCommand implements LocalCommand {
+public class GetUserStatusCommand implements JsonRpcLocalCommand {
 
     private final static Logger logger = LoggerFactory.getLogger(GetUserStatusCommand.class);
     private final OutputWriter outputWriter;
@@ -33,11 +31,6 @@ public class GetUserStatusCommand implements LocalCommand {
         this.outputWriter = outputWriter;
     }
 
-    @Override
-    public Set<OutputType> getSupportedOutputTypes() {
-        return Set.of(OutputType.PLAIN_TEXT, OutputType.JSON);
-    }
-
     @Override
     public void handleCommand(final Namespace ns, final Manager m) throws CommandException {
         // Get a map of registration statuses
@@ -60,7 +53,7 @@ public class GetUserStatusCommand implements LocalCommand {
 
             jsonWriter.write(jsonUserStatuses);
         } else {
-            final var writer = (PlainTextWriterImpl) outputWriter;
+            final var writer = (PlainTextWriter) outputWriter;
 
             for (var entry : registered.entrySet()) {
                 writer.println("{}: {}", entry.getKey(), entry.getValue());

src/main/java/org/asamk/signal/commands/JoinGroupCommand.java

@@ -3,8 +3,9 @@ package org.asamk.signal.commands;
 import net.sourceforge.argparse4j.inf.Namespace;
 import net.sourceforge.argparse4j.inf.Subparser;
 
+import org.asamk.signal.JsonWriter;
 import org.asamk.signal.OutputWriter;
-import org.asamk.signal.PlainTextWriterImpl;
+import org.asamk.signal.PlainTextWriter;
 import org.asamk.signal.commands.exceptions.CommandException;
 import org.asamk.signal.commands.exceptions.IOErrorException;
 import org.asamk.signal.commands.exceptions.UnexpectedErrorException;
@@ -16,10 +17,11 @@ import org.whispersystems.signalservice.api.groupsv2.GroupLinkNotActiveException
 import org.whispersystems.signalservice.internal.push.exceptions.GroupPatchNotAcceptedException;
 
 import java.io.IOException;
+import java.util.Map;
 
-import static org.asamk.signal.util.ErrorUtils.handleTimestampAndSendMessageResults;
+import static org.asamk.signal.util.ErrorUtils.handleSendMessageResults;
 
-public class JoinGroupCommand implements LocalCommand {
+public class JoinGroupCommand implements JsonRpcLocalCommand {
 
     private final OutputWriter outputWriter;
 
@@ -49,16 +51,24 @@ public class JoinGroupCommand implements LocalCommand {
         }
 
         try {
-            final var writer = (PlainTextWriterImpl) outputWriter;
-
             final var results = m.joinGroup(linkUrl);
             var newGroupId = results.first();
-            if (!m.getGroup(newGroupId).isMember(m.getSelfRecipientId())) {
+            if (outputWriter instanceof JsonWriter) {
-                writer.println("Requested to join group \"{}\"", newGroupId.toBase64());
+                final var writer = (JsonWriter) outputWriter;
+                if (!m.getGroup(newGroupId).isMember(m.getSelfRecipientId())) {
+                    writer.write(Map.of("groupId", newGroupId.toBase64(), "onlyRequested", true));
+                } else {
+                    writer.write(Map.of("groupId", newGroupId.toBase64()));
+                }
             } else {
-                writer.println("Joined group \"{}\"", newGroupId.toBase64());
+                final var writer = (PlainTextWriter) outputWriter;
+                if (!m.getGroup(newGroupId).isMember(m.getSelfRecipientId())) {
+                    writer.println("Requested to join group \"{}\"", newGroupId.toBase64());
+                } else {
+                    writer.println("Joined group \"{}\"", newGroupId.toBase64());
+                }
             }
-            handleTimestampAndSendMessageResults(writer, 0, results.second());
+            handleSendMessageResults(results.second());
         } catch (GroupPatchNotAcceptedException e) {
             throw new UserErrorException("Failed to join group, maybe already a member");
         } catch (IOException e) {

src/main/java/org/asamk/signal/commands/JsonRpcCommand.java

@@ -0,0 +1,22 @@
+package org.asamk.signal.commands;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+
+import org.asamk.signal.OutputType;
+import org.asamk.signal.commands.exceptions.CommandException;
+import org.asamk.signal.manager.Manager;
+
+import java.util.Set;
+
+public interface JsonRpcCommand<T> extends Command {
+
+    default TypeReference<T> getRequestType() {
+        return null;
+    }
+
+    void handleCommand(T request, Manager m) throws CommandException;
+
+    default Set<OutputType> getSupportedOutputTypes() {
+        return Set.of(OutputType.JSON);
+    }
+}

src/main/java/org/asamk/signal/commands/JsonRpcDispatcherCommand.java

@@ -0,0 +1,175 @@
+package org.asamk.signal.commands;
+
+import com.fasterxml.jackson.core.TreeNode;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ContainerNode;
+
+import net.sourceforge.argparse4j.impl.Arguments;
+import net.sourceforge.argparse4j.inf.Namespace;
+import net.sourceforge.argparse4j.inf.Subparser;
+
+import org.asamk.signal.JsonReceiveMessageHandler;
+import org.asamk.signal.JsonWriter;
+import org.asamk.signal.OutputType;
+import org.asamk.signal.OutputWriter;
+import org.asamk.signal.commands.exceptions.CommandException;
+import org.asamk.signal.commands.exceptions.IOErrorException;
+import org.asamk.signal.commands.exceptions.UntrustedKeyErrorException;
+import org.asamk.signal.commands.exceptions.UserErrorException;
+import org.asamk.signal.jsonrpc.JsonRpcException;
+import org.asamk.signal.jsonrpc.JsonRpcReader;
+import org.asamk.signal.jsonrpc.JsonRpcRequest;
+import org.asamk.signal.jsonrpc.JsonRpcResponse;
+import org.asamk.signal.jsonrpc.JsonRpcSender;
+import org.asamk.signal.manager.Manager;
+import org.asamk.signal.util.Util;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.Map;
+import java.util.Set;
+import java.util.concurrent.TimeUnit;
+
+public class JsonRpcDispatcherCommand implements LocalCommand {
+
+    private final static Logger logger = LoggerFactory.getLogger(JsonRpcDispatcherCommand.class);
+
+    private static final int USER_ERROR = -1;
+    private static final int IO_ERROR = -3;
+    private static final int UNTRUSTED_KEY_ERROR = -4;
+
+    private final OutputWriter outputWriter;
+
+    public static void attachToSubparser(final Subparser subparser) {
+        subparser.help("Take commands from standard input as line-delimited JSON RPC while receiving messages.");
+        subparser.addArgument("--ignore-attachments")
+                .help("Don’t download attachments of received messages.")
+                .action(Arguments.storeTrue());
+    }
+
+    public JsonRpcDispatcherCommand(final OutputWriter outputWriter) {
+        this.outputWriter = outputWriter;
+    }
+
+    @Override
+    public Set<OutputType> getSupportedOutputTypes() {
+        return Set.of(OutputType.JSON);
+    }
+
+    @Override
+    public void handleCommand(final Namespace ns, final Manager m) throws CommandException {
+        final boolean ignoreAttachments = ns.getBoolean("ignore-attachments");
+
+        final var objectMapper = Util.createJsonObjectMapper();
+        final var jsonRpcSender = new JsonRpcSender((JsonWriter) outputWriter);
+
+        final var receiveThread = receiveMessages(s -> jsonRpcSender.sendRequest(JsonRpcRequest.forNotification(
+                "receive",
+                objectMapper.valueToTree(s),
+                null)), m, ignoreAttachments);
+
+        final BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
+
+        final var jsonRpcReader = new JsonRpcReader(jsonRpcSender, () -> {
+            try {
+                return reader.readLine();
+            } catch (IOException e) {
+                throw new AssertionError(e);
+            }
+        });
+        jsonRpcReader.readRequests((method, params) -> handleRequest(m, objectMapper, method, params),
+                response -> logger.debug("Received unexpected response for id {}", response.getId()));
+
+        receiveThread.interrupt();
+        try {
+            receiveThread.join();
+        } catch (InterruptedException ignored) {
+        }
+    }
+
+    private JsonNode handleRequest(
+            final Manager m, final ObjectMapper objectMapper, final String method, ContainerNode<?> params
+    ) throws JsonRpcException {
+        final Object[] result = {null};
+        final JsonWriter commandOutputWriter = s -> {
+            if (result[0] != null) {
+                throw new AssertionError("Command may only write one json result");
+            }
+
+            result[0] = s;
+        };
+
+        var command = Commands.getCommand(method, commandOutputWriter);
+        if (!(command instanceof JsonRpcCommand)) {
+            throw new JsonRpcException(new JsonRpcResponse.Error(JsonRpcResponse.Error.METHOD_NOT_FOUND,
+                    "Method not implemented",
+                    null));
+        }
+
+        try {
+            parseParamsAndRunCommand(m, objectMapper, params, (JsonRpcCommand<?>) command);
+        } catch (JsonMappingException e) {
+            throw new JsonRpcException(new JsonRpcResponse.Error(JsonRpcResponse.Error.INVALID_REQUEST,
+                    e.getMessage(),
+                    null));
+        } catch (UserErrorException e) {
+            throw new JsonRpcException(new JsonRpcResponse.Error(USER_ERROR, e.getMessage(), null));
+        } catch (IOErrorException e) {
+            throw new JsonRpcException(new JsonRpcResponse.Error(IO_ERROR, e.getMessage(), null));
+        } catch (UntrustedKeyErrorException e) {
+            throw new JsonRpcException(new JsonRpcResponse.Error(UNTRUSTED_KEY_ERROR, e.getMessage(), null));
+        } catch (Throwable e) {
+            logger.error("Command execution failed", e);
+            throw new JsonRpcException(new JsonRpcResponse.Error(JsonRpcResponse.Error.INTERNAL_ERROR,
+                    e.getMessage(),
+                    null));
+        }
+
+        Object output = result[0] == null ? Map.of() : result[0];
+        return objectMapper.valueToTree(output);
+    }
+
+    private <T> void parseParamsAndRunCommand(
+            final Manager m, final ObjectMapper objectMapper, final TreeNode params, final JsonRpcCommand<T> command
+    ) throws CommandException, JsonMappingException {
+        T requestParams = null;
+        final var requestType = command.getRequestType();
+        if (params != null && requestType != null) {
+            try {
+                requestParams = objectMapper.readValue(objectMapper.treeAsTokens(params), requestType);
+            } catch (JsonMappingException e) {
+                throw e;
+            } catch (IOException e) {
+                throw new AssertionError(e);
+            }
+        }
+        command.handleCommand(requestParams, m);
+    }
+
+    private Thread receiveMessages(
+            JsonWriter jsonWriter, Manager m, boolean ignoreAttachments
+    ) {
+        final var thread = new Thread(() -> {
+            while (!Thread.interrupted()) {
+                try {
+                    final var receiveMessageHandler = new JsonReceiveMessageHandler(m, jsonWriter);
+                    m.receiveMessages(1, TimeUnit.HOURS, false, ignoreAttachments, receiveMessageHandler);
+                    break;
+                } catch (IOException e) {
+                    logger.warn("Receiving messages failed, retrying", e);
+                } catch (InterruptedException e) {
+                    break;
+                }
+            }
+        });
+
+        thread.start();
+
+        return thread;
+    }
+}

src/main/java/org/asamk/signal/commands/JsonRpcLocalCommand.java

@@ -0,0 +1,72 @@
+package org.asamk.signal.commands;
+
+import com.fasterxml.jackson.core.type.TypeReference;
+
+import net.sourceforge.argparse4j.inf.Namespace;
+
+import org.asamk.signal.OutputType;
+import org.asamk.signal.commands.exceptions.CommandException;
+import org.asamk.signal.manager.Manager;
+import org.asamk.signal.util.Util;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+
+public interface JsonRpcLocalCommand extends JsonRpcCommand<Map<String, Object>> {
+
+    void handleCommand(Namespace ns, Manager m) throws CommandException;
+
+    default TypeReference<Map<String, Object>> getRequestType() {
+        return new TypeReference<>() {
+        };
+    }
+
+    default void handleCommand(Map<String, Object> request, Manager m) throws CommandException {
+        Namespace commandNamespace = new JsonRpcNamespace(request == null ? Map.of() : request);
+        handleCommand(commandNamespace, m);
+    }
+
+    default Set<OutputType> getSupportedOutputTypes() {
+        return Set.of(OutputType.PLAIN_TEXT, OutputType.JSON);
+    }
+
+    /**
+     * Namepace implementation, that defaults booleans to false and converts camel case keys to dashed strings
+     */
+    final class JsonRpcNamespace extends Namespace {
+
+        public JsonRpcNamespace(final Map<String, Object> attrs) {
+            super(attrs);
+        }
+
+        public <T> T get(String dest) {
+            final T value = super.get(dest);
+            if (value != null) {
+                return value;
+            }
+
+            final var camelCaseString = Util.dashSeparatedToCamelCaseString(dest);
+            return super.get(camelCaseString);
+        }
+
+        @Override
+        public <E> List<E> getList(final String dest) {
+            final List<E> value = super.getList(dest);
+            if (value != null) {
+                return value;
+            }
+
+            return super.getList(dest + "s");
+        }
+
+        @Override
+        public Boolean getBoolean(String dest) {
+            Boolean maybeGotten = this.get(dest);
+            if (maybeGotten == null) {
+                maybeGotten = false;
+            }
+            return maybeGotten;
+        }
+    }
+}

src/main/java/org/asamk/signal/commands/LinkCommand.java

@@ -4,7 +4,7 @@ import net.sourceforge.argparse4j.inf.Namespace;
 import net.sourceforge.argparse4j.inf.Subparser;
 
 import org.asamk.signal.OutputWriter;
-import org.asamk.signal.PlainTextWriterImpl;
+import org.asamk.signal.PlainTextWriter;
 import org.asamk.signal.commands.exceptions.CommandException;
 import org.asamk.signal.commands.exceptions.IOErrorException;
 import org.asamk.signal.commands.exceptions.UserErrorException;
@@ -32,7 +32,7 @@ public class LinkCommand implements ProvisioningCommand {
 
     @Override
     public void handleCommand(final Namespace ns, final ProvisioningManager m) throws CommandException {
-        final var writer = (PlainTextWriterImpl) outputWriter;
+        final var writer = (PlainTextWriter) outputWriter;
 
         var deviceName = ns.getString("name");
         if (deviceName == null) {

src/main/java/org/asamk/signal/commands/ListContactsCommand.java

@@ -4,7 +4,7 @@ import net.sourceforge.argparse4j.inf.Namespace;
 import net.sourceforge.argparse4j.inf.Subparser;
 
 import org.asamk.signal.OutputWriter;
-import org.asamk.signal.PlainTextWriterImpl;
+import org.asamk.signal.PlainTextWriter;
 import org.asamk.signal.manager.Manager;
 
 import static org.asamk.signal.util.Util.getLegacyIdentifier;
@@ -23,7 +23,7 @@ public class ListContactsCommand implements LocalCommand {
 
     @Override
     public void handleCommand(final Namespace ns, final Manager m) {
-        final var writer = (PlainTextWriterImpl) outputWriter;
+        final var writer = (PlainTextWriter) outputWriter;
 
         var contacts = m.getContacts();
         for (var c : contacts) {

src/main/java/org/asamk/signal/commands/ListDevicesCommand.java

@@ -4,7 +4,7 @@ import net.sourceforge.argparse4j.inf.Namespace;
 import net.sourceforge.argparse4j.inf.Subparser;
 
 import org.asamk.signal.OutputWriter;
-import org.asamk.signal.PlainTextWriterImpl;
+import org.asamk.signal.PlainTextWriter;
 import org.asamk.signal.commands.exceptions.CommandException;
 import org.asamk.signal.commands.exceptions.IOErrorException;
 import org.asamk.signal.manager.Manager;
@@ -31,7 +31,7 @@ public class ListDevicesCommand implements LocalCommand {
 
     @Override
     public void handleCommand(final Namespace ns, final Manager m) throws CommandException {
-        final var writer = (PlainTextWriterImpl) outputWriter;
+        final var writer = (PlainTextWriter) outputWriter;
 
         List<Device> devices;
         try {

src/main/java/org/asamk/signal/commands/ListGroupsCommand.java

@@ -5,7 +5,6 @@ import net.sourceforge.argparse4j.inf.Namespace;
 import net.sourceforge.argparse4j.inf.Subparser;
 
 import org.asamk.signal.JsonWriter;
-import org.asamk.signal.OutputType;
 import org.asamk.signal.OutputWriter;
 import org.asamk.signal.PlainTextWriter;
 import org.asamk.signal.commands.exceptions.CommandException;
@@ -19,7 +18,7 @@ import org.slf4j.LoggerFactory;
 import java.util.Set;
 import java.util.stream.Collectors;
 
-public class ListGroupsCommand implements LocalCommand {
+public class ListGroupsCommand implements JsonRpcLocalCommand {
 
     private final static Logger logger = LoggerFactory.getLogger(ListGroupsCommand.class);
 
@@ -70,11 +69,6 @@ public class ListGroupsCommand implements LocalCommand {
         this.outputWriter = outputWriter;
     }
 
-    @Override
-    public Set<OutputType> getSupportedOutputTypes() {
-        return Set.of(OutputType.PLAIN_TEXT, OutputType.JSON);
-    }
-
     @Override
     public void handleCommand(final Namespace ns, final Manager m) throws CommandException {
         final var groups = m.getGroups();

src/main/java/org/asamk/signal/commands/ListIdentitiesCommand.java

@@ -5,7 +5,6 @@ import net.sourceforge.argparse4j.inf.Subparser;
 
 import org.asamk.signal.OutputWriter;
 import org.asamk.signal.PlainTextWriter;
-import org.asamk.signal.PlainTextWriterImpl;
 import org.asamk.signal.commands.exceptions.CommandException;
 import org.asamk.signal.commands.exceptions.UserErrorException;
 import org.asamk.signal.manager.Manager;
@@ -46,7 +45,7 @@ public class ListIdentitiesCommand implements LocalCommand {
 
     @Override
     public void handleCommand(final Namespace ns, final Manager m) throws CommandException {
-        final var writer = (PlainTextWriterImpl) outputWriter;
+        final var writer = (PlainTextWriter) outputWriter;
 
         var number = ns.getString("number");
 

src/main/java/org/asamk/signal/commands/QuitGroupCommand.java

@@ -4,8 +4,9 @@ import net.sourceforge.argparse4j.impl.Arguments;
 import net.sourceforge.argparse4j.inf.Namespace;
 import net.sourceforge.argparse4j.inf.Subparser;
 
+import org.asamk.signal.JsonWriter;
 import org.asamk.signal.OutputWriter;
-import org.asamk.signal.PlainTextWriterImpl;
+import org.asamk.signal.PlainTextWriter;
 import org.asamk.signal.commands.exceptions.CommandException;
 import org.asamk.signal.commands.exceptions.IOErrorException;
 import org.asamk.signal.commands.exceptions.UserErrorException;
@@ -22,11 +23,12 @@ import org.whispersystems.signalservice.api.util.InvalidNumberException;
 
 import java.io.IOException;
 import java.util.HashSet;
+import java.util.Map;
 import java.util.Set;
 
-import static org.asamk.signal.util.ErrorUtils.handleTimestampAndSendMessageResults;
+import static org.asamk.signal.util.ErrorUtils.handleSendMessageResults;
 
-public class QuitGroupCommand implements LocalCommand {
+public class QuitGroupCommand implements JsonRpcLocalCommand {
 
     private final static Logger logger = LoggerFactory.getLogger(QuitGroupCommand.class);
     private final OutputWriter outputWriter;
@@ -37,7 +39,7 @@ public class QuitGroupCommand implements LocalCommand {
 
     public static void attachToSubparser(final Subparser subparser) {
         subparser.help("Send a quit group message to all group members and remove self from member list.");
-        subparser.addArgument("-g", "--group").required(true).help("Specify the recipient group ID.");
+        subparser.addArgument("-g", "--group-id", "--group").required(true).help("Specify the recipient group ID.");
         subparser.addArgument("--delete")
                 .action(Arguments.storeTrue())
                 .help("Delete local group data completely after quitting group.");
@@ -48,11 +50,9 @@ public class QuitGroupCommand implements LocalCommand {
 
     @Override
     public void handleCommand(final Namespace ns, final Manager m) throws CommandException {
-        final var writer = (PlainTextWriterImpl) outputWriter;
-
         final GroupId groupId;
         try {
-            groupId = Util.decodeGroupId(ns.getString("group"));
+            groupId = Util.decodeGroupId(ns.getString("group-id"));
         } catch (GroupIdFormatException e) {
             throw new UserErrorException("Invalid group id: " + e.getMessage());
         }
@@ -63,7 +63,9 @@ public class QuitGroupCommand implements LocalCommand {
             try {
                 final var results = m.sendQuitGroupMessage(groupId,
                         groupAdmins == null ? Set.of() : new HashSet<>(groupAdmins));
-                handleTimestampAndSendMessageResults(writer, results.first(), results.second());
+                final var timestamp = results.first();
+                outputResult(timestamp);
+                handleSendMessageResults(results.second());
             } catch (NotAGroupMemberException e) {
                 logger.info("User is not a group member");
             }
@@ -81,4 +83,14 @@ public class QuitGroupCommand implements LocalCommand {
             throw new UserErrorException("You need to specify a new admin with --admin: " + e.getMessage());
         }
     }
+
+    private void outputResult(final long timestamp) {
+        if (outputWriter instanceof PlainTextWriter) {
+            final var writer = (PlainTextWriter) outputWriter;
+            writer.println("{}", timestamp);
+        } else {
+            final var writer = (JsonWriter) outputWriter;
+            writer.write(Map.of("timestamp", timestamp));
+        }
+    }
 }

src/main/java/org/asamk/signal/commands/ReceiveCommand.java

@@ -10,7 +10,6 @@ import org.asamk.signal.JsonWriter;
 import org.asamk.signal.OutputType;
 import org.asamk.signal.OutputWriter;
 import org.asamk.signal.PlainTextWriter;
-import org.asamk.signal.PlainTextWriterImpl;
 import org.asamk.signal.ReceiveMessageHandler;
 import org.asamk.signal.commands.exceptions.CommandException;
 import org.asamk.signal.commands.exceptions.IOErrorException;
@@ -79,7 +78,7 @@ public class ReceiveCommand implements ExtendedDbusCommand, LocalCommand {
                     jsonWriter.write(object);
                 });
             } else {
-                final var writer = (PlainTextWriterImpl) outputWriter;
+                final var writer = (PlainTextWriter) outputWriter;
 
                 dbusconnection.addSigHandler(Signal.MessageReceived.class, signal, messageReceived -> {
                     writer.println("Envelope from: {}", messageReceived.getSender());
@@ -156,6 +155,7 @@ public class ReceiveCommand implements ExtendedDbusCommand, LocalCommand {
                     handler);
         } catch (IOException e) {
             throw new IOErrorException("Error while receiving messages: " + e.getMessage());
+        } catch (InterruptedException ignored) {
         }
     }
 }

src/main/java/org/asamk/signal/commands/RemoteDeleteCommand.java

@@ -4,19 +4,23 @@ import net.sourceforge.argparse4j.inf.Namespace;
 import net.sourceforge.argparse4j.inf.Subparser;
 
 import org.asamk.Signal;
+import org.asamk.signal.JsonWriter;
 import org.asamk.signal.OutputWriter;
-import org.asamk.signal.PlainTextWriterImpl;
+import org.asamk.signal.PlainTextWriter;
 import org.asamk.signal.commands.exceptions.CommandException;
 import org.asamk.signal.commands.exceptions.UnexpectedErrorException;
 import org.asamk.signal.commands.exceptions.UserErrorException;
+import org.asamk.signal.dbus.DbusSignalImpl;
+import org.asamk.signal.manager.Manager;
 import org.asamk.signal.manager.groups.GroupIdFormatException;
 import org.asamk.signal.util.Util;
 import org.freedesktop.dbus.errors.UnknownObject;
 import org.freedesktop.dbus.exceptions.DBusExecutionException;
 
 import java.util.List;
+import java.util.Map;
 
-public class RemoteDeleteCommand implements DbusCommand {
+public class RemoteDeleteCommand implements DbusCommand, JsonRpcLocalCommand {
 
     private final OutputWriter outputWriter;
 
@@ -30,14 +34,14 @@ public class RemoteDeleteCommand implements DbusCommand {
                 .required(true)
                 .type(long.class)
                 .help("Specify the timestamp of the message to delete.");
-        subparser.addArgument("-g", "--group").help("Specify the recipient group ID.");
+        subparser.addArgument("-g", "--group-id", "--group").help("Specify the recipient group ID.");
         subparser.addArgument("recipient").help("Specify the recipients' phone number.").nargs("*");
     }
 
     @Override
     public void handleCommand(final Namespace ns, final Signal signal) throws CommandException {
         final List<String> recipients = ns.getList("recipient");
-        final var groupIdString = ns.getString("group");
+        final var groupIdString = ns.getString("group-id");
 
         final var noRecipients = recipients == null || recipients.isEmpty();
         if (noRecipients && groupIdString == null) {
@@ -49,8 +53,6 @@ public class RemoteDeleteCommand implements DbusCommand {
 
         final long targetTimestamp = ns.getLong("target-timestamp");
 
-        final var writer = (PlainTextWriterImpl) outputWriter;
-
         byte[] groupId = null;
         if (groupIdString != null) {
             try {
@@ -67,7 +69,7 @@ public class RemoteDeleteCommand implements DbusCommand {
             } else {
                 timestamp = signal.sendRemoteDeleteMessage(targetTimestamp, recipients);
             }
-            writer.println("{}", timestamp);
+            outputResult(timestamp);
         } catch (UnknownObject e) {
             throw new UserErrorException("Failed to find dbus object, maybe missing the -u flag: " + e.getMessage());
         } catch (Signal.Error.InvalidNumber e) {
@@ -78,4 +80,19 @@ public class RemoteDeleteCommand implements DbusCommand {
             throw new UnexpectedErrorException("Failed to send message: " + e.getMessage());
         }
     }
+
+    @Override
+    public void handleCommand(final Namespace ns, final Manager m) throws CommandException {
+        handleCommand(ns, new DbusSignalImpl(m, null));
+    }
+
+    private void outputResult(final long timestamp) {
+        if (outputWriter instanceof PlainTextWriter) {
+            final var writer = (PlainTextWriter) outputWriter;
+            writer.println("{}", timestamp);
+        } else {
+            final var writer = (JsonWriter) outputWriter;
+            writer.write(Map.of("timestamp", timestamp));
+        }
+    }
 }

src/main/java/org/asamk/signal/commands/RemoveDeviceCommand.java

@@ -10,7 +10,7 @@ import org.asamk.signal.manager.Manager;
 
 import java.io.IOException;
 
-public class RemoveDeviceCommand implements LocalCommand {
+public class RemoveDeviceCommand implements JsonRpcLocalCommand {
 
     public RemoveDeviceCommand(final OutputWriter outputWriter) {
     }

src/main/java/org/asamk/signal/commands/RemovePinCommand.java

@@ -13,7 +13,7 @@ import org.whispersystems.signalservice.internal.contacts.crypto.Unauthenticated
 
 import java.io.IOException;
 
-public class RemovePinCommand implements LocalCommand {
+public class RemovePinCommand implements JsonRpcLocalCommand {
 
     public RemovePinCommand(final OutputWriter outputWriter) {
     }

src/main/java/org/asamk/signal/commands/SendCommand.java

@@ -5,14 +5,16 @@ import net.sourceforge.argparse4j.inf.Namespace;
 import net.sourceforge.argparse4j.inf.Subparser;
 
 import org.asamk.Signal;
+import org.asamk.signal.JsonWriter;
 import org.asamk.signal.OutputWriter;
-import org.asamk.signal.PlainTextWriterImpl;
+import org.asamk.signal.PlainTextWriter;
 import org.asamk.signal.commands.exceptions.CommandException;
 import org.asamk.signal.commands.exceptions.UnexpectedErrorException;
 import org.asamk.signal.commands.exceptions.UntrustedKeyErrorException;
 import org.asamk.signal.commands.exceptions.UserErrorException;
 import org.asamk.signal.dbus.DbusAttachment;
-
+import org.asamk.signal.dbus.DbusSignalImpl;
+import org.asamk.signal.manager.Manager;
 import org.asamk.signal.manager.groups.GroupIdFormatException;
 import org.asamk.signal.util.IOUtils;
 import org.asamk.signal.util.Util;
@@ -26,8 +28,9 @@ import java.io.IOException;
 import java.nio.charset.Charset;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 
-public class SendCommand implements DbusCommand {
+public class SendCommand implements DbusCommand, JsonRpcLocalCommand {
 
     private final static Logger logger = LoggerFactory.getLogger(SendCommand.class);
     private final OutputWriter outputWriter;
@@ -40,14 +43,14 @@ public class SendCommand implements DbusCommand {
         subparser.help("Send a message to another user or group.");
         subparser.addArgument("recipient").help("Specify the recipients' phone number.").nargs("*");
         final var mutuallyExclusiveGroup = subparser.addMutuallyExclusiveGroup();
-        mutuallyExclusiveGroup.addArgument("-g", "--group").help("Specify the recipient group ID.");
+        mutuallyExclusiveGroup.addArgument("-g", "--group-id", "--group").help("Specify the recipient group ID.");
         mutuallyExclusiveGroup.addArgument("--note-to-self")
                 .help("Send the message to self without notification.")
                 .action(Arguments.storeTrue());
 
         subparser.addArgument("-m", "--message").help("Specify the message, if missing standard input is used.");
         subparser.addArgument("-a", "--attachment").nargs("*").help("Add file as attachment");
-        subparser.addArgument("-e", "--endsession")
+        subparser.addArgument("-e", "--end-session", "--endsession")
                 .help("Clear session state and send end session message.")
                 .action(Arguments.storeTrue());
     }
@@ -55,8 +58,8 @@ public class SendCommand implements DbusCommand {
     @Override
     public void handleCommand(final Namespace ns, final Signal signal) throws CommandException {
         final List<String> recipients = ns.getList("recipient");
-        final var isEndSession = ns.getBoolean("endsession");
+        final var isEndSession = ns.getBoolean("end-session");
-        final var groupIdString = ns.getString("group");
+        final var groupIdString = ns.getString("group-id");
         final var isNoteToSelf = ns.getBoolean("note-to-self");
 
         final var noRecipients = recipients == null || recipients.isEmpty();
@@ -96,8 +99,6 @@ public class SendCommand implements DbusCommand {
             attachmentNames = List.of();
         }
 
-        final var writer = (PlainTextWriterImpl) outputWriter;
-
         ArrayList<DbusAttachment> dBusAttachments = new ArrayList<>();
         if (!attachmentNames.isEmpty()) {
             for (var attachmentName : attachmentNames) {
@@ -116,7 +117,7 @@ public class SendCommand implements DbusCommand {
 
             try {
                 var timestamp = signal.sendGroupMessage(messageText, attachmentNames, groupId);
-                writer.println("{}", timestamp);
+                outputResult(timestamp);
                 return;
             } catch (DBusExecutionException e) {
                 throw new UnexpectedErrorException("Failed to send group message: " + e.getMessage());
@@ -126,7 +127,7 @@ public class SendCommand implements DbusCommand {
         if (isNoteToSelf) {
             try {
                 var timestamp = signal.sendNoteToSelfMessage(messageText, attachmentNames);
-                writer.println("{}", timestamp);
+                outputResult(timestamp);
                 return;
             } catch (Signal.Error.UntrustedIdentity e) {
                 throw new UntrustedKeyErrorException("Failed to send note to self message: " + e.getMessage());
@@ -137,8 +138,7 @@ public class SendCommand implements DbusCommand {
 
         try {
             var timestamp = signal.sendMessageWithDBusAttachments(messageText, dBusAttachments, recipients);
-            writer.println("{}", timestamp);
+            outputResult(timestamp);
-
         } catch (UnknownObject e) {
             throw new UserErrorException("Failed to find dbus object, maybe missing the -u flag: " + e.getMessage());
         } catch (Signal.Error.UntrustedIdentity e) {
@@ -147,4 +147,19 @@ public class SendCommand implements DbusCommand {
             throw new UnexpectedErrorException("Failed to send message, did not find attachment: " + e.getMessage());
         }
     }
+
+    private void outputResult(final long timestamp) {
+        if (outputWriter instanceof PlainTextWriter) {
+            final var writer = (PlainTextWriter) outputWriter;
+            writer.println("{}", timestamp);
+        } else {
+            final var writer = (JsonWriter) outputWriter;
+            writer.write(Map.of("timestamp", timestamp));
+        }
+    }
+
+    @Override
+    public void handleCommand(final Namespace ns, final Manager m) throws CommandException {
+        handleCommand(ns, new DbusSignalImpl(m, null));
+    }
 }

src/main/java/org/asamk/signal/commands/SendContactsCommand.java

@@ -12,7 +12,7 @@ import org.whispersystems.signalservice.api.crypto.UntrustedIdentityException;
 
 import java.io.IOException;
 
-public class SendContactsCommand implements LocalCommand {
+public class SendContactsCommand implements JsonRpcLocalCommand {
 
     public SendContactsCommand(final OutputWriter outputWriter) {
     }

src/main/java/org/asamk/signal/commands/SendReactionCommand.java

@@ -5,19 +5,23 @@ import net.sourceforge.argparse4j.inf.Namespace;
 import net.sourceforge.argparse4j.inf.Subparser;
 
 import org.asamk.Signal;
+import org.asamk.signal.JsonWriter;
 import org.asamk.signal.OutputWriter;
-import org.asamk.signal.PlainTextWriterImpl;
+import org.asamk.signal.PlainTextWriter;
 import org.asamk.signal.commands.exceptions.CommandException;
 import org.asamk.signal.commands.exceptions.UnexpectedErrorException;
 import org.asamk.signal.commands.exceptions.UserErrorException;
+import org.asamk.signal.dbus.DbusSignalImpl;
+import org.asamk.signal.manager.Manager;
 import org.asamk.signal.manager.groups.GroupIdFormatException;
 import org.asamk.signal.util.Util;
 import org.freedesktop.dbus.errors.UnknownObject;
 import org.freedesktop.dbus.exceptions.DBusExecutionException;
 
 import java.util.List;
+import java.util.Map;
 
-public class SendReactionCommand implements DbusCommand {
+public class SendReactionCommand implements DbusCommand, JsonRpcLocalCommand {
 
     private final OutputWriter outputWriter;
 
@@ -27,7 +31,7 @@ public class SendReactionCommand implements DbusCommand {
 
     public static void attachToSubparser(final Subparser subparser) {
         subparser.help("Send reaction to a previously received or sent message.");
-        subparser.addArgument("-g", "--group").help("Specify the recipient group ID.");
+        subparser.addArgument("-g", "--group-id", "--group").help("Specify the recipient group ID.");
         subparser.addArgument("recipient").help("Specify the recipients' phone number.").nargs("*");
         subparser.addArgument("-e", "--emoji")
                 .required(true)
@@ -45,7 +49,7 @@ public class SendReactionCommand implements DbusCommand {
     @Override
     public void handleCommand(final Namespace ns, final Signal signal) throws CommandException {
         final List<String> recipients = ns.getList("recipient");
-        final var groupIdString = ns.getString("group");
+        final var groupIdString = ns.getString("group-id");
 
         final var noRecipients = recipients == null || recipients.isEmpty();
         if (noRecipients && groupIdString == null) {
@@ -60,8 +64,6 @@ public class SendReactionCommand implements DbusCommand {
         final var targetAuthor = ns.getString("target-author");
         final long targetTimestamp = ns.getLong("target-timestamp");
 
-        final var writer = (PlainTextWriterImpl) outputWriter;
-
         byte[] groupId = null;
         if (groupIdString != null) {
             try {
@@ -78,7 +80,7 @@ public class SendReactionCommand implements DbusCommand {
             } else {
                 timestamp = signal.sendMessageReaction(emoji, isRemove, targetAuthor, targetTimestamp, recipients);
             }
-            writer.println("{}", timestamp);
+            outputResult(timestamp);
         } catch (UnknownObject e) {
             throw new UserErrorException("Failed to find dbus object, maybe missing the -u flag: " + e.getMessage());
         } catch (Signal.Error.InvalidNumber e) {
@@ -89,4 +91,19 @@ public class SendReactionCommand implements DbusCommand {
             throw new UnexpectedErrorException("Failed to send message: " + e.getMessage());
         }
     }
+
+    @Override
+    public void handleCommand(final Namespace ns, final Manager m) throws CommandException {
+        handleCommand(ns, new DbusSignalImpl(m, null));
+    }
+
+    private void outputResult(final long timestamp) {
+        if (outputWriter instanceof PlainTextWriter) {
+            final var writer = (PlainTextWriter) outputWriter;
+            writer.println("{}", timestamp);
+        } else {
+            final var writer = (JsonWriter) outputWriter;
+            writer.write(Map.of("timestamp", timestamp));
+        }
+    }
 }

src/main/java/org/asamk/signal/commands/SendSyncRequestCommand.java

@@ -10,7 +10,7 @@ import org.asamk.signal.manager.Manager;
 
 import java.io.IOException;
 
-public class SendSyncRequestCommand implements LocalCommand {
+public class SendSyncRequestCommand implements JsonRpcLocalCommand {
 
     public SendSyncRequestCommand(final OutputWriter outputWriter) {
     }

src/main/java/org/asamk/signal/commands/SendTypingCommand.java

@@ -20,7 +20,7 @@ import org.whispersystems.signalservice.api.util.InvalidNumberException;
 import java.io.IOException;
 import java.util.HashSet;
 
-public class SendTypingCommand implements LocalCommand {
+public class SendTypingCommand implements JsonRpcLocalCommand {
 
     public SendTypingCommand(final OutputWriter outputWriter) {
     }
@@ -28,7 +28,7 @@ public class SendTypingCommand implements LocalCommand {
     public static void attachToSubparser(final Subparser subparser) {
         subparser.help(
                 "Send typing message to trigger a typing indicator for the recipient. Indicator will be shown for 15seconds unless a typing STOP message is sent first.");
-        subparser.addArgument("-g", "--group").help("Specify the recipient group ID.");
+        subparser.addArgument("-g", "--group-id", "--group").help("Specify the recipient group ID.");
         subparser.addArgument("recipient").help("Specify the recipients' phone number.").nargs("*");
         subparser.addArgument("-s", "--stop").help("Send a typing STOP message.").action(Arguments.storeTrue());
     }
@@ -36,7 +36,7 @@ public class SendTypingCommand implements LocalCommand {
     @Override
     public void handleCommand(final Namespace ns, final Manager m) throws CommandException {
         final var recipients = ns.<String>getList("recipient");
-        final var groupIdString = ns.getString("group");
+        final var groupIdString = ns.getString("group-id");
 
         final var noRecipients = recipients == null || recipients.isEmpty();
         if (noRecipients && groupIdString == null) {

src/main/java/org/asamk/signal/commands/SetPinCommand.java

@@ -13,21 +13,21 @@ import org.whispersystems.signalservice.internal.contacts.crypto.Unauthenticated
 
 import java.io.IOException;
 
-public class SetPinCommand implements LocalCommand {
+public class SetPinCommand implements JsonRpcLocalCommand {
 
     public SetPinCommand(final OutputWriter outputWriter) {
     }
 
     public static void attachToSubparser(final Subparser subparser) {
         subparser.help("Set a registration lock pin, to prevent others from registering this number.");
-        subparser.addArgument("registrationLockPin")
+        subparser.addArgument("pin")
                 .help("The registration lock PIN, that will be required for new registrations (resets after 7 days of inactivity)");
     }
 
     @Override
     public void handleCommand(final Namespace ns, final Manager m) throws CommandException {
         try {
-            var registrationLockPin = ns.getString("registrationLockPin");
+            var registrationLockPin = ns.getString("pin");
             m.setRegistrationLockPin(Optional.of(registrationLockPin));
         } catch (UnauthenticatedResponseException e) {
             throw new UnexpectedErrorException("Set pin error failed with unauthenticated response: " + e.getMessage());

src/main/java/org/asamk/signal/commands/TrustCommand.java

@@ -13,7 +13,7 @@ import org.whispersystems.signalservice.api.util.InvalidNumberException;
 
 import java.util.Locale;
 
-public class TrustCommand implements LocalCommand {
+public class TrustCommand implements JsonRpcLocalCommand {
 
     public TrustCommand(final OutputWriter outputWriter) {
     }

src/main/java/org/asamk/signal/commands/UnblockCommand.java

@@ -15,7 +15,7 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.whispersystems.signalservice.api.util.InvalidNumberException;
 
-public class UnblockCommand implements LocalCommand {
+public class UnblockCommand implements JsonRpcLocalCommand {
 
     private final static Logger logger = LoggerFactory.getLogger(UnblockCommand.class);
 
@@ -25,7 +25,7 @@ public class UnblockCommand implements LocalCommand {
     public static void attachToSubparser(final Subparser subparser) {
         subparser.help("Unblock the given contacts or groups (messages will be received again)");
         subparser.addArgument("contact").help("Contact number").nargs("*");
-        subparser.addArgument("-g", "--group").help("Group ID").nargs("*");
+        subparser.addArgument("-g", "--group-id", "--group").help("Group ID").nargs("*");
     }
 
     @Override
@@ -40,8 +40,8 @@ public class UnblockCommand implements LocalCommand {
             }
         }
 
-        if (ns.<String>getList("group") != null) {
+        if (ns.<String>getList("group-id") != null) {
-            for (var groupIdString : ns.<String>getList("group")) {
+            for (var groupIdString : ns.<String>getList("group-id")) {
                 try {
                     var groupId = Util.decodeGroupId(groupIdString);
                     m.setGroupBlocked(groupId, false);

src/main/java/org/asamk/signal/commands/UnregisterCommand.java

@@ -32,7 +32,6 @@ public class UnregisterCommand implements LocalCommand {
                 m.unregister();
             }
         } catch (IOException e) {
-            e.printStackTrace();
             throw new IOErrorException("Unregister error: " + e.getMessage());
         }
     }

src/main/java/org/asamk/signal/commands/UpdateAccountCommand.java

@@ -10,7 +10,7 @@ import org.asamk.signal.manager.Manager;
 
 import java.io.IOException;
 
-public class UpdateAccountCommand implements LocalCommand {
+public class UpdateAccountCommand implements JsonRpcLocalCommand {
 
     public UpdateAccountCommand(final OutputWriter outputWriter) {
     }

src/main/java/org/asamk/signal/commands/UpdateContactCommand.java

@@ -13,7 +13,7 @@ import org.whispersystems.signalservice.api.util.InvalidNumberException;
 
 import java.io.IOException;
 
-public class UpdateContactCommand implements LocalCommand {
+public class UpdateContactCommand implements JsonRpcLocalCommand {
 
     public UpdateContactCommand(final OutputWriter outputWriter) {
     }

src/main/java/org/asamk/signal/commands/UpdateGroupCommand.java

@@ -5,10 +5,9 @@ import net.sourceforge.argparse4j.inf.Namespace;
 import net.sourceforge.argparse4j.inf.Subparser;
 
 import org.asamk.Signal;
-import org.asamk.signal.GroupLinkState;
+import org.asamk.signal.JsonWriter;
-import org.asamk.signal.GroupPermission;
 import org.asamk.signal.OutputWriter;
-import org.asamk.signal.PlainTextWriterImpl;
+import org.asamk.signal.PlainTextWriter;
 import org.asamk.signal.commands.exceptions.CommandException;
 import org.asamk.signal.commands.exceptions.UnexpectedErrorException;
 import org.asamk.signal.commands.exceptions.UserErrorException;
@@ -16,7 +15,9 @@ import org.asamk.signal.manager.AttachmentInvalidException;
 import org.asamk.signal.manager.Manager;
 import org.asamk.signal.manager.groups.GroupId;
 import org.asamk.signal.manager.groups.GroupIdFormatException;
+import org.asamk.signal.manager.groups.GroupLinkState;
 import org.asamk.signal.manager.groups.GroupNotFoundException;
+import org.asamk.signal.manager.groups.GroupPermission;
 import org.asamk.signal.manager.groups.NotAGroupMemberException;
 import org.asamk.signal.util.ErrorUtils;
 import org.asamk.signal.util.Util;
@@ -28,10 +29,10 @@ import org.whispersystems.signalservice.api.util.InvalidNumberException;
 import java.io.File;
 import java.io.IOException;
 import java.util.ArrayList;
-import java.util.Base64;
+import java.util.HashMap;
 import java.util.List;
 
-public class UpdateGroupCommand implements DbusCommand, LocalCommand {
+public class UpdateGroupCommand implements DbusCommand, JsonRpcLocalCommand {
 
     private final static Logger logger = LoggerFactory.getLogger(UpdateGroupCommand.class);
     private final OutputWriter outputWriter;
@@ -42,7 +43,7 @@ public class UpdateGroupCommand implements DbusCommand, LocalCommand {
 
     public static void attachToSubparser(final Subparser subparser) {
         subparser.help("Create or update a group.");
-        subparser.addArgument("-g", "--group").help("Specify the recipient group ID.");
+        subparser.addArgument("-g", "--group-id", "--group").help("Specify the group ID.");
         subparser.addArgument("-n", "--name").help("Specify the new group name.");
         subparser.addArgument("-d", "--description").help("Specify the new group description.");
         subparser.addArgument("-a", "--avatar").help("Specify a new group avatar image file");
@@ -60,23 +61,55 @@ public class UpdateGroupCommand implements DbusCommand, LocalCommand {
                 .help("Reset group link and create new link password");
         subparser.addArgument("--link")
                 .help("Set group link state, with or without admin approval")
-                .type(Arguments.enumStringType(GroupLinkState.class));
+                .choices("enabled", "enabled-with-approval", "disabled");
 
         subparser.addArgument("--set-permission-add-member")
                 .help("Set permission to add new group members")
-                .type(Arguments.enumStringType(GroupPermission.class));
+                .choices("every-member", "only-admins");
         subparser.addArgument("--set-permission-edit-details")
                 .help("Set permission to edit group details")
-                .type(Arguments.enumStringType(GroupPermission.class));
+                .choices("every-member", "only-admins");
 
         subparser.addArgument("-e", "--expiration").type(int.class).help("Set expiration time of messages (seconds)");
     }
 
+    GroupLinkState getGroupLinkState(String value) throws UserErrorException {
+        if (value == null) {
+            return null;
+        }
+        switch (value) {
+            case "enabled":
+                return GroupLinkState.ENABLED;
+            case "enabled-with-approval":
+            case "enabledWithApproval":
+                return GroupLinkState.ENABLED_WITH_APPROVAL;
+            case "disabled":
+                return GroupLinkState.DISABLED;
+            default:
+                throw new UserErrorException("Invalid group link state: " + value);
+        }
+    }
+
+    GroupPermission getGroupPermission(String value) throws UserErrorException {
+        if (value == null) {
+            return null;
+        }
+        switch (value) {
+            case "every-member":
+            case "everyMember":
+                return GroupPermission.EVERY_MEMBER;
+            case "only-admins":
+            case "onlyAdmins":
+                return GroupPermission.ONLY_ADMINS;
+            default:
+                throw new UserErrorException("Invalid group permission: " + value);
+        }
+    }
+
     @Override
     public void handleCommand(final Namespace ns, final Manager m) throws CommandException {
-        final var writer = (PlainTextWriterImpl) outputWriter;
         GroupId groupId = null;
-        final var groupIdString = ns.getString("group");
+        final var groupIdString = ns.getString("group-id");
         if (groupIdString != null) {
             try {
                 groupId = Util.decodeGroupId(groupIdString);
@@ -93,19 +126,20 @@ public class UpdateGroupCommand implements DbusCommand, LocalCommand {
         var groupRemoveAdmins = ns.<String>getList("remove-admin");
         var groupAvatar = ns.getString("avatar");
         var groupResetLink = ns.getBoolean("reset-link");
-        var groupLinkState = ns.<GroupLinkState>get("link");
+        var groupLinkState = getGroupLinkState(ns.getString("link"));
         var groupExpiration = ns.getInt("expiration");
-        var groupAddMemberPermission = ns.<GroupPermission>get("set-permission-add-member");
+        var groupAddMemberPermission = getGroupPermission(ns.getString("set-permission-add-member"));
-        var groupEditDetailsPermission = ns.<GroupPermission>get("set-permission-edit-details");
+        var groupEditDetailsPermission = getGroupPermission(ns.getString("set-permission-edit-details"));
 
         try {
+            boolean isNewGroup = false;
             if (groupId == null) {
+                isNewGroup = true;
                 var results = m.createGroup(groupName,
                         groupMembers,
                         groupAvatar == null ? null : new File(groupAvatar));
-                ErrorUtils.handleTimestampAndSendMessageResults(writer, 0, results.second());
+                ErrorUtils.handleSendMessageResults(results.second());
                 groupId = results.first();
-                writer.println("Created new group: \"{}\"", groupId.toBase64());
                 groupName = null;
                 groupMembers = null;
                 groupAvatar = null;
@@ -119,14 +153,17 @@ public class UpdateGroupCommand implements DbusCommand, LocalCommand {
                     groupAdmins,
                     groupRemoveAdmins,
                     groupResetLink,
-                    groupLinkState != null ? groupLinkState.toLinkState() : null,
+                    groupLinkState,
-                    groupAddMemberPermission != null ? groupAddMemberPermission.toManager() : null,
+                    groupAddMemberPermission,
-                    groupEditDetailsPermission != null ? groupEditDetailsPermission.toManager() : null,
+                    groupEditDetailsPermission,
                     groupAvatar == null ? null : new File(groupAvatar),
                     groupExpiration);
+            Long timestamp = null;
             if (results != null) {
-                ErrorUtils.handleTimestampAndSendMessageResults(writer, results.first(), results.second());
+                timestamp = results.first();
+                ErrorUtils.handleSendMessageResults(results.second());
             }
+            outputResult(timestamp, isNewGroup ? groupId : null);
         } catch (AttachmentInvalidException e) {
             throw new UserErrorException("Failed to add avatar attachment for group\": " + e.getMessage());
         } catch (GroupNotFoundException e) {
@@ -142,11 +179,10 @@ public class UpdateGroupCommand implements DbusCommand, LocalCommand {
 
     @Override
     public void handleCommand(final Namespace ns, final Signal signal) throws CommandException {
-        final var writer = (PlainTextWriterImpl) outputWriter;
         byte[] groupId = null;
-        if (ns.getString("group") != null) {
+        if (ns.getString("group-id") != null) {
             try {
-                groupId = Util.decodeGroupId(ns.getString("group")).serialize();
+                groupId = Util.decodeGroupId(ns.getString("group-id")).serialize();
             } catch (GroupIdFormatException e) {
                 throw new UserErrorException("Invalid group id: " + e.getMessage());
             }
@@ -173,7 +209,7 @@ public class UpdateGroupCommand implements DbusCommand, LocalCommand {
         try {
             var newGroupId = signal.updateGroup(groupId, groupName, groupMembers, groupAvatar);
             if (groupId.length != newGroupId.length) {
-                writer.println("Created new group: \"{}\"", Base64.getEncoder().encodeToString(newGroupId));
+                outputResult(null, GroupId.unknownVersion(newGroupId));
             }
         } catch (Signal.Error.AttachmentInvalid e) {
             throw new UserErrorException("Failed to add avatar attachment for group\": " + e.getMessage());
@@ -181,4 +217,26 @@ public class UpdateGroupCommand implements DbusCommand, LocalCommand {
             throw new UnexpectedErrorException("Failed to send message: " + e.getMessage());
         }
     }
+
+    private void outputResult(final Long timestamp, final GroupId groupId) {
+        if (outputWriter instanceof PlainTextWriter) {
+            final var writer = (PlainTextWriter) outputWriter;
+            if (groupId != null) {
+                writer.println("Created new group: \"{}\"", groupId.toBase64());
+            }
+            if (timestamp != null) {
+                writer.println("{}", timestamp);
+            }
+        } else {
+            final var writer = (JsonWriter) outputWriter;
+            final var result = new HashMap<>();
+            if (timestamp != null) {
+                result.put("timestamp", timestamp);
+            }
+            if (groupId != null) {
+                result.put("groupId", groupId.toBase64());
+            }
+            writer.write(result);
+        }
+    }
 }

src/main/java/org/asamk/signal/commands/UpdateProfileCommand.java

@@ -13,7 +13,7 @@ import org.whispersystems.libsignal.util.guava.Optional;
 import java.io.File;
 import java.io.IOException;
 
-public class UpdateProfileCommand implements LocalCommand {
+public class UpdateProfileCommand implements JsonRpcLocalCommand {
 
     public UpdateProfileCommand(final OutputWriter outputWriter) {
     }

src/main/java/org/asamk/signal/commands/UploadStickerPackCommand.java

@@ -4,7 +4,7 @@ import net.sourceforge.argparse4j.inf.Namespace;
 import net.sourceforge.argparse4j.inf.Subparser;
 
 import org.asamk.signal.OutputWriter;
-import org.asamk.signal.PlainTextWriterImpl;
+import org.asamk.signal.PlainTextWriter;
 import org.asamk.signal.commands.exceptions.CommandException;
 import org.asamk.signal.commands.exceptions.IOErrorException;
 import org.asamk.signal.commands.exceptions.UserErrorException;
@@ -33,7 +33,7 @@ public class UploadStickerPackCommand implements LocalCommand {
 
     @Override
     public void handleCommand(final Namespace ns, final Manager m) throws CommandException {
-        final var writer = (PlainTextWriterImpl) outputWriter;
+        final var writer = (PlainTextWriter) outputWriter;
         var path = new File(ns.getString("path"));
 
         try {

src/main/java/org/asamk/signal/commands/VersionCommand.java

@@ -0,0 +1,24 @@
+package org.asamk.signal.commands;
+
+import org.asamk.signal.BaseConfig;
+import org.asamk.signal.JsonWriter;
+import org.asamk.signal.OutputWriter;
+import org.asamk.signal.commands.exceptions.CommandException;
+import org.asamk.signal.manager.Manager;
+
+import java.util.Map;
+
+public class VersionCommand implements JsonRpcCommand<Void> {
+
+    private final OutputWriter outputWriter;
+
+    public VersionCommand(final OutputWriter outputWriter) {
+        this.outputWriter = outputWriter;
+    }
+
+    @Override
+    public void handleCommand(final Void request, final Manager m) throws CommandException {
+        final var jsonWriter = (JsonWriter) outputWriter;
+        jsonWriter.write(Map.of("version", BaseConfig.PROJECT_VERSION));
+    }
+}

src/main/java/org/asamk/signal/jsonrpc/JsonRpcBulkMessage.java

@@ -0,0 +1,18 @@
+package org.asamk.signal.jsonrpc;
+
+import com.fasterxml.jackson.databind.JsonNode;
+
+import java.util.List;
+
+public class JsonRpcBulkMessage extends JsonRpcMessage {
+
+    List<JsonNode> messages;
+
+    public JsonRpcBulkMessage(final List<JsonNode> messages) {
+        this.messages = messages;
+    }
+
+    public List<JsonNode> getMessages() {
+        return messages;
+    }
+}

src/main/java/org/asamk/signal/jsonrpc/JsonRpcException.java

@@ -0,0 +1,14 @@
+package org.asamk.signal.jsonrpc;
+
+public class JsonRpcException extends Exception {
+
+    private final JsonRpcResponse.Error error;
+
+    public JsonRpcException(final JsonRpcResponse.Error error) {
+        this.error = error;
+    }
+
+    public JsonRpcResponse.Error getError() {
+        return error;
+    }
+}

src/main/java/org/asamk/signal/jsonrpc/JsonRpcMessage.java

@@ -0,0 +1,9 @@
+package org.asamk.signal.jsonrpc;
+
+/**
+ * Represents a JSON-RPC (bulk) request or (bulk) response.
+ * https://www.jsonrpc.org/specification
+ */
+public abstract class JsonRpcMessage {
+
+}

src/main/java/org/asamk/signal/jsonrpc/JsonRpcReader.java

@@ -0,0 +1,216 @@
+package org.asamk.signal.jsonrpc;
+
+import com.fasterxml.jackson.core.JsonParseException;
+import com.fasterxml.jackson.databind.JsonMappingException;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ContainerNode;
+import com.fasterxml.jackson.databind.node.ValueNode;
+
+import org.asamk.signal.util.Util;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.io.IOException;
+import java.util.Objects;
+import java.util.function.Consumer;
+import java.util.function.Supplier;
+import java.util.stream.Collectors;
+import java.util.stream.StreamSupport;
+
+public class JsonRpcReader {
+
+    private final static Logger logger = LoggerFactory.getLogger(JsonRpcReader.class);
+
+    private final JsonRpcSender jsonRpcSender;
+    private final ObjectMapper objectMapper;
+    private final Supplier<String> lineSupplier;
+
+    public JsonRpcReader(
+            final JsonRpcSender jsonRpcSender, final Supplier<String> lineSupplier
+    ) {
+        this.jsonRpcSender = jsonRpcSender;
+        this.lineSupplier = lineSupplier;
+        this.objectMapper = Util.createJsonObjectMapper();
+    }
+
+    public void readRequests(
+            final RequestHandler requestHandler, final Consumer<JsonRpcResponse> responseHandler
+    ) {
+        while (!Thread.interrupted()) {
+            JsonRpcMessage message = readMessage();
+            if (message == null) break;
+
+            if (message instanceof JsonRpcRequest) {
+                final var response = handleRequest(requestHandler, (JsonRpcRequest) message);
+                if (response != null) {
+                    jsonRpcSender.sendResponse(response);
+                }
+            } else if (message instanceof JsonRpcResponse) {
+                responseHandler.accept((JsonRpcResponse) message);
+            } else {
+                final var responseList = ((JsonRpcBulkMessage) message).getMessages().stream().map(jsonNode -> {
+                    final JsonRpcRequest request;
+                    try {
+                        request = parseJsonRpcRequest(jsonNode);
+                    } catch (JsonRpcException e) {
+                        return JsonRpcResponse.forError(e.getError(), getId(jsonNode));
+                    }
+
+                    return handleRequest(requestHandler, request);
+                }).filter(Objects::nonNull).collect(Collectors.toList());
+
+                jsonRpcSender.sendBulkResponses(responseList);
+            }
+        }
+    }
+
+    private JsonRpcResponse handleRequest(final RequestHandler requestHandler, final JsonRpcRequest request) {
+        try {
+            final var result = requestHandler.apply(request.getMethod(), request.getParams());
+            if (request.getId() != null) {
+                return JsonRpcResponse.forSuccess(result, request.getId());
+            }
+        } catch (JsonRpcException e) {
+            if (request.getId() != null) {
+                return JsonRpcResponse.forError(e.getError(), request.getId());
+            }
+        }
+        return null;
+    }
+
+    private JsonRpcMessage readMessage() {
+        while (!Thread.interrupted()) {
+            String input = lineSupplier.get();
+
+            if (input == null) {
+                // Reached end of input stream
+                break;
+            }
+
+            JsonRpcMessage message = parseJsonRpcMessage(input);
+            if (message == null) continue;
+
+            return message;
+        }
+
+        return null;
+    }
+
+    private JsonRpcMessage parseJsonRpcMessage(final String input) {
+        final JsonNode jsonNode;
+        try {
+            jsonNode = objectMapper.readTree(input);
+        } catch (JsonParseException e) {
+            jsonRpcSender.sendResponse(JsonRpcResponse.forError(new JsonRpcResponse.Error(JsonRpcResponse.Error.PARSE_ERROR,
+                    e.getMessage(),
+                    null), null));
+            return null;
+        } catch (IOException e) {
+            throw new AssertionError(e);
+        }
+
+        if (jsonNode == null) {
+            jsonRpcSender.sendResponse(JsonRpcResponse.forError(new JsonRpcResponse.Error(JsonRpcResponse.Error.INVALID_REQUEST,
+                    "invalid request",
+                    null), null));
+            return null;
+        } else if (jsonNode.isArray()) {
+            if (jsonNode.size() == 0) {
+                jsonRpcSender.sendResponse(JsonRpcResponse.forError(new JsonRpcResponse.Error(JsonRpcResponse.Error.INVALID_REQUEST,
+                        "invalid request",
+                        null), null));
+                return null;
+            }
+            return new JsonRpcBulkMessage(StreamSupport.stream(jsonNode.spliterator(), false)
+                    .collect(Collectors.toList()));
+        } else if (jsonNode.isObject()) {
+            if (jsonNode.has("result") || jsonNode.has("error")) {
+                return parseJsonRpcResponse(jsonNode);
+            } else {
+                try {
+                    return parseJsonRpcRequest(jsonNode);
+                } catch (JsonRpcException e) {
+                    jsonRpcSender.sendResponse(JsonRpcResponse.forError(e.getError(), getId(jsonNode)));
+                    return null;
+                }
+            }
+        } else {
+            jsonRpcSender.sendResponse(JsonRpcResponse.forError(new JsonRpcResponse.Error(JsonRpcResponse.Error.INVALID_REQUEST,
+                    "unexpected type: " + jsonNode.getNodeType().name(),
+                    null), null));
+            return null;
+        }
+    }
+
+    private ValueNode getId(JsonNode jsonNode) {
+        final var id = jsonNode.get("id");
+        return id instanceof ValueNode ? (ValueNode) id : null;
+    }
+
+    private JsonRpcRequest parseJsonRpcRequest(final JsonNode input) throws JsonRpcException {
+        JsonRpcRequest request;
+        try {
+            request = objectMapper.treeToValue(input, JsonRpcRequest.class);
+        } catch (JsonMappingException e) {
+            throw new JsonRpcException(new JsonRpcResponse.Error(JsonRpcResponse.Error.INVALID_REQUEST,
+                    e.getMessage(),
+                    null));
+        } catch (IOException e) {
+            throw new AssertionError(e);
+        }
+
+        if (!"2.0".equals(request.getJsonrpc())) {
+            throw new JsonRpcException(new JsonRpcResponse.Error(JsonRpcResponse.Error.INVALID_REQUEST,
+                    "only jsonrpc version 2.0 is supported",
+                    null));
+        }
+
+        if (request.getMethod() == null) {
+            throw new JsonRpcException(new JsonRpcResponse.Error(JsonRpcResponse.Error.INVALID_REQUEST,
+                    "method field must be set",
+                    null));
+        }
+
+        return request;
+    }
+
+    private JsonRpcResponse parseJsonRpcResponse(final JsonNode input) {
+        JsonRpcResponse response;
+        try {
+            response = objectMapper.treeToValue(input, JsonRpcResponse.class);
+        } catch (JsonParseException | JsonMappingException e) {
+            logger.debug("Received invalid jsonrpc response {}", e.getMessage());
+            return null;
+        } catch (IOException e) {
+            throw new AssertionError(e);
+        }
+
+        if (!"2.0".equals(response.getJsonrpc())) {
+            logger.debug("Received invalid jsonrpc response with invalid version {}", response.getJsonrpc());
+            return null;
+        }
+
+        if (response.getResult() != null && response.getError() != null) {
+            logger.debug("Received invalid jsonrpc response with both result and error");
+            return null;
+        }
+
+        if (response.getResult() == null && response.getError() == null) {
+            logger.debug("Received invalid jsonrpc response without result and error");
+            return null;
+        }
+
+        if (response.getId() == null || response.getId().isNull()) {
+            logger.debug("Received invalid jsonrpc response without id");
+            return null;
+        }
+
+        return response;
+    }
+
+    public interface RequestHandler {
+
+        JsonNode apply(String method, ContainerNode<?> params) throws JsonRpcException;
+    }
+}

src/main/java/org/asamk/signal/jsonrpc/JsonRpcRequest.java

@@ -0,0 +1,73 @@
+package org.asamk.signal.jsonrpc;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.databind.node.ContainerNode;
+import com.fasterxml.jackson.databind.node.ValueNode;
+
+/**
+ * Represents a JSON-RPC request.
+ * https://www.jsonrpc.org/specification#request_object
+ */
+public class JsonRpcRequest extends JsonRpcMessage {
+
+    /**
+     * A String specifying the version of the JSON-RPC protocol. MUST be exactly "2.0".
+     */
+    String jsonrpc;
+
+    /**
+     * A String containing the name of the method to be invoked.
+     * Method names that begin with the word rpc followed by a period character (U+002E or ASCII 46)
+     * are reserved for rpc-internal methods and extensions and MUST NOT be used for anything else.
+     */
+    String method;
+
+    /**
+     * A Structured value that holds the parameter values to be used during the invocation of the method.
+     * This member MAY be omitted.
+     */
+    @JsonInclude(JsonInclude.Include.NON_NULL)
+    ContainerNode<?> params;
+
+    /**
+     * An identifier established by the Client that MUST contain a String, Number, or NULL value if included.
+     * If it is not included it is assumed to be a notification.
+     * The value SHOULD normally not be Null and Numbers SHOULD NOT contain fractional parts
+     */
+    @JsonInclude(JsonInclude.Include.NON_NULL)
+    ValueNode id;
+
+    public static JsonRpcRequest forNotification(
+            final String method, final ContainerNode<?> params, final ValueNode id
+    ) {
+        return new JsonRpcRequest("2.0", method, params, id);
+    }
+
+    private JsonRpcRequest() {
+    }
+
+    private JsonRpcRequest(
+            final String jsonrpc, final String method, final ContainerNode<?> params, final ValueNode id
+    ) {
+        this.jsonrpc = jsonrpc;
+        this.method = method;
+        this.params = params;
+        this.id = id;
+    }
+
+    public String getJsonrpc() {
+        return jsonrpc;
+    }
+
+    public String getMethod() {
+        return method;
+    }
+
+    public ContainerNode<?> getParams() {
+        return params;
+    }
+
+    public ValueNode getId() {
+        return id;
+    }
+}

src/main/java/org/asamk/signal/jsonrpc/JsonRpcResponse.java

@@ -0,0 +1,120 @@
+package org.asamk.signal.jsonrpc;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.ValueNode;
+
+/**
+ * Represents a JSON-RPC response.
+ * https://www.jsonrpc.org/specification#response_object
+ */
+public class JsonRpcResponse extends JsonRpcMessage {
+
+    /**
+     * A String specifying the version of the JSON-RPC protocol. MUST be exactly "2.0".
+     */
+    String jsonrpc;
+
+    /**
+     * This member is REQUIRED on success.
+     * This member MUST NOT exist if there was an error invoking the method.
+     * The value of this member is determined by the method invoked on the Server.
+     */
+    @JsonInclude(JsonInclude.Include.NON_NULL)
+    JsonNode result;
+
+    /**
+     * This member is REQUIRED on error.
+     * This member MUST NOT exist if there was no error triggered during invocation.
+     * The value for this member MUST be an Object as defined in section 5.1.
+     */
+    @JsonInclude(JsonInclude.Include.NON_NULL)
+    Error error;
+
+    /**
+     * This member is REQUIRED.
+     * It MUST be the same as the value of the id member in the Request Object.
+     * If there was an error in detecting the id in the Request object (e.g. Parse error/Invalid Request), it MUST be Null.
+     */
+    ValueNode id;
+
+    public static JsonRpcResponse forSuccess(JsonNode result, ValueNode id) {
+        return new JsonRpcResponse("2.0", result, null, id);
+    }
+
+    public static JsonRpcResponse forError(Error error, ValueNode id) {
+        return new JsonRpcResponse("2.0", null, error, id);
+    }
+
+    private JsonRpcResponse() {
+    }
+
+    private JsonRpcResponse(final String jsonrpc, final JsonNode result, final Error error, final ValueNode id) {
+        this.jsonrpc = jsonrpc;
+        this.result = result;
+        this.error = error;
+        this.id = id;
+    }
+
+    public String getJsonrpc() {
+        return jsonrpc;
+    }
+
+    public JsonNode getResult() {
+        return result;
+    }
+
+    public Error getError() {
+        return error;
+    }
+
+    public ValueNode getId() {
+        return id;
+    }
+
+    public static class Error {
+
+        public static final int PARSE_ERROR = -32700;
+        public static final int INVALID_REQUEST = -32600;
+        public static final int METHOD_NOT_FOUND = -32601;
+        public static final int INVALID_PARAMS = -32602;
+        public static final int INTERNAL_ERROR = -32603;
+
+        /**
+         * A Number that indicates the error type that occurred.
+         * This MUST be an integer.
+         */
+        int code;
+
+        /**
+         * A String providing a short description of the error.
+         * The message SHOULD be limited to a concise single sentence.
+         */
+        String message;
+
+        /**
+         * A Primitive or Structured value that contains additional information about the error.
+         * This may be omitted.
+         * The value of this member is defined by the Server (e.g. detailed error information, nested errors etc.).
+         */
+        JsonNode data;
+
+        public Error(final int code, final String message, final JsonNode data) {
+            this.code = code;
+            this.message = message;
+            this.data = data;
+        }
+
+        public int getCode() {
+            return code;
+        }
+
+        public String getMessage() {
+            return message;
+        }
+
+        public JsonNode getData() {
+            return data;
+        }
+    }
+}

src/main/java/org/asamk/signal/jsonrpc/JsonRpcSender.java

@@ -0,0 +1,30 @@
+package org.asamk.signal.jsonrpc;
+
+import org.asamk.signal.JsonWriter;
+
+import java.util.List;
+
+public class JsonRpcSender {
+
+    private final JsonWriter jsonWriter;
+
+    public JsonRpcSender(final JsonWriter jsonWriter) {
+        this.jsonWriter = jsonWriter;
+    }
+
+    public void sendRequest(JsonRpcRequest request) {
+        jsonWriter.write(request);
+    }
+
+    public void sendBulkRequests(List<JsonRpcRequest> requests) {
+        jsonWriter.write(requests);
+    }
+
+    public void sendResponse(JsonRpcResponse response) {
+        jsonWriter.write(response);
+    }
+
+    public void sendBulkResponses(List<JsonRpcResponse> responses) {
+        jsonWriter.write(responses);
+    }
+}

src/main/java/org/asamk/signal/util/ErrorUtils.java

@@ -1,6 +1,5 @@
 package org.asamk.signal.util;
 
-import org.asamk.signal.PlainTextWriter;
 import org.asamk.signal.commands.exceptions.CommandException;
 import org.asamk.signal.commands.exceptions.IOErrorException;
 import org.slf4j.Logger;
@@ -21,12 +20,9 @@ public class ErrorUtils {
     private ErrorUtils() {
     }
 
-    public static void handleTimestampAndSendMessageResults(
+    public static void handleSendMessageResults(
-            PlainTextWriter writer, long timestamp, List<SendMessageResult> results
+            List<SendMessageResult> results
     ) throws CommandException {
-        if (timestamp != 0) {
-            writer.println("{}", timestamp);
-        }
         var errors = getErrorMessagesFromSendMessageResults(results);
         handleSendMessageResultErrors(errors);
     }

src/main/java/org/asamk/signal/util/Util.java

@@ -1,16 +1,22 @@
 package org.asamk.signal.util;
 
-import java.io.IOException;
+import com.fasterxml.jackson.annotation.JsonAutoDetect;
-import java.util.ArrayList;
+import com.fasterxml.jackson.annotation.PropertyAccessor;
-import java.util.List;
+import com.fasterxml.jackson.core.JsonGenerator;
+import com.fasterxml.jackson.databind.ObjectMapper;
 
-import org.asamk.signal.dbus.DbusAttachment;
 import org.asamk.signal.manager.groups.GroupId;
 import org.asamk.signal.manager.groups.GroupIdFormatException;
+import org.asamk.signal.dbus.DbusAttachment;
 import org.whispersystems.libsignal.util.guava.Optional;
 import org.whispersystems.signalservice.api.messages.SignalServiceAttachment;
 import org.whispersystems.signalservice.api.push.SignalServiceAddress;
 
+import java.util.Arrays;
+import java.util.List;
+import java.util.Locale;
+import java.util.stream.Collectors;
+
 public class Util {
 
     private Util() {
@@ -24,6 +30,22 @@ public class Util {
         return string;
     }
 
+    public static String dashSeparatedToCamelCaseString(String s) {
+        var parts = s.split("-");
+        return toCamelCaseString(Arrays.asList(parts));
+    }
+
+    private static String toCamelCaseString(List<String> strings) {
+        if (strings.size() == 0) {
+            return "";
+        }
+        return strings.get(0) + strings.stream()
+                .skip(1)
+                .filter(s -> s.length() > 0)
+                .map(s -> Character.toUpperCase(s.charAt(0)) + s.substring(1).toLowerCase(Locale.ROOT))
+                .collect(Collectors.joining());
+    }
+
     public static String formatSafetyNumber(String digits) {
         final var partCount = 12;
         var partSize = digits.length() / partCount;
@@ -41,4 +63,11 @@ public class Util {
     public static String getLegacyIdentifier(final SignalServiceAddress address) {
         return address.getNumber().or(() -> address.getUuid().get().toString());
     }
+
+    public static ObjectMapper createJsonObjectMapper() {
+        var objectMapper = new ObjectMapper();
+        objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.PUBLIC_ONLY);
+        objectMapper.disable(JsonGenerator.Feature.AUTO_CLOSE_TARGET);
+        return objectMapper;
+    }
 }