Add Delegate Signer and wire into Client (#143)

* Add encoded_credential to CovnoOutcome

* Add DelegateSigner

* Add test for DirectV1

* Add support for undecodable credentials

* Add docs

* Clean + fixes

* clippy fixes

* Add unit tests

* Update trait bounds

Cargo.lock

@@ -774,7 +774,7 @@ dependencies = [
  "objc2-foundation",
  "parking_lot",
  "percent-encoding",
- "windows-sys 0.60.2",
+ "windows-sys 0.59.0",
  "x11rb",
 ]
 
@@ -1814,7 +1814,7 @@ dependencies = [
 [[package]]
 name = "de-mls"
 version = "3.0.0"
-source = "git+https://github.com/vacp2p/de-mls?branch=develop#d838e832994fd1d14f624783741bc60b31510fa0"
+source = "git+https://github.com/vacp2p/de-mls?branch=develop#2dfcd8c71668856e8d7027968c2c64d87ec7fea7"
 dependencies = [
  "hashgraph-like-consensus",
  "indexmap 2.14.0",
@@ -2104,7 +2104,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
 dependencies = [
  "libc",
- "windows-sys 0.61.2",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -3601,9 +3601,12 @@ dependencies = [
  "chat-sqlite",
  "components",
  "crossbeam-channel",
+ "crypto",
+ "hex",
  "libchat",
  "logos-account",
  "parking_lot",
+ "shared-traits",
  "tempfile",
  "thiserror",
  "tracing",
@@ -3703,7 +3706,7 @@ version = "0.50.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7957b9740744892f114936ab4a57b3f487491bbeafaf8083688b16841a4240e5"
 dependencies = [
- "windows-sys 0.61.2",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -4534,7 +4537,7 @@ dependencies = [
  "once_cell",
  "socket2",
  "tracing",
- "windows-sys 0.60.2",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -5028,7 +5031,7 @@ dependencies = [
  "errno",
  "libc",
  "linux-raw-sys 0.12.1",
- "windows-sys 0.61.2",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -5086,7 +5089,7 @@ dependencies = [
  "security-framework",
  "security-framework-sys",
  "webpki-root-certs",
- "windows-sys 0.61.2",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -5696,7 +5699,7 @@ dependencies = [
  "getrandom 0.4.2",
  "once_cell",
  "rustix 1.1.4",
- "windows-sys 0.61.2",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -6394,7 +6397,7 @@ version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c2a7b1c03c876122aa43f3020e6c3c3ee5c05081c9a00739faf7503aeba10d22"
 dependencies = [
- "windows-sys 0.61.2",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -6468,7 +6471,7 @@ version = "0.52.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
 dependencies = [
- "windows-targets 0.52.6",
+ "windows-targets",
 ]
 
 [[package]]
@@ -6477,16 +6480,7 @@ version = "0.59.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1e38bc4d79ed67fd075bcc251a1c39b32a1776bbe92e5bef1f0bf1f8c531853b"
 dependencies = [
- "windows-targets 0.52.6",
+ "windows-targets",
-]
-
-[[package]]
-name = "windows-sys"
-version = "0.60.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f2f500e4d28234f72040990ec9d39e3a6b950f9f22d3dba18416c35882612bcb"
-dependencies = [
- "windows-targets 0.53.5",
 ]
 
 [[package]]
@@ -6504,31 +6498,14 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9b724f72796e036ab90c1021d4780d4d3d648aca59e491e6b98e725b84e99973"
 dependencies = [
- "windows_aarch64_gnullvm 0.52.6",
+ "windows_aarch64_gnullvm",
- "windows_aarch64_msvc 0.52.6",
+ "windows_aarch64_msvc",
- "windows_i686_gnu 0.52.6",
+ "windows_i686_gnu",
- "windows_i686_gnullvm 0.52.6",
+ "windows_i686_gnullvm",
- "windows_i686_msvc 0.52.6",
+ "windows_i686_msvc",
- "windows_x86_64_gnu 0.52.6",
+ "windows_x86_64_gnu",
- "windows_x86_64_gnullvm 0.52.6",
+ "windows_x86_64_gnullvm",
- "windows_x86_64_msvc 0.52.6",
+ "windows_x86_64_msvc",
-]
-
-[[package]]
-name = "windows-targets"
-version = "0.53.5"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4945f9f551b88e0d65f3db0bc25c33b8acea4d9e41163edf90dcd0b19f9069f3"
-dependencies = [
- "windows-link",
- "windows_aarch64_gnullvm 0.53.1",
- "windows_aarch64_msvc 0.53.1",
- "windows_i686_gnu 0.53.1",
- "windows_i686_gnullvm 0.53.1",
- "windows_i686_msvc 0.53.1",
- "windows_x86_64_gnu 0.53.1",
- "windows_x86_64_gnullvm 0.53.1",
- "windows_x86_64_msvc 0.53.1",
 ]
 
 [[package]]
@@ -6537,96 +6514,48 @@ version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "32a4622180e7a0ec044bb555404c800bc9fd9ec262ec147edd5989ccd0c02cd3"
 
-[[package]]
-name = "windows_aarch64_gnullvm"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a9d8416fa8b42f5c947f8482c43e7d89e73a173cead56d044f6a56104a6d1b53"
-
 [[package]]
 name = "windows_aarch64_msvc"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "09ec2a7bb152e2252b53fa7803150007879548bc709c039df7627cabbd05d469"
 
-[[package]]
-name = "windows_aarch64_msvc"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b9d782e804c2f632e395708e99a94275910eb9100b2114651e04744e9b125006"
-
 [[package]]
 name = "windows_i686_gnu"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "8e9b5ad5ab802e97eb8e295ac6720e509ee4c243f69d781394014ebfe8bbfa0b"
 
-[[package]]
-name = "windows_i686_gnu"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "960e6da069d81e09becb0ca57a65220ddff016ff2d6af6a223cf372a506593a3"
-
 [[package]]
 name = "windows_i686_gnullvm"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "0eee52d38c090b3caa76c563b86c3a4bd71ef1a819287c19d586d7334ae8ed66"
 
-[[package]]
-name = "windows_i686_gnullvm"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa7359d10048f68ab8b09fa71c3daccfb0e9b559aed648a8f95469c27057180c"
-
 [[package]]
 name = "windows_i686_msvc"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "240948bc05c5e7c6dabba28bf89d89ffce3e303022809e73deaefe4f6ec56c66"
 
-[[package]]
-name = "windows_i686_msvc"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e7ac75179f18232fe9c285163565a57ef8d3c89254a30685b57d83a38d326c2"
-
 [[package]]
 name = "windows_x86_64_gnu"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "147a5c80aabfbf0c7d901cb5895d1de30ef2907eb21fbbab29ca94c5b08b1a78"
 
-[[package]]
-name = "windows_x86_64_gnu"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9c3842cdd74a865a8066ab39c8a7a473c0778a3f29370b5fd6b4b9aa7df4a499"
-
 [[package]]
 name = "windows_x86_64_gnullvm"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "24d5b23dc417412679681396f2b49f3de8c1473deb516bd34410872eff51ed0d"
 
-[[package]]
-name = "windows_x86_64_gnullvm"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0ffa179e2d07eee8ad8f57493436566c7cc30ac536a3379fdf008f47f6bb7ae1"
-
 [[package]]
 name = "windows_x86_64_msvc"
 version = "0.52.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "589f6da84c646204747d1270a2a5661ea66ed1cced2631d546fdfb155959f9ec"
 
-[[package]]
-name = "windows_x86_64_msvc"
-version = "0.53.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d6bbff5f0aada427a1e5a6da5f1f98158182f26556f345ac9e04d36d0ebed650"
-
 [[package]]
 name = "winnow"
 version = "1.0.1"

bin/chat-cli/src/app.rs

@@ -5,7 +5,7 @@ use std::path::{Path, PathBuf};
 use anyhow::Result;
 use arboard::Clipboard;
 use crossbeam_channel::Receiver;
-use logos_chat::{ChatClient, DeliveryService, EphemeralRegistry, Event, RegistrationService};
+use logos_chat::{ChatClient, EphemeralRegistry, Event, RegistrationService, Transport};
 use serde::{Deserialize, Serialize};
 
 use crate::utils::now;
@@ -41,7 +41,7 @@ pub struct AppState {
     pub active_chat: Option<String>,
 }
 
-pub struct ChatApp<T: DeliveryService, R: RegistrationService = EphemeralRegistry> {
+pub struct ChatApp<T: Transport, R: RegistrationService = EphemeralRegistry> {
     pub client: ChatClient<T, R>,
     events: Receiver<Event>,
     pub state: AppState,
@@ -55,7 +55,7 @@ pub struct ChatApp<T: DeliveryService, R: RegistrationService = EphemeralRegistr
 
 impl<T, R> ChatApp<T, R>
 where
-    T: DeliveryService + Send + 'static,
+    T: Transport,
     R: RegistrationService + Send + 'static,
 {
     pub fn new(

bin/chat-cli/src/main.rs

@@ -8,9 +8,7 @@ use std::path::{Path, PathBuf};
 use anyhow::{Context, Result};
 use clap::{Parser, ValueEnum};
 use crossbeam_channel::Receiver;
-use logos_chat::{
+use logos_chat::{ChatClient, Event, HttpRegistry, RegistrationService, StorageConfig, Transport};
-    ChatClient, DeliveryService, Event, HttpRegistry, RegistrationService, StorageConfig, Transport,
-};
 
 use app::ChatApp;
 
@@ -132,7 +130,7 @@ fn run<T: Transport>(transport: T, cli: &Cli) -> Result<()> {
 
 fn launch_tui<T, R>(client: ChatClient<T, R>, events: Receiver<Event>, cli: &Cli) -> Result<()>
 where
-    T: DeliveryService + Send + 'static,
+    T: Transport,
     R: RegistrationService + Send + 'static,
 {
     let mut app = ChatApp::new(client, events, &cli.name, &cli.data)?;
@@ -213,7 +211,7 @@ fn run_logos_delivery(cli: Cli) -> Result<()> {
 
 fn run_app<T, R>(terminal: &mut ui::Tui, app: &mut ChatApp<T, R>) -> Result<()>
 where
-    T: DeliveryService + Send + 'static,
+    T: Transport,
     R: RegistrationService + Send + 'static,
 {
     loop {

bin/chat-cli/src/ui.rs

@@ -16,7 +16,7 @@ use ratatui::{
     widgets::{Block, Borders, List, ListItem, Paragraph, Wrap},
 };
 
-use logos_chat::{DeliveryService, RegistrationService};
+use logos_chat::{RegistrationService, Transport};
 
 use crate::app::ChatApp;
 
@@ -38,7 +38,7 @@ pub fn restore() -> io::Result<()> {
 }
 
 /// Draw the UI.
-pub fn draw<D: DeliveryService + Send + 'static, R: RegistrationService + Send + 'static>(
+pub fn draw<D: Transport, R: RegistrationService + Send + 'static>(
     frame: &mut Frame,
     app: &ChatApp<D, R>,
 ) {
@@ -58,7 +58,7 @@ pub fn draw<D: DeliveryService + Send + 'static, R: RegistrationService + Send +
     draw_status(frame, app, chunks[3]);
 }
 
-fn draw_header<D: DeliveryService + Send + 'static, R: RegistrationService + Send + 'static>(
+fn draw_header<D: Transport, R: RegistrationService + Send + 'static>(
     frame: &mut Frame,
     app: &ChatApp<D, R>,
     area: Rect,
@@ -85,7 +85,7 @@ fn draw_header<D: DeliveryService + Send + 'static, R: RegistrationService + Sen
     frame.render_widget(header, area);
 }
 
-fn draw_messages<D: DeliveryService + Send + 'static, R: RegistrationService + Send + 'static>(
+fn draw_messages<D: Transport, R: RegistrationService + Send + 'static>(
     frame: &mut Frame,
     app: &ChatApp<D, R>,
     area: Rect,
@@ -175,7 +175,7 @@ fn draw_messages<D: DeliveryService + Send + 'static, R: RegistrationService + S
     frame.render_stateful_widget(messages_widget, area, &mut list_state);
 }
 
-fn draw_input<D: DeliveryService + Send + 'static, R: RegistrationService + Send + 'static>(
+fn draw_input<D: Transport, R: RegistrationService + Send + 'static>(
     frame: &mut Frame,
     app: &ChatApp<D, R>,
     area: Rect,
@@ -206,7 +206,7 @@ fn draw_input<D: DeliveryService + Send + 'static, R: RegistrationService + Send
     frame.set_cursor_position((cursor_x, area.y + 1));
 }
 
-fn draw_status<D: DeliveryService + Send + 'static, R: RegistrationService + Send + 'static>(
+fn draw_status<D: Transport, R: RegistrationService + Send + 'static>(
     frame: &mut Frame,
     app: &ChatApp<D, R>,
     area: Rect,
@@ -220,10 +220,7 @@ fn draw_status<D: DeliveryService + Send + 'static, R: RegistrationService + Sen
 }
 
 /// Handle keyboard events.
-pub fn handle_events<
+pub fn handle_events<D: Transport, R: RegistrationService + Send + 'static>(
-    D: DeliveryService + Send + 'static,
-    R: RegistrationService + Send + 'static,
->(
     app: &mut ChatApp<D, R>,
 ) -> io::Result<bool> {
     // Poll for events with a short timeout to allow checking incoming messages

core/conversations/src/conversation/group_v1.rs

@@ -255,12 +255,15 @@ impl<S: ExternalServices> Convo<S> for GroupV1Convo {
             .process_message(&cx.mls_provider, protocol_message)
             .map_err(ChatError::generic)?;
 
+        let cred_bytes = processed.credential().serialized_content().to_vec();
+
         let content = match processed.into_content() {
             ProcessedMessageContent::ApplicationMessage(msg) => {
                 let reliable = ReliablePayload::decode(msg.into_bytes().as_slice())?;
                 cx.causal.on_receive(&self.convo_id, &reliable);
                 Some(Content {
                     bytes: reliable.content.to_vec(),
+                    encoded_credential: cred_bytes,
                 })
             }
             ProcessedMessageContent::StagedCommitMessage(commit) => {

core/conversations/src/conversation/group_v2.rs

@@ -184,7 +184,7 @@ impl GroupV2Convo {
     pub fn new<S: ExternalServices>(
         service_ctx: &mut ServiceContext<S>,
     ) -> Result<Self, ChatError> {
-        let setup = DemlsSetup::new(service_ctx.mls_identity.display_name())?;
+        let setup = DemlsSetup::new(service_ctx.mls_identity.id().as_str().to_string())?;
         let convo_id = rand_string(5);
         let conversation = Conversation::create(&convo_id, setup.deps())?;
         let convo = GroupV2Convo {
@@ -205,7 +205,7 @@ impl GroupV2Convo {
     pub fn new_pending<S: ExternalServices>(
         service_ctx: &mut ServiceContext<S>,
     ) -> Result<Self, ChatError> {
-        let name = service_ctx.mls_identity.display_name();
+        let name = service_ctx.mls_identity.id().as_str().to_string();
         let setup = DemlsSetup::new(name.clone())?;
         let kp = setup.factory.generate_key_package()?;
 
@@ -458,12 +458,16 @@ impl GroupV2Convo {
         events.iter().find_map(|evt| match evt {
             ConversationEvent::AppMessage(AppMessageProto {
                 payload: Some(app_message::Payload::ConversationMessage(cm)),
-            }) => Some(ConvoOutcome {
+            }) => {
-                convo_id: self.convo_id.clone(),
+                let cred = cm.sender.as_bytes().to_vec();
-                content: Some(Content {
+                Some(ConvoOutcome {
-                    bytes: cm.message.clone(),
+                    convo_id: self.convo_id.clone(),
-                }),
+                    content: Some(Content {
-            }),
+                        bytes: cm.message.clone(),
+                        encoded_credential: cred,
+                    }),
+                })
+            }
             _ => None,
         })
     }

core/conversations/src/conversation/privatev1.rs

@@ -197,6 +197,7 @@ impl PrivateV1Convo {
     fn handle_content(&self, bytes: Bytes) -> Content {
         Content {
             bytes: bytes.into(),
+            encoded_credential: vec![],
         }
     }
 

core/conversations/src/lib.rs

@@ -31,4 +31,4 @@ pub use service_traits::{DeliveryService, RegistrationService, WakeupService};
 pub use shared_traits::{IdentId, IdentIdRef, IdentityProvider};
 pub use storage::ConversationKind;
 pub use types::AddressedEnvelope;
-pub use utils::hex_trunc;
+pub use utils::{hex_trunc, trunc};

core/conversations/src/outcomes.rs

@@ -13,6 +13,9 @@ use crate::conversation::ConversationId;
 #[derive(Debug, Clone)]
 pub struct Content {
     pub bytes: Vec<u8>,
+    /// Hex-encoded [`DelegateCredential`] of the sender, if present in the message.
+    /// Empty when the sender did not attach a credential.
+    pub encoded_credential: Vec<u8>,
 }
 
 #[derive(Debug, Clone)]

core/conversations/src/utils.rs

@@ -71,3 +71,19 @@ pub fn hex_trunc(data: &[u8]) -> String {
         )
     }
 }
+
+pub fn trunc(data: &str) -> String {
+    if data.chars().count() <= 8 {
+        return data.to_string();
+    }
+    let head: String = data.chars().take(4).collect();
+    let tail: String = data
+        .chars()
+        .rev()
+        .take(4)
+        .collect::<String>()
+        .chars()
+        .rev()
+        .collect();
+    format!("{head}..{tail}")
+}

crates/client/Cargo.toml

@@ -11,10 +11,13 @@ crate-type = ["rlib"]
 chat-sqlite = { workspace = true }
 components = { workspace = true }
 crossbeam-channel = { workspace = true }
+crypto = { workspace = true }
 libchat = { workspace = true }
 logos-account = { workspace = true, features = ["dev"]}
+shared-traits = { workspace =  true }
 
 # External dependencies (sorted)
+hex = "0.4.3"
 parking_lot = "0.12"
 thiserror = "2"
 tracing = "0.1"

crates/client/src/client.rs

@@ -7,13 +7,13 @@ use libchat::{
     ChatError, ChatStorage, ConversationId, ConvoOutcome, Core, DeliveryService, IdentId,
     IdentIdRef, InboxOutcome, Introduction, PayloadOutcome, RegistrationService, StorageConfig,
 };
-use logos_account::TestLogosAccount;
 use parking_lot::Mutex;
 
+use crate::delegate::{DelegateCredential, DelegateSigner};
 use crate::errors::ClientError;
 use crate::event::Event;
 
-type ClientCore<T, R> = Core<(TestLogosAccount, T, R, ThreadedWakeupService, ChatStorage)>;
+type ClientCore<T, R> = Core<(DelegateSigner, T, R, ThreadedWakeupService, ChatStorage)>;
 type AccountAddressRef<'a> = &'a str;
 type LocalSignerId = IdentId;
 
@@ -51,13 +51,14 @@ pub struct ChatClient<T: DeliveryService, R: RegistrationService = EphemeralRegi
 
 impl<T: Transport> ChatClient<T, EphemeralRegistry> {
     /// Create an in-memory, ephemeral client. Identity is lost on drop.
-    pub fn new(name: impl Into<String>, mut transport: T) -> (Self, Receiver<Event>) {
+    pub fn new(_: impl Into<String>, mut transport: T) -> (Self, Receiver<Event>) {
         let inbound = transport.inbound();
-        let ident = TestLogosAccount::new(name);
+        let delegate = DelegateSigner::random();
+
         let (wakeup_tx, wakeup_rx) = crossbeam_channel::unbounded();
         let wakeup_service = ThreadedWakeupService::new(wakeup_tx);
         let core = Core::new_with_name(
-            ident,
+            delegate,
             transport,
             EphemeralRegistry::new(),
             wakeup_service,
@@ -72,17 +73,17 @@ impl<T: Transport> ChatClient<T, EphemeralRegistry> {
     /// If an identity already exists in storage it is loaded; otherwise a new
     /// one is created and saved.
     pub fn open(
-        name: impl Into<String>,
+        _: impl Into<String>,
         config: StorageConfig,
         mut transport: T,
     ) -> Result<(Self, Receiver<Event>), ClientError> {
         let store = ChatStorage::new(config).map_err(ChatError::from)?;
         let inbound = transport.inbound();
-        let ident = TestLogosAccount::new(name);
+        let delegate = DelegateSigner::random();
         let (wakeup_tx, wakeup_rx) = crossbeam_channel::unbounded();
         let wakeup_service = ThreadedWakeupService::new(wakeup_tx);
         let core = Core::new_from_store(
-            ident,
+            delegate,
             transport,
             EphemeralRegistry::new(),
             wakeup_service,
@@ -96,7 +97,7 @@ impl<T: Transport> ChatClient<T, EphemeralRegistry> {
 
 impl<T, R> ChatClient<T, R>
 where
-    T: DeliveryService + Send + 'static,
+    T: Transport + Send + 'static,
     R: RegistrationService + Send + 'static,
 {
     /// Open or create a persistent client with a caller-supplied registration
@@ -108,7 +109,7 @@ where
     /// when a real registry is wired in we want each session to publish so
     /// other clients can fetch it.
     pub fn open_with_registry(
-        name: impl Into<String>,
+        _: impl Into<String>,
         config: StorageConfig,
         mut transport: T,
         registry: R,
@@ -118,14 +119,34 @@ where
     {
         let store = ChatStorage::new(config).map_err(ChatError::from)?;
         let inbound = transport.inbound();
-        let ident = TestLogosAccount::new(name);
+        let delegate = DelegateSigner::random();
         let (wakeup_tx, wakeup_rx) = crossbeam_channel::unbounded();
         let wakeup_service = ThreadedWakeupService::new(wakeup_tx);
-        let mut core = Core::new_from_store(ident, transport, registry, wakeup_service, store)?;
+        let mut core = Core::new_from_store(delegate, transport, registry, wakeup_service, store)?;
         core.register_keypackage()?;
         Ok(Self::spawn(core, inbound, wakeup_rx))
     }
 
+    /// Create a client with ephemeral storage with the provided Transport and RegistrationService.
+    pub fn new_ephemeral(
+        delegate: DelegateSigner,
+        mut transport: T,
+        reg: R,
+    ) -> Result<(Self, Receiver<Event>), ClientError> {
+        let inbound = transport.inbound();
+
+        let (wakeup_tx, wakeup_rx) = crossbeam_channel::unbounded();
+        let wakeup_service = ThreadedWakeupService::new(wakeup_tx);
+        let core = Core::new_with_name(
+            delegate,
+            transport,
+            reg,
+            wakeup_service,
+            ChatStorage::in_memory(),
+        )?;
+        Ok(Self::spawn(core, inbound, wakeup_rx))
+    }
+
     fn spawn(
         core: ClientCore<T, R>,
         inbound: Receiver<Vec<u8>>,
@@ -287,12 +308,24 @@ fn events_from_inbound(result: PayloadOutcome) -> Vec<Event> {
     }
 }
 
+fn decode_credential(encoded: Vec<u8>) {
+    if let Ok(data) = hex::decode(encoded)
+        && let Ok(cred) = DelegateCredential::try_from(data)
+    {
+        tracing::debug!(?cred, "decoded sender credential");
+        // TODO: Integration Point
+    }
+}
+
 fn convo_events(outcome: ConvoOutcome) -> Vec<Event> {
     let ConvoOutcome { convo_id, content } = outcome;
     content
-        .map(|c| Event::MessageReceived {
+        .map(|c| {
-            convo_id: Arc::from(convo_id),
+            decode_credential(c.encoded_credential);
-            content: c.bytes,
+            Event::MessageReceived {
+                convo_id: Arc::from(convo_id),
+                content: c.bytes,
+            }
         })
         .into_iter()
         .collect()
@@ -310,6 +343,7 @@ fn inbox_events(outcome: InboxOutcome) -> Vec<Event> {
         class: new_conversation.class,
     });
     if let Some(c) = initial.and_then(|co| co.content) {
+        decode_credential(c.encoded_credential);
         events.push(Event::MessageReceived {
             convo_id: Arc::clone(&id),
             content: c.bytes,

crates/client/src/delegate.rs

@@ -0,0 +1,290 @@
+use crypto::{Ed25519SigningKey, Ed25519VerifyingKey};
+use libchat::{IdentId, IdentityProvider, trunc};
+
+use crate::ClientError;
+
+type AccountAddr = String;
+
+/// A local signing identity that holds an Ed25519 keypair.
+///
+/// Can be standalone (unassociated) or authorized to act on behalf of an account
+/// via [`DelegateSigner::associate`].
+pub struct DelegateSigner {
+    signing_key: Ed25519SigningKey,
+    verifying_key: Ed25519VerifyingKey,
+    identifier: IdentId,
+    account_addr: Option<AccountAddr>,
+}
+
+impl DelegateSigner {
+    /// Create a new signer with a randomly generated keypair.
+    pub fn random() -> Self {
+        let signing_key = Ed25519SigningKey::generate();
+        let verifying_key = signing_key.verifying_key();
+        let identifier = DelegateCredential::unassociated(&verifying_key).into();
+        Self {
+            signing_key,
+            verifying_key,
+            identifier,
+            account_addr: None,
+        }
+    }
+
+    /// Associate a DelegateSigner with an Account.
+    pub fn associate(&mut self, account_addr: AccountAddr) {
+        self.identifier =
+            DelegateCredential::associated(&self.verifying_key, account_addr.as_str()).into();
+        self.account_addr = Some(account_addr);
+    }
+
+    pub fn account_addr(&self) -> Option<&str> {
+        self.account_addr.as_deref()
+    }
+}
+
+impl IdentityProvider for DelegateSigner {
+    fn id(&self) -> libchat::IdentIdRef<'_> {
+        &self.identifier
+    }
+
+    fn display_name(&self) -> String {
+        trunc(self.identifier.as_str())
+    }
+
+    fn sign(&self, payload: &[u8]) -> crypto::Ed25519Signature {
+        self.signing_key.sign(payload)
+    }
+
+    fn public_key(&self) -> &Ed25519VerifyingKey {
+        &self.verifying_key
+    }
+}
+
+/// A credential issued to a delegate key, optionally bound to an account address.
+///
+/// Serialized as a TLV byte sequence prefixed with magic bytes `0x23 0x23`.
+/// A credential without an `account_addr` is *unassociated* — it identifies the
+/// delegate key but has not yet been linked to an account.
+#[derive(Debug)]
+pub struct DelegateCredential {
+    delegate_id: Ed25519VerifyingKey,
+    account_addr: Option<AccountAddr>,
+}
+
+impl DelegateCredential {
+    const TAG_DELEGATE_ID: u8 = 0x01;
+    const TAG_ACCOUNT_ADDR: u8 = 0x02;
+
+    pub fn unassociated(delegate: &Ed25519VerifyingKey) -> Self {
+        Self {
+            delegate_id: delegate.clone(),
+            account_addr: None,
+        }
+    }
+
+    pub fn associated(delegate: &Ed25519VerifyingKey, account: &str) -> Self {
+        Self {
+            delegate_id: delegate.clone(),
+            account_addr: Some(account.to_string()),
+        }
+    }
+
+    pub fn serialize(self) -> Vec<u8> {
+        let mut data = Vec::new();
+        data.extend_from_slice(&[0x23, 0x23]);
+        let key_bytes = self.delegate_id.as_ref();
+        debug_assert!(
+            key_bytes.len() <= 255,
+            "delegate_id too large for 1-byte TLV length"
+        );
+        data.extend_from_slice(&[Self::TAG_DELEGATE_ID, key_bytes.len() as u8]);
+        data.extend_from_slice(key_bytes);
+        if let Some(addr) = self.account_addr {
+            let addr_bytes = addr.as_bytes();
+            debug_assert!(
+                addr_bytes.len() <= 255,
+                "account_addr too large for 1-byte TLV length"
+            );
+            data.extend_from_slice(&[Self::TAG_ACCOUNT_ADDR, addr_bytes.len() as u8]);
+            data.extend_from_slice(addr_bytes);
+        }
+        data
+    }
+}
+
+impl From<DelegateCredential> for Vec<u8> {
+    fn from(value: DelegateCredential) -> Self {
+        value.serialize()
+    }
+}
+
+impl TryFrom<Vec<u8>> for DelegateCredential {
+    type Error = ClientError;
+
+    fn try_from(value: Vec<u8>) -> Result<Self, Self::Error> {
+        if value.get(..2) != Some(&[0x23, 0x23]) {
+            return Err(ClientError::BadlyFormedCredential);
+        }
+        let mut delegate_id = None;
+        let mut account_addr = None;
+        let mut i = 2;
+        while i + 2 <= value.len() {
+            let tag = value[i];
+            let len = value[i + 1] as usize;
+            i += 2;
+            let v = value
+                .get(i..i + len)
+                .ok_or(ClientError::BadlyFormedCredential)?;
+            i += len;
+            match tag {
+                DelegateCredential::TAG_DELEGATE_ID => {
+                    let bytes: &[u8; 32] = v
+                        .try_into()
+                        .map_err(|_| ClientError::BadlyFormedCredential)?;
+                    delegate_id = Some(
+                        Ed25519VerifyingKey::from_bytes(bytes)
+                            .map_err(|_| ClientError::BadlyFormedCredential)?,
+                    );
+                }
+                DelegateCredential::TAG_ACCOUNT_ADDR => {
+                    account_addr = Some(
+                        String::from_utf8(v.to_vec())
+                            .map_err(|_| ClientError::BadlyFormedCredential)?,
+                    );
+                }
+                _ => {}
+            }
+        }
+        Ok(Self {
+            delegate_id: delegate_id.ok_or(ClientError::BadlyFormedCredential)?,
+            account_addr,
+        })
+    }
+}
+
+impl From<DelegateCredential> for IdentId {
+    fn from(value: DelegateCredential) -> Self {
+        IdentId::new(hex::encode(value.serialize()))
+    }
+}
+
+impl TryFrom<IdentId> for DelegateCredential {
+    type Error = ClientError;
+
+    fn try_from(value: IdentId) -> Result<Self, Self::Error> {
+        hex::decode(value.as_str())
+            .map_err(|_| ClientError::BadlyFormedCredential)?
+            .try_into()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crypto::Ed25519SigningKey;
+
+    fn test_key() -> Ed25519VerifyingKey {
+        Ed25519SigningKey::generate().verifying_key()
+    }
+
+    #[test]
+    fn roundtrip_unassociated() {
+        let key = test_key();
+        let bytes = DelegateCredential::unassociated(&key).serialize();
+        let recovered: DelegateCredential = bytes.clone().try_into().unwrap();
+        assert_eq!(recovered.serialize(), bytes);
+    }
+
+    #[test]
+    fn roundtrip_associated() {
+        let key = test_key();
+        let bytes = DelegateCredential::associated(&key, "user@example.com").serialize();
+        let recovered: DelegateCredential = bytes.clone().try_into().unwrap();
+        assert_eq!(recovered.serialize(), bytes);
+    }
+
+    #[test]
+    fn ident_id_roundtrip_unassociated() {
+        let key = test_key();
+        let original = DelegateCredential::unassociated(&key).serialize();
+        let ident_id: IdentId = DelegateCredential::unassociated(&key).into();
+        let recovered: DelegateCredential = ident_id.try_into().unwrap();
+        assert_eq!(recovered.serialize(), original);
+    }
+
+    #[test]
+    fn ident_id_roundtrip_associated() {
+        let key = test_key();
+        let addr = "user@example.com";
+        let original = DelegateCredential::associated(&key, addr).serialize();
+        let ident_id: IdentId = DelegateCredential::associated(&key, addr).into();
+        let recovered: DelegateCredential = ident_id.try_into().unwrap();
+        assert_eq!(recovered.serialize(), original);
+    }
+
+    #[test]
+    fn account_addr_preserved_across_roundtrip() {
+        let key = test_key();
+        let addr = "alice@libchat.example";
+        let recovered: DelegateCredential = DelegateCredential::associated(&key, addr)
+            .serialize()
+            .try_into()
+            .unwrap();
+        assert_eq!(recovered.account_addr.as_deref(), Some(addr));
+    }
+
+    #[test]
+    fn unassociated_has_no_account_after_roundtrip() {
+        let key = test_key();
+        let recovered: DelegateCredential = DelegateCredential::unassociated(&key)
+            .serialize()
+            .try_into()
+            .unwrap();
+        assert!(recovered.account_addr.is_none());
+    }
+
+    #[test]
+    fn bad_magic_bytes_rejected() {
+        let bytes = vec![0x00, 0x00, 0x01, 0x20];
+        assert!(matches!(
+            DelegateCredential::try_from(bytes),
+            Err(ClientError::BadlyFormedCredential)
+        ));
+    }
+
+    #[test]
+    fn truncated_payload_rejected() {
+        // Magic + TAG_DELEGATE_ID + len=32, but only 16 bytes of key data
+        let mut bytes = vec![0x23, 0x23, 0x01, 32];
+        bytes.extend_from_slice(&[0u8; 16]);
+        assert!(matches!(
+            DelegateCredential::try_from(bytes),
+            Err(ClientError::BadlyFormedCredential)
+        ));
+    }
+
+    #[test]
+    fn missing_delegate_id_rejected() {
+        // Valid magic but no TLV fields
+        let bytes = vec![0x23, 0x23];
+        assert!(matches!(
+            DelegateCredential::try_from(bytes),
+            Err(ClientError::BadlyFormedCredential)
+        ));
+    }
+
+    #[test]
+    fn invalid_utf8_account_addr_rejected() {
+        let key = test_key();
+        // Build a valid credential then corrupt the account_addr bytes
+        let mut bytes = DelegateCredential::unassociated(&key).serialize();
+        // Append a TAG_ACCOUNT_ADDR field with invalid UTF-8
+        bytes.push(DelegateCredential::TAG_ACCOUNT_ADDR);
+        bytes.push(3); // len
+        bytes.extend_from_slice(&[0xFF, 0xFE, 0xFD]); // invalid UTF-8
+        assert!(matches!(
+            DelegateCredential::try_from(bytes),
+            Err(ClientError::BadlyFormedCredential)
+        ));
+    }
+}

crates/client/src/errors.rs

@@ -4,4 +4,6 @@ use libchat::ChatError;
 pub enum ClientError {
     #[error(transparent)]
     Chat(#[from] ChatError),
+    #[error("received credential could not be parsed")]
+    BadlyFormedCredential,
 }

crates/client/src/lib.rs

@@ -1,9 +1,11 @@
 mod client;
+mod delegate;
 mod delivery_in_process;
 mod errors;
 mod event;
 
 pub use client::{ChatClient, Transport};
+pub use delegate::DelegateSigner;
 pub use delivery_in_process::{InProcessDelivery, MessageBus};
 pub use errors::ClientError;
 pub use event::Event;

crates/client/tests/saro_and_raya.rs

@@ -1,9 +1,12 @@
 use std::time::Duration;
 
+use components::EphemeralRegistry;
 use crossbeam_channel::{Receiver, Sender};
+use libchat::IdentityProvider;
+use logos_account::TestLogosAccount;
 use logos_chat::{
-    AddressedEnvelope, ChatClient, DeliveryService, Event, InProcessDelivery, MessageBus,
+    AddressedEnvelope, ChatClient, DelegateSigner, DeliveryService, Event, InProcessDelivery,
-    StorageConfig, Transport,
+    MessageBus, StorageConfig, Transport,
 };
 
 /// Block until the next event arrives and matches; panic on timeout/mismatch.
@@ -17,6 +20,52 @@ where
     f(event).unwrap_or_else(|other| panic!("expected {label}, got {other:?}"))
 }
 
+#[test]
+fn direct_v1_integration() {
+    let bus = MessageBus::default();
+    let saro_delivery = InProcessDelivery::new(bus.clone());
+    let raya_delivery = InProcessDelivery::new(bus);
+
+    let reg_service = EphemeralRegistry::new();
+
+    // Create Accounts, Deletage and Associate the two.
+    let saro_account = TestLogosAccount::new("Saro");
+    let mut saro_delegate = DelegateSigner::random();
+    // TODO: Submit Delegate to Account for auth.
+    saro_delegate.associate(saro_account.id().to_string());
+
+    let raya_account = TestLogosAccount::new("Raya");
+    let mut raya_delegate = DelegateSigner::random();
+    // TODO: Submit Delegate to Account for auth.
+    raya_delegate.associate(raya_account.id().to_string());
+    let raya_delegate_id = raya_delegate.id().clone();
+
+    let (mut saro, _saro_events) =
+        ChatClient::new_ephemeral(saro_delegate, saro_delivery, reg_service.clone()).unwrap();
+    let (_raya, raya_events) =
+        ChatClient::new_ephemeral(raya_delegate, raya_delivery, reg_service.clone()).unwrap();
+
+    let convo_id = saro
+        .create_direct_conversation(raya_delegate_id.as_str())
+        .unwrap();
+
+    // The invite payload yields ConversationStarted then MessageReceived.
+    expect_event(&raya_events, "ConversationStarted", |e| match e {
+        Event::ConversationStarted { convo_id, .. } => Ok(convo_id),
+        other => Err(other),
+    });
+
+    saro.send_message(&convo_id, b"Hey from saro")
+        .expect("payload mismatch");
+    expect_event(&raya_events, "MessageReceived", |e| match e {
+        Event::MessageReceived { content, .. } => {
+            assert_eq!(content.as_slice(), b"Hey from saro");
+            Ok(())
+        }
+        other => Err(other),
+    });
+}
+
 #[test]
 fn saro_raya_message_exchange() {
     let bus = MessageBus::default();