expose signal chat history to claude as message history

with role attributions, and a new compaction command which just
discards the message buffer.

signal-gateway/src/claude/mod.rs

@@ -4,12 +4,14 @@ mod tools;
 mod worker;
 
 pub use tools::{Tool, ToolExecutor};
+pub use worker::SentBy;
 
+use chrono::{DateTime, Utc};
 use conf::Conf;
 use std::path::PathBuf;
 use std::sync::Weak;
 use tokio::sync::{mpsc, oneshot};
-use worker::{ClaudeRequest, ClaudeWorker};
+use worker::{ChatMessage, ClaudeWorker, Input};
 
 /// The Anthropic API version header value. This is a stable version identifier,
 /// not a date indicating when the API was released. Anthropic adds new features
@@ -58,7 +60,7 @@ pub enum ClaudeError {
     Request(#[from] reqwest::Error),
     /// API returned an error response.
     #[error("API error: {0}")]
-    ApiError(String),
+    ApiError(Box<str>),
     /// Too many tool use iterations.
     #[error("exceeded maximum tool use iterations ({0})")]
     TooManyIterations(u32),
@@ -81,7 +83,7 @@ pub enum ClaudeError {
 /// Requests are processed serially by a background worker to prevent
 /// concurrent API calls.
 pub struct ClaudeApi {
-    request_tx: mpsc::Sender<ClaudeRequest>,
+    input_tx: mpsc::Sender<Input>,
     stop_tx: mpsc::Sender<()>,
     #[allow(dead_code)]
     worker_handle: tokio::task::JoinHandle<()>,
@@ -100,10 +102,10 @@ impl ClaudeApi {
         config: ClaudeConfig,
         tool_executor: Weak<dyn ToolExecutor>,
     ) -> Result<Self, ClaudeError> {
-        let (request_tx, request_rx) = mpsc::channel(REQUEST_QUEUE_SIZE);
+        let (input_tx, input_rx) = mpsc::channel(REQUEST_QUEUE_SIZE);
         let (stop_tx, stop_rx) = mpsc::channel(REQUEST_QUEUE_SIZE);
 
-        let worker = ClaudeWorker::new(config, tool_executor, request_rx, stop_rx)?;
+        let worker = ClaudeWorker::new(config, tool_executor, input_rx, stop_rx)?;
 
         let worker_handle = tokio::spawn(async move {
             worker.run().await;
@@ -111,26 +113,29 @@ impl ClaudeApi {
         });
 
         Ok(Self {
-            request_tx,
+            input_tx,
             stop_tx,
             worker_handle,
         })
     }
 
-    /// Send a request to the Claude API and return the response text.
+    /// Send a prompt to the Claude API, execute tools etc., and return the response text.
     ///
     /// Returns a future that resolves when the request is complete.
     /// Returns `QueueFull` error if the request queue is full.
-    pub async fn request(&self, prompt: &str) -> Result<String, ClaudeError> {
+    pub async fn request(&self, prompt: &str, ts_ms: u64) -> Result<String, ClaudeError> {
         let (result_tx, result_rx) = oneshot::channel();
 
-        let request = ClaudeRequest {
-            prompt: prompt.to_owned(),
-            result_sender: result_tx,
+        let timestamp = DateTime::from_timestamp_millis(ts_ms as i64).unwrap_or_else(Utc::now);
+        let msg = ChatMessage {
+            sent_by: SentBy::UserToClaude,
+            text: prompt.into(),
+            timestamp,
+            result_sender: Some(result_tx),
         };
 
-        self.request_tx
-            .try_send(request)
+        self.input_tx
+            .try_send(Input::Chat(msg))
             .map_err(|_| ClaudeError::QueueFull)?;
 
         // result_rx.await has type Result<Result<String, ClaudeError>, RecvError>
@@ -138,7 +143,26 @@ impl ClaudeApi {
         result_rx.await.map_err(|_| ClaudeError::WorkerGone)?
     }
 
-    /// Request the worker to stop processing.
+    /// Record a message into claude's chat log that claude is not expected to respond to
+    pub fn record_message(&self, sent_by: SentBy, text: &str, ts_ms: u64) {
+        let timestamp = DateTime::from_timestamp_millis(ts_ms as i64).unwrap_or_else(Utc::now);
+        let msg = ChatMessage {
+            sent_by,
+            text: text.into(),
+            timestamp,
+            result_sender: None,
+        };
+
+        let _ = self.input_tx.try_send(Input::Chat(msg));
+    }
+
+    /// Request the worker to perform compaction (summarizing their recent message history and discarding it)
+    pub fn request_compaction(&self) {
+        let _ = self.input_tx.try_send(Input::Compact);
+    }
+
+    /// Request the worker to interrupt any prompts it is responding to, discard any queued messages,
+    /// and get ready to accept different prompts.
     ///
     /// This will cause the current request (if any) to be interrupted at the
     /// next opportunity, and all pending requests to receive `StopRequested` errors.

signal-gateway/src/claude/worker.rs

@@ -1,16 +1,70 @@
 //! Background worker that processes Claude API requests serially.
 
 use super::{ANTHROPIC_API_VERSION, ClaudeConfig, ClaudeError, Tool, ToolExecutor};
+use chrono::{DateTime, Utc};
 use serde::{Deserialize, Serialize};
 use serde_json::Value;
 use std::sync::Weak;
 use tokio::sync::{mpsc, oneshot};
 use tracing::info;
 
-/// A request to be processed by the Claude worker.
-pub struct ClaudeRequest {
-    pub prompt: String,
-    pub result_sender: oneshot::Sender<Result<String, ClaudeError>>,
+/// Sent with inputs to claude that claude is expected to respond to. The sender
+/// gives the worker a way to return the results to the caller asynchronously.
+pub type ResultSender = oneshot::Sender<Result<String, ClaudeError>>;
+
+/// Indicates the "role" i.e. the manner in which a particular message was sent
+pub enum SentBy {
+    /// User message directed at the system (commands, etc.)
+    UserToSystem,
+    /// User message directed at Claude (prompts)
+    UserToClaude,
+    /// Response from Claude
+    Claude,
+    /// System-generated message
+    System,
+    /// Alert from alertmanager
+    AlertManager,
+}
+
+impl SentBy {
+    fn role(&self) -> &str {
+        match self {
+            Self::UserToSystem => "user (speaking to system)",
+            Self::UserToClaude => "user (speaking to assistant)",
+            Self::Claude => "assistant",
+            Self::System => "system",
+            Self::AlertManager => "alertmanager",
+        }
+    }
+}
+
+/// An input to the worker sent through the channel
+pub enum Input {
+    Chat(ChatMessage),
+    Compact,
+}
+
+/// A chat message
+pub struct ChatMessage {
+    pub sent_by: SentBy,
+    pub timestamp: DateTime<Utc>,
+    pub text: Box<str>,
+    /// Present when claude is expected to respond to the message
+    pub result_sender: Option<ResultSender>,
+}
+
+impl ChatMessage {
+    fn into_content_and_sender(self) -> (MessageContent, Option<ResultSender>) {
+        let mc = MessageContent {
+            role: self.sent_by.role().into(),
+            content: vec![ContentBlock::Text {
+                text: self.text,
+                timestamp: Some(self.timestamp),
+            }],
+        };
+
+        (mc, self.result_sender)
+    }
 }
 
 /// Background worker that processes Claude API requests serially.
@@ -19,8 +73,12 @@ pub struct ClaudeWorker {
     client: reqwest::Client,
     api_key: String,
     system_prompt: String,
+    // FIXME: use this and append to system prompt within <summary> </summary> tags
+    #[allow(dead_code)]
+    summary: String,
+    messages: Vec<MessageContent>,
     tool_executor: Weak<dyn ToolExecutor>,
-    request_rx: mpsc::Receiver<ClaudeRequest>,
+    input_rx: mpsc::Receiver<Input>,
     stop_rx: mpsc::Receiver<()>,
 }
 
@@ -31,7 +89,7 @@ impl ClaudeWorker {
     pub fn new(
         config: ClaudeConfig,
         tool_executor: Weak<dyn ToolExecutor>,
-        request_rx: mpsc::Receiver<ClaudeRequest>,
+        input_rx: mpsc::Receiver<Input>,
         stop_rx: mpsc::Receiver<()>,
     ) -> Result<Self, ClaudeError> {
         let api_key = std::fs::read_to_string(&config.api_key_file)
@@ -47,8 +105,10 @@ impl ClaudeWorker {
             client: reqwest::Client::new(),
             api_key,
             system_prompt,
+            summary: String::new(),
+            messages: Default::default(),
             tool_executor,
-            request_rx,
+            input_rx,
             stop_rx,
         })
     }
@@ -57,18 +117,29 @@ impl ClaudeWorker {
     pub async fn run(mut self) {
         loop {
             tokio::select! {
-                request = self.request_rx.recv() => {
-                    let Some(request) = request else {
+                input = self.input_rx.recv() => {
+                    let Some(input) = input else {
                         // Channel closed, exit
                         break;
                     };
-                    let result = self.handle_request(&request.prompt).await;
-                    // If handle_request was interrupted by stop request, go on to drain the queues
-                    if matches!(result, Err(ClaudeError::StopRequested)) {
-                        self.handle_stop();
+                    match input {
+                        Input::Chat(msg) => {
+                            let (mc, maybe_sender) = msg.into_content_and_sender();
+                            self.messages.push(mc);
+                            if let Some(sender) = maybe_sender {
+                                let result = self.handle_request().await;
+                                // If handle_request was interrupted by stop request, go on to drain the queues
+                                if matches!(result, Err(ClaudeError::StopRequested)) {
+                                    self.handle_stop();
+                                }
+                                // Ignore send errors - the caller may have dropped the receiver
+                                let _ = sender.send(result);
+                            }
+                        },
+                        Input::Compact => {
+                            self.handle_compact().await;
+                        }
                     }
-                    // Ignore send errors - the caller may have dropped the receiver
-                    let _ = request.result_sender.send(result);
                 }
                 _ = self.stop_rx.recv() => {
                     self.handle_stop();
@@ -82,9 +153,18 @@ impl ClaudeWorker {
         // Drain the stop_rx queue
         while self.stop_rx.try_recv().is_ok() {}
 
-        // Drain the request_rx queue and send StopRequested to each
-        while let Ok(request) = self.request_rx.try_recv() {
-            let _ = request.result_sender.send(Err(ClaudeError::StopRequested));
+        // Drain the input_rx queue and send StopRequested to each prompt request
+        while let Ok(input) = self.input_rx.try_recv() {
+            match input {
+                Input::Chat(msg) => {
+                    let (mc, maybe_sender) = msg.into_content_and_sender();
+                    self.messages.push(mc);
+                    if let Some(sender) = maybe_sender {
+                        let _ = sender.send(Err(ClaudeError::StopRequested));
+                    }
+                }
+                Input::Compact => {}
+            }
         }
     }
 
@@ -97,16 +177,25 @@ impl ClaudeWorker {
         }
     }
 
+    /// Perform compaction
+    async fn handle_compact(&mut self) {
+        // FIXME: we should actually try to summarize messages using an api request, and then store it, before tossing messages
+        self.messages.clear();
+    }
+
     /// Handle a single request to the Claude API.
-    async fn handle_request(&mut self, prompt: &str) -> Result<String, ClaudeError> {
+    async fn handle_request(&mut self) -> Result<String, ClaudeError> {
         let max_iterations = self.config.claude_max_iterations;
 
         // Get tools from the executor if still alive
         let executor = self.tool_executor.upgrade();
         let tools = executor.as_ref().map(|te| te.tools()).unwrap_or_default();
-        let mut messages = vec![MessageContent::user(prompt)];
 
-        info!("Claude request: {}", prompt);
+        if let Some(last) = self.messages.last() {
+            if let Some(ContentBlock::Text { text, .. }) = last.content.first() {
+                info!("Claude request: {}", text);
+            }
+        }
 
         for iteration in 0..max_iterations {
             // Check for stop before making API call
@@ -116,7 +205,7 @@ impl ClaudeWorker {
                 model: &self.config.claude_model,
                 max_tokens: self.config.claude_max_tokens,
                 system: &self.system_prompt,
-                messages: messages.clone(),
+                messages: &self.messages,
                 tools: tools.clone(),
             };
 
@@ -142,14 +231,15 @@ impl ClaudeWorker {
             );
 
             // Check if we need to handle tool use
-            if response.stop_reason == "tool_use" {
+            if response.stop_reason.as_ref() == "tool_use" {
                 // Try to get a strong reference to the executor
                 let Some(executor) = self.tool_executor.upgrade() else {
                     return Err(ClaudeError::ToolExecutorGone);
                 };
 
                 // Add assistant's response to messages
-                messages.push(MessageContent::assistant(response.content.clone()));
+                self.messages
+                    .push(MessageContent::assistant(response.content.clone()));
 
                 // Execute each tool use and collect results
                 for block in &response.content {
@@ -168,7 +258,11 @@ impl ClaudeWorker {
                                 (err, true)
                             }
                         };
-                        messages.push(MessageContent::tool_result(id.clone(), result, is_error));
+                        self.messages.push(MessageContent::tool_result(
+                            id.to_string(),
+                            result,
+                            is_error,
+                        ));
                     }
                 }
 
@@ -182,7 +276,7 @@ impl ClaudeWorker {
                 .content
                 .into_iter()
                 .filter_map(|block| {
-                    if let ContentBlock::Text { text } = block {
+                    if let ContentBlock::Text { text, .. } = block {
                         Some(text)
                     } else {
                         None
@@ -205,7 +299,7 @@ struct MessagesRequest<'a> {
     model: &'a str,
     max_tokens: u32,
     system: &'a str,
-    messages: Vec<MessageContent>,
+    messages: &'a [MessageContent],
     #[serde(skip_serializing_if = "Vec::is_empty")]
     tools: Vec<Tool>,
 }
@@ -213,33 +307,24 @@ struct MessagesRequest<'a> {
 /// A message in the conversation (can have multiple content blocks).
 #[derive(Clone, Debug, Serialize, Deserialize)]
 struct MessageContent {
-    role: String,
+    role: Box<str>,
     content: Vec<ContentBlock>,
 }
 
 impl MessageContent {
-    fn user(text: &str) -> Self {
-        Self {
-            role: "user".to_owned(),
-            content: vec![ContentBlock::Text {
-                text: text.to_owned(),
-            }],
-        }
-    }
-
     fn assistant(blocks: Vec<ContentBlock>) -> Self {
         Self {
-            role: "assistant".to_owned(),
+            role: "assistant".into(),
             content: blocks,
         }
     }
 
     fn tool_result(tool_use_id: String, content: String, is_error: bool) -> Self {
         Self {
-            role: "user".to_owned(),
+            role: "user".into(),
             content: vec![ContentBlock::ToolResult {
-                tool_use_id,
-                content,
+                tool_use_id: tool_use_id.into(),
+                content: content.into(),
                 is_error: if is_error { Some(true) } else { None },
             }],
         }
@@ -251,16 +336,18 @@ impl MessageContent {
 #[serde(tag = "type", rename_all = "snake_case")]
 enum ContentBlock {
     Text {
-        text: String,
+        text: Box<str>,
+        #[serde(default, skip_serializing_if = "Option::is_none")]
+        timestamp: Option<DateTime<Utc>>,
     },
     ToolUse {
-        id: String,
-        name: String,
+        id: Box<str>,
+        name: Box<str>,
         input: Value,
     },
     ToolResult {
-        tool_use_id: String,
-        content: String,
+        tool_use_id: Box<str>,
+        content: Box<str>,
         #[serde(skip_serializing_if = "Option::is_none")]
         is_error: Option<bool>,
     },
@@ -270,7 +357,7 @@ enum ContentBlock {
 #[derive(Debug, Deserialize)]
 struct MessagesResponse {
     content: Vec<ContentBlock>,
-    stop_reason: String,
+    stop_reason: Box<str>,
 }
 
 /// Error response from the Claude API.
@@ -281,5 +368,5 @@ struct ErrorResponse {
 
 #[derive(Deserialize)]
 struct ApiErrorDetail {
-    message: String,
+    message: Box<str>,
 }

signal-gateway/src/gateway/mod.rs

@@ -4,7 +4,7 @@
 use crate::signal_jsonrpc::connect_ipc;
 use crate::{
     alertmanager::AlertPost,
-    claude::{ClaudeApi, ClaudeConfig, Tool, ToolExecutor},
+    claude::{ClaudeApi, ClaudeConfig, SentBy, Tool, ToolExecutor},
     log_message::{LogMessage, Origin},
     message_handler::{
         AdminMessage, AdminMessageResponse, Context, MessageHandler, MessageHandlerResult,
@@ -147,6 +147,9 @@ enum GatewayCommand {
     /// Stop current Claude request
     #[conf(name = "cs", alias = "CS")]
     ClaudeStop,
+    /// Compact Claude's message history
+    #[conf(name = "compact", alias = "COMPACT")]
+    ClaudeCompact,
 }
 
 /// Parse a gateway command from a string (with or without leading /)
@@ -405,9 +408,13 @@ impl Gateway {
                         SignalMessage {
                             sender: self.config.signal_account.clone(),
                             target,
-                            message,
+                            message: message.clone(),
                             attachments,
                         }.send(signal_cli).await?;
+
+                        if let Some(claude) = self.claude.get() {
+                            claude.record_message(SentBy::System, &message, Utc::now().timestamp_millis() as u64);
+                        }
                     } else {
                         warn!("alert_rx is closed, halting service");
                         self.token.cancel();
@@ -455,7 +462,7 @@ impl Gateway {
                                 AdminMessageResponse::new(text)
                             });
 
-                            let attachments = resp.attachments.into_iter().map(|p| p.to_str().expect("attachments must have utf8 paths").to_owned()).collect();
+                            let attachments = resp.attachments.iter().map(|p| p.to_str().expect("attachments must have utf8 paths").to_owned()).collect();
 
                             // Reply to group if message came from a group, otherwise reply to sender
                             let target = if let Some(group_id) = from_group {
@@ -467,9 +474,14 @@ impl Gateway {
                             SignalMessage {
                                 sender: self.config.signal_account.clone(),
                                 target,
-                                message: resp.text,
+                                message: resp.text.clone(),
                                 attachments,
                             }.send(signal_cli).await?;
+
+                            if let Some(claude) = self.claude.get() {
+                                let sent_by = if resp.is_claude { SentBy::Claude } else { SentBy::System };
+                                claude.record_message(sent_by, &resp.text, Utc::now().timestamp_millis() as u64);
+                            }
                         }
                     }
                 }
@@ -488,8 +500,31 @@ impl Gateway {
             // Parse the command using conf
             let cmd = parse_gateway_command(&data.message).map_err(|err| (400u16, err.into()))?;
 
-            self.handle_gateway_command(cmd).await
+            // Record this as a system command in Claude's history, unless it's a Claude
+            // prompt command (which will be recorded when we call request())
+            let is_claude = matches!(cmd, GatewayCommand::Claude { .. });
+            if !is_claude {
+                if let Some(claude) = self.claude.get() {
+                    claude.record_message(
+                        SentBy::UserToSystem,
+                        &data.message,
+                        data.timestamp,
+                    );
+                }
+            }
+
+            let resp = self.handle_gateway_command(cmd, data.timestamp).await?;
+            Ok(if is_claude { resp.from_claude() } else { resp })
         } else if let Some(handler) = &self.message_handler {
+            // Record this as a system message in Claude's history (not directed at Claude)
+            if let Some(claude) = self.claude.get() {
+                claude.record_message(
+                    SentBy::UserToSystem,
+                    &data.message,
+                    data.timestamp,
+                );
+            }
+
             let msg = AdminMessage {
                 message: data.message.clone(),
                 timestamp: data.timestamp,
@@ -566,7 +601,11 @@ impl Gateway {
         }
     }
 
-    async fn handle_gateway_command(&self, cmd: GatewayCommand) -> MessageHandlerResult {
+    async fn handle_gateway_command(
+        &self,
+        cmd: GatewayCommand,
+        ts_ms: u64,
+    ) -> MessageHandlerResult {
         match cmd {
             GatewayCommand::Log { filter } => {
                 let text = self.log_handler.format_logs(filter.as_deref()).await;
@@ -713,7 +752,7 @@ impl Gateway {
                     .ok_or_else(|| (501u16, "claude was not configured".into()))?;
 
                 let prompt_text = prompt.join(" ");
-                match claude.request(&prompt_text).await {
+                match claude.request(&prompt_text, ts_ms).await {
                     Ok(response) => Ok(AdminMessageResponse::new(response)),
                     Err(err) => Err((500, err.to_string().into())),
                 }
@@ -727,6 +766,15 @@ impl Gateway {
                 claude.request_stop();
                 Ok(AdminMessageResponse::new("stop requested"))
             }
+            GatewayCommand::ClaudeCompact => {
+                let claude = self
+                    .claude
+                    .get()
+                    .ok_or_else(|| (501u16, "claude was not configured".into()))?;
+
+                claude.request_compaction();
+                Ok(AdminMessageResponse::new("compaction requested"))
+            }
         }
     }
 

signal-gateway/src/message_handler.rs

@@ -35,6 +35,8 @@ pub struct AdminMessageResponse {
     pub text: String,
     /// Optional file attachments to include with the response.
     pub attachments: Vec<PathBuf>,
+    /// Whether this response came from Claude (true) or the system (false).
+    pub(crate) is_claude: bool,
 }
 
 impl AdminMessageResponse {
@@ -43,6 +45,7 @@ impl AdminMessageResponse {
         Self {
             text: text.into(),
             attachments: Vec::new(),
+            is_claude: false,
         }
     }
 
@@ -62,6 +65,12 @@ impl AdminMessageResponse {
         self.attachments.extend(paths.into_iter().map(Into::into));
         self
     }
+
+    /// Mark this response as coming from Claude.
+    pub(crate) fn from_claude(mut self) -> Self {
+        self.is_claude = true;
+        self
+    }
 }
 
 /// Builder for constructing an [`AdminMessageResponse`].
@@ -95,6 +104,7 @@ impl AdminMessageResponseBuilder {
         AdminMessageResponse {
             text: self.text,
             attachments: self.attachments,
+            is_claude: false,
         }
     }
 }