Revert "feat(agent): add parallel tool execution with concurrency-safe batching"

This reverts commit 0c0d0c14436a230ca34c0cd9647c8fc14f62d7cc.

src/agent/agent_loop.rs

@@ -51,22 +51,26 @@ fn encode_image_to_base64(path: &str) -> Result<(String, String), std::io::Error
 pub struct AgentLoop {
     provider: Box<dyn LLMProvider>,
     tools: Arc<ToolRegistry>,
-    max_iterations: u32,
 }
 
 impl AgentLoop {
     pub fn new(provider_config: LLMProviderConfig) -> Result<Self, AgentError> {
-        Self::with_tools(provider_config, Arc::new(ToolRegistry::new()))
+        let provider = create_provider(provider_config)
+            .map_err(|e| AgentError::ProviderCreation(e.to_string()))?;
+
+        Ok(Self {
+            provider,
+            tools: Arc::new(ToolRegistry::new()),
+        })
     }
 
     pub fn with_tools(provider_config: LLMProviderConfig, tools: Arc<ToolRegistry>) -> Result<Self, AgentError> {
-        let provider = create_provider(provider_config.clone())
+        let provider = create_provider(provider_config)
             .map_err(|e| AgentError::ProviderCreation(e.to_string()))?;
 
         Ok(Self {
             provider,
             tools,
-            max_iterations: provider_config.max_iterations,
         })
     }
 
@@ -76,80 +80,8 @@ impl AgentLoop {
 
     /// Process a message using the provided conversation history.
     /// History management is handled externally by SessionManager.
-    /// Returns (final_response, complete_message_history) where the history includes
+    pub async fn process(&self, messages: Vec<ChatMessage>) -> Result<ChatMessage, AgentError> {
-    /// all tool calls and results for proper session continuity.
+        let messages_for_llm: Vec<Message> = messages
-    pub async fn process(&self, messages: Vec<ChatMessage>) -> Result<(ChatMessage, Vec<ChatMessage>), AgentError> {
-        let mut messages = messages;
-        let mut final_content: String = String::new();
-
-        for iteration in 0..self.max_iterations {
-            tracing::debug!(iteration, history_len = messages.len(), "Starting iteration");
-
-            let messages_for_llm = self.build_messages_for_llm(&messages);
-
-            let tools = if self.tools.has_tools() {
-                Some(self.tools.get_definitions())
-            } else {
-                None
-            };
-
-            let request = ChatCompletionRequest {
-                messages: messages_for_llm,
-                temperature: None,
-                max_tokens: None,
-                tools,
-            };
-
-            let response = (*self.provider).chat(request).await
-                .map_err(|e| {
-                    tracing::error!(error = %e, "LLM request failed");
-                    AgentError::LlmError(e.to_string())
-                })?;
-
-            tracing::debug!(
-                response_len = response.content.len(),
-                tool_calls_len = response.tool_calls.len(),
-                "LLM response received"
-            );
-
-            if !response.tool_calls.is_empty() {
-                tracing::info!(count = response.tool_calls.len(), iteration, tools = ?response.tool_calls.iter().map(|tc| &tc.name).collect::<Vec<_>>(), "Tool calls detected, executing tools");
-
-                let assistant_message = ChatMessage::assistant(response.content.clone());
-                messages.push(assistant_message);
-
-                let tool_results = self.execute_tools(&response.tool_calls).await;
-
-                for (tool_call, result) in response.tool_calls.iter().zip(tool_results.iter()) {
-                    let tool_message = ChatMessage::tool(
-                        tool_call.id.clone(),
-                        tool_call.name.clone(),
-                        result.clone(),
-                    );
-                    messages.push(tool_message);
-                }
-
-                tracing::debug!(iteration, "Tool execution completed, continuing to next iteration");
-                continue;
-            }
-
-            tracing::debug!(iteration, "No tool calls in response, agent loop ending");
-            final_content = response.content;
-            break;
-        }
-
-        if final_content.is_empty() {
-            tracing::warn!(iterations = self.max_iterations, "Max iterations reached without final response");
-            final_content = format!("Error: Max iterations ({}) reached without final response", self.max_iterations);
-        }
-
-        let final_message = ChatMessage::assistant(final_content);
-        // Return both the final message and the complete history for session persistence
-        Ok((final_message, messages))
-    }
-
-    fn build_messages_for_llm(&self, messages: &[ChatMessage]) -> Vec<Message> {
-        messages
             .iter()
             .map(|m| {
                 let content = if m.media_refs.is_empty() {
@@ -168,62 +100,114 @@ impl AgentLoop {
                     name: m.tool_name.clone(),
                 }
             })
-            .collect()
+            .collect();
+
+        #[cfg(debug_assertions)]
+        tracing::debug!(history_len = messages.len(), "Sending request to LLM");
+
+        let tools = if self.tools.has_tools() {
+            Some(self.tools.get_definitions())
+        } else {
+            None
+        };
+
+        let request = ChatCompletionRequest {
+            messages: messages_for_llm,
+            temperature: None,
+            max_tokens: None,
+            tools,
+        };
+
+        let response = (*self.provider).chat(request).await
+            .map_err(|e| {
+                tracing::error!(error = %e, "LLM request failed");
+                AgentError::LlmError(e.to_string())
+            })?;
+
+        #[cfg(debug_assertions)]
+        tracing::debug!(
+            response_len = response.content.len(),
+            tool_calls_len = response.tool_calls.len(),
+            "LLM response received"
+        );
+
+        if !response.tool_calls.is_empty() {
+            tracing::info!(count = response.tool_calls.len(), "Tool calls detected, executing tools");
+
+            let mut updated_messages = messages.clone();
+            let assistant_message = ChatMessage::assistant(response.content.clone());
+            updated_messages.push(assistant_message.clone());
+
+            let tool_results = self.execute_tools(&response.tool_calls).await;
+
+            for (tool_call, result) in response.tool_calls.iter().zip(tool_results.iter()) {
+                let tool_message = ChatMessage::tool(
+                    tool_call.id.clone(),
+                    tool_call.name.clone(),
+                    result.clone(),
+                );
+                updated_messages.push(tool_message);
+            }
+
+            return self.continue_with_tool_results(updated_messages).await;
+        }
+
+        let assistant_message = ChatMessage::assistant(response.content);
+        Ok(assistant_message)
+    }
+
+    async fn continue_with_tool_results(&self, messages: Vec<ChatMessage>) -> Result<ChatMessage, AgentError> {
+        let messages_for_llm: Vec<Message> = messages
+            .iter()
+            .map(|m| {
+                let content = if m.media_refs.is_empty() {
+                    vec![ContentBlock::text(&m.content)]
+                } else {
+                    build_content_blocks(&m.content, &m.media_refs)
+                };
+                Message {
+                    role: m.role.clone(),
+                    content,
+                    tool_call_id: m.tool_call_id.clone(),
+                    name: m.tool_name.clone(),
+                }
+            })
+            .collect();
+
+        let tools = if self.tools.has_tools() {
+            Some(self.tools.get_definitions())
+        } else {
+            None
+        };
+
+        let request = ChatCompletionRequest {
+            messages: messages_for_llm,
+            temperature: None,
+            max_tokens: None,
+            tools,
+        };
+
+        let response = (*self.provider).chat(request).await
+            .map_err(|e| {
+                tracing::error!(error = %e, "LLM continuation request failed");
+                AgentError::LlmError(e.to_string())
+            })?;
+
+        let assistant_message = ChatMessage::assistant(response.content);
+        Ok(assistant_message)
     }
 
     async fn execute_tools(&self, tool_calls: &[ToolCall]) -> Vec<String> {
-        let batches = self.partition_tool_batches(tool_calls);
         let mut results = Vec::with_capacity(tool_calls.len());
 
-        for batch in batches {
+        for tool_call in tool_calls {
-            if batch.len() == 1 {
+            let result = self.execute_tool(tool_call).await;
-                // Single tool — run directly (no spawn overhead)
+            results.push(result);
-                results.push(self.execute_tool(&batch[0]).await);
-            } else {
-                // Multiple tools — run in parallel via join_all
-                use futures_util::future::join_all;
-                let futures = batch.iter().map(|tc| self.execute_tool(tc));
-                let batch_results = join_all(futures).await;
-                results.extend(batch_results);
-            }
         }
 
         results
     }
 
-    /// Partition tool calls into batches based on concurrency safety.
-    ///
-    /// `concurrency_safe` tools are grouped together; each `exclusive` tool
-    /// runs in its own batch. This matches the approach used in Nanobot's
-    /// `_partition_tool_batches` and Zeroclaw's `parallel_tools` config.
-    fn partition_tool_batches(&self, tool_calls: &[ToolCall]) -> Vec<Vec<ToolCall>> {
-        let mut batches: Vec<Vec<ToolCall>> = Vec::new();
-        let mut current: Vec<ToolCall> = Vec::new();
-
-        for tc in tool_calls {
-            let concurrency_safe = self
-                .tools
-                .get(&tc.name)
-                .map(|t| t.concurrency_safe())
-                .unwrap_or(false);
-
-            if concurrency_safe {
-                current.push(tc.clone());
-            } else {
-                if !current.is_empty() {
-                    batches.push(std::mem::take(&mut current));
-                }
-                batches.push(vec![tc.clone()]);
-            }
-        }
-
-        if !current.is_empty() {
-            batches.push(current);
-        }
-
-        batches
-    }
-
     async fn execute_tool(&self, tool_call: &ToolCall) -> String {
         let tool = match self.tools.get(&tool_call.name) {
             Some(t) => t,
@@ -267,140 +251,3 @@ impl std::fmt::Display for AgentError {
 }
 
 impl std::error::Error for AgentError {}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::providers::ToolCall;
-    use crate::tools::ToolRegistry;
-    use crate::tools::CalculatorTool;
-    use crate::tools::BashTool;
-    use crate::tools::FileReadTool;
-    use std::sync::Arc;
-    use serde_json::json;
-
-    fn make_tc(name: &str, args: serde_json::Value) -> ToolCall {
-        ToolCall {
-            id: format!("tc_{}", name),
-            name: name.to_string(),
-            arguments: args,
-        }
-    }
-
-    /// Verify that partition_tool_batches groups concurrency-safe tools together
-    /// and isolates exclusive tools, matching the nanobot/zeroclaw approach.
-    #[test]
-    fn test_partition_batches_mixes_safe_and_exclusive() {
-        let registry = Arc::new({
-            let mut r = ToolRegistry::new();
-            r.register(CalculatorTool::new());  // concurrency_safe = true
-            r.register(BashTool::new());          // concurrency_safe = false (exclusive)
-            r.register(FileReadTool::new());      // concurrency_safe = true
-            r
-        });
-
-        // agent_loop needs a provider to construct; test the partitioning logic directly
-        let tcs = vec![
-            make_tc("calculator", json!({})),
-            make_tc("bash", json!({"command": "ls"})),
-            make_tc("file_read", json!({"path": "/tmp/foo"})),
-            make_tc("calculator", json!({})),
-        ];
-
-        // Expected:
-        // batch 1: calculator (safe, first run)
-        // batch 2: bash (exclusive, alone)
-        // batch 3: file_read, calculator (both safe, run together)
-        let batches = partition_for_test(&registry, &tcs);
-        assert_eq!(batches.len(), 3);
-        assert_eq!(batches[0].len(), 1);
-        assert_eq!(batches[0][0].name, "calculator");
-        assert_eq!(batches[1].len(), 1);
-        assert_eq!(batches[1][0].name, "bash");
-        assert_eq!(batches[2].len(), 2);
-        assert_eq!(batches[2][0].name, "file_read");
-        assert_eq!(batches[2][1].name, "calculator");
-    }
-
-    /// All-safe tool calls should produce a single batch (parallel execution).
-    #[test]
-    fn test_partition_batches_all_safe_single_batch() {
-        let registry = Arc::new({
-            let mut r = ToolRegistry::new();
-            r.register(CalculatorTool::new());
-            r.register(FileReadTool::new());
-            r
-        });
-
-        let tcs = vec![
-            make_tc("calculator", json!({})),
-            make_tc("file_read", json!({"path": "/tmp/foo"})),
-        ];
-
-        let batches = partition_for_test(&registry, &tcs);
-        assert_eq!(batches.len(), 1);
-        assert_eq!(batches[0].len(), 2);
-    }
-
-    /// All-exclusive tool calls should each get their own batch (sequential execution).
-    #[test]
-    fn test_partition_batches_all_exclusive_separate_batches() {
-        let registry = Arc::new({
-            let mut r = ToolRegistry::new();
-            r.register(BashTool::new());
-            r
-        });
-
-        let tcs = vec![
-            make_tc("bash", json!({"command": "ls"})),
-            make_tc("bash", json!({"command": "pwd"})),
-        ];
-
-        let batches = partition_for_test(&registry, &tcs);
-        assert_eq!(batches.len(), 2);
-        assert_eq!(batches[0].len(), 1);
-        assert_eq!(batches[1].len(), 1);
-    }
-
-    /// Unknown tools (not in registry) default to non-concurrency-safe (single batch).
-    #[test]
-    fn test_partition_batches_unknown_tool_gets_own_batch() {
-        let registry = Arc::new(ToolRegistry::new());
-
-        let tcs = vec![
-            make_tc("calculator", json!({})),
-            make_tc("unknown_tool", json!({})),
-        ];
-
-        let batches = partition_for_test(&registry, &tcs);
-        assert_eq!(batches.len(), 2);
-    }
-
-    /// Expose partition logic for testing without needing a full AgentLoop.
-    fn partition_for_test(registry: &Arc<ToolRegistry>, tool_calls: &[ToolCall]) -> Vec<Vec<ToolCall>> {
-        let mut batches: Vec<Vec<ToolCall>> = Vec::new();
-        let mut current: Vec<ToolCall> = Vec::new();
-
-        for tc in tool_calls {
-            let concurrency_safe = registry
-                .get(&tc.name)
-                .map(|t| t.concurrency_safe())
-                .unwrap_or(false);
-
-            if concurrency_safe {
-                current.push(tc.clone());
-            } else {
-                if !current.is_empty() {
-                    batches.push(std::mem::take(&mut current));
-                }
-                batches.push(vec![tc.clone()]);
-            }
-        }
-
-        if !current.is_empty() {
-            batches.push(current);
-        }
-
-        batches
-    }
-}

src/config/mod.rs

@@ -45,7 +45,7 @@ fn default_media_dir() -> String {
 }
 
 fn default_reaction_emoji() -> String {
-    "Typing".to_string()
+    "THUMBSUP".to_string()
 }
 
 #[derive(Debug, Clone, Deserialize, Serialize)]
@@ -73,12 +73,6 @@ pub struct ModelConfig {
 pub struct AgentConfig {
     pub provider: String,
     pub model: String,
-    #[serde(default = "default_max_iterations")]
-    pub max_iterations: u32,
-}
-
-fn default_max_iterations() -> u32 {
-    15
 }
 
 #[derive(Debug, Clone, Deserialize, Serialize)]
@@ -138,7 +132,6 @@ pub struct LLMProviderConfig {
     pub temperature: Option<f32>,
     pub max_tokens: Option<u32>,
     pub model_extra: HashMap<String, serde_json::Value>,
-    pub max_iterations: u32,
 }
 
 fn get_default_config_path() -> PathBuf {
@@ -198,7 +191,6 @@ impl Config {
             temperature: model.temperature,
             max_tokens: model.max_tokens,
             model_extra: model.extra.clone(),
-            max_iterations: agent.max_iterations,
         })
     }
 }

src/tools/calculator.rs

@@ -92,10 +92,6 @@ impl Tool for CalculatorTool {
         })
     }
 
-    fn read_only(&self) -> bool {
-        true
-    }
-
     async fn execute(&self, args: serde_json::Value) -> anyhow::Result<ToolResult> {
         let function = match args.get("function").and_then(|v| v.as_str()) {
             Some(f) => f,