feat: add support for preToolUse and postToolUse hook (#2875)

Author: erbenmo

crates/chat-cli/src/cli/agent/hook.rs

@@ -1,4 +1,3 @@
-use std::collections::HashMap;
 use std::fmt::Display;
 
 use schemars::JsonSchema;
@@ -11,23 +10,26 @@ const DEFAULT_TIMEOUT_MS: u64 = 30_000;
 const DEFAULT_MAX_OUTPUT_SIZE: usize = 1024 * 10;
 const DEFAULT_CACHE_TTL_SECONDS: u64 = 0;
 
-#[derive(Debug, Clone, Serialize, Deserialize, Eq, PartialEq, JsonSchema)]
-pub struct Hooks(HashMap<HookTrigger, Hook>);
-
 #[derive(Debug, Clone, Copy, Serialize, Deserialize, Eq, PartialEq, JsonSchema, Hash)]
 #[serde(rename_all = "camelCase")]
 pub enum HookTrigger {
     /// Triggered during agent spawn
     AgentSpawn,
     /// Triggered per user message submission
     UserPromptSubmit,
+    /// Triggered before tool execution
+    PreToolUse,
+    /// Triggered after tool execution
+    PostToolUse,
 }
 
 impl Display for HookTrigger {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         match self {
             HookTrigger::AgentSpawn => write!(f, "agentSpawn"),
             HookTrigger::UserPromptSubmit => write!(f, "userPromptSubmit"),
+            HookTrigger::PreToolUse => write!(f, "preToolUse"),
+            HookTrigger::PostToolUse => write!(f, "postToolUse"),
         }
     }
 }
@@ -61,6 +63,11 @@ pub struct Hook {
     #[serde(default = "Hook::default_cache_ttl_seconds")]
     pub cache_ttl_seconds: u64,
 
+    /// Optional glob matcher for hook
+    /// Currently used for matching tool name of PreToolUse and PostToolUse hook
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub matcher: Option<String>,
+
     #[schemars(skip)]
     #[serde(default, skip_serializing)]
     pub source: Source,
@@ -73,6 +80,7 @@ impl Hook {
             timeout_ms: Self::default_timeout_ms(),
             max_output_size: Self::default_max_output_size(),
             cache_ttl_seconds: Self::default_cache_ttl_seconds(),
+            matcher: None,
             source,
         }
     }

crates/chat-cli/src/cli/agent/legacy/hooks.rs

@@ -80,6 +80,7 @@ impl From<LegacyHook> for Option<Hook> {
             timeout_ms: value.timeout_ms,
             max_output_size: value.max_output_size,
             cache_ttl_seconds: value.cache_ttl_seconds,
+            matcher: None,
             source: Default::default(),
         })
     }

crates/chat-cli/src/cli/agent/mod.rs

@@ -959,6 +959,7 @@ mod tests {
     use serde_json::json;
 
     use super::*;
+    use crate::cli::agent::hook::Source;
     const INPUT: &str = r#"
             {
               "name": "some_agent",
@@ -968,21 +969,21 @@ mod tests {
                 "fetch": { "command": "fetch3.1", "args": [] },
                 "git": { "command": "git-mcp", "args": [] }
               },
-              "tools": [                                    
+              "tools": [
                 "@git"
               ],
               "toolAliases": {
                   "@gits/some_tool": "some_tool2"
               },
-              "allowedTools": [                           
-                "fs_read",                               
+              "allowedTools": [
+                "fs_read",
                 "@fetch",
                 "@gits/git_status"
               ],
-              "resources": [                        
+              "resources": [
                 "file://~/my-genai-prompts/unittest.md"
               ],
-              "toolsSettings": {                     
+              "toolsSettings": {
                 "fs_write": { "allowedPaths": ["~/**"] },
                 "@git/git_status": { "git_user": "$GIT_USER" }
               }
@@ -1353,4 +1354,70 @@ mod tests {
 
         assert_eq!(agents.get_active().and_then(|a| a.model.as_ref()), None);
     }
+
+    #[test]
+    fn test_agent_with_hooks() {
+        let agent_json = json!({
+            "name": "test-agent",
+            "hooks": {
+                "agentSpawn": [
+                    {
+                        "command": "git status"
+                    }
+                ],
+                "preToolUse": [
+                    {
+                        "matcher": "fs_write",
+                        "command": "validate-tool.sh"
+                    },
+                    {
+                        "matcher": "fs_read",
+                        "command": "enforce-tdd.sh"
+                    }
+                ],
+                "postToolUse": [
+                    {
+                        "matcher": "fs_write",
+                        "command": "format-python.sh"
+                    }
+                ]
+            }
+        });
+
+        let agent: Agent = serde_json::from_value(agent_json).expect("Failed to deserialize agent");
+
+        // Verify agent name
+        assert_eq!(agent.name, "test-agent");
+
+        // Verify agentSpawn hook
+        assert!(agent.hooks.contains_key(&HookTrigger::AgentSpawn));
+        let agent_spawn_hooks = &agent.hooks[&HookTrigger::AgentSpawn];
+        assert_eq!(agent_spawn_hooks.len(), 1);
+        assert_eq!(agent_spawn_hooks[0].command, "git status");
+        assert_eq!(agent_spawn_hooks[0].matcher, None);
+
+        // Verify preToolUse hooks
+        assert!(agent.hooks.contains_key(&HookTrigger::PreToolUse));
+        let pre_tool_hooks = &agent.hooks[&HookTrigger::PreToolUse];
+        assert_eq!(pre_tool_hooks.len(), 2);
+
+        assert_eq!(pre_tool_hooks[0].command, "validate-tool.sh");
+        assert_eq!(pre_tool_hooks[0].matcher, Some("fs_write".to_string()));
+
+        assert_eq!(pre_tool_hooks[1].command, "enforce-tdd.sh");
+        assert_eq!(pre_tool_hooks[1].matcher, Some("fs_read".to_string()));
+
+        // Verify postToolUse hooks
+        assert!(agent.hooks.contains_key(&HookTrigger::PostToolUse));
+
+        // Verify default values are set correctly
+        for hooks in agent.hooks.values() {
+            for hook in hooks {
+                assert_eq!(hook.timeout_ms, 30_000);
+                assert_eq!(hook.max_output_size, 10_240);
+                assert_eq!(hook.cache_ttl_seconds, 0);
+                assert_eq!(hook.source, Source::Agent);
+            }
+        }
+    }
 }