feat: hook-pipeline progress — tests passing

rust/crates/api/src/client.rs

@@ -1,5 +1,4 @@
 use std::collections::VecDeque;
-use std::sync::{Arc, Mutex};
 use std::time::{Duration, SystemTime, UNIX_EPOCH};
 
 use runtime::{
@@ -9,9 +8,8 @@ use runtime::{
 use serde::Deserialize;
 
 use crate::error::ApiError;
-use crate::prompt_cache::{PromptCache, PromptCacheRecord, PromptCacheStats};
 use crate::sse::SseParser;
-use crate::types::{MessageRequest, MessageResponse, StreamEvent, Usage};
+use crate::types::{MessageRequest, MessageResponse, StreamEvent};
 
 const DEFAULT_BASE_URL: &str = "https://api.anthropic.com";
 const ANTHROPIC_VERSION: &str = "2023-06-01";
@@ -110,8 +108,6 @@ pub struct AnthropicClient {
     max_retries: u32,
     initial_backoff: Duration,
     max_backoff: Duration,
-    prompt_cache: Option<PromptCache>,
-    last_prompt_cache_record: Arc<Mutex<Option<PromptCacheRecord>>>,
 }
 
 impl AnthropicClient {
@@ -124,8 +120,6 @@ impl AnthropicClient {
             max_retries: DEFAULT_MAX_RETRIES,
             initial_backoff: DEFAULT_INITIAL_BACKOFF,
             max_backoff: DEFAULT_MAX_BACKOFF,
-            prompt_cache: None,
-            last_prompt_cache_record: Arc::new(Mutex::new(None)),
         }
     }
 
@@ -138,8 +132,6 @@ impl AnthropicClient {
             max_retries: DEFAULT_MAX_RETRIES,
             initial_backoff: DEFAULT_INITIAL_BACKOFF,
             max_backoff: DEFAULT_MAX_BACKOFF,
-            prompt_cache: None,
-            last_prompt_cache_record: Arc::new(Mutex::new(None)),
         }
     }
 
@@ -197,30 +189,6 @@ impl AnthropicClient {
         self
     }
 
-    #[must_use]
-    pub fn with_prompt_cache(mut self, prompt_cache: PromptCache) -> Self {
-        self.prompt_cache = Some(prompt_cache);
-        self
-    }
-
-    #[must_use]
-    pub fn prompt_cache(&self) -> Option<&PromptCache> {
-        self.prompt_cache.as_ref()
-    }
-
-    #[must_use]
-    pub fn prompt_cache_stats(&self) -> Option<PromptCacheStats> {
-        self.prompt_cache.as_ref().map(PromptCache::stats)
-    }
-
-    #[must_use]
-    pub fn take_last_prompt_cache_record(&self) -> Option<PromptCacheRecord> {
-        self.last_prompt_cache_record()
-            .lock()
-            .unwrap_or_else(std::sync::PoisonError::into_inner)
-            .take()
-    }
-
     #[must_use]
     pub fn auth_source(&self) -> &AuthSource {
         &self.auth
@@ -230,19 +198,10 @@ impl AnthropicClient {
         &self,
         request: &MessageRequest,
     ) -> Result<MessageResponse, ApiError> {
-        self.store_last_prompt_cache_record(None);
         let request = MessageRequest {
             stream: false,
             ..request.clone()
         };
-        if let Some(prompt_cache) = &self.prompt_cache {
-            if let Some(response) = prompt_cache.lookup_completion(&request) {
-                self.store_last_prompt_cache_record(Some(prompt_cache_record_from_stats(
-                    prompt_cache.stats(),
-                )));
-                return Ok(response);
-            }
-        }
         let response = self.send_with_retry(&request).await?;
         let request_id = request_id_from_headers(response.headers());
         let mut response = response
@@ -252,10 +211,6 @@ impl AnthropicClient {
         if response.request_id.is_none() {
             response.request_id = request_id;
         }
-        if let Some(prompt_cache) = &self.prompt_cache {
-            let record = prompt_cache.record_response(&request, &response);
-            self.store_last_prompt_cache_record(Some(record));
-        }
         Ok(response)
     }
 
@@ -263,7 +218,6 @@ impl AnthropicClient {
         &self,
         request: &MessageRequest,
     ) -> Result<MessageStream, ApiError> {
-        self.store_last_prompt_cache_record(None);
         let response = self
             .send_with_retry(&request.clone().with_streaming())
             .await?;
@@ -273,30 +227,9 @@ impl AnthropicClient {
             parser: SseParser::new(),
             pending: VecDeque::new(),
             done: false,
-            cache_tracking: self
-                .prompt_cache
-                .as_ref()
-                .map(|prompt_cache| StreamCacheTracking {
-                    prompt_cache: prompt_cache.clone(),
-                    request: request.clone().with_streaming(),
-                    last_usage: None,
-                    finalized: false,
-                    last_record: self.last_prompt_cache_record.clone(),
-                }),
         })
     }
 
-    fn store_last_prompt_cache_record(&self, record: Option<PromptCacheRecord>) {
-        *self
-            .last_prompt_cache_record()
-            .lock()
-            .unwrap_or_else(std::sync::PoisonError::into_inner) = record;
-    }
-
-    fn last_prompt_cache_record(&self) -> &Arc<Mutex<Option<PromptCacheRecord>>> {
-        &self.last_prompt_cache_record
-    }
-
     pub async fn exchange_oauth_code(
         &self,
         config: &OAuthConfig,
@@ -594,7 +527,6 @@ pub struct MessageStream {
     parser: SseParser,
     pending: VecDeque<StreamEvent>,
     done: bool,
-    cache_tracking: Option<StreamCacheTracking>,
 }
 
 impl MessageStream {
@@ -606,9 +538,6 @@ impl MessageStream {
     pub async fn next_event(&mut self) -> Result<Option<StreamEvent>, ApiError> {
         loop {
             if let Some(event) = self.pending.pop_front() {
-                if let Some(cache_tracking) = &mut self.cache_tracking {
-                    cache_tracking.observe(&event);
-                }
                 return Ok(Some(event));
             }
 
@@ -616,14 +545,8 @@ impl MessageStream {
                 let remaining = self.parser.finish()?;
                 self.pending.extend(remaining);
                 if let Some(event) = self.pending.pop_front() {
-                    if let Some(cache_tracking) = &mut self.cache_tracking {
-                        cache_tracking.observe(&event);
-                    }
                     return Ok(Some(event));
                 }
-                if let Some(cache_tracking) = &mut self.cache_tracking {
-                    cache_tracking.finalize();
-                }
                 return Ok(None);
             }
 
@@ -639,53 +562,6 @@ impl MessageStream {
     }
 }
 
-#[derive(Debug, Clone)]
-struct StreamCacheTracking {
-    prompt_cache: PromptCache,
-    request: MessageRequest,
-    last_usage: Option<Usage>,
-    finalized: bool,
-    last_record: Arc<Mutex<Option<PromptCacheRecord>>>,
-}
-
-impl StreamCacheTracking {
-    fn observe(&mut self, event: &StreamEvent) {
-        match event {
-            StreamEvent::MessageStart(event) => {
-                self.last_usage = Some(event.message.usage.clone());
-            }
-            StreamEvent::MessageDelta(event) => {
-                self.last_usage = Some(event.usage.clone());
-            }
-            StreamEvent::ContentBlockStart(_)
-            | StreamEvent::ContentBlockDelta(_)
-            | StreamEvent::ContentBlockStop(_)
-            | StreamEvent::MessageStop(_) => {}
-        }
-    }
-
-    fn finalize(&mut self) {
-        if self.finalized {
-            return;
-        }
-        if let Some(usage) = &self.last_usage {
-            let record = self.prompt_cache.record_usage(&self.request, usage);
-            *self
-                .last_record
-                .lock()
-                .unwrap_or_else(std::sync::PoisonError::into_inner) = Some(record);
-        }
-        self.finalized = true;
-    }
-}
-
-fn prompt_cache_record_from_stats(stats: PromptCacheStats) -> PromptCacheRecord {
-    PromptCacheRecord {
-        cache_break: None,
-        stats,
-    }
-}
-
 async fn expect_success(response: reqwest::Response) -> Result<reqwest::Response, ApiError> {
     let status = response.status();
     if status.is_success() {
@@ -730,7 +606,7 @@ mod tests {
     use super::{ALT_REQUEST_ID_HEADER, REQUEST_ID_HEADER};
     use std::io::{Read, Write};
     use std::net::TcpListener;
-    use std::sync::atomic::{AtomicU64, Ordering};
+    use std::sync::{Mutex, OnceLock};
     use std::thread;
     use std::time::{Duration, SystemTime, UNIX_EPOCH};
 
@@ -740,15 +616,19 @@ mod tests {
         now_unix_timestamp, oauth_token_is_expired, resolve_saved_oauth_token,
         resolve_startup_auth_source, AnthropicClient, AuthSource, OAuthTokenSet,
     };
-    use crate::test_env_lock;
     use crate::types::{ContentBlockDelta, MessageRequest};
 
+    fn env_lock() -> std::sync::MutexGuard<'static, ()> {
+        static LOCK: OnceLock<Mutex<()>> = OnceLock::new();
+        LOCK.get_or_init(|| Mutex::new(()))
+            .lock()
+            .expect("env lock")
+    }
+
     fn temp_config_home() -> std::path::PathBuf {
-        static NEXT_ID: AtomicU64 = AtomicU64::new(0);
         std::env::temp_dir().join(format!(
-            "api-oauth-test-{}-{}-{}",
+            "api-oauth-test-{}-{}",
             std::process::id(),
-            NEXT_ID.fetch_add(1, Ordering::Relaxed),
             SystemTime::now()
                 .duration_since(UNIX_EPOCH)
                 .expect("time")
@@ -788,7 +668,7 @@ mod tests {
 
     #[test]
     fn read_api_key_requires_presence() {
-        let _guard = test_env_lock();
+        let _guard = env_lock();
         std::env::remove_var("ANTHROPIC_AUTH_TOKEN");
         std::env::remove_var("ANTHROPIC_API_KEY");
         std::env::remove_var("CLAUDE_CONFIG_HOME");
@@ -798,7 +678,7 @@ mod tests {
 
     #[test]
     fn read_api_key_requires_non_empty_value() {
-        let _guard = test_env_lock();
+        let _guard = env_lock();
         std::env::set_var("ANTHROPIC_AUTH_TOKEN", "");
         std::env::remove_var("ANTHROPIC_API_KEY");
         let error = super::read_api_key().expect_err("empty key should error");
@@ -808,7 +688,7 @@ mod tests {
 
     #[test]
     fn read_api_key_prefers_api_key_env() {
-        let _guard = test_env_lock();
+        let _guard = env_lock();
         std::env::set_var("ANTHROPIC_AUTH_TOKEN", "auth-token");
         std::env::set_var("ANTHROPIC_API_KEY", "legacy-key");
         assert_eq!(
@@ -821,7 +701,7 @@ mod tests {
 
     #[test]
     fn read_auth_token_reads_auth_token_env() {
-        let _guard = test_env_lock();
+        let _guard = env_lock();
         std::env::set_var("ANTHROPIC_AUTH_TOKEN", "auth-token");
         assert_eq!(super::read_auth_token().as_deref(), Some("auth-token"));
         std::env::remove_var("ANTHROPIC_AUTH_TOKEN");
@@ -841,7 +721,7 @@ mod tests {
 
     #[test]
     fn auth_source_from_env_combines_api_key_and_bearer_token() {
-        let _guard = test_env_lock();
+        let _guard = env_lock();
         std::env::set_var("ANTHROPIC_AUTH_TOKEN", "auth-token");
         std::env::set_var("ANTHROPIC_API_KEY", "legacy-key");
         let auth = AuthSource::from_env().expect("env auth");
@@ -853,7 +733,7 @@ mod tests {
 
     #[test]
     fn auth_source_from_saved_oauth_when_env_absent() {
-        let _guard = test_env_lock();
+        let _guard = env_lock();
         let config_home = temp_config_home();
         std::env::set_var("CLAUDE_CONFIG_HOME", &config_home);
         std::env::remove_var("ANTHROPIC_AUTH_TOKEN");
@@ -892,7 +772,7 @@ mod tests {
 
     #[test]
     fn resolve_saved_oauth_token_refreshes_expired_credentials() {
-        let _guard = test_env_lock();
+        let _guard = env_lock();
         let config_home = temp_config_home();
         std::env::set_var("CLAUDE_CONFIG_HOME", &config_home);
         std::env::remove_var("ANTHROPIC_AUTH_TOKEN");
@@ -924,7 +804,7 @@ mod tests {
 
     #[test]
     fn resolve_startup_auth_source_uses_saved_oauth_without_loading_config() {
-        let _guard = test_env_lock();
+        let _guard = env_lock();
         let config_home = temp_config_home();
         std::env::set_var("CLAUDE_CONFIG_HOME", &config_home);
         std::env::remove_var("ANTHROPIC_AUTH_TOKEN");
@@ -948,7 +828,7 @@ mod tests {
 
     #[test]
     fn resolve_startup_auth_source_errors_when_refreshable_token_lacks_config() {
-        let _guard = test_env_lock();
+        let _guard = env_lock();
         let config_home = temp_config_home();
         std::env::set_var("CLAUDE_CONFIG_HOME", &config_home);
         std::env::remove_var("ANTHROPIC_AUTH_TOKEN");
@@ -980,7 +860,7 @@ mod tests {
 
     #[test]
     fn resolve_saved_oauth_token_preserves_refresh_token_when_refresh_response_omits_it() {
-        let _guard = test_env_lock();
+        let _guard = env_lock();
         let config_home = temp_config_home();
         std::env::set_var("CLAUDE_CONFIG_HOME", &config_home);
         std::env::remove_var("ANTHROPIC_AUTH_TOKEN");

rust/crates/api/src/lib.rs

@@ -1,6 +1,5 @@
 mod client;
 mod error;
-mod prompt_cache;
 mod sse;
 mod types;
 
@@ -9,10 +8,6 @@ pub use client::{
     AnthropicClient, AuthSource, MessageStream, OAuthTokenSet,
 };
 pub use error::ApiError;
-pub use prompt_cache::{
-    CacheBreakEvent, PromptCache, PromptCacheConfig, PromptCachePaths, PromptCacheRecord,
-    PromptCacheStats,
-};
 pub use sse::{parse_frame, SseParser};
 pub use types::{
     ContentBlockDelta, ContentBlockDeltaEvent, ContentBlockStartEvent, ContentBlockStopEvent,
@@ -20,11 +15,3 @@ pub use types::{
     MessageResponse, MessageStartEvent, MessageStopEvent, OutputContentBlock, StreamEvent,
     ToolChoice, ToolDefinition, ToolResultContentBlock, Usage,
 };
-
-#[cfg(test)]
-pub(crate) fn test_env_lock() -> std::sync::MutexGuard<'static, ()> {
-    static LOCK: std::sync::OnceLock<std::sync::Mutex<()>> = std::sync::OnceLock::new();
-    LOCK.get_or_init(|| std::sync::Mutex::new(()))
-        .lock()
-        .unwrap_or_else(std::sync::PoisonError::into_inner)
-}

rust/crates/api/src/prompt_cache.rs

@@ -1,727 +0,0 @@
-use std::fs;
-use std::path::{Path, PathBuf};
-use std::sync::{Arc, Mutex};
-use std::time::{Duration, SystemTime, UNIX_EPOCH};
-
-use serde::{Deserialize, Serialize};
-
-use crate::types::{MessageRequest, MessageResponse, Usage};
-
-const DEFAULT_COMPLETION_TTL_SECS: u64 = 30;
-const DEFAULT_PROMPT_TTL_SECS: u64 = 5 * 60;
-const DEFAULT_BREAK_MIN_DROP: u32 = 2_000;
-const MAX_SANITIZED_LENGTH: usize = 80;
-const REQUEST_FINGERPRINT_VERSION: u32 = 1;
-const REQUEST_FINGERPRINT_PREFIX: &str = "v1";
-const FNV_OFFSET_BASIS: u64 = 0xcbf2_9ce4_8422_2325;
-const FNV_PRIME: u64 = 0x0000_0100_0000_01b3;
-
-#[derive(Debug, Clone)]
-pub struct PromptCacheConfig {
-    pub session_id: String,
-    pub completion_ttl: Duration,
-    pub prompt_ttl: Duration,
-    pub cache_break_min_drop: u32,
-}
-
-impl PromptCacheConfig {
-    #[must_use]
-    pub fn new(session_id: impl Into<String>) -> Self {
-        Self {
-            session_id: session_id.into(),
-            completion_ttl: Duration::from_secs(DEFAULT_COMPLETION_TTL_SECS),
-            prompt_ttl: Duration::from_secs(DEFAULT_PROMPT_TTL_SECS),
-            cache_break_min_drop: DEFAULT_BREAK_MIN_DROP,
-        }
-    }
-}
-
-impl Default for PromptCacheConfig {
-    fn default() -> Self {
-        Self::new("default")
-    }
-}
-
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
-pub struct PromptCachePaths {
-    pub root: PathBuf,
-    pub session_dir: PathBuf,
-    pub completion_dir: PathBuf,
-    pub session_state_path: PathBuf,
-    pub stats_path: PathBuf,
-}
-
-impl PromptCachePaths {
-    #[must_use]
-    pub fn for_session(session_id: &str) -> Self {
-        let root = base_cache_root();
-        let session_dir = root.join(sanitize_path_segment(session_id));
-        let completion_dir = session_dir.join("completions");
-        Self {
-            root,
-            session_state_path: session_dir.join("session-state.json"),
-            stats_path: session_dir.join("stats.json"),
-            session_dir,
-            completion_dir,
-        }
-    }
-
-    #[must_use]
-    pub fn completion_entry_path(&self, request_hash: &str) -> PathBuf {
-        self.completion_dir.join(format!("{request_hash}.json"))
-    }
-}
-
-#[derive(Debug, Clone, Default, PartialEq, Eq, Serialize, Deserialize)]
-pub struct PromptCacheStats {
-    pub tracked_requests: u64,
-    pub completion_cache_hits: u64,
-    pub completion_cache_misses: u64,
-    pub completion_cache_writes: u64,
-    pub expected_invalidations: u64,
-    pub unexpected_cache_breaks: u64,
-    pub total_cache_creation_input_tokens: u64,
-    pub total_cache_read_input_tokens: u64,
-    pub last_cache_creation_input_tokens: Option<u32>,
-    pub last_cache_read_input_tokens: Option<u32>,
-    pub last_request_hash: Option<String>,
-    pub last_completion_cache_key: Option<String>,
-    pub last_break_reason: Option<String>,
-    pub last_cache_source: Option<String>,
-}
-
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
-pub struct CacheBreakEvent {
-    pub unexpected: bool,
-    pub reason: String,
-    pub previous_cache_read_input_tokens: u32,
-    pub current_cache_read_input_tokens: u32,
-    pub token_drop: u32,
-}
-
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct PromptCacheRecord {
-    pub cache_break: Option<CacheBreakEvent>,
-    pub stats: PromptCacheStats,
-}
-
-#[derive(Debug, Clone)]
-pub struct PromptCache {
-    inner: Arc<Mutex<PromptCacheInner>>,
-}
-
-impl PromptCache {
-    #[must_use]
-    pub fn new(session_id: impl Into<String>) -> Self {
-        Self::with_config(PromptCacheConfig::new(session_id))
-    }
-
-    #[must_use]
-    pub fn with_config(config: PromptCacheConfig) -> Self {
-        let paths = PromptCachePaths::for_session(&config.session_id);
-        let stats = read_json::<PromptCacheStats>(&paths.stats_path).unwrap_or_default();
-        let previous = read_json::<TrackedPromptState>(&paths.session_state_path);
-        Self {
-            inner: Arc::new(Mutex::new(PromptCacheInner {
-                config,
-                paths,
-                stats,
-                previous,
-            })),
-        }
-    }
-
-    #[must_use]
-    pub fn paths(&self) -> PromptCachePaths {
-        self.lock().paths.clone()
-    }
-
-    #[must_use]
-    pub fn stats(&self) -> PromptCacheStats {
-        self.lock().stats.clone()
-    }
-
-    #[must_use]
-    pub fn lookup_completion(&self, request: &MessageRequest) -> Option<MessageResponse> {
-        let request_hash = request_hash_hex(request);
-        let (paths, ttl) = {
-            let inner = self.lock();
-            (inner.paths.clone(), inner.config.completion_ttl)
-        };
-        let entry_path = paths.completion_entry_path(&request_hash);
-        let entry = read_json::<CompletionCacheEntry>(&entry_path);
-        let Some(entry) = entry else {
-            let mut inner = self.lock();
-            inner.stats.completion_cache_misses += 1;
-            inner.stats.last_completion_cache_key = Some(request_hash);
-            persist_state(&inner);
-            return None;
-        };
-
-        if entry.fingerprint_version != current_fingerprint_version() {
-            let mut inner = self.lock();
-            inner.stats.completion_cache_misses += 1;
-            inner.stats.last_completion_cache_key = Some(request_hash.clone());
-            let _ = fs::remove_file(entry_path);
-            persist_state(&inner);
-            return None;
-        }
-
-        let expired = now_unix_secs().saturating_sub(entry.cached_at_unix_secs) >= ttl.as_secs();
-        let mut inner = self.lock();
-        inner.stats.last_completion_cache_key = Some(request_hash.clone());
-        if expired {
-            inner.stats.completion_cache_misses += 1;
-            let _ = fs::remove_file(entry_path);
-            persist_state(&inner);
-            return None;
-        }
-
-        inner.stats.completion_cache_hits += 1;
-        apply_usage_to_stats(
-            &mut inner.stats,
-            &entry.response.usage,
-            &request_hash,
-            "completion-cache",
-        );
-        inner.previous = Some(TrackedPromptState::from_usage(
-            request,
-            &entry.response.usage,
-        ));
-        persist_state(&inner);
-        Some(entry.response)
-    }
-
-    #[must_use]
-    pub fn record_response(
-        &self,
-        request: &MessageRequest,
-        response: &MessageResponse,
-    ) -> PromptCacheRecord {
-        self.record_usage_internal(request, &response.usage, Some(response))
-    }
-
-    #[must_use]
-    pub fn record_usage(&self, request: &MessageRequest, usage: &Usage) -> PromptCacheRecord {
-        self.record_usage_internal(request, usage, None)
-    }
-
-    fn record_usage_internal(
-        &self,
-        request: &MessageRequest,
-        usage: &Usage,
-        response: Option<&MessageResponse>,
-    ) -> PromptCacheRecord {
-        let request_hash = request_hash_hex(request);
-        let mut inner = self.lock();
-        let previous = inner.previous.clone();
-        let current = TrackedPromptState::from_usage(request, usage);
-        let cache_break = detect_cache_break(&inner.config, previous.as_ref(), &current);
-
-        inner.stats.tracked_requests += 1;
-        apply_usage_to_stats(&mut inner.stats, usage, &request_hash, "api-response");
-        if let Some(event) = &cache_break {
-            if event.unexpected {
-                inner.stats.unexpected_cache_breaks += 1;
-            } else {
-                inner.stats.expected_invalidations += 1;
-            }
-            inner.stats.last_break_reason = Some(event.reason.clone());
-        }
-
-        inner.previous = Some(current);
-        if let Some(response) = response {
-            write_completion_entry(&inner.paths, &request_hash, response);
-            inner.stats.completion_cache_writes += 1;
-        }
-        persist_state(&inner);
-
-        PromptCacheRecord {
-            cache_break,
-            stats: inner.stats.clone(),
-        }
-    }
-
-    fn lock(&self) -> std::sync::MutexGuard<'_, PromptCacheInner> {
-        self.inner
-            .lock()
-            .unwrap_or_else(std::sync::PoisonError::into_inner)
-    }
-}
-
-#[derive(Debug)]
-struct PromptCacheInner {
-    config: PromptCacheConfig,
-    paths: PromptCachePaths,
-    stats: PromptCacheStats,
-    previous: Option<TrackedPromptState>,
-}
-
-#[derive(Debug, Clone, Serialize, Deserialize)]
-struct CompletionCacheEntry {
-    cached_at_unix_secs: u64,
-    #[serde(default = "current_fingerprint_version")]
-    fingerprint_version: u32,
-    response: MessageResponse,
-}
-
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
-struct TrackedPromptState {
-    observed_at_unix_secs: u64,
-    #[serde(default = "current_fingerprint_version")]
-    fingerprint_version: u32,
-    model_hash: u64,
-    system_hash: u64,
-    tools_hash: u64,
-    messages_hash: u64,
-    cache_read_input_tokens: u32,
-}
-
-impl TrackedPromptState {
-    fn from_usage(request: &MessageRequest, usage: &Usage) -> Self {
-        let hashes = RequestFingerprints::from_request(request);
-        Self {
-            observed_at_unix_secs: now_unix_secs(),
-            fingerprint_version: current_fingerprint_version(),
-            model_hash: hashes.model,
-            system_hash: hashes.system,
-            tools_hash: hashes.tools,
-            messages_hash: hashes.messages,
-            cache_read_input_tokens: usage.cache_read_input_tokens,
-        }
-    }
-}
-
-#[derive(Debug, Clone, Copy)]
-struct RequestFingerprints {
-    model: u64,
-    system: u64,
-    tools: u64,
-    messages: u64,
-}
-
-impl RequestFingerprints {
-    fn from_request(request: &MessageRequest) -> Self {
-        Self {
-            model: hash_serializable(&request.model),
-            system: hash_serializable(&request.system),
-            tools: hash_serializable(&request.tools),
-            messages: hash_serializable(&request.messages),
-        }
-    }
-}
-
-fn detect_cache_break(
-    config: &PromptCacheConfig,
-    previous: Option<&TrackedPromptState>,
-    current: &TrackedPromptState,
-) -> Option<CacheBreakEvent> {
-    let previous = previous?;
-    if previous.fingerprint_version != current.fingerprint_version {
-        return Some(CacheBreakEvent {
-            unexpected: false,
-            reason: format!(
-                "fingerprint version changed (v{} -> v{})",
-                previous.fingerprint_version, current.fingerprint_version
-            ),
-            previous_cache_read_input_tokens: previous.cache_read_input_tokens,
-            current_cache_read_input_tokens: current.cache_read_input_tokens,
-            token_drop: previous
-                .cache_read_input_tokens
-                .saturating_sub(current.cache_read_input_tokens),
-        });
-    }
-    let token_drop = previous
-        .cache_read_input_tokens
-        .saturating_sub(current.cache_read_input_tokens);
-    if token_drop < config.cache_break_min_drop {
-        return None;
-    }
-
-    let mut reasons = Vec::new();
-    if previous.model_hash != current.model_hash {
-        reasons.push("model changed");
-    }
-    if previous.system_hash != current.system_hash {
-        reasons.push("system prompt changed");
-    }
-    if previous.tools_hash != current.tools_hash {
-        reasons.push("tool definitions changed");
-    }
-    if previous.messages_hash != current.messages_hash {
-        reasons.push("message payload changed");
-    }
-
-    let elapsed = current
-        .observed_at_unix_secs
-        .saturating_sub(previous.observed_at_unix_secs);
-
-    let (unexpected, reason) = if reasons.is_empty() {
-        if elapsed > config.prompt_ttl.as_secs() {
-            (
-                false,
-                format!("possible prompt cache TTL expiry after {elapsed}s"),
-            )
-        } else {
-            (
-                true,
-                "cache read tokens dropped while prompt fingerprint remained stable".to_string(),
-            )
-        }
-    } else {
-        (false, reasons.join(", "))
-    };
-
-    Some(CacheBreakEvent {
-        unexpected,
-        reason,
-        previous_cache_read_input_tokens: previous.cache_read_input_tokens,
-        current_cache_read_input_tokens: current.cache_read_input_tokens,
-        token_drop,
-    })
-}
-
-fn apply_usage_to_stats(
-    stats: &mut PromptCacheStats,
-    usage: &Usage,
-    request_hash: &str,
-    source: &str,
-) {
-    stats.total_cache_creation_input_tokens += u64::from(usage.cache_creation_input_tokens);
-    stats.total_cache_read_input_tokens += u64::from(usage.cache_read_input_tokens);
-    stats.last_cache_creation_input_tokens = Some(usage.cache_creation_input_tokens);
-    stats.last_cache_read_input_tokens = Some(usage.cache_read_input_tokens);
-    stats.last_request_hash = Some(request_hash.to_string());
-    stats.last_cache_source = Some(source.to_string());
-}
-
-fn persist_state(inner: &PromptCacheInner) {
-    let _ = ensure_cache_dirs(&inner.paths);
-    let _ = write_json(&inner.paths.stats_path, &inner.stats);
-    if let Some(previous) = &inner.previous {
-        let _ = write_json(&inner.paths.session_state_path, previous);
-    }
-}
-
-fn write_completion_entry(
-    paths: &PromptCachePaths,
-    request_hash: &str,
-    response: &MessageResponse,
-) {
-    let _ = ensure_cache_dirs(paths);
-    let entry = CompletionCacheEntry {
-        cached_at_unix_secs: now_unix_secs(),
-        fingerprint_version: current_fingerprint_version(),
-        response: response.clone(),
-    };
-    let _ = write_json(&paths.completion_entry_path(request_hash), &entry);
-}
-
-fn ensure_cache_dirs(paths: &PromptCachePaths) -> std::io::Result<()> {
-    fs::create_dir_all(&paths.completion_dir)
-}
-
-fn write_json<T: Serialize>(path: &Path, value: &T) -> std::io::Result<()> {
-    let json = serde_json::to_vec_pretty(value)
-        .map_err(|error| std::io::Error::new(std::io::ErrorKind::InvalidData, error))?;
-    fs::write(path, json)
-}
-
-fn read_json<T: for<'de> Deserialize<'de>>(path: &Path) -> Option<T> {
-    let bytes = fs::read(path).ok()?;
-    serde_json::from_slice(&bytes).ok()
-}
-
-fn request_hash_hex(request: &MessageRequest) -> String {
-    format!(
-        "{REQUEST_FINGERPRINT_PREFIX}-{:016x}",
-        hash_serializable(request)
-    )
-}
-
-fn hash_serializable<T: Serialize>(value: &T) -> u64 {
-    let json = serde_json::to_vec(value).unwrap_or_default();
-    stable_hash_bytes(&json)
-}
-
-fn sanitize_path_segment(value: &str) -> String {
-    let sanitized: String = value
-        .chars()
-        .map(|ch| if ch.is_ascii_alphanumeric() { ch } else { '-' })
-        .collect();
-    if sanitized.len() <= MAX_SANITIZED_LENGTH {
-        return sanitized;
-    }
-    let suffix = format!("-{:x}", hash_string(value));
-    format!(
-        "{}{}",
-        &sanitized[..MAX_SANITIZED_LENGTH.saturating_sub(suffix.len())],
-        suffix
-    )
-}
-
-fn hash_string(value: &str) -> u64 {
-    stable_hash_bytes(value.as_bytes())
-}
-
-fn base_cache_root() -> PathBuf {
-    if let Some(config_home) = std::env::var_os("CLAUDE_CONFIG_HOME") {
-        return PathBuf::from(config_home)
-            .join("cache")
-            .join("prompt-cache");
-    }
-    if let Some(home) = std::env::var_os("HOME") {
-        return PathBuf::from(home)
-            .join(".claude")
-            .join("cache")
-            .join("prompt-cache");
-    }
-    std::env::temp_dir().join("claude-prompt-cache")
-}
-
-fn now_unix_secs() -> u64 {
-    SystemTime::now()
-        .duration_since(UNIX_EPOCH)
-        .map_or(0, |duration| duration.as_secs())
-}
-
-const fn current_fingerprint_version() -> u32 {
-    REQUEST_FINGERPRINT_VERSION
-}
-
-fn stable_hash_bytes(bytes: &[u8]) -> u64 {
-    let mut hash = FNV_OFFSET_BASIS;
-    for byte in bytes {
-        hash ^= u64::from(*byte);
-        hash = hash.wrapping_mul(FNV_PRIME);
-    }
-    hash
-}
-
-#[cfg(test)]
-mod tests {
-    use std::time::{Duration, SystemTime, UNIX_EPOCH};
-
-    use super::{
-        detect_cache_break, read_json, request_hash_hex, sanitize_path_segment, PromptCache,
-        PromptCacheConfig, PromptCachePaths, TrackedPromptState, REQUEST_FINGERPRINT_PREFIX,
-    };
-    use crate::test_env_lock;
-    use crate::types::{InputMessage, MessageRequest, MessageResponse, OutputContentBlock, Usage};
-
-    #[test]
-    fn path_builder_sanitizes_session_identifier() {
-        let paths = PromptCachePaths::for_session("session:/with spaces");
-        let session_dir = paths
-            .session_dir
-            .file_name()
-            .and_then(|value| value.to_str())
-            .expect("session dir name");
-        assert_eq!(session_dir, "session--with-spaces");
-        assert!(paths.completion_dir.ends_with("completions"));
-        assert!(paths.stats_path.ends_with("stats.json"));
-        assert!(paths.session_state_path.ends_with("session-state.json"));
-    }
-
-    #[test]
-    fn request_fingerprint_drives_unexpected_break_detection() {
-        let request = sample_request("same");
-        let previous = TrackedPromptState::from_usage(
-            &request,
-            &Usage {
-                input_tokens: 0,
-                cache_creation_input_tokens: 0,
-                cache_read_input_tokens: 6_000,
-                output_tokens: 0,
-            },
-        );
-        let current = TrackedPromptState::from_usage(
-            &request,
-            &Usage {
-                input_tokens: 0,
-                cache_creation_input_tokens: 0,
-                cache_read_input_tokens: 1_000,
-                output_tokens: 0,
-            },
-        );
-        let event = detect_cache_break(&PromptCacheConfig::default(), Some(&previous), &current)
-            .expect("break should be detected");
-        assert!(event.unexpected);
-        assert!(event.reason.contains("stable"));
-    }
-
-    #[test]
-    fn changed_prompt_marks_break_as_expected() {
-        let previous_request = sample_request("first");
-        let current_request = sample_request("second");
-        let previous = TrackedPromptState::from_usage(
-            &previous_request,
-            &Usage {
-                input_tokens: 0,
-                cache_creation_input_tokens: 0,
-                cache_read_input_tokens: 6_000,
-                output_tokens: 0,
-            },
-        );
-        let current = TrackedPromptState::from_usage(
-            &current_request,
-            &Usage {
-                input_tokens: 0,
-                cache_creation_input_tokens: 0,
-                cache_read_input_tokens: 1_000,
-                output_tokens: 0,
-            },
-        );
-        let event = detect_cache_break(&PromptCacheConfig::default(), Some(&previous), &current)
-            .expect("break should be detected");
-        assert!(!event.unexpected);
-        assert!(event.reason.contains("message payload changed"));
-    }
-
-    #[test]
-    fn completion_cache_round_trip_persists_recent_response() {
-        let _guard = test_env_lock();
-        let temp_root = std::env::temp_dir().join(format!(
-            "prompt-cache-test-{}-{}",
-            std::process::id(),
-            SystemTime::now()
-                .duration_since(UNIX_EPOCH)
-                .expect("time")
-                .as_nanos()
-        ));
-        std::env::set_var("CLAUDE_CONFIG_HOME", &temp_root);
-        let cache = PromptCache::new("unit-test-session");
-        let request = sample_request("cache me");
-        let response = sample_response(42, 12, "cached");
-
-        assert!(cache.lookup_completion(&request).is_none());
-        let record = cache.record_response(&request, &response);
-        assert!(record.cache_break.is_none());
-
-        let cached = cache
-            .lookup_completion(&request)
-            .expect("cached response should load");
-        assert_eq!(cached.content, response.content);
-
-        let stats = cache.stats();
-        assert_eq!(stats.completion_cache_hits, 1);
-        assert_eq!(stats.completion_cache_misses, 1);
-        assert_eq!(stats.completion_cache_writes, 1);
-
-        let persisted = read_json::<super::PromptCacheStats>(&cache.paths().stats_path)
-            .expect("stats should persist");
-        assert_eq!(persisted.completion_cache_hits, 1);
-
-        std::fs::remove_dir_all(temp_root).expect("cleanup temp root");
-        std::env::remove_var("CLAUDE_CONFIG_HOME");
-    }
-
-    #[test]
-    fn distinct_requests_do_not_collide_in_completion_cache() {
-        let _guard = test_env_lock();
-        let temp_root = std::env::temp_dir().join(format!(
-            "prompt-cache-distinct-{}-{}",
-            std::process::id(),
-            SystemTime::now()
-                .duration_since(UNIX_EPOCH)
-                .expect("time")
-                .as_nanos()
-        ));
-        std::env::set_var("CLAUDE_CONFIG_HOME", &temp_root);
-        let cache = PromptCache::new("distinct-request-session");
-        let first_request = sample_request("first");
-        let second_request = sample_request("second");
-
-        let response = sample_response(42, 12, "cached");
-        let _ = cache.record_response(&first_request, &response);
-
-        assert!(cache.lookup_completion(&second_request).is_none());
-
-        std::fs::remove_dir_all(temp_root).expect("cleanup temp root");
-        std::env::remove_var("CLAUDE_CONFIG_HOME");
-    }
-
-    #[test]
-    fn expired_completion_entries_are_not_reused() {
-        let _guard = test_env_lock();
-        let temp_root = std::env::temp_dir().join(format!(
-            "prompt-cache-expired-{}-{}",
-            std::process::id(),
-            SystemTime::now()
-                .duration_since(UNIX_EPOCH)
-                .expect("time")
-                .as_nanos()
-        ));
-        std::env::set_var("CLAUDE_CONFIG_HOME", &temp_root);
-        let cache = PromptCache::with_config(PromptCacheConfig {
-            session_id: "expired-session".to_string(),
-            completion_ttl: Duration::ZERO,
-            ..PromptCacheConfig::default()
-        });
-        let request = sample_request("expire me");
-        let response = sample_response(7, 3, "stale");
-
-        let _ = cache.record_response(&request, &response);
-
-        assert!(cache.lookup_completion(&request).is_none());
-        let stats = cache.stats();
-        assert_eq!(stats.completion_cache_hits, 0);
-        assert_eq!(stats.completion_cache_misses, 1);
-
-        std::fs::remove_dir_all(temp_root).expect("cleanup temp root");
-        std::env::remove_var("CLAUDE_CONFIG_HOME");
-    }
-
-    #[test]
-    fn sanitize_path_caps_long_values() {
-        let long_value = "x".repeat(200);
-        let sanitized = sanitize_path_segment(&long_value);
-        assert!(sanitized.len() <= 80);
-    }
-
-    #[test]
-    fn request_hashes_are_versioned_and_stable() {
-        let request = sample_request("stable");
-        let first = request_hash_hex(&request);
-        let second = request_hash_hex(&request);
-        assert_eq!(first, second);
-        assert!(first.starts_with(REQUEST_FINGERPRINT_PREFIX));
-    }
-
-    fn sample_request(text: &str) -> MessageRequest {
-        MessageRequest {
-            model: "claude-3-7-sonnet-latest".to_string(),
-            max_tokens: 64,
-            messages: vec![InputMessage::user_text(text)],
-            system: Some("system".to_string()),
-            tools: None,
-            tool_choice: None,
-            stream: false,
-        }
-    }
-
-    fn sample_response(
-        cache_read_input_tokens: u32,
-        output_tokens: u32,
-        text: &str,
-    ) -> MessageResponse {
-        MessageResponse {
-            id: "msg_test".to_string(),
-            kind: "message".to_string(),
-            role: "assistant".to_string(),
-            content: vec![OutputContentBlock::Text {
-                text: text.to_string(),
-            }],
-            model: "claude-3-7-sonnet-latest".to_string(),
-            stop_reason: Some("end_turn".to_string()),
-            stop_sequence: None,
-            usage: Usage {
-                input_tokens: 10,
-                cache_creation_input_tokens: 5,
-                cache_read_input_tokens,
-                output_tokens,
-            },
-            request_id: Some("req_test".to_string()),
-        }
-    }
-}

rust/crates/api/tests/client_integration.rs

@@ -1,25 +1,17 @@
 use std::collections::HashMap;
 use std::sync::Arc;
-use std::sync::{Mutex as StdMutex, OnceLock};
 use std::time::Duration;
 
 use api::{
     AnthropicClient, ApiError, ContentBlockDelta, ContentBlockDeltaEvent, ContentBlockStartEvent,
     InputContentBlock, InputMessage, MessageDeltaEvent, MessageRequest, OutputContentBlock,
-    PromptCache, StreamEvent, ToolChoice, ToolDefinition,
+    StreamEvent, ToolChoice, ToolDefinition,
 };
 use serde_json::json;
 use tokio::io::{AsyncReadExt, AsyncWriteExt};
 use tokio::net::TcpListener;
 use tokio::sync::Mutex;
 
-fn env_lock() -> std::sync::MutexGuard<'static, ()> {
-    static LOCK: OnceLock<StdMutex<()>> = OnceLock::new();
-    LOCK.get_or_init(|| StdMutex::new(()))
-        .lock()
-        .unwrap_or_else(std::sync::PoisonError::into_inner)
-}
-
 #[tokio::test]
 async fn send_message_posts_json_and_parses_response() {
     let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
@@ -53,8 +45,6 @@ async fn send_message_posts_json_and_parses_response() {
     assert_eq!(response.id, "msg_test");
     assert_eq!(response.total_tokens(), 16);
     assert_eq!(response.request_id.as_deref(), Some("req_body_123"));
-    assert_eq!(response.usage.cache_creation_input_tokens, 0);
-    assert_eq!(response.usage.cache_read_input_tokens, 0);
     assert_eq!(
         response.content,
         vec![OutputContentBlock::Text {
@@ -86,55 +76,11 @@ async fn send_message_posts_json_and_parses_response() {
 }
 
 #[tokio::test]
-async fn send_message_parses_prompt_cache_token_usage_from_response() {
-    let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
-    let body = concat!(
-        "{",
-        "\"id\":\"msg_cache_tokens\",",
-        "\"type\":\"message\",",
-        "\"role\":\"assistant\",",
-        "\"content\":[{\"type\":\"text\",\"text\":\"Cache tokens\"}],",
-        "\"model\":\"claude-3-7-sonnet-latest\",",
-        "\"stop_reason\":\"end_turn\",",
-        "\"stop_sequence\":null,",
-        "\"usage\":{\"input_tokens\":12,\"cache_creation_input_tokens\":321,\"cache_read_input_tokens\":654,\"output_tokens\":4}",
-        "}"
-    );
-    let server = spawn_server(
-        state,
-        vec![http_response("200 OK", "application/json", body)],
-    )
-    .await;
-
-    let client = AnthropicClient::new("test-key").with_base_url(server.base_url());
-    let response = client
-        .send_message(&sample_request(false))
-        .await
-        .expect("request should succeed");
-
-    assert_eq!(response.usage.input_tokens, 12);
-    assert_eq!(response.usage.cache_creation_input_tokens, 321);
-    assert_eq!(response.usage.cache_read_input_tokens, 654);
-    assert_eq!(response.usage.output_tokens, 4);
-}
-
-#[tokio::test]
-#[allow(clippy::await_holding_lock)]
 async fn stream_message_parses_sse_events_with_tool_use() {
-    let _guard = env_lock();
-    let temp_root = std::env::temp_dir().join(format!(
-        "api-stream-cache-{}-{}",
-        std::process::id(),
-        std::time::SystemTime::now()
-            .duration_since(std::time::UNIX_EPOCH)
-            .expect("time")
-            .as_nanos()
-    ));
-    std::env::set_var("CLAUDE_CONFIG_HOME", &temp_root);
     let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
     let sse = concat!(
         "event: message_start\n",
-        "data: {\"type\":\"message_start\",\"message\":{\"id\":\"msg_stream\",\"type\":\"message\",\"role\":\"assistant\",\"content\":[],\"model\":\"claude-3-7-sonnet-latest\",\"stop_reason\":null,\"stop_sequence\":null,\"usage\":{\"input_tokens\":8,\"cache_creation_input_tokens\":13,\"cache_read_input_tokens\":21,\"output_tokens\":0}}}\n\n",
+        "data: {\"type\":\"message_start\",\"message\":{\"id\":\"msg_stream\",\"type\":\"message\",\"role\":\"assistant\",\"content\":[],\"model\":\"claude-3-7-sonnet-latest\",\"stop_reason\":null,\"stop_sequence\":null,\"usage\":{\"input_tokens\":8,\"output_tokens\":0}}}\n\n",
         "event: content_block_start\n",
         "data: {\"type\":\"content_block_start\",\"index\":0,\"content_block\":{\"type\":\"tool_use\",\"id\":\"toolu_123\",\"name\":\"get_weather\",\"input\":{}}}\n\n",
         "event: content_block_delta\n",
@@ -142,7 +88,7 @@ async fn stream_message_parses_sse_events_with_tool_use() {
         "event: content_block_stop\n",
         "data: {\"type\":\"content_block_stop\",\"index\":0}\n\n",
         "event: message_delta\n",
-        "data: {\"type\":\"message_delta\",\"delta\":{\"stop_reason\":\"tool_use\",\"stop_sequence\":null},\"usage\":{\"input_tokens\":8,\"cache_creation_input_tokens\":34,\"cache_read_input_tokens\":55,\"output_tokens\":1}}\n\n",
+        "data: {\"type\":\"message_delta\",\"delta\":{\"stop_reason\":\"tool_use\",\"stop_sequence\":null},\"usage\":{\"input_tokens\":8,\"output_tokens\":1}}\n\n",
         "event: message_stop\n",
         "data: {\"type\":\"message_stop\"}\n\n",
         "data: [DONE]\n\n"
@@ -160,8 +106,7 @@ async fn stream_message_parses_sse_events_with_tool_use() {
 
     let client = AnthropicClient::new("test-key")
         .with_auth_token(Some("proxy-token".to_string()))
-        .with_base_url(server.base_url())
-        .with_prompt_cache(PromptCache::new("stream-session"));
+        .with_base_url(server.base_url());
     let mut stream = client
         .stream_message(&sample_request(false))
         .await
@@ -215,20 +160,6 @@ async fn stream_message_parses_sse_events_with_tool_use() {
     let captured = state.lock().await;
     let request = captured.first().expect("server should capture request");
     assert!(request.body.contains("\"stream\":true"));
-
-    let cache_stats = client
-        .prompt_cache_stats()
-        .expect("prompt cache stats should exist");
-    assert_eq!(cache_stats.tracked_requests, 1);
-    assert_eq!(cache_stats.last_cache_creation_input_tokens, Some(34));
-    assert_eq!(cache_stats.last_cache_read_input_tokens, Some(55));
-    assert_eq!(
-        cache_stats.last_cache_source.as_deref(),
-        Some("api-response")
-    );
-
-    std::fs::remove_dir_all(temp_root).expect("cleanup temp root");
-    std::env::remove_var("CLAUDE_CONFIG_HOME");
 }
 
 #[tokio::test]
@@ -312,121 +243,6 @@ async fn surfaces_retry_exhaustion_for_persistent_retryable_errors() {
     }
 }
 
-#[tokio::test]
-#[allow(clippy::await_holding_lock)]
-async fn send_message_reuses_recent_completion_cache_entries() {
-    let _guard = env_lock();
-    let temp_root = std::env::temp_dir().join(format!(
-        "api-prompt-cache-{}-{}",
-        std::process::id(),
-        std::time::SystemTime::now()
-            .duration_since(std::time::UNIX_EPOCH)
-            .expect("time")
-            .as_nanos()
-    ));
-    std::env::set_var("CLAUDE_CONFIG_HOME", &temp_root);
-
-    let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
-    let server = spawn_server(
-        state.clone(),
-        vec![http_response(
-            "200 OK",
-            "application/json",
-            "{\"id\":\"msg_cached\",\"type\":\"message\",\"role\":\"assistant\",\"content\":[{\"type\":\"text\",\"text\":\"Cached once\"}],\"model\":\"claude-3-7-sonnet-latest\",\"stop_reason\":\"end_turn\",\"stop_sequence\":null,\"usage\":{\"input_tokens\":3,\"cache_creation_input_tokens\":5,\"cache_read_input_tokens\":4000,\"output_tokens\":2}}",
-        )],
-    )
-    .await;
-
-    let client = AnthropicClient::new("test-key")
-        .with_base_url(server.base_url())
-        .with_prompt_cache(PromptCache::new("integration-session"));
-
-    let first = client
-        .send_message(&sample_request(false))
-        .await
-        .expect("first request should succeed");
-    let second = client
-        .send_message(&sample_request(false))
-        .await
-        .expect("second request should reuse cache");
-
-    assert_eq!(first.content, second.content);
-    assert_eq!(state.lock().await.len(), 1);
-
-    let cache_stats = client
-        .prompt_cache_stats()
-        .expect("prompt cache stats should exist");
-    assert_eq!(cache_stats.completion_cache_hits, 1);
-    assert_eq!(cache_stats.completion_cache_misses, 1);
-    assert_eq!(cache_stats.completion_cache_writes, 1);
-
-    std::fs::remove_dir_all(temp_root).expect("cleanup temp root");
-    std::env::remove_var("CLAUDE_CONFIG_HOME");
-}
-
-#[tokio::test]
-#[allow(clippy::await_holding_lock)]
-async fn send_message_tracks_unexpected_prompt_cache_breaks() {
-    let _guard = env_lock();
-    let temp_root = std::env::temp_dir().join(format!(
-        "api-prompt-break-{}-{}",
-        std::process::id(),
-        std::time::SystemTime::now()
-            .duration_since(std::time::UNIX_EPOCH)
-            .expect("time")
-            .as_nanos()
-    ));
-    std::env::set_var("CLAUDE_CONFIG_HOME", &temp_root);
-
-    let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
-    let server = spawn_server(
-        state,
-        vec![
-            http_response(
-                "200 OK",
-                "application/json",
-                "{\"id\":\"msg_one\",\"type\":\"message\",\"role\":\"assistant\",\"content\":[{\"type\":\"text\",\"text\":\"One\"}],\"model\":\"claude-3-7-sonnet-latest\",\"stop_reason\":\"end_turn\",\"stop_sequence\":null,\"usage\":{\"input_tokens\":3,\"cache_creation_input_tokens\":5,\"cache_read_input_tokens\":6000,\"output_tokens\":2}}",
-            ),
-            http_response(
-                "200 OK",
-                "application/json",
-                "{\"id\":\"msg_two\",\"type\":\"message\",\"role\":\"assistant\",\"content\":[{\"type\":\"text\",\"text\":\"Two\"}],\"model\":\"claude-3-7-sonnet-latest\",\"stop_reason\":\"end_turn\",\"stop_sequence\":null,\"usage\":{\"input_tokens\":3,\"cache_creation_input_tokens\":0,\"cache_read_input_tokens\":1000,\"output_tokens\":2}}",
-            ),
-        ],
-    )
-    .await;
-
-    let request = sample_request(false);
-    let client = AnthropicClient::new("test-key")
-        .with_base_url(server.base_url())
-        .with_prompt_cache(PromptCache::with_config(api::PromptCacheConfig {
-            session_id: "break-session".to_string(),
-            completion_ttl: Duration::from_secs(0),
-            ..api::PromptCacheConfig::default()
-        }));
-
-    client
-        .send_message(&request)
-        .await
-        .expect("first response should succeed");
-    client
-        .send_message(&request)
-        .await
-        .expect("second response should succeed");
-
-    let cache_stats = client
-        .prompt_cache_stats()
-        .expect("prompt cache stats should exist");
-    assert_eq!(cache_stats.unexpected_cache_breaks, 1);
-    assert_eq!(
-        cache_stats.last_break_reason.as_deref(),
-        Some("cache read tokens dropped while prompt fingerprint remained stable")
-    );
-
-    std::fs::remove_dir_all(temp_root).expect("cleanup temp root");
-    std::env::remove_var("CLAUDE_CONFIG_HOME");
-}
-
 #[tokio::test]
 #[ignore = "requires ANTHROPIC_API_KEY and network access"]
 async fn live_stream_smoke_test() {

rust/crates/runtime/src/config.rs

@@ -42,6 +42,7 @@ pub struct RuntimeFeatureConfig {
     oauth: Option<OAuthConfig>,
     model: Option<String>,
     permission_mode: Option<ResolvedPermissionMode>,
+    permission_rules: RuntimePermissionRuleConfig,
     sandbox: SandboxConfig,
 }
 
@@ -49,6 +50,14 @@ pub struct RuntimeFeatureConfig {
 pub struct RuntimeHookConfig {
     pre_tool_use: Vec<String>,
     post_tool_use: Vec<String>,
+    post_tool_use_failure: Vec<String>,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Default)]
+pub struct RuntimePermissionRuleConfig {
+    allow: Vec<String>,
+    deny: Vec<String>,
+    ask: Vec<String>,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Default)]
@@ -235,6 +244,7 @@ impl ConfigLoader {
             oauth: parse_optional_oauth_config(&merged_value, "merged settings.oauth")?,
             model: parse_optional_model(&merged_value),
             permission_mode: parse_optional_permission_mode(&merged_value)?,
+            permission_rules: parse_optional_permission_rules(&merged_value)?,
             sandbox: parse_optional_sandbox_config(&merged_value)?,
         };
 
@@ -306,6 +316,11 @@ impl RuntimeConfig {
         self.feature_config.permission_mode
     }
 
+    #[must_use]
+    pub fn permission_rules(&self) -> &RuntimePermissionRuleConfig {
+        &self.feature_config.permission_rules
+    }
+
     #[must_use]
     pub fn sandbox(&self) -> &SandboxConfig {
         &self.feature_config.sandbox
@@ -344,6 +359,11 @@ impl RuntimeFeatureConfig {
         self.permission_mode
     }
 
+    #[must_use]
+    pub fn permission_rules(&self) -> &RuntimePermissionRuleConfig {
+        &self.permission_rules
+    }
+
     #[must_use]
     pub fn sandbox(&self) -> &SandboxConfig {
         &self.sandbox
@@ -352,10 +372,15 @@ impl RuntimeFeatureConfig {
 
 impl RuntimeHookConfig {
     #[must_use]
-    pub fn new(pre_tool_use: Vec<String>, post_tool_use: Vec<String>) -> Self {
+    pub fn new(
+        pre_tool_use: Vec<String>,
+        post_tool_use: Vec<String>,
+        post_tool_use_failure: Vec<String>,
+    ) -> Self {
         Self {
             pre_tool_use,
             post_tool_use,
+            post_tool_use_failure,
         }
     }
 
@@ -368,6 +393,33 @@ impl RuntimeHookConfig {
     pub fn post_tool_use(&self) -> &[String] {
         &self.post_tool_use
     }
+
+    #[must_use]
+    pub fn post_tool_use_failure(&self) -> &[String] {
+        &self.post_tool_use_failure
+    }
+}
+
+impl RuntimePermissionRuleConfig {
+    #[must_use]
+    pub fn new(allow: Vec<String>, deny: Vec<String>, ask: Vec<String>) -> Self {
+        Self { allow, deny, ask }
+    }
+
+    #[must_use]
+    pub fn allow(&self) -> &[String] {
+        &self.allow
+    }
+
+    #[must_use]
+    pub fn deny(&self) -> &[String] {
+        &self.deny
+    }
+
+    #[must_use]
+    pub fn ask(&self) -> &[String] {
+        &self.ask
+    }
 }
 
 impl McpConfigCollection {
@@ -481,6 +533,32 @@ fn parse_optional_hooks_config(root: &JsonValue) -> Result<RuntimeHookConfig, Co
             .unwrap_or_default(),
         post_tool_use: optional_string_array(hooks, "PostToolUse", "merged settings.hooks")?
             .unwrap_or_default(),
+        post_tool_use_failure: optional_string_array(
+            hooks,
+            "PostToolUseFailure",
+            "merged settings.hooks",
+        )?
+        .unwrap_or_default(),
+    })
+}
+
+fn parse_optional_permission_rules(
+    root: &JsonValue,
+) -> Result<RuntimePermissionRuleConfig, ConfigError> {
+    let Some(object) = root.as_object() else {
+        return Ok(RuntimePermissionRuleConfig::default());
+    };
+    let Some(permissions) = object.get("permissions").and_then(JsonValue::as_object) else {
+        return Ok(RuntimePermissionRuleConfig::default());
+    };
+
+    Ok(RuntimePermissionRuleConfig {
+        allow: optional_string_array(permissions, "allow", "merged settings.permissions")?
+            .unwrap_or_default(),
+        deny: optional_string_array(permissions, "deny", "merged settings.permissions")?
+            .unwrap_or_default(),
+        ask: optional_string_array(permissions, "ask", "merged settings.permissions")?
+            .unwrap_or_default(),
     })
 }
 
@@ -843,7 +921,7 @@ mod tests {
         .expect("write user compat config");
         fs::write(
             home.join("settings.json"),
-            r#"{"model":"sonnet","env":{"A2":"1"},"hooks":{"PreToolUse":["base"]},"permissions":{"defaultMode":"plan"}}"#,
+            r#"{"model":"sonnet","env":{"A2":"1"},"hooks":{"PreToolUse":["base"]},"permissions":{"defaultMode":"plan","allow":["Read"],"deny":["Bash(rm -rf)"]}}"#,
         )
         .expect("write user settings");
         fs::write(
@@ -853,7 +931,7 @@ mod tests {
         .expect("write project compat config");
         fs::write(
             cwd.join(".claude").join("settings.json"),
-            r#"{"env":{"C":"3"},"hooks":{"PostToolUse":["project"]},"mcpServers":{"project":{"command":"uvx","args":["project"]}}}"#,
+            r#"{"env":{"C":"3"},"hooks":{"PostToolUse":["project"],"PostToolUseFailure":["project-failure"]},"permissions":{"ask":["Edit"]},"mcpServers":{"project":{"command":"uvx","args":["project"]}}}"#,
         )
         .expect("write project settings");
         fs::write(
@@ -898,6 +976,16 @@ mod tests {
             .contains_key("PostToolUse"));
         assert_eq!(loaded.hooks().pre_tool_use(), &["base".to_string()]);
         assert_eq!(loaded.hooks().post_tool_use(), &["project".to_string()]);
+        assert_eq!(
+            loaded.hooks().post_tool_use_failure(),
+            &["project-failure".to_string()]
+        );
+        assert_eq!(loaded.permission_rules().allow(), &["Read".to_string()]);
+        assert_eq!(
+            loaded.permission_rules().deny(),
+            &["Bash(rm -rf)".to_string()]
+        );
+        assert_eq!(loaded.permission_rules().ask(), &["Edit".to_string()]);
         assert!(loaded.mcp().get("home").is_some());
         assert!(loaded.mcp().get("project").is_some());
 

rust/crates/runtime/src/conversation.rs

@@ -5,8 +5,10 @@ use crate::compact::{
     compact_session, estimate_session_tokens, CompactionConfig, CompactionResult,
 };
 use crate::config::RuntimeFeatureConfig;
-use crate::hooks::{HookRunResult, HookRunner};
-use crate::permissions::{PermissionOutcome, PermissionPolicy, PermissionPrompter};
+use crate::hooks::{HookAbortSignal, HookProgressReporter, HookRunResult, HookRunner};
+use crate::permissions::{
+    PermissionContext, PermissionOutcome, PermissionPolicy, PermissionPrompter,
+};
 use crate::session::{ContentBlock, ConversationMessage, Session};
 use crate::usage::{TokenUsage, UsageTracker};
 
@@ -25,19 +27,9 @@ pub enum AssistantEvent {
         input: String,
     },
     Usage(TokenUsage),
-    PromptCache(PromptCacheEvent),
     MessageStop,
 }
 
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub struct PromptCacheEvent {
-    pub unexpected: bool,
-    pub reason: String,
-    pub previous_cache_read_input_tokens: u32,
-    pub current_cache_read_input_tokens: u32,
-    pub token_drop: u32,
-}
-
 pub trait ApiClient {
     fn stream(&mut self, request: ApiRequest) -> Result<Vec<AssistantEvent>, RuntimeError>;
 }
@@ -94,7 +86,6 @@ impl std::error::Error for RuntimeError {}
 pub struct TurnSummary {
     pub assistant_messages: Vec<ConversationMessage>,
     pub tool_results: Vec<ConversationMessage>,
-    pub prompt_cache_events: Vec<PromptCacheEvent>,
     pub iterations: usize,
     pub usage: TokenUsage,
 }
@@ -108,6 +99,8 @@ pub struct ConversationRuntime<C, T> {
     max_iterations: usize,
     usage_tracker: UsageTracker,
     hook_runner: HookRunner,
+    hook_abort_signal: HookAbortSignal,
+    hook_progress_reporter: Option<Box<dyn HookProgressReporter>>,
 }
 
 impl<C, T> ConversationRuntime<C, T>
@@ -129,18 +122,19 @@ where
             tool_executor,
             permission_policy,
             system_prompt,
-            &RuntimeFeatureConfig::default(),
+            RuntimeFeatureConfig::default(),
         )
     }
 
     #[must_use]
+    #[allow(clippy::needless_pass_by_value)]
     pub fn new_with_features(
         session: Session,
         api_client: C,
         tool_executor: T,
         permission_policy: PermissionPolicy,
         system_prompt: Vec<String>,
-        feature_config: &RuntimeFeatureConfig,
+        feature_config: RuntimeFeatureConfig,
     ) -> Self {
         let usage_tracker = UsageTracker::from_session(&session);
         Self {
@@ -151,7 +145,9 @@ where
             system_prompt,
             max_iterations: usize::MAX,
             usage_tracker,
-            hook_runner: HookRunner::from_feature_config(feature_config),
+            hook_runner: HookRunner::from_feature_config(&feature_config),
+            hook_abort_signal: HookAbortSignal::default(),
+            hook_progress_reporter: None,
         }
     }
 
@@ -161,6 +157,93 @@ where
         self
     }
 
+    #[must_use]
+    pub fn with_hook_abort_signal(mut self, hook_abort_signal: HookAbortSignal) -> Self {
+        self.hook_abort_signal = hook_abort_signal;
+        self
+    }
+
+    #[must_use]
+    pub fn with_hook_progress_reporter(
+        mut self,
+        hook_progress_reporter: Box<dyn HookProgressReporter>,
+    ) -> Self {
+        self.hook_progress_reporter = Some(hook_progress_reporter);
+        self
+    }
+
+    fn run_pre_tool_use_hook(&mut self, tool_name: &str, input: &str) -> HookRunResult {
+        if let Some(reporter) = self.hook_progress_reporter.as_mut() {
+            self.hook_runner.run_pre_tool_use_with_context(
+                tool_name,
+                input,
+                Some(&self.hook_abort_signal),
+                Some(reporter.as_mut()),
+            )
+        } else {
+            self.hook_runner.run_pre_tool_use_with_context(
+                tool_name,
+                input,
+                Some(&self.hook_abort_signal),
+                None,
+            )
+        }
+    }
+
+    fn run_post_tool_use_hook(
+        &mut self,
+        tool_name: &str,
+        input: &str,
+        output: &str,
+        is_error: bool,
+    ) -> HookRunResult {
+        if let Some(reporter) = self.hook_progress_reporter.as_mut() {
+            self.hook_runner.run_post_tool_use_with_context(
+                tool_name,
+                input,
+                output,
+                is_error,
+                Some(&self.hook_abort_signal),
+                Some(reporter.as_mut()),
+            )
+        } else {
+            self.hook_runner.run_post_tool_use_with_context(
+                tool_name,
+                input,
+                output,
+                is_error,
+                Some(&self.hook_abort_signal),
+                None,
+            )
+        }
+    }
+
+    fn run_post_tool_use_failure_hook(
+        &mut self,
+        tool_name: &str,
+        input: &str,
+        output: &str,
+    ) -> HookRunResult {
+        if let Some(reporter) = self.hook_progress_reporter.as_mut() {
+            self.hook_runner.run_post_tool_use_failure_with_context(
+                tool_name,
+                input,
+                output,
+                Some(&self.hook_abort_signal),
+                Some(reporter.as_mut()),
+            )
+        } else {
+            self.hook_runner.run_post_tool_use_failure_with_context(
+                tool_name,
+                input,
+                output,
+                Some(&self.hook_abort_signal),
+                None,
+            )
+        }
+    }
+
+    #[allow(clippy::too_many_lines)]
     pub fn run_turn(
         &mut self,
         user_input: impl Into<String>,
@@ -172,7 +255,6 @@ where
 
         let mut assistant_messages = Vec::new();
         let mut tool_results = Vec::new();
-        let mut prompt_cache_events = Vec::new();
         let mut iterations = 0;
 
         loop {
@@ -188,12 +270,10 @@ where
                 messages: self.session.messages.clone(),
             };
             let events = self.api_client.stream(request)?;
-            let (assistant_message, usage, turn_prompt_cache_events) =
-                build_assistant_message(events)?;
+            let (assistant_message, usage) = build_assistant_message(events)?;
             if let Some(usage) = usage {
                 self.usage_tracker.record(usage);
             }
-            prompt_cache_events.extend(turn_prompt_cache_events);
             let pending_tool_uses = assistant_message
                 .blocks
                 .iter()
@@ -213,55 +293,85 @@ where
             }
 
             for (tool_use_id, tool_name, input) in pending_tool_uses {
-                let permission_outcome = if let Some(prompt) = prompter.as_mut() {
-                    self.permission_policy
-                        .authorize(&tool_name, &input, Some(*prompt))
+                let pre_hook_result = self.run_pre_tool_use_hook(&tool_name, &input);
+                let effective_input = pre_hook_result
+                    .updated_input()
+                    .map_or_else(|| input.clone(), ToOwned::to_owned);
+                let permission_context = PermissionContext::new(
+                    pre_hook_result.permission_override(),
+                    pre_hook_result.permission_reason().map(ToOwned::to_owned),
+                );
+
+                let permission_outcome = if pre_hook_result.is_cancelled() {
+                    PermissionOutcome::Deny {
+                        reason: format_hook_message(
+                            &pre_hook_result,
+                            &format!("PreToolUse hook cancelled tool `{tool_name}`"),
+                        ),
+                    }
+                } else if pre_hook_result.is_denied() {
+                    PermissionOutcome::Deny {
+                        reason: format_hook_message(
+                            &pre_hook_result,
+                            &format!("PreToolUse hook denied tool `{tool_name}`"),
+                        ),
+                    }
+                } else if let Some(prompt) = prompter.as_mut() {
+                    self.permission_policy.authorize_with_context(
+                        &tool_name,
+                        &effective_input,
+                        &permission_context,
+                        Some(*prompt),
+                    )
                 } else {
-                    self.permission_policy.authorize(&tool_name, &input, None)
+                    self.permission_policy.authorize_with_context(
+                        &tool_name,
+                        &effective_input,
+                        &permission_context,
+                        None,
+                    )
                 };
 
                 let result_message = match permission_outcome {
                     PermissionOutcome::Allow => {
-                        let pre_hook_result = self.hook_runner.run_pre_tool_use(&tool_name, &input);
-                        if pre_hook_result.is_denied() {
-                            let deny_message = format!("PreToolUse hook denied tool `{tool_name}`");
-                            ConversationMessage::tool_result(
-                                tool_use_id,
-                                tool_name,
-                                format_hook_message(&pre_hook_result, &deny_message),
-                                true,
+                        let (mut output, mut is_error) =
+                            match self.tool_executor.execute(&tool_name, &effective_input) {
+                                Ok(output) => (output, false),
+                                Err(error) => (error.to_string(), true),
+                            };
+                        output = merge_hook_feedback(pre_hook_result.messages(), output, false);
+
+                        let post_hook_result = if is_error {
+                            self.run_post_tool_use_failure_hook(
+                                &tool_name,
+                                &effective_input,
+                                &output,
                             )
                         } else {
-                            let (mut output, mut is_error) =
-                                match self.tool_executor.execute(&tool_name, &input) {
-                                    Ok(output) => (output, false),
-                                    Err(error) => (error.to_string(), true),
-                                };
-                            output = merge_hook_feedback(pre_hook_result.messages(), output, false);
-
-                            let post_hook_result = self
-                                .hook_runner
-                                .run_post_tool_use(&tool_name, &input, &output, is_error);
-                            if post_hook_result.is_denied() {
-                                is_error = true;
-                            }
-                            output = merge_hook_feedback(
-                                post_hook_result.messages(),
-                                output,
-                                post_hook_result.is_denied(),
-                            );
-
-                            ConversationMessage::tool_result(
-                                tool_use_id,
-                                tool_name,
-                                output,
-                                is_error,
+                            self.run_post_tool_use_hook(
+                                &tool_name,
+                                &effective_input,
+                                &output,
+                                false,
                             )
+                        };
+                        if post_hook_result.is_denied() || post_hook_result.is_cancelled() {
+                            is_error = true;
                         }
+                        output = merge_hook_feedback(
+                            post_hook_result.messages(),
+                            output,
+                            post_hook_result.is_denied() || post_hook_result.is_cancelled(),
+                        );
+
+                        ConversationMessage::tool_result(tool_use_id, tool_name, output, is_error)
                     }
-                    PermissionOutcome::Deny { reason } => {
-                        ConversationMessage::tool_result(tool_use_id, tool_name, reason, true)
-                    }
+                    PermissionOutcome::Deny { reason } => ConversationMessage::tool_result(
+                        tool_use_id,
+                        tool_name,
+                        merge_hook_feedback(pre_hook_result.messages(), reason, true),
+                        true,
+                    ),
                 };
                 self.session.messages.push(result_message.clone());
                 tool_results.push(result_message);
@@ -271,7 +381,6 @@ where
         Ok(TurnSummary {
             assistant_messages,
             tool_results,
-            prompt_cache_events,
             iterations,
             usage: self.usage_tracker.cumulative_usage(),
         })
@@ -305,17 +414,9 @@ where
 
 fn build_assistant_message(
     events: Vec<AssistantEvent>,
-) -> Result<
-    (
-        ConversationMessage,
-        Option<TokenUsage>,
-        Vec<PromptCacheEvent>,
-    ),
-    RuntimeError,
-> {
+) -> Result<(ConversationMessage, Option<TokenUsage>), RuntimeError> {
     let mut text = String::new();
     let mut blocks = Vec::new();
-    let mut prompt_cache_events = Vec::new();
     let mut finished = false;
     let mut usage = None;
 
@@ -327,7 +428,6 @@ fn build_assistant_message(
                 blocks.push(ContentBlock::ToolUse { id, name, input });
             }
             AssistantEvent::Usage(value) => usage = Some(value),
-            AssistantEvent::PromptCache(event) => prompt_cache_events.push(event),
             AssistantEvent::MessageStop => {
                 finished = true;
             }
@@ -348,7 +448,6 @@ fn build_assistant_message(
     Ok((
         ConversationMessage::assistant_with_usage(blocks, usage),
         usage,
-        prompt_cache_events,
     ))
 }
 
@@ -421,7 +520,7 @@ impl ToolExecutor for StaticToolExecutor {
 #[cfg(test)]
 mod tests {
     use super::{
-        ApiClient, ApiRequest, AssistantEvent, ConversationRuntime, PromptCacheEvent, RuntimeError,
+        ApiClient, ApiRequest, AssistantEvent, ConversationRuntime, RuntimeError,
         StaticToolExecutor,
     };
     use crate::compact::CompactionConfig;
@@ -478,15 +577,6 @@ mod tests {
                             cache_creation_input_tokens: 1,
                             cache_read_input_tokens: 3,
                         }),
-                        AssistantEvent::PromptCache(PromptCacheEvent {
-                            unexpected: true,
-                            reason:
-                                "cache read tokens dropped while prompt fingerprint remained stable"
-                                    .to_string(),
-                            previous_cache_read_input_tokens: 6_000,
-                            current_cache_read_input_tokens: 1_000,
-                            token_drop: 5_000,
-                        }),
                         AssistantEvent::MessageStop,
                     ])
                 }
@@ -540,10 +630,8 @@ mod tests {
         assert_eq!(summary.iterations, 2);
         assert_eq!(summary.assistant_messages.len(), 2);
         assert_eq!(summary.tool_results.len(), 1);
-        assert_eq!(summary.prompt_cache_events.len(), 1);
         assert_eq!(runtime.session().messages.len(), 4);
         assert_eq!(summary.usage.output_tokens, 10);
-        assert!(summary.prompt_cache_events[0].unexpected);
         assert!(matches!(
             runtime.session().messages[1].blocks[1],
             ContentBlock::ToolUse { .. }
@@ -645,9 +733,10 @@ mod tests {
             }),
             PermissionPolicy::new(PermissionMode::DangerFullAccess),
             vec!["system".to_string()],
-            &RuntimeFeatureConfig::default().with_hooks(RuntimeHookConfig::new(
+            RuntimeFeatureConfig::default().with_hooks(RuntimeHookConfig::new(
                 vec![shell_snippet("printf 'blocked by hook'; exit 2")],
                 Vec::new(),
+                Vec::new(),
             )),
         );
 
@@ -711,9 +800,10 @@ mod tests {
             StaticToolExecutor::new().register("add", |_input| Ok("4".to_string())),
             PermissionPolicy::new(PermissionMode::DangerFullAccess),
             vec!["system".to_string()],
-            &RuntimeFeatureConfig::default().with_hooks(RuntimeHookConfig::new(
+            RuntimeFeatureConfig::default().with_hooks(RuntimeHookConfig::new(
                 vec![shell_snippet("printf 'pre hook ran'")],
                 vec![shell_snippet("printf 'post hook ran'")],
+                Vec::new(),
             )),
         );
 

rust/crates/runtime/src/hooks.rs

@@ -1,29 +1,90 @@
 use std::ffi::OsStr;
-use std::process::Command;
+use std::io::Write;
+use std::process::{Command, Stdio};
+use std::sync::{
+    atomic::{AtomicBool, Ordering},
+    Arc,
+};
+use std::thread;
+use std::time::Duration;
 
-use serde_json::json;
+use serde_json::{json, Value};
 
 use crate::config::{RuntimeFeatureConfig, RuntimeHookConfig};
+use crate::permissions::PermissionOverride;
+
+pub type HookPermissionDecision = PermissionOverride;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum HookEvent {
     PreToolUse,
     PostToolUse,
+    PostToolUseFailure,
 }
 
 impl HookEvent {
-    fn as_str(self) -> &'static str {
+    #[must_use]
+    pub fn as_str(self) -> &'static str {
         match self {
             Self::PreToolUse => "PreToolUse",
             Self::PostToolUse => "PostToolUse",
+            Self::PostToolUseFailure => "PostToolUseFailure",
         }
     }
 }
 
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum HookProgressEvent {
+    Started {
+        event: HookEvent,
+        tool_name: String,
+        command: String,
+    },
+    Completed {
+        event: HookEvent,
+        tool_name: String,
+        command: String,
+    },
+    Cancelled {
+        event: HookEvent,
+        tool_name: String,
+        command: String,
+    },
+}
+
+pub trait HookProgressReporter {
+    fn on_event(&mut self, event: &HookProgressEvent);
+}
+
+#[derive(Debug, Clone, Default)]
+pub struct HookAbortSignal {
+    aborted: Arc<AtomicBool>,
+}
+
+impl HookAbortSignal {
+    #[must_use]
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    pub fn abort(&self) {
+        self.aborted.store(true, Ordering::SeqCst);
+    }
+
+    #[must_use]
+    pub fn is_aborted(&self) -> bool {
+        self.aborted.load(Ordering::SeqCst)
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct HookRunResult {
     denied: bool,
+    cancelled: bool,
     messages: Vec<String>,
+    permission_override: Option<PermissionOverride>,
+    permission_reason: Option<String>,
+    updated_input: Option<String>,
 }
 
 impl HookRunResult {
@@ -31,7 +92,11 @@ impl HookRunResult {
     pub fn allow(messages: Vec<String>) -> Self {
         Self {
             denied: false,
+            cancelled: false,
             messages,
+            permission_override: None,
+            permission_reason: None,
+            updated_input: None,
         }
     }
 
@@ -40,10 +105,40 @@ impl HookRunResult {
         self.denied
     }
 
+    #[must_use]
+    pub fn is_cancelled(&self) -> bool {
+        self.cancelled
+    }
+
     #[must_use]
     pub fn messages(&self) -> &[String] {
         &self.messages
     }
+
+    #[must_use]
+    pub fn permission_override(&self) -> Option<PermissionOverride> {
+        self.permission_override
+    }
+
+    #[must_use]
+    pub fn permission_decision(&self) -> Option<HookPermissionDecision> {
+        self.permission_override
+    }
+
+    #[must_use]
+    pub fn permission_reason(&self) -> Option<&str> {
+        self.permission_reason.as_deref()
+    }
+
+    #[must_use]
+    pub fn updated_input(&self) -> Option<&str> {
+        self.updated_input.as_deref()
+    }
+
+    #[must_use]
+    pub fn updated_input_json(&self) -> Option<&str> {
+        self.updated_input()
+    }
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Default)]
@@ -64,6 +159,17 @@ impl HookRunner {
 
     #[must_use]
     pub fn run_pre_tool_use(&self, tool_name: &str, tool_input: &str) -> HookRunResult {
+        self.run_pre_tool_use_with_context(tool_name, tool_input, None, None)
+    }
+
+    #[must_use]
+    pub fn run_pre_tool_use_with_context(
+        &self,
+        tool_name: &str,
+        tool_input: &str,
+        abort_signal: Option<&HookAbortSignal>,
+        reporter: Option<&mut dyn HookProgressReporter>,
+    ) -> HookRunResult {
         Self::run_commands(
             HookEvent::PreToolUse,
             self.config.pre_tool_use(),
@@ -71,9 +177,21 @@ impl HookRunner {
             tool_input,
             None,
             false,
+            abort_signal,
+            reporter,
         )
     }
 
+    #[must_use]
+    pub fn run_pre_tool_use_with_signal(
+        &self,
+        tool_name: &str,
+        tool_input: &str,
+        abort_signal: Option<&HookAbortSignal>,
+    ) -> HookRunResult {
+        self.run_pre_tool_use_with_context(tool_name, tool_input, abort_signal, None)
+    }
+
     #[must_use]
     pub fn run_post_tool_use(
         &self,
@@ -81,6 +199,26 @@ impl HookRunner {
         tool_input: &str,
         tool_output: &str,
         is_error: bool,
+    ) -> HookRunResult {
+        self.run_post_tool_use_with_context(
+            tool_name,
+            tool_input,
+            tool_output,
+            is_error,
+            None,
+            None,
+        )
+    }
+
+    #[must_use]
+    pub fn run_post_tool_use_with_context(
+        &self,
+        tool_name: &str,
+        tool_input: &str,
+        tool_output: &str,
+        is_error: bool,
+        abort_signal: Option<&HookAbortSignal>,
+        reporter: Option<&mut dyn HookProgressReporter>,
     ) -> HookRunResult {
         Self::run_commands(
             HookEvent::PostToolUse,
@@ -89,9 +227,79 @@ impl HookRunner {
             tool_input,
             Some(tool_output),
             is_error,
+            abort_signal,
+            reporter,
         )
     }
 
+    #[must_use]
+    pub fn run_post_tool_use_with_signal(
+        &self,
+        tool_name: &str,
+        tool_input: &str,
+        tool_output: &str,
+        is_error: bool,
+        abort_signal: Option<&HookAbortSignal>,
+    ) -> HookRunResult {
+        self.run_post_tool_use_with_context(
+            tool_name,
+            tool_input,
+            tool_output,
+            is_error,
+            abort_signal,
+            None,
+        )
+    }
+
+    #[must_use]
+    pub fn run_post_tool_use_failure(
+        &self,
+        tool_name: &str,
+        tool_input: &str,
+        tool_error: &str,
+    ) -> HookRunResult {
+        self.run_post_tool_use_failure_with_context(tool_name, tool_input, tool_error, None, None)
+    }
+
+    #[must_use]
+    pub fn run_post_tool_use_failure_with_context(
+        &self,
+        tool_name: &str,
+        tool_input: &str,
+        tool_error: &str,
+        abort_signal: Option<&HookAbortSignal>,
+        reporter: Option<&mut dyn HookProgressReporter>,
+    ) -> HookRunResult {
+        Self::run_commands(
+            HookEvent::PostToolUseFailure,
+            self.config.post_tool_use_failure(),
+            tool_name,
+            tool_input,
+            Some(tool_error),
+            true,
+            abort_signal,
+            reporter,
+        )
+    }
+
+    #[must_use]
+    pub fn run_post_tool_use_failure_with_signal(
+        &self,
+        tool_name: &str,
+        tool_input: &str,
+        tool_error: &str,
+        abort_signal: Option<&HookAbortSignal>,
+    ) -> HookRunResult {
+        self.run_post_tool_use_failure_with_context(
+            tool_name,
+            tool_input,
+            tool_error,
+            abort_signal,
+            None,
+        )
+    }
+
+    #[allow(clippy::too_many_arguments)]
     fn run_commands(
         event: HookEvent,
         commands: &[String],
@@ -99,24 +307,39 @@ impl HookRunner {
         tool_input: &str,
         tool_output: Option<&str>,
         is_error: bool,
+        abort_signal: Option<&HookAbortSignal>,
+        mut reporter: Option<&mut dyn HookProgressReporter>,
     ) -> HookRunResult {
         if commands.is_empty() {
             return HookRunResult::allow(Vec::new());
         }
 
-        let payload = json!({
-            "hook_event_name": event.as_str(),
-            "tool_name": tool_name,
-            "tool_input": parse_tool_input(tool_input),
-            "tool_input_json": tool_input,
-            "tool_output": tool_output,
-            "tool_result_is_error": is_error,
-        })
-        .to_string();
+        if abort_signal.is_some_and(HookAbortSignal::is_aborted) {
+            return HookRunResult {
+                denied: false,
+                cancelled: true,
+                messages: vec![format!(
+                    "{} hook cancelled before execution",
+                    event.as_str()
+                )],
+                permission_override: None,
+                permission_reason: None,
+                updated_input: None,
+            };
+        }
 
-        let mut messages = Vec::new();
+        let payload = hook_payload(event, tool_name, tool_input, tool_output, is_error).to_string();
+        let mut result = HookRunResult::allow(Vec::new());
 
         for command in commands {
+            if let Some(reporter) = reporter.as_deref_mut() {
+                reporter.on_event(&HookProgressEvent::Started {
+                    event,
+                    tool_name: tool_name.to_string(),
+                    command: command.clone(),
+                });
+            }
+
             match Self::run_command(
                 command,
                 event,
@@ -125,29 +348,59 @@ impl HookRunner {
                 tool_output,
                 is_error,
                 &payload,
+                abort_signal,
             ) {
-                HookCommandOutcome::Allow { message } => {
-                    if let Some(message) = message {
-                        messages.push(message);
+                HookCommandOutcome::Allow { parsed } => {
+                    if let Some(reporter) = reporter.as_deref_mut() {
+                        reporter.on_event(&HookProgressEvent::Completed {
+                            event,
+                            tool_name: tool_name.to_string(),
+                            command: command.clone(),
+                        });
                     }
+                    merge_parsed_hook_output(&mut result, parsed);
                 }
-                HookCommandOutcome::Deny { message } => {
-                    let message = message.unwrap_or_else(|| {
-                        format!("{} hook denied tool `{tool_name}`", event.as_str())
-                    });
-                    messages.push(message);
-                    return HookRunResult {
-                        denied: true,
-                        messages,
-                    };
+                HookCommandOutcome::Deny { parsed } => {
+                    if let Some(reporter) = reporter.as_deref_mut() {
+                        reporter.on_event(&HookProgressEvent::Completed {
+                            event,
+                            tool_name: tool_name.to_string(),
+                            command: command.clone(),
+                        });
+                    }
+                    merge_parsed_hook_output(&mut result, parsed);
+                    result.denied = true;
+                    return result;
+                }
+                HookCommandOutcome::Warn { message } => {
+                    if let Some(reporter) = reporter.as_deref_mut() {
+                        reporter.on_event(&HookProgressEvent::Completed {
+                            event,
+                            tool_name: tool_name.to_string(),
+                            command: command.clone(),
+                        });
+                    }
+                    result.messages.push(message);
+                }
+                HookCommandOutcome::Cancelled { message } => {
+                    if let Some(reporter) = reporter.as_deref_mut() {
+                        reporter.on_event(&HookProgressEvent::Cancelled {
+                            event,
+                            tool_name: tool_name.to_string(),
+                            command: command.clone(),
+                        });
+                    }
+                    result.cancelled = true;
+                    result.messages.push(message);
+                    return result;
                 }
-                HookCommandOutcome::Warn { message } => messages.push(message),
             }
         }
 
-        HookRunResult::allow(messages)
+        result
     }
 
+    #[allow(clippy::too_many_arguments)]
     fn run_command(
         command: &str,
         event: HookEvent,
@@ -156,11 +409,12 @@ impl HookRunner {
         tool_output: Option<&str>,
         is_error: bool,
         payload: &str,
+        abort_signal: Option<&HookAbortSignal>,
     ) -> HookCommandOutcome {
         let mut child = shell_command(command);
-        child.stdin(std::process::Stdio::piped());
-        child.stdout(std::process::Stdio::piped());
-        child.stderr(std::process::Stdio::piped());
+        child.stdin(Stdio::piped());
+        child.stdout(Stdio::piped());
+        child.stderr(Stdio::piped());
         child.env("HOOK_EVENT", event.as_str());
         child.env("HOOK_TOOL_NAME", tool_name);
         child.env("HOOK_TOOL_INPUT", tool_input);
@@ -169,19 +423,30 @@ impl HookRunner {
             child.env("HOOK_TOOL_OUTPUT", tool_output);
         }
 
-        match child.output_with_stdin(payload.as_bytes()) {
-            Ok(output) => {
+        match child.output_with_stdin(payload.as_bytes(), abort_signal) {
+            Ok(CommandExecution::Finished(output)) => {
                 let stdout = String::from_utf8_lossy(&output.stdout).trim().to_string();
                 let stderr = String::from_utf8_lossy(&output.stderr).trim().to_string();
-                let message = (!stdout.is_empty()).then_some(stdout);
+                let parsed = parse_hook_output(&stdout);
                 match output.status.code() {
-                    Some(0) => HookCommandOutcome::Allow { message },
-                    Some(2) => HookCommandOutcome::Deny { message },
+                    Some(0) => {
+                        if parsed.deny {
+                            HookCommandOutcome::Deny { parsed }
+                        } else {
+                            HookCommandOutcome::Allow { parsed }
+                        }
+                    }
+                    Some(2) => HookCommandOutcome::Deny {
+                        parsed: parsed.with_fallback_message(format!(
+                            "{} hook denied tool `{tool_name}`",
+                            event.as_str()
+                        )),
+                    },
                     Some(code) => HookCommandOutcome::Warn {
                         message: format_hook_warning(
                             command,
                             code,
-                            message.as_deref(),
+                            parsed.primary_message(),
                             stderr.as_str(),
                         ),
                     },
@@ -193,6 +458,12 @@ impl HookRunner {
                     },
                 }
             }
+            Ok(CommandExecution::Cancelled) => HookCommandOutcome::Cancelled {
+                message: format!(
+                    "{} hook `{command}` cancelled while handling `{tool_name}`",
+                    event.as_str()
+                ),
+            },
             Err(error) => HookCommandOutcome::Warn {
                 message: format!(
                     "{} hook `{command}` failed to start for `{tool_name}`: {error}",
@@ -204,12 +475,131 @@ impl HookRunner {
 }
 
 enum HookCommandOutcome {
-    Allow { message: Option<String> },
-    Deny { message: Option<String> },
+    Allow { parsed: ParsedHookOutput },
+    Deny { parsed: ParsedHookOutput },
     Warn { message: String },
+    Cancelled { message: String },
 }
 
-fn parse_tool_input(tool_input: &str) -> serde_json::Value {
+#[derive(Debug, Clone, PartialEq, Eq, Default)]
+struct ParsedHookOutput {
+    messages: Vec<String>,
+    deny: bool,
+    permission_override: Option<PermissionOverride>,
+    permission_reason: Option<String>,
+    updated_input: Option<String>,
+}
+
+impl ParsedHookOutput {
+    fn with_fallback_message(mut self, fallback: String) -> Self {
+        if self.messages.is_empty() {
+            self.messages.push(fallback);
+        }
+        self
+    }
+
+    fn primary_message(&self) -> Option<&str> {
+        self.messages.first().map(String::as_str)
+    }
+}
+
+fn merge_parsed_hook_output(target: &mut HookRunResult, parsed: ParsedHookOutput) {
+    target.messages.extend(parsed.messages);
+    if parsed.permission_override.is_some() {
+        target.permission_override = parsed.permission_override;
+    }
+    if parsed.permission_reason.is_some() {
+        target.permission_reason = parsed.permission_reason;
+    }
+    if parsed.updated_input.is_some() {
+        target.updated_input = parsed.updated_input;
+    }
+}
+
+fn parse_hook_output(stdout: &str) -> ParsedHookOutput {
+    if stdout.is_empty() {
+        return ParsedHookOutput::default();
+    }
+
+    let Ok(Value::Object(root)) = serde_json::from_str::<Value>(stdout) else {
+        return ParsedHookOutput {
+            messages: vec![stdout.to_string()],
+            ..ParsedHookOutput::default()
+        };
+    };
+
+    let mut parsed = ParsedHookOutput::default();
+
+    if let Some(message) = root.get("systemMessage").and_then(Value::as_str) {
+        parsed.messages.push(message.to_string());
+    }
+    if let Some(message) = root.get("reason").and_then(Value::as_str) {
+        parsed.messages.push(message.to_string());
+    }
+    if root.get("continue").and_then(Value::as_bool) == Some(false)
+        || root.get("decision").and_then(Value::as_str) == Some("block")
+    {
+        parsed.deny = true;
+    }
+
+    if let Some(Value::Object(specific)) = root.get("hookSpecificOutput") {
+        if let Some(Value::String(additional_context)) = specific.get("additionalContext") {
+            parsed.messages.push(additional_context.clone());
+        }
+        if let Some(decision) = specific.get("permissionDecision").and_then(Value::as_str) {
+            parsed.permission_override = match decision {
+                "allow" => Some(PermissionOverride::Allow),
+                "deny" => Some(PermissionOverride::Deny),
+                "ask" => Some(PermissionOverride::Ask),
+                _ => None,
+            };
+        }
+        if let Some(reason) = specific
+            .get("permissionDecisionReason")
+            .and_then(Value::as_str)
+        {
+            parsed.permission_reason = Some(reason.to_string());
+        }
+        if let Some(updated_input) = specific.get("updatedInput") {
+            parsed.updated_input = serde_json::to_string(updated_input).ok();
+        }
+    }
+
+    if parsed.messages.is_empty() {
+        parsed.messages.push(stdout.to_string());
+    }
+
+    parsed
+}
+
+fn hook_payload(
+    event: HookEvent,
+    tool_name: &str,
+    tool_input: &str,
+    tool_output: Option<&str>,
+    is_error: bool,
+) -> Value {
+    match event {
+        HookEvent::PostToolUseFailure => json!({
+            "hook_event_name": event.as_str(),
+            "tool_name": tool_name,
+            "tool_input": parse_tool_input(tool_input),
+            "tool_input_json": tool_input,
+            "tool_error": tool_output,
+            "tool_result_is_error": true,
+        }),
+        _ => json!({
+            "hook_event_name": event.as_str(),
+            "tool_name": tool_name,
+            "tool_input": parse_tool_input(tool_input),
+            "tool_input_json": tool_input,
+            "tool_output": tool_output,
+            "tool_result_is_error": is_error,
+        }),
+    }
+}
+
+fn parse_tool_input(tool_input: &str) -> Value {
     serde_json::from_str(tool_input).unwrap_or_else(|_| json!({ "raw": tool_input }))
 }
 
@@ -253,17 +643,17 @@ impl CommandWithStdin {
         Self { command }
     }
 
-    fn stdin(&mut self, cfg: std::process::Stdio) -> &mut Self {
+    fn stdin(&mut self, cfg: Stdio) -> &mut Self {
         self.command.stdin(cfg);
         self
     }
 
-    fn stdout(&mut self, cfg: std::process::Stdio) -> &mut Self {
+    fn stdout(&mut self, cfg: Stdio) -> &mut Self {
         self.command.stdout(cfg);
         self
     }
 
-    fn stderr(&mut self, cfg: std::process::Stdio) -> &mut Self {
+    fn stderr(&mut self, cfg: Stdio) -> &mut Self {
         self.command.stderr(cfg);
         self
     }
@@ -277,26 +667,64 @@ impl CommandWithStdin {
         self
     }
 
-    fn output_with_stdin(&mut self, stdin: &[u8]) -> std::io::Result<std::process::Output> {
+    fn output_with_stdin(
+        &mut self,
+        stdin: &[u8],
+        abort_signal: Option<&HookAbortSignal>,
+    ) -> std::io::Result<CommandExecution> {
         let mut child = self.command.spawn()?;
         if let Some(mut child_stdin) = child.stdin.take() {
-            use std::io::Write;
             child_stdin.write_all(stdin)?;
         }
-        child.wait_with_output()
+
+        loop {
+            if abort_signal.is_some_and(HookAbortSignal::is_aborted) {
+                let _ = child.kill();
+                let _ = child.wait_with_output();
+                return Ok(CommandExecution::Cancelled);
+            }
+
+            match child.try_wait()? {
+                Some(_) => return child.wait_with_output().map(CommandExecution::Finished),
+                None => thread::sleep(Duration::from_millis(20)),
+            }
+        }
     }
 }
 
+enum CommandExecution {
+    Finished(std::process::Output),
+    Cancelled,
+}
+
 #[cfg(test)]
 mod tests {
-    use super::{HookRunResult, HookRunner};
+    use std::thread;
+    use std::time::Duration;
+
+    use super::{
+        HookAbortSignal, HookEvent, HookProgressEvent, HookProgressReporter, HookRunResult,
+        HookRunner,
+    };
     use crate::config::{RuntimeFeatureConfig, RuntimeHookConfig};
+    use crate::permissions::PermissionOverride;
+
+    struct RecordingReporter {
+        events: Vec<HookProgressEvent>,
+    }
+
+    impl HookProgressReporter for RecordingReporter {
+        fn on_event(&mut self, event: &HookProgressEvent) {
+            self.events.push(event.clone());
+        }
+    }
 
     #[test]
     fn allows_exit_code_zero_and_captures_stdout() {
         let runner = HookRunner::new(RuntimeHookConfig::new(
             vec![shell_snippet("printf 'pre ok'")],
             Vec::new(),
+            Vec::new(),
         ));
 
         let result = runner.run_pre_tool_use("Read", r#"{"path":"README.md"}"#);
@@ -309,6 +737,7 @@ mod tests {
         let runner = HookRunner::new(RuntimeHookConfig::new(
             vec![shell_snippet("printf 'blocked by hook'; exit 2")],
             Vec::new(),
+            Vec::new(),
         ));
 
         let result = runner.run_pre_tool_use("Bash", r#"{"command":"pwd"}"#);
@@ -323,6 +752,7 @@ mod tests {
             RuntimeHookConfig::new(
                 vec![shell_snippet("printf 'warning hook'; exit 1")],
                 Vec::new(),
+                Vec::new(),
             ),
         ));
 
@@ -335,6 +765,82 @@ mod tests {
             .any(|message| message.contains("allowing tool execution to continue")));
     }
 
+    #[test]
+    fn parses_pre_hook_permission_override_and_updated_input() {
+        let runner = HookRunner::new(RuntimeHookConfig::new(
+            vec![shell_snippet(
+                r#"printf '%s' '{"systemMessage":"updated","hookSpecificOutput":{"permissionDecision":"allow","permissionDecisionReason":"hook ok","updatedInput":{"command":"git status"}}}'"#,
+            )],
+            Vec::new(),
+            Vec::new(),
+        ));
+
+        let result = runner.run_pre_tool_use("bash", r#"{"command":"pwd"}"#);
+
+        assert_eq!(
+            result.permission_override(),
+            Some(PermissionOverride::Allow)
+        );
+        assert_eq!(result.permission_reason(), Some("hook ok"));
+        assert_eq!(result.updated_input(), Some(r#"{"command":"git status"}"#));
+        assert!(result.messages().iter().any(|message| message == "updated"));
+    }
+
+    #[test]
+    fn runs_post_tool_use_failure_hooks() {
+        let runner = HookRunner::new(RuntimeHookConfig::new(
+            Vec::new(),
+            Vec::new(),
+            vec![shell_snippet("printf 'failure hook ran'")],
+        ));
+
+        let result =
+            runner.run_post_tool_use_failure("bash", r#"{"command":"false"}"#, "command failed");
+
+        assert!(!result.is_denied());
+        assert_eq!(result.messages(), &["failure hook ran".to_string()]);
+    }
+
+    #[test]
+    fn abort_signal_cancels_long_running_hook_and_reports_progress() {
+        let runner = HookRunner::new(RuntimeHookConfig::new(
+            vec![shell_snippet("sleep 5")],
+            Vec::new(),
+            Vec::new(),
+        ));
+        let abort_signal = HookAbortSignal::new();
+        let abort_signal_for_thread = abort_signal.clone();
+        let mut reporter = RecordingReporter { events: Vec::new() };
+
+        thread::spawn(move || {
+            thread::sleep(Duration::from_millis(100));
+            abort_signal_for_thread.abort();
+        });
+
+        let result = runner.run_pre_tool_use_with_context(
+            "bash",
+            r#"{"command":"sleep 5"}"#,
+            Some(&abort_signal),
+            Some(&mut reporter),
+        );
+
+        assert!(result.is_cancelled());
+        assert!(reporter.events.iter().any(|event| matches!(
+            event,
+            HookProgressEvent::Started {
+                event: HookEvent::PreToolUse,
+                ..
+            }
+        )));
+        assert!(reporter.events.iter().any(|event| matches!(
+            event,
+            HookProgressEvent::Cancelled {
+                event: HookEvent::PreToolUse,
+                ..
+            }
+        )));
+    }
+
     #[cfg(windows)]
     fn shell_snippet(script: &str) -> String {
         script.replace('\'', "\"")

rust/crates/runtime/src/lib.rs

@@ -28,18 +28,20 @@ pub use config::{
     McpConfigCollection, McpOAuthConfig, McpRemoteServerConfig, McpSdkServerConfig,
     McpServerConfig, McpStdioServerConfig, McpTransport, McpWebSocketServerConfig, OAuthConfig,
     ResolvedPermissionMode, RuntimeConfig, RuntimeFeatureConfig, RuntimeHookConfig,
-    ScopedMcpServerConfig, CLAUDE_CODE_SETTINGS_SCHEMA_NAME,
+    RuntimePermissionRuleConfig, ScopedMcpServerConfig, CLAUDE_CODE_SETTINGS_SCHEMA_NAME,
 };
 pub use conversation::{
-    ApiClient, ApiRequest, AssistantEvent, ConversationRuntime, PromptCacheEvent, RuntimeError,
-    StaticToolExecutor, ToolError, ToolExecutor, TurnSummary,
+    ApiClient, ApiRequest, AssistantEvent, ConversationRuntime, RuntimeError, StaticToolExecutor,
+    ToolError, ToolExecutor, TurnSummary,
 };
 pub use file_ops::{
     edit_file, glob_search, grep_search, read_file, write_file, EditFileOutput, GlobSearchOutput,
     GrepSearchInput, GrepSearchOutput, ReadFileOutput, StructuredPatchHunk, TextFilePayload,
     WriteFileOutput,
 };
-pub use hooks::{HookEvent, HookRunResult, HookRunner};
+pub use hooks::{
+    HookAbortSignal, HookEvent, HookProgressEvent, HookProgressReporter, HookRunResult, HookRunner,
+};
 pub use mcp::{
     mcp_server_signature, mcp_tool_name, mcp_tool_prefix, normalize_name_for_mcp,
     scoped_mcp_config_hash, unwrap_ccr_proxy_url,
@@ -64,8 +66,8 @@ pub use oauth::{
     PkceChallengeMethod, PkceCodePair,
 };
 pub use permissions::{
-    PermissionMode, PermissionOutcome, PermissionPolicy, PermissionPromptDecision,
-    PermissionPrompter, PermissionRequest,
+    PermissionContext, PermissionMode, PermissionOutcome, PermissionOverride, PermissionPolicy,
+    PermissionPromptDecision, PermissionPrompter, PermissionRequest,
 };
 pub use prompt::{
     load_system_prompt, prepend_bullets, ContextFile, ProjectContext, PromptBuildError,

rust/crates/runtime/src/permissions.rs

@@ -1,5 +1,9 @@
 use std::collections::BTreeMap;
 
+use serde_json::Value;
+
+use crate::config::RuntimePermissionRuleConfig;
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord)]
 pub enum PermissionMode {
     ReadOnly,
@@ -22,12 +26,49 @@ impl PermissionMode {
     }
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum PermissionOverride {
+    Allow,
+    Deny,
+    Ask,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, Default)]
+pub struct PermissionContext {
+    override_decision: Option<PermissionOverride>,
+    override_reason: Option<String>,
+}
+
+impl PermissionContext {
+    #[must_use]
+    pub fn new(
+        override_decision: Option<PermissionOverride>,
+        override_reason: Option<String>,
+    ) -> Self {
+        Self {
+            override_decision,
+            override_reason,
+        }
+    }
+
+    #[must_use]
+    pub fn override_decision(&self) -> Option<PermissionOverride> {
+        self.override_decision
+    }
+
+    #[must_use]
+    pub fn override_reason(&self) -> Option<&str> {
+        self.override_reason.as_deref()
+    }
+}
+
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub struct PermissionRequest {
     pub tool_name: String,
     pub input: String,
     pub current_mode: PermissionMode,
     pub required_mode: PermissionMode,
+    pub reason: Option<String>,
 }
 
 #[derive(Debug, Clone, PartialEq, Eq)]
@@ -50,6 +91,9 @@ pub enum PermissionOutcome {
 pub struct PermissionPolicy {
     active_mode: PermissionMode,
     tool_requirements: BTreeMap<String, PermissionMode>,
+    allow_rules: Vec<PermissionRule>,
+    deny_rules: Vec<PermissionRule>,
+    ask_rules: Vec<PermissionRule>,
 }
 
 impl PermissionPolicy {
@@ -58,6 +102,9 @@ impl PermissionPolicy {
         Self {
             active_mode,
             tool_requirements: BTreeMap::new(),
+            allow_rules: Vec::new(),
+            deny_rules: Vec::new(),
+            ask_rules: Vec::new(),
         }
     }
 
@@ -72,6 +119,26 @@ impl PermissionPolicy {
         self
     }
 
+    #[must_use]
+    pub fn with_permission_rules(mut self, config: &RuntimePermissionRuleConfig) -> Self {
+        self.allow_rules = config
+            .allow()
+            .iter()
+            .map(|rule| PermissionRule::parse(rule))
+            .collect();
+        self.deny_rules = config
+            .deny()
+            .iter()
+            .map(|rule| PermissionRule::parse(rule))
+            .collect();
+        self.ask_rules = config
+            .ask()
+            .iter()
+            .map(|rule| PermissionRule::parse(rule))
+            .collect();
+        self
+    }
+
     #[must_use]
     pub fn active_mode(&self) -> PermissionMode {
         self.active_mode
@@ -90,38 +157,121 @@ impl PermissionPolicy {
         &self,
         tool_name: &str,
         input: &str,
-        mut prompter: Option<&mut dyn PermissionPrompter>,
+        prompter: Option<&mut dyn PermissionPrompter>,
     ) -> PermissionOutcome {
-        let current_mode = self.active_mode();
-        let required_mode = self.required_mode_for(tool_name);
-        if current_mode == PermissionMode::Allow || current_mode >= required_mode {
-            return PermissionOutcome::Allow;
+        self.authorize_with_context(tool_name, input, &PermissionContext::default(), prompter)
+    }
+
+    #[must_use]
+    #[allow(clippy::too_many_lines)]
+    pub fn authorize_with_context(
+        &self,
+        tool_name: &str,
+        input: &str,
+        context: &PermissionContext,
+        prompter: Option<&mut dyn PermissionPrompter>,
+    ) -> PermissionOutcome {
+        if let Some(rule) = Self::find_matching_rule(&self.deny_rules, tool_name, input) {
+            return PermissionOutcome::Deny {
+                reason: format!(
+                    "Permission to use {tool_name} has been denied by rule '{}'",
+                    rule.raw
+                ),
+            };
         }
 
-        let request = PermissionRequest {
-            tool_name: tool_name.to_string(),
-            input: input.to_string(),
-            current_mode,
-            required_mode,
-        };
+        let current_mode = self.active_mode();
+        let required_mode = self.required_mode_for(tool_name);
+        let ask_rule = Self::find_matching_rule(&self.ask_rules, tool_name, input);
+        let allow_rule = Self::find_matching_rule(&self.allow_rules, tool_name, input);
+
+        match context.override_decision() {
+            Some(PermissionOverride::Deny) => {
+                return PermissionOutcome::Deny {
+                    reason: context.override_reason().map_or_else(
+                        || format!("tool '{tool_name}' denied by hook"),
+                        ToOwned::to_owned,
+                    ),
+                };
+            }
+            Some(PermissionOverride::Ask) => {
+                let reason = context.override_reason().map_or_else(
+                    || format!("tool '{tool_name}' requires approval due to hook guidance"),
+                    ToOwned::to_owned,
+                );
+                return Self::prompt_or_deny(
+                    tool_name,
+                    input,
+                    current_mode,
+                    required_mode,
+                    Some(reason),
+                    prompter,
+                );
+            }
+            Some(PermissionOverride::Allow) => {
+                if let Some(rule) = ask_rule {
+                    let reason = format!(
+                        "tool '{tool_name}' requires approval due to ask rule '{}'",
+                        rule.raw
+                    );
+                    return Self::prompt_or_deny(
+                        tool_name,
+                        input,
+                        current_mode,
+                        required_mode,
+                        Some(reason),
+                        prompter,
+                    );
+                }
+                if allow_rule.is_some()
+                    || current_mode == PermissionMode::Allow
+                    || current_mode >= required_mode
+                {
+                    return PermissionOutcome::Allow;
+                }
+            }
+            None => {}
+        }
+
+        if let Some(rule) = ask_rule {
+            let reason = format!(
+                "tool '{tool_name}' requires approval due to ask rule '{}'",
+                rule.raw
+            );
+            return Self::prompt_or_deny(
+                tool_name,
+                input,
+                current_mode,
+                required_mode,
+                Some(reason),
+                prompter,
+            );
+        }
+
+        if allow_rule.is_some()
+            || current_mode == PermissionMode::Allow
+            || current_mode >= required_mode
+        {
+            return PermissionOutcome::Allow;
+        }
 
         if current_mode == PermissionMode::Prompt
             || (current_mode == PermissionMode::WorkspaceWrite
                 && required_mode == PermissionMode::DangerFullAccess)
         {
-            return match prompter.as_mut() {
-                Some(prompter) => match prompter.decide(&request) {
-                    PermissionPromptDecision::Allow => PermissionOutcome::Allow,
-                    PermissionPromptDecision::Deny { reason } => PermissionOutcome::Deny { reason },
-                },
-                None => PermissionOutcome::Deny {
-                    reason: format!(
-                        "tool '{tool_name}' requires approval to escalate from {} to {}",
-                        current_mode.as_str(),
-                        required_mode.as_str()
-                    ),
-                },
-            };
+            let reason = Some(format!(
+                "tool '{tool_name}' requires approval to escalate from {} to {}",
+                current_mode.as_str(),
+                required_mode.as_str()
+            ));
+            return Self::prompt_or_deny(
+                tool_name,
+                input,
+                current_mode,
+                required_mode,
+                reason,
+                prompter,
+            );
         }
 
         PermissionOutcome::Deny {
@@ -132,14 +282,191 @@ impl PermissionPolicy {
             ),
         }
     }
+
+    fn prompt_or_deny(
+        tool_name: &str,
+        input: &str,
+        current_mode: PermissionMode,
+        required_mode: PermissionMode,
+        reason: Option<String>,
+        mut prompter: Option<&mut dyn PermissionPrompter>,
+    ) -> PermissionOutcome {
+        let request = PermissionRequest {
+            tool_name: tool_name.to_string(),
+            input: input.to_string(),
+            current_mode,
+            required_mode,
+            reason: reason.clone(),
+        };
+
+        match prompter.as_mut() {
+            Some(prompter) => match prompter.decide(&request) {
+                PermissionPromptDecision::Allow => PermissionOutcome::Allow,
+                PermissionPromptDecision::Deny { reason } => PermissionOutcome::Deny { reason },
+            },
+            None => PermissionOutcome::Deny {
+                reason: reason.unwrap_or_else(|| {
+                    format!(
+                        "tool '{tool_name}' requires approval to run while mode is {}",
+                        current_mode.as_str()
+                    )
+                }),
+            },
+        }
+    }
+
+    fn find_matching_rule<'a>(
+        rules: &'a [PermissionRule],
+        tool_name: &str,
+        input: &str,
+    ) -> Option<&'a PermissionRule> {
+        rules.iter().find(|rule| rule.matches(tool_name, input))
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+struct PermissionRule {
+    raw: String,
+    tool_name: String,
+    matcher: PermissionRuleMatcher,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+enum PermissionRuleMatcher {
+    Any,
+    Exact(String),
+    Prefix(String),
+}
+
+impl PermissionRule {
+    fn parse(raw: &str) -> Self {
+        let trimmed = raw.trim();
+        let open = find_first_unescaped(trimmed, '(');
+        let close = find_last_unescaped(trimmed, ')');
+
+        if let (Some(open), Some(close)) = (open, close) {
+            if close == trimmed.len() - 1 && open < close {
+                let tool_name = trimmed[..open].trim();
+                let content = &trimmed[open + 1..close];
+                if !tool_name.is_empty() {
+                    let matcher = parse_rule_matcher(content);
+                    return Self {
+                        raw: trimmed.to_string(),
+                        tool_name: tool_name.to_string(),
+                        matcher,
+                    };
+                }
+            }
+        }
+
+        Self {
+            raw: trimmed.to_string(),
+            tool_name: trimmed.to_string(),
+            matcher: PermissionRuleMatcher::Any,
+        }
+    }
+
+    fn matches(&self, tool_name: &str, input: &str) -> bool {
+        if self.tool_name != tool_name {
+            return false;
+        }
+
+        match &self.matcher {
+            PermissionRuleMatcher::Any => true,
+            PermissionRuleMatcher::Exact(expected) => {
+                extract_permission_subject(input).is_some_and(|candidate| candidate == *expected)
+            }
+            PermissionRuleMatcher::Prefix(prefix) => extract_permission_subject(input)
+                .is_some_and(|candidate| candidate.starts_with(prefix)),
+        }
+    }
+}
+
+fn parse_rule_matcher(content: &str) -> PermissionRuleMatcher {
+    let unescaped = unescape_rule_content(content.trim());
+    if unescaped.is_empty() || unescaped == "*" {
+        PermissionRuleMatcher::Any
+    } else if let Some(prefix) = unescaped.strip_suffix(":*") {
+        PermissionRuleMatcher::Prefix(prefix.to_string())
+    } else {
+        PermissionRuleMatcher::Exact(unescaped)
+    }
+}
+
+fn unescape_rule_content(content: &str) -> String {
+    content
+        .replace(r"\(", "(")
+        .replace(r"\)", ")")
+        .replace(r"\\", r"\")
+}
+
+fn find_first_unescaped(value: &str, needle: char) -> Option<usize> {
+    let mut escaped = false;
+    for (idx, ch) in value.char_indices() {
+        if ch == '\\' {
+            escaped = !escaped;
+            continue;
+        }
+        if ch == needle && !escaped {
+            return Some(idx);
+        }
+        escaped = false;
+    }
+    None
+}
+
+fn find_last_unescaped(value: &str, needle: char) -> Option<usize> {
+    let chars = value.char_indices().collect::<Vec<_>>();
+    for (pos, (idx, ch)) in chars.iter().enumerate().rev() {
+        if *ch != needle {
+            continue;
+        }
+        let mut backslashes = 0;
+        for (_, prev) in chars[..pos].iter().rev() {
+            if *prev == '\\' {
+                backslashes += 1;
+            } else {
+                break;
+            }
+        }
+        if backslashes % 2 == 0 {
+            return Some(*idx);
+        }
+    }
+    None
+}
+
+fn extract_permission_subject(input: &str) -> Option<String> {
+    let parsed = serde_json::from_str::<Value>(input).ok();
+    if let Some(Value::Object(object)) = parsed {
+        for key in [
+            "command",
+            "path",
+            "file_path",
+            "filePath",
+            "notebook_path",
+            "notebookPath",
+            "url",
+            "pattern",
+            "code",
+            "message",
+        ] {
+            if let Some(value) = object.get(key).and_then(Value::as_str) {
+                return Some(value.to_string());
+            }
+        }
+    }
+
+    (!input.trim().is_empty()).then(|| input.to_string())
 }
 
 #[cfg(test)]
 mod tests {
     use super::{
-        PermissionMode, PermissionOutcome, PermissionPolicy, PermissionPromptDecision,
-        PermissionPrompter, PermissionRequest,
+        PermissionContext, PermissionMode, PermissionOutcome, PermissionOverride, PermissionPolicy,
+        PermissionPromptDecision, PermissionPrompter, PermissionRequest,
     };
+    use crate::config::RuntimePermissionRuleConfig;
 
     struct RecordingPrompter {
         seen: Vec<PermissionRequest>,
@@ -229,4 +556,120 @@ mod tests {
             PermissionOutcome::Deny { reason } if reason == "not now"
         ));
     }
+
+    #[test]
+    fn applies_rule_based_denials_and_allows() {
+        let rules = RuntimePermissionRuleConfig::new(
+            vec!["bash(git:*)".to_string()],
+            vec!["bash(rm -rf:*)".to_string()],
+            Vec::new(),
+        );
+        let policy = PermissionPolicy::new(PermissionMode::ReadOnly)
+            .with_tool_requirement("bash", PermissionMode::DangerFullAccess)
+            .with_permission_rules(&rules);
+
+        assert_eq!(
+            policy.authorize("bash", r#"{"command":"git status"}"#, None),
+            PermissionOutcome::Allow
+        );
+        assert!(matches!(
+            policy.authorize("bash", r#"{"command":"rm -rf /tmp/x"}"#, None),
+            PermissionOutcome::Deny { reason } if reason.contains("denied by rule")
+        ));
+    }
+
+    #[test]
+    fn ask_rules_force_prompt_even_when_mode_allows() {
+        let rules = RuntimePermissionRuleConfig::new(
+            Vec::new(),
+            Vec::new(),
+            vec!["bash(git:*)".to_string()],
+        );
+        let policy = PermissionPolicy::new(PermissionMode::DangerFullAccess)
+            .with_tool_requirement("bash", PermissionMode::DangerFullAccess)
+            .with_permission_rules(&rules);
+        let mut prompter = RecordingPrompter {
+            seen: Vec::new(),
+            allow: true,
+        };
+
+        let outcome = policy.authorize("bash", r#"{"command":"git status"}"#, Some(&mut prompter));
+
+        assert_eq!(outcome, PermissionOutcome::Allow);
+        assert_eq!(prompter.seen.len(), 1);
+        assert!(prompter.seen[0]
+            .reason
+            .as_deref()
+            .is_some_and(|reason| reason.contains("ask rule")));
+    }
+
+    #[test]
+    fn hook_allow_still_respects_ask_rules() {
+        let rules = RuntimePermissionRuleConfig::new(
+            Vec::new(),
+            Vec::new(),
+            vec!["bash(git:*)".to_string()],
+        );
+        let policy = PermissionPolicy::new(PermissionMode::ReadOnly)
+            .with_tool_requirement("bash", PermissionMode::DangerFullAccess)
+            .with_permission_rules(&rules);
+        let context = PermissionContext::new(
+            Some(PermissionOverride::Allow),
+            Some("hook approved".to_string()),
+        );
+        let mut prompter = RecordingPrompter {
+            seen: Vec::new(),
+            allow: true,
+        };
+
+        let outcome = policy.authorize_with_context(
+            "bash",
+            r#"{"command":"git status"}"#,
+            &context,
+            Some(&mut prompter),
+        );
+
+        assert_eq!(outcome, PermissionOutcome::Allow);
+        assert_eq!(prompter.seen.len(), 1);
+    }
+
+    #[test]
+    fn hook_deny_short_circuits_permission_flow() {
+        let policy = PermissionPolicy::new(PermissionMode::DangerFullAccess)
+            .with_tool_requirement("bash", PermissionMode::DangerFullAccess);
+        let context = PermissionContext::new(
+            Some(PermissionOverride::Deny),
+            Some("blocked by hook".to_string()),
+        );
+
+        assert_eq!(
+            policy.authorize_with_context("bash", "{}", &context, None),
+            PermissionOutcome::Deny {
+                reason: "blocked by hook".to_string(),
+            }
+        );
+    }
+
+    #[test]
+    fn hook_ask_forces_prompt() {
+        let policy = PermissionPolicy::new(PermissionMode::DangerFullAccess)
+            .with_tool_requirement("bash", PermissionMode::DangerFullAccess);
+        let context = PermissionContext::new(
+            Some(PermissionOverride::Ask),
+            Some("hook requested confirmation".to_string()),
+        );
+        let mut prompter = RecordingPrompter {
+            seen: Vec::new(),
+            allow: true,
+        };
+
+        let outcome = policy.authorize_with_context("bash", "{}", &context, Some(&mut prompter));
+
+        assert_eq!(outcome, PermissionOutcome::Allow);
+        assert_eq!(prompter.seen.len(), 1);
+        assert_eq!(
+            prompter.seen[0].reason.as_deref(),
+            Some("hook requested confirmation")
+        );
+    }
 }

rust/crates/rusty-claude-cli/Cargo.toml

@@ -19,7 +19,7 @@ rustyline = "15"
 runtime = { path = "../runtime" }
 serde_json = "1"
 syntect = "5"
-tokio = { version = "1", features = ["rt-multi-thread", "time"] }
+tokio = { version = "1", features = ["rt-multi-thread", "signal", "time"] }
 tools = { path = "../tools" }
 
 [lints]

rust/crates/rusty-claude-cli/src/main.rs

@@ -9,13 +9,14 @@ use std::io::{self, Read, Write};
 use std::net::TcpListener;
 use std::path::{Path, PathBuf};
 use std::process::Command;
+use std::sync::mpsc::{self, Receiver, Sender};
+use std::thread::{self, JoinHandle};
 use std::time::{SystemTime, UNIX_EPOCH};
 
 use api::{
     resolve_startup_auth_source, AnthropicClient, AuthSource, ContentBlockDelta, InputContentBlock,
-    InputMessage, MessageRequest, MessageResponse, OutputContentBlock, PromptCache,
-    PromptCacheRecord, StreamEvent as ApiStreamEvent, ToolChoice, ToolDefinition,
-    ToolResultContentBlock,
+    InputMessage, MessageRequest, MessageResponse, OutputContentBlock,
+    StreamEvent as ApiStreamEvent, ToolChoice, ToolDefinition, ToolResultContentBlock,
 };
 
 use commands::{
@@ -29,8 +30,8 @@ use runtime::{
     parse_oauth_callback_request_target, save_oauth_credentials, ApiClient, ApiRequest,
     AssistantEvent, CompactionConfig, ConfigLoader, ConfigSource, ContentBlock,
     ConversationMessage, ConversationRuntime, MessageRole, OAuthAuthorizationRequest, OAuthConfig,
-    OAuthTokenExchangeRequest, PermissionMode, PermissionPolicy, ProjectContext, PromptCacheEvent,
-    RuntimeError, Session, TokenUsage, ToolError, ToolExecutor, UsageTracker,
+    OAuthTokenExchangeRequest, PermissionMode, PermissionPolicy, ProjectContext, RuntimeError,
+    Session, TokenUsage, ToolError, ToolExecutor, UsageTracker,
 };
 use serde_json::json;
 use tools::{execute_tool, mvp_tool_specs, ToolSpec};
@@ -985,6 +986,61 @@ struct LiveCli {
     session: SessionHandle,
 }
 
+struct HookAbortMonitor {
+    stop_tx: Option<Sender<()>>,
+    join_handle: Option<JoinHandle<()>>,
+}
+
+impl HookAbortMonitor {
+    fn spawn(abort_signal: runtime::HookAbortSignal) -> Self {
+        Self::spawn_with_waiter(abort_signal, move |stop_rx, abort_signal| {
+            let Ok(runtime) = tokio::runtime::Builder::new_current_thread()
+                .enable_all()
+                .build()
+            else {
+                return;
+            };
+
+            runtime.block_on(async move {
+                let wait_for_stop = tokio::task::spawn_blocking(move || {
+                    let _ = stop_rx.recv();
+                });
+
+                tokio::select! {
+                    result = tokio::signal::ctrl_c() => {
+                        if result.is_ok() {
+                            abort_signal.abort();
+                        }
+                    }
+                    _ = wait_for_stop => {}
+                }
+            });
+        })
+    }
+
+    fn spawn_with_waiter<F>(abort_signal: runtime::HookAbortSignal, wait_for_interrupt: F) -> Self
+    where
+        F: FnOnce(Receiver<()>, runtime::HookAbortSignal) + Send + 'static,
+    {
+        let (stop_tx, stop_rx) = mpsc::channel();
+        let join_handle = thread::spawn(move || wait_for_interrupt(stop_rx, abort_signal));
+
+        Self {
+            stop_tx: Some(stop_tx),
+            join_handle: Some(join_handle),
+        }
+    }
+
+    fn stop(mut self) {
+        if let Some(stop_tx) = self.stop_tx.take() {
+            let _ = stop_tx.send(());
+        }
+        if let Some(join_handle) = self.join_handle.take() {
+            let _ = join_handle.join();
+        }
+    }
+}
+
 impl LiveCli {
     fn new(
         model: String,
@@ -996,7 +1052,6 @@ impl LiveCli {
         let session = create_managed_session_handle()?;
         let runtime = build_runtime(
             Session::new(),
-            session.id.clone(),
             model.clone(),
             system_prompt.clone(),
             enable_tools,
@@ -1041,7 +1096,34 @@ impl LiveCli {
         )
     }
 
+    fn prepare_turn_runtime(
+        &self,
+        emit_output: bool,
+    ) -> Result<
+        (
+            ConversationRuntime<AnthropicRuntimeClient, CliToolExecutor>,
+            HookAbortMonitor,
+        ),
+        Box<dyn std::error::Error>,
+    > {
+        let hook_abort_signal = runtime::HookAbortSignal::new();
+        let runtime = build_runtime(
+            self.runtime.session().clone(),
+            self.model.clone(),
+            self.system_prompt.clone(),
+            true,
+            emit_output,
+            self.allowed_tools.clone(),
+            self.permission_mode,
+        )?
+        .with_hook_abort_signal(hook_abort_signal.clone());
+        let hook_abort_monitor = HookAbortMonitor::spawn(hook_abort_signal);
+
+        Ok((runtime, hook_abort_monitor))
+    }
+
     fn run_turn(&mut self, input: &str) -> Result<(), Box<dyn std::error::Error>> {
+        let (mut runtime, hook_abort_monitor) = self.prepare_turn_runtime(true)?;
         let mut spinner = Spinner::new();
         let mut stdout = io::stdout();
         spinner.tick(
@@ -1050,16 +1132,17 @@ impl LiveCli {
             &mut stdout,
         )?;
         let mut permission_prompter = CliPermissionPrompter::new(self.permission_mode);
-        let result = self.runtime.run_turn(input, Some(&mut permission_prompter));
+        let result = runtime.run_turn(input, Some(&mut permission_prompter));
+        hook_abort_monitor.stop();
+        self.runtime = runtime;
         match result {
-            Ok(summary) => {
+            Ok(_) => {
                 spinner.finish(
                     "✨ Done",
                     TerminalRenderer::new().color_theme(),
                     &mut stdout,
                 )?;
                 println!();
-                print_prompt_cache_events(&summary);
                 self.persist_session()?;
                 Ok(())
             }
@@ -1086,19 +1169,11 @@ impl LiveCli {
     }
 
     fn run_prompt_json(&mut self, input: &str) -> Result<(), Box<dyn std::error::Error>> {
-        let session = self.runtime.session().clone();
-        let mut runtime = build_runtime(
-            session,
-            self.session.id.clone(),
-            self.model.clone(),
-            self.system_prompt.clone(),
-            true,
-            false,
-            self.allowed_tools.clone(),
-            self.permission_mode,
-        )?;
+        let (mut runtime, hook_abort_monitor) = self.prepare_turn_runtime(false)?;
         let mut permission_prompter = CliPermissionPrompter::new(self.permission_mode);
-        let summary = runtime.run_turn(input, Some(&mut permission_prompter))?;
+        let result = runtime.run_turn(input, Some(&mut permission_prompter));
+        hook_abort_monitor.stop();
+        let summary = result?;
         self.runtime = runtime;
         self.persist_session()?;
         println!(
@@ -1109,7 +1184,6 @@ impl LiveCli {
                 "iterations": summary.iterations,
                 "tool_uses": collect_tool_uses(&summary),
                 "tool_results": collect_tool_results(&summary),
-                "prompt_cache_events": collect_prompt_cache_events(&summary),
                 "usage": {
                     "input_tokens": summary.usage.input_tokens,
                     "output_tokens": summary.usage.output_tokens,
@@ -1237,7 +1311,6 @@ impl LiveCli {
         let message_count = session.messages.len();
         self.runtime = build_runtime(
             session,
-            self.session.id.clone(),
             model.clone(),
             self.system_prompt.clone(),
             true,
@@ -1281,7 +1354,6 @@ impl LiveCli {
         self.permission_mode = permission_mode_from_label(normalized);
         self.runtime = build_runtime(
             session,
-            self.session.id.clone(),
             self.model.clone(),
             self.system_prompt.clone(),
             true,
@@ -1307,7 +1379,6 @@ impl LiveCli {
         self.session = create_managed_session_handle()?;
         self.runtime = build_runtime(
             Session::new(),
-            self.session.id.clone(),
             self.model.clone(),
             self.system_prompt.clone(),
             true,
@@ -1343,7 +1414,6 @@ impl LiveCli {
         let message_count = session.messages.len();
         self.runtime = build_runtime(
             session,
-            handle.id.clone(),
             self.model.clone(),
             self.system_prompt.clone(),
             true,
@@ -1416,7 +1486,6 @@ impl LiveCli {
                 let message_count = session.messages.len();
                 self.runtime = build_runtime(
                     session,
-                    handle.id.clone(),
                     self.model.clone(),
                     self.system_prompt.clone(),
                     true,
@@ -1447,7 +1516,6 @@ impl LiveCli {
         let skipped = removed == 0;
         self.runtime = build_runtime(
             result.compacted_session,
-            self.session.id.clone(),
             self.model.clone(),
             self.system_prompt.clone(),
             true,
@@ -1923,10 +1991,8 @@ fn build_runtime_feature_config(
         .clone())
 }
 
-#[allow(clippy::too_many_arguments)]
 fn build_runtime(
     session: Session,
-    session_id: String,
     model: String,
     system_prompt: Vec<String>,
     enable_tools: bool,
@@ -1935,20 +2001,52 @@ fn build_runtime(
     permission_mode: PermissionMode,
 ) -> Result<ConversationRuntime<AnthropicRuntimeClient, CliToolExecutor>, Box<dyn std::error::Error>>
 {
-    Ok(ConversationRuntime::new_with_features(
+    let feature_config = build_runtime_feature_config()?;
+    let mut runtime = ConversationRuntime::new_with_features(
         session,
-        AnthropicRuntimeClient::new(
-            model,
-            enable_tools,
-            emit_output,
-            allowed_tools.clone(),
-            session_id,
-        )?,
+        AnthropicRuntimeClient::new(model, enable_tools, emit_output, allowed_tools.clone())?,
         CliToolExecutor::new(allowed_tools, emit_output),
-        permission_policy(permission_mode),
+        permission_policy(permission_mode, &feature_config),
         system_prompt,
-        &build_runtime_feature_config()?,
-    ))
+        feature_config,
+    );
+    if emit_output {
+        runtime = runtime.with_hook_progress_reporter(Box::new(CliHookProgressReporter));
+    }
+    Ok(runtime)
+}
+
+struct CliHookProgressReporter;
+
+impl runtime::HookProgressReporter for CliHookProgressReporter {
+    fn on_event(&mut self, event: &runtime::HookProgressEvent) {
+        match event {
+            runtime::HookProgressEvent::Started {
+                event,
+                tool_name,
+                command,
+            } => eprintln!(
+                "[hook {event_name}] {tool_name}: {command}",
+                event_name = event.as_str()
+            ),
+            runtime::HookProgressEvent::Completed {
+                event,
+                tool_name,
+                command,
+            } => eprintln!(
+                "[hook done {event_name}] {tool_name}: {command}",
+                event_name = event.as_str()
+            ),
+            runtime::HookProgressEvent::Cancelled {
+                event,
+                tool_name,
+                command,
+            } => eprintln!(
+                "[hook cancelled {event_name}] {tool_name}: {command}",
+                event_name = event.as_str()
+            ),
+        }
+    }
 }
 
 struct CliPermissionPrompter {
@@ -1971,6 +2069,9 @@ impl runtime::PermissionPrompter for CliPermissionPrompter {
         println!("  Tool             {}", request.tool_name);
         println!("  Current mode     {}", self.current_mode.as_str());
         println!("  Required mode    {}", request.required_mode.as_str());
+        if let Some(reason) = &request.reason {
+            println!("  Reason           {reason}");
+        }
         println!("  Input            {}", request.input);
         print!("Approve this tool call? [y/N]: ");
         let _ = io::stdout().flush();
@@ -2012,13 +2113,11 @@ impl AnthropicRuntimeClient {
         enable_tools: bool,
         emit_output: bool,
         allowed_tools: Option<AllowedToolSet>,
-        session_id: impl Into<String>,
     ) -> Result<Self, Box<dyn std::error::Error>> {
         Ok(Self {
             runtime: tokio::runtime::Runtime::new()?,
             client: AnthropicClient::from_auth(resolve_cli_auth_source()?)
-                .with_base_url(api::read_base_url())
-                .with_prompt_cache(PromptCache::new(session_id)),
+                .with_base_url(api::read_base_url()),
             model,
             enable_tools,
             emit_output,
@@ -2133,8 +2232,8 @@ impl ApiClient for AnthropicRuntimeClient {
                         events.push(AssistantEvent::Usage(TokenUsage {
                             input_tokens: delta.usage.input_tokens,
                             output_tokens: delta.usage.output_tokens,
-                            cache_creation_input_tokens: delta.usage.cache_creation_input_tokens,
-                            cache_read_input_tokens: delta.usage.cache_read_input_tokens,
+                            cache_creation_input_tokens: 0,
+                            cache_read_input_tokens: 0,
                         }));
                     }
                     ApiStreamEvent::MessageStop(_) => {
@@ -2149,8 +2248,6 @@ impl ApiClient for AnthropicRuntimeClient {
                 }
             }
 
-            push_prompt_cache_record(&self.client, &mut events);
-
             if !saw_stop
                 && events.iter().any(|event| {
                     matches!(event, AssistantEvent::TextDelta(text) if !text.is_empty())
@@ -2175,9 +2272,7 @@ impl ApiClient for AnthropicRuntimeClient {
                 })
                 .await
                 .map_err(|error| RuntimeError::new(error.to_string()))?;
-            let mut events = response_to_events(response, out)?;
-            push_prompt_cache_record(&self.client, &mut events);
-            Ok(events)
+            response_to_events(response, out)
         })
     }
 }
@@ -2238,39 +2333,6 @@ fn collect_tool_results(summary: &runtime::TurnSummary) -> Vec<serde_json::Value
         .collect()
 }
 
-fn collect_prompt_cache_events(summary: &runtime::TurnSummary) -> Vec<serde_json::Value> {
-    summary
-        .prompt_cache_events
-        .iter()
-        .map(|event| {
-            json!({
-                "unexpected": event.unexpected,
-                "reason": event.reason,
-                "previous_cache_read_input_tokens": event.previous_cache_read_input_tokens,
-                "current_cache_read_input_tokens": event.current_cache_read_input_tokens,
-                "token_drop": event.token_drop,
-            })
-        })
-        .collect()
-}
-
-fn print_prompt_cache_events(summary: &runtime::TurnSummary) {
-    for event in &summary.prompt_cache_events {
-        let label = if event.unexpected {
-            "Prompt cache break"
-        } else {
-            "Prompt cache invalidation"
-        };
-        println!(
-            "{label}: {} (cache read {} -> {}, drop {})",
-            event.reason,
-            event.previous_cache_read_input_tokens,
-            event.current_cache_read_input_tokens,
-            event.token_drop,
-        );
-    }
-}
-
 fn slash_command_completion_candidates() -> Vec<String> {
     slash_command_specs()
         .iter()
@@ -2417,19 +2479,19 @@ fn first_visible_line(text: &str) -> &str {
 }
 
 fn format_bash_result(icon: &str, parsed: &serde_json::Value) -> String {
-    use std::fmt::Write as _;
-
     let mut lines = vec![format!("{icon} \x1b[38;5;245mbash\x1b[0m")];
     if let Some(task_id) = parsed
         .get("backgroundTaskId")
         .and_then(|value| value.as_str())
     {
+        use std::fmt::Write as _;
         let _ = write!(lines[0], " backgrounded ({task_id})");
     } else if let Some(status) = parsed
         .get("returnCodeInterpretation")
         .and_then(|value| value.as_str())
         .filter(|status| !status.is_empty())
     {
+        use std::fmt::Write as _;
         let _ = write!(lines[0], " {status}");
     }
 
@@ -2680,26 +2742,6 @@ fn response_to_events(
     Ok(events)
 }
 
-fn push_prompt_cache_record(client: &AnthropicClient, events: &mut Vec<AssistantEvent>) {
-    if let Some(event) = client
-        .take_last_prompt_cache_record()
-        .and_then(prompt_cache_record_to_runtime_event)
-    {
-        events.push(AssistantEvent::PromptCache(event));
-    }
-}
-
-fn prompt_cache_record_to_runtime_event(record: PromptCacheRecord) -> Option<PromptCacheEvent> {
-    let cache_break = record.cache_break?;
-    Some(PromptCacheEvent {
-        unexpected: cache_break.unexpected,
-        reason: cache_break.reason,
-        previous_cache_read_input_tokens: cache_break.previous_cache_read_input_tokens,
-        current_cache_read_input_tokens: cache_break.current_cache_read_input_tokens,
-        token_drop: cache_break.token_drop,
-    })
-}
-
 struct CliToolExecutor {
     renderer: TerminalRenderer,
     emit_output: bool,
@@ -2752,12 +2794,14 @@ impl ToolExecutor for CliToolExecutor {
     }
 }
 
-fn permission_policy(mode: PermissionMode) -> PermissionPolicy {
-    tool_permission_specs()
-        .into_iter()
-        .fold(PermissionPolicy::new(mode), |policy, spec| {
-            policy.with_tool_requirement(spec.name, spec.required_permission)
-        })
+fn permission_policy(
+    mode: PermissionMode,
+    feature_config: &runtime::RuntimeFeatureConfig,
+) -> PermissionPolicy {
+    tool_permission_specs().into_iter().fold(
+        PermissionPolicy::new(mode).with_permission_rules(feature_config.permission_rules()),
+        |policy, spec| policy.with_tool_requirement(spec.name, spec.required_permission),
+    )
 }
 
 fn tool_permission_specs() -> Vec<ToolSpec> {
@@ -2906,12 +2950,17 @@ mod tests {
         normalize_permission_mode, parse_args, parse_git_status_metadata, print_help_to,
         push_output_block, render_config_report, render_memory_report, render_repl_help,
         resolve_model_alias, response_to_events, resume_supported_slash_commands, status_context,
-        CliAction, CliOutputFormat, SlashCommand, StatusUsage, DEFAULT_MODEL,
+        CliAction, CliOutputFormat, HookAbortMonitor, SlashCommand, StatusUsage, DEFAULT_MODEL,
     };
     use api::{MessageResponse, OutputContentBlock, Usage};
-    use runtime::{AssistantEvent, ContentBlock, ConversationMessage, MessageRole, PermissionMode};
+    use runtime::{
+        AssistantEvent, ContentBlock, ConversationMessage, HookAbortSignal, MessageRole,
+        PermissionMode,
+    };
     use serde_json::json;
     use std::path::PathBuf;
+    use std::sync::mpsc;
+    use std::time::Duration;
 
     #[test]
     fn defaults_to_repl_when_no_args() {
@@ -3570,4 +3619,43 @@ mod tests {
                 if name == "read_file" && input == "{\"path\":\"rust/Cargo.toml\"}"
         ));
     }
+
+    #[test]
+    fn hook_abort_monitor_stops_without_aborting() {
+        let abort_signal = HookAbortSignal::new();
+        let (ready_tx, ready_rx) = mpsc::channel();
+        let monitor = HookAbortMonitor::spawn_with_waiter(
+            abort_signal.clone(),
+            move |stop_rx, abort_signal| {
+                ready_tx.send(()).expect("ready signal");
+                let _ = stop_rx.recv();
+                assert!(!abort_signal.is_aborted());
+            },
+        );
+
+        ready_rx.recv().expect("waiter should be ready");
+        monitor.stop();
+
+        assert!(!abort_signal.is_aborted());
+    }
+
+    #[test]
+    fn hook_abort_monitor_propagates_interrupt() {
+        let abort_signal = HookAbortSignal::new();
+        let (done_tx, done_rx) = mpsc::channel();
+        let monitor = HookAbortMonitor::spawn_with_waiter(
+            abort_signal.clone(),
+            move |_stop_rx, abort_signal| {
+                abort_signal.abort();
+                done_tx.send(()).expect("done signal");
+            },
+        );
+
+        done_rx
+            .recv_timeout(Duration::from_secs(1))
+            .expect("interrupt should complete");
+        monitor.stop();
+
+        assert!(abort_signal.is_aborted());
+    }
 }

rust/crates/tools/src/lib.rs

@@ -5,15 +5,15 @@ use std::time::{Duration, Instant};
 
 use api::{
     read_base_url, AnthropicClient, ContentBlockDelta, InputContentBlock, InputMessage,
-    MessageRequest, MessageResponse, OutputContentBlock, PromptCache, PromptCacheRecord,
-    StreamEvent as ApiStreamEvent, ToolChoice, ToolDefinition, ToolResultContentBlock,
+    MessageRequest, MessageResponse, OutputContentBlock, StreamEvent as ApiStreamEvent, ToolChoice,
+    ToolDefinition, ToolResultContentBlock,
 };
 use reqwest::blocking::Client;
 use runtime::{
     edit_file, execute_bash, glob_search, grep_search, load_system_prompt, read_file, write_file,
     ApiClient, ApiRequest, AssistantEvent, BashCommandInput, ContentBlock, ConversationMessage,
     ConversationRuntime, GrepSearchInput, MessageRole, PermissionMode, PermissionPolicy,
-    PromptCacheEvent, RuntimeError, Session, TokenUsage, ToolError, ToolExecutor,
+    RuntimeError, Session, TokenUsage, ToolError, ToolExecutor,
 };
 use serde::{Deserialize, Serialize};
 use serde_json::{json, Value};
@@ -1466,8 +1466,7 @@ fn build_agent_runtime(
         .clone()
         .unwrap_or_else(|| DEFAULT_AGENT_MODEL.to_string());
     let allowed_tools = job.allowed_tools.clone();
-    let api_client =
-        AnthropicRuntimeClient::new(model, allowed_tools.clone(), job.manifest.agent_id.clone())?;
+    let api_client = AnthropicRuntimeClient::new(model, allowed_tools.clone())?;
     let tool_executor = SubagentToolExecutor::new(allowed_tools);
     Ok(ConversationRuntime::new(
         Session::new(),
@@ -1644,15 +1643,10 @@ struct AnthropicRuntimeClient {
 }
 
 impl AnthropicRuntimeClient {
-    fn new(
-        model: String,
-        allowed_tools: BTreeSet<String>,
-        session_id: impl Into<String>,
-    ) -> Result<Self, String> {
+    fn new(model: String, allowed_tools: BTreeSet<String>) -> Result<Self, String> {
         let client = AnthropicClient::from_env()
             .map_err(|error| error.to_string())?
-            .with_base_url(read_base_url())
-            .with_prompt_cache(PromptCache::new(session_id));
+            .with_base_url(read_base_url());
         Ok(Self {
             runtime: tokio::runtime::Runtime::new().map_err(|error| error.to_string())?,
             client,
@@ -1663,7 +1657,6 @@ impl AnthropicRuntimeClient {
 }
 
 impl ApiClient for AnthropicRuntimeClient {
-    #[allow(clippy::too_many_lines)]
     fn stream(&mut self, request: ApiRequest) -> Result<Vec<AssistantEvent>, RuntimeError> {
         let tools = tool_specs_for_allowed_tools(Some(&self.allowed_tools))
             .into_iter()
@@ -1733,8 +1726,8 @@ impl ApiClient for AnthropicRuntimeClient {
                         events.push(AssistantEvent::Usage(TokenUsage {
                             input_tokens: delta.usage.input_tokens,
                             output_tokens: delta.usage.output_tokens,
-                            cache_creation_input_tokens: delta.usage.cache_creation_input_tokens,
-                            cache_read_input_tokens: delta.usage.cache_read_input_tokens,
+                            cache_creation_input_tokens: 0,
+                            cache_read_input_tokens: 0,
                         }));
                     }
                     ApiStreamEvent::MessageStop(_) => {
@@ -1744,8 +1737,6 @@ impl ApiClient for AnthropicRuntimeClient {
                 }
             }
 
-            push_prompt_cache_record(&self.client, &mut events);
-
             if !saw_stop
                 && events.iter().any(|event| {
                     matches!(event, AssistantEvent::TextDelta(text) if !text.is_empty())
@@ -1770,9 +1761,7 @@ impl ApiClient for AnthropicRuntimeClient {
                 })
                 .await
                 .map_err(|error| RuntimeError::new(error.to_string()))?;
-            let mut events = response_to_events(response);
-            push_prompt_cache_record(&self.client, &mut events);
-            Ok(events)
+            Ok(response_to_events(response))
         })
     }
 }
@@ -1895,26 +1884,6 @@ fn response_to_events(response: MessageResponse) -> Vec<AssistantEvent> {
     events
 }
 
-fn push_prompt_cache_record(client: &AnthropicClient, events: &mut Vec<AssistantEvent>) {
-    if let Some(event) = client
-        .take_last_prompt_cache_record()
-        .and_then(prompt_cache_record_to_runtime_event)
-    {
-        events.push(AssistantEvent::PromptCache(event));
-    }
-}
-
-fn prompt_cache_record_to_runtime_event(record: PromptCacheRecord) -> Option<PromptCacheEvent> {
-    let cache_break = record.cache_break?;
-    Some(PromptCacheEvent {
-        unexpected: cache_break.unexpected,
-        reason: cache_break.reason,
-        previous_cache_read_input_tokens: cache_break.previous_cache_read_input_tokens,
-        current_cache_read_input_tokens: cache_break.current_cache_read_input_tokens,
-        token_drop: cache_break.token_drop,
-    })
-}
-
 fn final_assistant_text(summary: &runtime::TurnSummary) -> String {
     summary
         .assistant_messages