wip: grok provider abstraction

feat: provider tests + grok integration
feat: grok provider tests + cargo fmt
2026-04-01 06:00:48 +00:00 · 2026-04-01 05:45:27 +00:00 · 2026-04-01 04:20:15 +00:00 · 2026-04-01 04:10:46 +00:00 · 2026-04-01 04:01:37 +00:00
16 changed files with 3234 additions and 2281 deletions
--- a/rust/crates/api/src/client.rs
+++ b/rust/crates/api/src/client.rs
--- a/rust/crates/api/src/error.rs
+++ b/rust/crates/api/src/error.rs
@@ -4,7 +4,10 @@ use std::time::Duration;

 #[derive(Debug)]
 pub enum ApiError {
-    MissingApiKey,
+    MissingCredentials {
+        provider: &'static str,
+        env_vars: &'static [&'static str],
+    },
    ExpiredOAuthToken,
    Auth(String),
    InvalidApiKeyEnv(VarError),
@@ -30,13 +33,21 @@ pub enum ApiError {
 }

 impl ApiError {
+    #[must_use]
+    pub const fn missing_credentials(
+        provider: &'static str,
+        env_vars: &'static [&'static str],
+    ) -> Self {
+        Self::MissingCredentials { provider, env_vars }
+    }
+
    #[must_use]
    pub fn is_retryable(&self) -> bool {
        match self {
            Self::Http(error) => error.is_connect() || error.is_timeout() || error.is_request(),
            Self::Api { retryable, .. } => *retryable,
            Self::RetriesExhausted { last_error, .. } => last_error.is_retryable(),
-            Self::MissingApiKey
+            Self::MissingCredentials { .. }
            | Self::ExpiredOAuthToken
            | Self::Auth(_)
            | Self::InvalidApiKeyEnv(_)
@@ -51,12 +62,11 @@ impl ApiError {
 impl Display for ApiError {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        match self {
-            Self::MissingApiKey => {
-                write!(
+            Self::MissingCredentials { provider, env_vars } => write!(
                f,
-                    "ANTHROPIC_AUTH_TOKEN or ANTHROPIC_API_KEY is not set; export one before calling the Anthropic API"
-                )
-            }
+                "missing {provider} credentials; export {} before calling the {provider} API",
+                env_vars.join(" or ")
+            ),
            Self::ExpiredOAuthToken => {
                write!(
                    f,
@@ -65,10 +75,7 @@ impl Display for ApiError {
            }
            Self::Auth(message) => write!(f, "auth error: {message}"),
            Self::InvalidApiKeyEnv(error) => {
-                write!(
-                    f,
-                    "failed to read ANTHROPIC_AUTH_TOKEN / ANTHROPIC_API_KEY: {error}"
-                )
+                write!(f, "failed to read credential environment variable: {error}")
            }
            Self::Http(error) => write!(f, "http error: {error}"),
            Self::Io(error) => write!(f, "io error: {error}"),
@@ -81,20 +88,14 @@ impl Display for ApiError {
                ..
            } => match (error_type, message) {
                (Some(error_type), Some(message)) => {
-                    write!(
-                        f,
-                        "anthropic api returned {status} ({error_type}): {message}"
-                    )
+                    write!(f, "api returned {status} ({error_type}): {message}")
                }
-                _ => write!(f, "anthropic api returned {status}: {body}"),
+                _ => write!(f, "api returned {status}: {body}"),
            },
            Self::RetriesExhausted {
                attempts,
                last_error,
-            } => write!(
-                f,
-                "anthropic api failed after {attempts} attempts: {last_error}"
-            ),
+            } => write!(f, "api failed after {attempts} attempts: {last_error}"),
            Self::InvalidSseFrame(message) => write!(f, "invalid sse frame: {message}"),
            Self::BackoffOverflow {
                attempt,
--- a/rust/crates/api/src/lib.rs
+++ b/rust/crates/api/src/lib.rs
@@ -1,17 +1,18 @@
 mod client;
 mod error;
-mod prompt_cache;
+mod providers;
 mod sse;
 mod types;

 pub use client::{
-    oauth_token_is_expired, read_base_url, resolve_saved_oauth_token, resolve_startup_auth_source,
-    AnthropicClient, AuthSource, MessageStream, OAuthTokenSet,
+    oauth_token_is_expired, read_base_url, read_xai_base_url, resolve_saved_oauth_token,
+    resolve_startup_auth_source, MessageStream, OAuthTokenSet, ProviderClient,
 };
 pub use error::ApiError;
-pub use prompt_cache::{
-    CacheBreakEvent, PromptCache, PromptCacheConfig, PromptCachePaths, PromptCacheRecord,
-    PromptCacheStats,
+pub use providers::anthropic::{AnthropicClient, AuthSource};
+pub use providers::openai_compat::{OpenAiCompatClient, OpenAiCompatConfig};
+pub use providers::{
+    detect_provider_kind, max_tokens_for_model, resolve_model_alias, ProviderKind,
 };
 pub use sse::{parse_frame, SseParser};
 pub use types::{
@@ -20,11 +21,3 @@ 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)
-}
--- a/rust/crates/api/src/prompt_cache.rs
+++ b/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()),
-        }
-    }
-}
--- a/rust/crates/api/src/providers/anthropic.rs
+++ b/rust/crates/api/src/providers/anthropic.rs
--- a/rust/crates/api/src/providers/mod.rs
+++ b/rust/crates/api/src/providers/mod.rs
@@ -0,0 +1,216 @@
+use std::future::Future;
+use std::pin::Pin;
+
+use crate::error::ApiError;
+use crate::types::{MessageRequest, MessageResponse};
+
+pub mod anthropic;
+pub mod openai_compat;
+
+pub type ProviderFuture<'a, T> = Pin<Box<dyn Future<Output = Result<T, ApiError>> + Send + 'a>>;
+
+pub trait Provider {
+    type Stream;
+
+    fn send_message<'a>(
+        &'a self,
+        request: &'a MessageRequest,
+    ) -> ProviderFuture<'a, MessageResponse>;
+
+    fn stream_message<'a>(
+        &'a self,
+        request: &'a MessageRequest,
+    ) -> ProviderFuture<'a, Self::Stream>;
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub enum ProviderKind {
+    Anthropic,
+    Xai,
+    OpenAi,
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub struct ProviderMetadata {
+    pub provider: ProviderKind,
+    pub auth_env: &'static str,
+    pub base_url_env: &'static str,
+    pub default_base_url: &'static str,
+}
+
+const MODEL_REGISTRY: &[(&str, ProviderMetadata)] = &[
+    (
+        "opus",
+        ProviderMetadata {
+            provider: ProviderKind::Anthropic,
+            auth_env: "ANTHROPIC_API_KEY",
+            base_url_env: "ANTHROPIC_BASE_URL",
+            default_base_url: anthropic::DEFAULT_BASE_URL,
+        },
+    ),
+    (
+        "sonnet",
+        ProviderMetadata {
+            provider: ProviderKind::Anthropic,
+            auth_env: "ANTHROPIC_API_KEY",
+            base_url_env: "ANTHROPIC_BASE_URL",
+            default_base_url: anthropic::DEFAULT_BASE_URL,
+        },
+    ),
+    (
+        "haiku",
+        ProviderMetadata {
+            provider: ProviderKind::Anthropic,
+            auth_env: "ANTHROPIC_API_KEY",
+            base_url_env: "ANTHROPIC_BASE_URL",
+            default_base_url: anthropic::DEFAULT_BASE_URL,
+        },
+    ),
+    (
+        "grok",
+        ProviderMetadata {
+            provider: ProviderKind::Xai,
+            auth_env: "XAI_API_KEY",
+            base_url_env: "XAI_BASE_URL",
+            default_base_url: openai_compat::DEFAULT_XAI_BASE_URL,
+        },
+    ),
+    (
+        "grok-3",
+        ProviderMetadata {
+            provider: ProviderKind::Xai,
+            auth_env: "XAI_API_KEY",
+            base_url_env: "XAI_BASE_URL",
+            default_base_url: openai_compat::DEFAULT_XAI_BASE_URL,
+        },
+    ),
+    (
+        "grok-mini",
+        ProviderMetadata {
+            provider: ProviderKind::Xai,
+            auth_env: "XAI_API_KEY",
+            base_url_env: "XAI_BASE_URL",
+            default_base_url: openai_compat::DEFAULT_XAI_BASE_URL,
+        },
+    ),
+    (
+        "grok-3-mini",
+        ProviderMetadata {
+            provider: ProviderKind::Xai,
+            auth_env: "XAI_API_KEY",
+            base_url_env: "XAI_BASE_URL",
+            default_base_url: openai_compat::DEFAULT_XAI_BASE_URL,
+        },
+    ),
+    (
+        "grok-2",
+        ProviderMetadata {
+            provider: ProviderKind::Xai,
+            auth_env: "XAI_API_KEY",
+            base_url_env: "XAI_BASE_URL",
+            default_base_url: openai_compat::DEFAULT_XAI_BASE_URL,
+        },
+    ),
+];
+
+#[must_use]
+pub fn resolve_model_alias(model: &str) -> String {
+    let trimmed = model.trim();
+    let lower = trimmed.to_ascii_lowercase();
+    MODEL_REGISTRY
+        .iter()
+        .find_map(|(alias, metadata)| {
+            (*alias == lower).then_some(match metadata.provider {
+                ProviderKind::Anthropic => match *alias {
+                    "opus" => "claude-opus-4-6",
+                    "sonnet" => "claude-sonnet-4-6",
+                    "haiku" => "claude-haiku-4-5-20251213",
+                    _ => trimmed,
+                },
+                ProviderKind::Xai => match *alias {
+                    "grok" | "grok-3" => "grok-3",
+                    "grok-mini" | "grok-3-mini" => "grok-3-mini",
+                    "grok-2" => "grok-2",
+                    _ => trimmed,
+                },
+                ProviderKind::OpenAi => trimmed,
+            })
+        })
+        .map_or_else(|| trimmed.to_string(), ToOwned::to_owned)
+}
+
+#[must_use]
+pub fn metadata_for_model(model: &str) -> Option<ProviderMetadata> {
+    let canonical = resolve_model_alias(model);
+    if canonical.starts_with("claude") {
+        return Some(ProviderMetadata {
+            provider: ProviderKind::Anthropic,
+            auth_env: "ANTHROPIC_API_KEY",
+            base_url_env: "ANTHROPIC_BASE_URL",
+            default_base_url: anthropic::DEFAULT_BASE_URL,
+        });
+    }
+    if canonical.starts_with("grok") {
+        return Some(ProviderMetadata {
+            provider: ProviderKind::Xai,
+            auth_env: "XAI_API_KEY",
+            base_url_env: "XAI_BASE_URL",
+            default_base_url: openai_compat::DEFAULT_XAI_BASE_URL,
+        });
+    }
+    None
+}
+
+#[must_use]
+pub fn detect_provider_kind(model: &str) -> ProviderKind {
+    if let Some(metadata) = metadata_for_model(model) {
+        return metadata.provider;
+    }
+    if anthropic::has_auth_from_env_or_saved().unwrap_or(false) {
+        return ProviderKind::Anthropic;
+    }
+    if openai_compat::has_api_key("OPENAI_API_KEY") {
+        return ProviderKind::OpenAi;
+    }
+    if openai_compat::has_api_key("XAI_API_KEY") {
+        return ProviderKind::Xai;
+    }
+    ProviderKind::Anthropic
+}
+
+#[must_use]
+pub fn max_tokens_for_model(model: &str) -> u32 {
+    let canonical = resolve_model_alias(model);
+    if canonical.contains("opus") {
+        32_000
+    } else {
+        64_000
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{detect_provider_kind, max_tokens_for_model, resolve_model_alias, ProviderKind};
+
+    #[test]
+    fn resolves_grok_aliases() {
+        assert_eq!(resolve_model_alias("grok"), "grok-3");
+        assert_eq!(resolve_model_alias("grok-mini"), "grok-3-mini");
+        assert_eq!(resolve_model_alias("grok-2"), "grok-2");
+    }
+
+    #[test]
+    fn detects_provider_from_model_name_first() {
+        assert_eq!(detect_provider_kind("grok"), ProviderKind::Xai);
+        assert_eq!(
+            detect_provider_kind("claude-sonnet-4-6"),
+            ProviderKind::Anthropic
+        );
+    }
+
+    #[test]
+    fn keeps_existing_max_token_heuristic() {
+        assert_eq!(max_tokens_for_model("opus"), 32_000);
+        assert_eq!(max_tokens_for_model("grok-3"), 64_000);
+    }
+}
--- a/rust/crates/api/src/providers/openai_compat.rs
+++ b/rust/crates/api/src/providers/openai_compat.rs
--- a/rust/crates/api/tests/client_integration.rs
+++ b/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,
+    AnthropicClient, ApiError, AuthSource, ContentBlockDelta, ContentBlockDeltaEvent,
+    ContentBlockStartEvent, InputContentBlock, InputMessage, MessageDeltaEvent, MessageRequest,
+    OutputContentBlock, ProviderClient, 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]
@@ -264,6 +195,47 @@ async fn retries_retryable_failures_before_succeeding() {
    assert_eq!(state.lock().await.len(), 2);
 }

+#[tokio::test]
+async fn provider_client_dispatches_anthropic_requests() {
+    let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
+    let server = spawn_server(
+        state.clone(),
+        vec![http_response(
+            "200 OK",
+            "application/json",
+            "{\"id\":\"msg_provider\",\"type\":\"message\",\"role\":\"assistant\",\"content\":[{\"type\":\"text\",\"text\":\"Dispatched\"}],\"model\":\"claude-3-7-sonnet-latest\",\"stop_reason\":\"end_turn\",\"stop_sequence\":null,\"usage\":{\"input_tokens\":3,\"output_tokens\":2}}",
+        )],
+    )
+    .await;
+
+    let client = ProviderClient::from_model_with_anthropic_auth(
+        "claude-sonnet-4-6",
+        Some(AuthSource::ApiKey("test-key".to_string())),
+    )
+    .expect("anthropic provider client should be constructed");
+    let client = match client {
+        ProviderClient::Anthropic(client) => {
+            ProviderClient::Anthropic(client.with_base_url(server.base_url()))
+        }
+        other => panic!("expected anthropic provider, got {other:?}"),
+    };
+
+    let response = client
+        .send_message(&sample_request(false))
+        .await
+        .expect("provider-dispatched request should succeed");
+
+    assert_eq!(response.total_tokens(), 5);
+
+    let captured = state.lock().await;
+    let request = captured.first().expect("server should capture request");
+    assert_eq!(request.path, "/v1/messages");
+    assert_eq!(
+        request.headers.get("x-api-key").map(String::as_str),
+        Some("test-key")
+    );
+}
+
 #[tokio::test]
 async fn surfaces_retry_exhaustion_for_persistent_retryable_errors() {
    let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
@@ -312,121 +284,6 @@ 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() {
--- a/rust/crates/api/tests/openai_compat_integration.rs
+++ b/rust/crates/api/tests/openai_compat_integration.rs
@@ -0,0 +1,415 @@
+use std::collections::HashMap;
+use std::ffi::OsString;
+use std::sync::Arc;
+use std::sync::{Mutex as StdMutex, OnceLock};
+
+use api::{
+    ContentBlockDelta, ContentBlockDeltaEvent, ContentBlockStartEvent, ContentBlockStopEvent,
+    InputContentBlock, InputMessage, MessageRequest, OpenAiCompatClient, OpenAiCompatConfig,
+    OutputContentBlock, ProviderClient, StreamEvent, ToolChoice, ToolDefinition,
+};
+use serde_json::json;
+use tokio::io::{AsyncReadExt, AsyncWriteExt};
+use tokio::net::TcpListener;
+use tokio::sync::Mutex;
+
+#[tokio::test]
+async fn send_message_uses_openai_compatible_endpoint_and_auth() {
+    let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
+    let body = concat!(
+        "{",
+        "\"id\":\"chatcmpl_test\",",
+        "\"model\":\"grok-3\",",
+        "\"choices\":[{",
+        "\"message\":{\"role\":\"assistant\",\"content\":\"Hello from Grok\",\"tool_calls\":[]},",
+        "\"finish_reason\":\"stop\"",
+        "}],",
+        "\"usage\":{\"prompt_tokens\":11,\"completion_tokens\":5}",
+        "}"
+    );
+    let server = spawn_server(
+        state.clone(),
+        vec![http_response("200 OK", "application/json", body)],
+    )
+    .await;
+
+    let client = OpenAiCompatClient::new("xai-test-key", OpenAiCompatConfig::xai())
+        .with_base_url(server.base_url());
+    let response = client
+        .send_message(&sample_request(false))
+        .await
+        .expect("request should succeed");
+
+    assert_eq!(response.model, "grok-3");
+    assert_eq!(response.total_tokens(), 16);
+    assert_eq!(
+        response.content,
+        vec![OutputContentBlock::Text {
+            text: "Hello from Grok".to_string(),
+        }]
+    );
+
+    let captured = state.lock().await;
+    let request = captured.first().expect("server should capture request");
+    assert_eq!(request.path, "/chat/completions");
+    assert_eq!(
+        request.headers.get("authorization").map(String::as_str),
+        Some("Bearer xai-test-key")
+    );
+    let body: serde_json::Value = serde_json::from_str(&request.body).expect("json body");
+    assert_eq!(body["model"], json!("grok-3"));
+    assert_eq!(body["messages"][0]["role"], json!("system"));
+    assert_eq!(body["tools"][0]["type"], json!("function"));
+}
+
+#[tokio::test]
+async fn send_message_accepts_full_chat_completions_endpoint_override() {
+    let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
+    let body = concat!(
+        "{",
+        "\"id\":\"chatcmpl_full_endpoint\",",
+        "\"model\":\"grok-3\",",
+        "\"choices\":[{",
+        "\"message\":{\"role\":\"assistant\",\"content\":\"Endpoint override works\",\"tool_calls\":[]},",
+        "\"finish_reason\":\"stop\"",
+        "}],",
+        "\"usage\":{\"prompt_tokens\":7,\"completion_tokens\":3}",
+        "}"
+    );
+    let server = spawn_server(
+        state.clone(),
+        vec![http_response("200 OK", "application/json", body)],
+    )
+    .await;
+
+    let endpoint_url = format!("{}/chat/completions", server.base_url());
+    let client = OpenAiCompatClient::new("xai-test-key", OpenAiCompatConfig::xai())
+        .with_base_url(endpoint_url);
+    let response = client
+        .send_message(&sample_request(false))
+        .await
+        .expect("request should succeed");
+
+    assert_eq!(response.total_tokens(), 10);
+
+    let captured = state.lock().await;
+    let request = captured.first().expect("server should capture request");
+    assert_eq!(request.path, "/chat/completions");
+}
+
+#[tokio::test]
+async fn stream_message_normalizes_text_and_multiple_tool_calls() {
+    let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
+    let sse = concat!(
+        "data: {\"id\":\"chatcmpl_stream\",\"model\":\"grok-3\",\"choices\":[{\"delta\":{\"content\":\"Hello\"}}]}\n\n",
+        "data: {\"id\":\"chatcmpl_stream\",\"choices\":[{\"delta\":{\"tool_calls\":[{\"index\":0,\"id\":\"call_1\",\"function\":{\"name\":\"weather\",\"arguments\":\"{\\\"city\\\":\\\"Paris\\\"}\"}},{\"index\":1,\"id\":\"call_2\",\"function\":{\"name\":\"clock\",\"arguments\":\"{\\\"zone\\\":\\\"UTC\\\"}\"}}]}}]}\n\n",
+        "data: {\"id\":\"chatcmpl_stream\",\"choices\":[{\"delta\":{},\"finish_reason\":\"tool_calls\"}]}\n\n",
+        "data: [DONE]\n\n"
+    );
+    let server = spawn_server(
+        state.clone(),
+        vec![http_response_with_headers(
+            "200 OK",
+            "text/event-stream",
+            sse,
+            &[("x-request-id", "req_grok_stream")],
+        )],
+    )
+    .await;
+
+    let client = OpenAiCompatClient::new("xai-test-key", OpenAiCompatConfig::xai())
+        .with_base_url(server.base_url());
+    let mut stream = client
+        .stream_message(&sample_request(false))
+        .await
+        .expect("stream should start");
+
+    assert_eq!(stream.request_id(), Some("req_grok_stream"));
+
+    let mut events = Vec::new();
+    while let Some(event) = stream.next_event().await.expect("event should parse") {
+        events.push(event);
+    }
+
+    assert!(matches!(events[0], StreamEvent::MessageStart(_)));
+    assert!(matches!(
+        events[1],
+        StreamEvent::ContentBlockStart(ContentBlockStartEvent {
+            content_block: OutputContentBlock::Text { .. },
+            ..
+        })
+    ));
+    assert!(matches!(
+        events[2],
+        StreamEvent::ContentBlockDelta(ContentBlockDeltaEvent {
+            delta: ContentBlockDelta::TextDelta { .. },
+            ..
+        })
+    ));
+    assert!(matches!(
+        events[3],
+        StreamEvent::ContentBlockStart(ContentBlockStartEvent {
+            index: 1,
+            content_block: OutputContentBlock::ToolUse { .. },
+        })
+    ));
+    assert!(matches!(
+        events[4],
+        StreamEvent::ContentBlockDelta(ContentBlockDeltaEvent {
+            index: 1,
+            delta: ContentBlockDelta::InputJsonDelta { .. },
+        })
+    ));
+    assert!(matches!(
+        events[5],
+        StreamEvent::ContentBlockStart(ContentBlockStartEvent {
+            index: 2,
+            content_block: OutputContentBlock::ToolUse { .. },
+        })
+    ));
+    assert!(matches!(
+        events[6],
+        StreamEvent::ContentBlockDelta(ContentBlockDeltaEvent {
+            index: 2,
+            delta: ContentBlockDelta::InputJsonDelta { .. },
+        })
+    ));
+    assert!(matches!(
+        events[7],
+        StreamEvent::ContentBlockStop(ContentBlockStopEvent { index: 1 })
+    ));
+    assert!(matches!(
+        events[8],
+        StreamEvent::ContentBlockStop(ContentBlockStopEvent { index: 2 })
+    ));
+    assert!(matches!(
+        events[9],
+        StreamEvent::ContentBlockStop(ContentBlockStopEvent { index: 0 })
+    ));
+    assert!(matches!(events[10], StreamEvent::MessageDelta(_)));
+    assert!(matches!(events[11], StreamEvent::MessageStop(_)));
+
+    let captured = state.lock().await;
+    let request = captured.first().expect("captured request");
+    assert_eq!(request.path, "/chat/completions");
+    assert!(request.body.contains("\"stream\":true"));
+}
+
+#[tokio::test]
+async fn provider_client_dispatches_xai_requests_from_env() {
+    let _lock = env_lock();
+    let _api_key = ScopedEnvVar::set("XAI_API_KEY", "xai-test-key");
+
+    let state = Arc::new(Mutex::new(Vec::<CapturedRequest>::new()));
+    let server = spawn_server(
+        state.clone(),
+        vec![http_response(
+            "200 OK",
+            "application/json",
+            "{\"id\":\"chatcmpl_provider\",\"model\":\"grok-3\",\"choices\":[{\"message\":{\"role\":\"assistant\",\"content\":\"Through provider client\",\"tool_calls\":[]},\"finish_reason\":\"stop\"}],\"usage\":{\"prompt_tokens\":9,\"completion_tokens\":4}}",
+        )],
+    )
+    .await;
+    let _base_url = ScopedEnvVar::set("XAI_BASE_URL", server.base_url());
+
+    let client =
+        ProviderClient::from_model("grok").expect("xAI provider client should be constructed");
+    assert!(matches!(client, ProviderClient::Xai(_)));
+
+    let response = client
+        .send_message(&sample_request(false))
+        .await
+        .expect("provider-dispatched request should succeed");
+
+    assert_eq!(response.total_tokens(), 13);
+
+    let captured = state.lock().await;
+    let request = captured.first().expect("captured request");
+    assert_eq!(request.path, "/chat/completions");
+    assert_eq!(
+        request.headers.get("authorization").map(String::as_str),
+        Some("Bearer xai-test-key")
+    );
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+struct CapturedRequest {
+    path: String,
+    headers: HashMap<String, String>,
+    body: String,
+}
+
+struct TestServer {
+    base_url: String,
+    join_handle: tokio::task::JoinHandle<()>,
+}
+
+impl TestServer {
+    fn base_url(&self) -> String {
+        self.base_url.clone()
+    }
+}
+
+impl Drop for TestServer {
+    fn drop(&mut self) {
+        self.join_handle.abort();
+    }
+}
+
+async fn spawn_server(
+    state: Arc<Mutex<Vec<CapturedRequest>>>,
+    responses: Vec<String>,
+) -> TestServer {
+    let listener = TcpListener::bind("127.0.0.1:0")
+        .await
+        .expect("listener should bind");
+    let address = listener.local_addr().expect("listener addr");
+    let join_handle = tokio::spawn(async move {
+        for response in responses {
+            let (mut socket, _) = listener.accept().await.expect("accept");
+            let mut buffer = Vec::new();
+            let mut header_end = None;
+            loop {
+                let mut chunk = [0_u8; 1024];
+                let read = socket.read(&mut chunk).await.expect("read request");
+                if read == 0 {
+                    break;
+                }
+                buffer.extend_from_slice(&chunk[..read]);
+                if let Some(position) = find_header_end(&buffer) {
+                    header_end = Some(position);
+                    break;
+                }
+            }
+
+            let header_end = header_end.expect("headers should exist");
+            let (header_bytes, remaining) = buffer.split_at(header_end);
+            let header_text = String::from_utf8(header_bytes.to_vec()).expect("utf8 headers");
+            let mut lines = header_text.split("\r\n");
+            let request_line = lines.next().expect("request line");
+            let path = request_line
+                .split_whitespace()
+                .nth(1)
+                .expect("path")
+                .to_string();
+            let mut headers = HashMap::new();
+            let mut content_length = 0_usize;
+            for line in lines {
+                if line.is_empty() {
+                    continue;
+                }
+                let (name, value) = line.split_once(':').expect("header");
+                let value = value.trim().to_string();
+                if name.eq_ignore_ascii_case("content-length") {
+                    content_length = value.parse().expect("content length");
+                }
+                headers.insert(name.to_ascii_lowercase(), value);
+            }
+
+            let mut body = remaining[4..].to_vec();
+            while body.len() < content_length {
+                let mut chunk = vec![0_u8; content_length - body.len()];
+                let read = socket.read(&mut chunk).await.expect("read body");
+                if read == 0 {
+                    break;
+                }
+                body.extend_from_slice(&chunk[..read]);
+            }
+
+            state.lock().await.push(CapturedRequest {
+                path,
+                headers,
+                body: String::from_utf8(body).expect("utf8 body"),
+            });
+
+            socket
+                .write_all(response.as_bytes())
+                .await
+                .expect("write response");
+        }
+    });
+
+    TestServer {
+        base_url: format!("http://{address}"),
+        join_handle,
+    }
+}
+
+fn find_header_end(bytes: &[u8]) -> Option<usize> {
+    bytes.windows(4).position(|window| window == b"\r\n\r\n")
+}
+
+fn http_response(status: &str, content_type: &str, body: &str) -> String {
+    http_response_with_headers(status, content_type, body, &[])
+}
+
+fn http_response_with_headers(
+    status: &str,
+    content_type: &str,
+    body: &str,
+    headers: &[(&str, &str)],
+) -> String {
+    let mut extra_headers = String::new();
+    for (name, value) in headers {
+        use std::fmt::Write as _;
+        write!(&mut extra_headers, "{name}: {value}\r\n").expect("header write");
+    }
+    format!(
+        "HTTP/1.1 {status}\r\ncontent-type: {content_type}\r\n{extra_headers}content-length: {}\r\nconnection: close\r\n\r\n{body}",
+        body.len()
+    )
+}
+
+fn sample_request(stream: bool) -> MessageRequest {
+    MessageRequest {
+        model: "grok-3".to_string(),
+        max_tokens: 64,
+        messages: vec![InputMessage {
+            role: "user".to_string(),
+            content: vec![InputContentBlock::Text {
+                text: "Say hello".to_string(),
+            }],
+        }],
+        system: Some("Use tools when needed".to_string()),
+        tools: Some(vec![ToolDefinition {
+            name: "weather".to_string(),
+            description: Some("Fetches weather".to_string()),
+            input_schema: json!({
+                "type": "object",
+                "properties": {"city": {"type": "string"}},
+                "required": ["city"]
+            }),
+        }]),
+        tool_choice: Some(ToolChoice::Auto),
+        stream,
+    }
+}
+
+fn env_lock() -> std::sync::MutexGuard<'static, ()> {
+    static LOCK: OnceLock<StdMutex<()>> = OnceLock::new();
+    LOCK.get_or_init(|| StdMutex::new(()))
+        .lock()
+        .unwrap_or_else(|poisoned| poisoned.into_inner())
+}
+
+struct ScopedEnvVar {
+    key: &'static str,
+    previous: Option<OsString>,
+}
+
+impl ScopedEnvVar {
+    fn set(key: &'static str, value: impl AsRef<std::ffi::OsStr>) -> Self {
+        let previous = std::env::var_os(key);
+        std::env::set_var(key, value);
+        Self { key, previous }
+    }
+}
+
+impl Drop for ScopedEnvVar {
+    fn drop(&mut self) {
+        match &self.previous {
+            Some(value) => std::env::set_var(self.key, value),
+            None => std::env::remove_var(self.key),
+        }
+    }
+}
--- a/rust/crates/api/tests/provider_client_integration.rs
+++ b/rust/crates/api/tests/provider_client_integration.rs
@@ -0,0 +1,86 @@
+use std::ffi::OsString;
+use std::sync::{Mutex, OnceLock};
+
+use api::{read_xai_base_url, ApiError, AuthSource, ProviderClient, ProviderKind};
+
+#[test]
+fn provider_client_routes_grok_aliases_through_xai() {
+    let _lock = env_lock();
+    let _xai_api_key = EnvVarGuard::set("XAI_API_KEY", Some("xai-test-key"));
+
+    let client = ProviderClient::from_model("grok-mini").expect("grok alias should resolve");
+
+    assert_eq!(client.provider_kind(), ProviderKind::Xai);
+}
+
+#[test]
+fn provider_client_reports_missing_xai_credentials_for_grok_models() {
+    let _lock = env_lock();
+    let _xai_api_key = EnvVarGuard::set("XAI_API_KEY", None);
+
+    let error = ProviderClient::from_model("grok-3")
+        .expect_err("grok requests without XAI_API_KEY should fail fast");
+
+    match error {
+        ApiError::MissingCredentials { provider, env_vars } => {
+            assert_eq!(provider, "xAI");
+            assert_eq!(env_vars, &["XAI_API_KEY"]);
+        }
+        other => panic!("expected missing xAI credentials, got {other:?}"),
+    }
+}
+
+#[test]
+fn provider_client_uses_explicit_anthropic_auth_without_env_lookup() {
+    let _lock = env_lock();
+    let _anthropic_api_key = EnvVarGuard::set("ANTHROPIC_API_KEY", None);
+    let _anthropic_auth_token = EnvVarGuard::set("ANTHROPIC_AUTH_TOKEN", None);
+
+    let client = ProviderClient::from_model_with_anthropic_auth(
+        "claude-sonnet-4-6",
+        Some(AuthSource::ApiKey("anthropic-test-key".to_string())),
+    )
+    .expect("explicit anthropic auth should avoid env lookup");
+
+    assert_eq!(client.provider_kind(), ProviderKind::Anthropic);
+}
+
+#[test]
+fn read_xai_base_url_prefers_env_override() {
+    let _lock = env_lock();
+    let _xai_base_url = EnvVarGuard::set("XAI_BASE_URL", Some("https://example.xai.test/v1"));
+
+    assert_eq!(read_xai_base_url(), "https://example.xai.test/v1");
+}
+
+fn env_lock() -> std::sync::MutexGuard<'static, ()> {
+    static LOCK: OnceLock<Mutex<()>> = OnceLock::new();
+    LOCK.get_or_init(|| Mutex::new(()))
+        .lock()
+        .unwrap_or_else(|poisoned| poisoned.into_inner())
+}
+
+struct EnvVarGuard {
+    key: &'static str,
+    original: Option<OsString>,
+}
+
+impl EnvVarGuard {
+    fn set(key: &'static str, value: Option<&str>) -> Self {
+        let original = std::env::var_os(key);
+        match value {
+            Some(value) => std::env::set_var(key, value),
+            None => std::env::remove_var(key),
+        }
+        Self { key, original }
+    }
+}
+
+impl Drop for EnvVarGuard {
+    fn drop(&mut self) {
+        match &self.original {
+            Some(value) => std::env::set_var(self.key, value),
+            None => std::env::remove_var(self.key),
+        }
+    }
+}
--- a/rust/crates/runtime/src/conversation.rs
+++ b/rust/crates/runtime/src/conversation.rs
@@ -25,19 +25,9 @@ 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 +84,6 @@ 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,
 }
@@ -172,7 +161,6 @@ 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 +176,10 @@ 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()
@@ -271,7 +257,6 @@ where
        Ok(TurnSummary {
            assistant_messages,
            tool_results,
-            prompt_cache_events,
            iterations,
            usage: self.usage_tracker.cumulative_usage(),
        })
@@ -305,17 +290,9 @@ 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 +304,6 @@ 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 +324,6 @@ fn build_assistant_message(
    Ok((
        ConversationMessage::assistant_with_usage(blocks, usage),
        usage,
-        prompt_cache_events,
    ))
 }

@@ -421,7 +396,7 @@ 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 +453,6 @@ 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 +506,8 @@ 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 { .. }
--- a/rust/crates/runtime/src/hooks.rs
+++ b/rust/crates/runtime/src/hooks.rs
@@ -51,6 +51,16 @@ pub struct HookRunner {
    config: RuntimeHookConfig,
 }

+#[derive(Debug, Clone, Copy)]
+struct HookCommandRequest<'a> {
+    event: HookEvent,
+    tool_name: &'a str,
+    tool_input: &'a str,
+    tool_output: Option<&'a str>,
+    is_error: bool,
+    payload: &'a str,
+}
+
 impl HookRunner {
    #[must_use]
    pub fn new(config: RuntimeHookConfig) -> Self {
@@ -64,7 +74,7 @@ impl HookRunner {

    #[must_use]
    pub fn run_pre_tool_use(&self, tool_name: &str, tool_input: &str) -> HookRunResult {
-        Self::run_commands(
+        self.run_commands(
            HookEvent::PreToolUse,
            self.config.pre_tool_use(),
            tool_name,
@@ -82,7 +92,7 @@ impl HookRunner {
        tool_output: &str,
        is_error: bool,
    ) -> HookRunResult {
-        Self::run_commands(
+        self.run_commands(
            HookEvent::PostToolUse,
            self.config.post_tool_use(),
            tool_name,
@@ -93,6 +103,7 @@ impl HookRunner {
    }

    fn run_commands(
+        &self,
        event: HookEvent,
        commands: &[String],
        tool_name: &str,
@@ -119,12 +130,14 @@ impl HookRunner {
        for command in commands {
            match Self::run_command(
                command,
+                HookCommandRequest {
                    event,
                    tool_name,
                    tool_input,
                    tool_output,
                    is_error,
-                &payload,
+                    payload: &payload,
+                },
            ) {
                HookCommandOutcome::Allow { message } => {
                    if let Some(message) = message {
@@ -148,28 +161,23 @@ impl HookRunner {
        HookRunResult::allow(messages)
    }

-    fn run_command(
-        command: &str,
-        event: HookEvent,
-        tool_name: &str,
-        tool_input: &str,
-        tool_output: Option<&str>,
-        is_error: bool,
-        payload: &str,
-    ) -> HookCommandOutcome {
+    fn run_command(command: &str, request: HookCommandRequest<'_>) -> 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.env("HOOK_EVENT", event.as_str());
-        child.env("HOOK_TOOL_NAME", tool_name);
-        child.env("HOOK_TOOL_INPUT", tool_input);
-        child.env("HOOK_TOOL_IS_ERROR", if is_error { "1" } else { "0" });
-        if let Some(tool_output) = tool_output {
+        child.env("HOOK_EVENT", request.event.as_str());
+        child.env("HOOK_TOOL_NAME", request.tool_name);
+        child.env("HOOK_TOOL_INPUT", request.tool_input);
+        child.env(
+            "HOOK_TOOL_IS_ERROR",
+            if request.is_error { "1" } else { "0" },
+        );
+        if let Some(tool_output) = request.tool_output {
            child.env("HOOK_TOOL_OUTPUT", tool_output);
        }

-        match child.output_with_stdin(payload.as_bytes()) {
+        match child.output_with_stdin(request.payload.as_bytes()) {
            Ok(output) => {
                let stdout = String::from_utf8_lossy(&output.stdout).trim().to_string();
                let stderr = String::from_utf8_lossy(&output.stderr).trim().to_string();
@@ -187,16 +195,18 @@ impl HookRunner {
                    },
                    None => HookCommandOutcome::Warn {
                        message: format!(
-                            "{} hook `{command}` terminated by signal while handling `{tool_name}`",
-                            event.as_str()
+                            "{} hook `{command}` terminated by signal while handling `{}`",
+                            request.event.as_str(),
+                            request.tool_name
                        ),
                    },
                }
            }
            Err(error) => HookCommandOutcome::Warn {
                message: format!(
-                    "{} hook `{command}` failed to start for `{tool_name}`: {error}",
-                    event.as_str()
+                    "{} hook `{command}` failed to start for `{}`: {error}",
+                    request.event.as_str(),
+                    request.tool_name
                ),
            },
        }
--- a/rust/crates/runtime/src/lib.rs
+++ b/rust/crates/runtime/src/lib.rs
@@ -31,8 +31,8 @@ pub use config::{
    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,
--- a/rust/crates/rusty-claude-cli/src/main.rs
+++ b/rust/crates/rusty-claude-cli/src/main.rs
@@ -12,10 +12,10 @@ use std::process::Command;
 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,
+    detect_provider_kind, max_tokens_for_model, resolve_model_alias, resolve_startup_auth_source,
+    AnthropicClient, AuthSource, ContentBlockDelta, InputContentBlock, InputMessage,
+    MessageRequest, MessageResponse, OutputContentBlock, ProviderClient, ProviderKind,
+    StreamEvent as ApiStreamEvent, ToolChoice, ToolDefinition, ToolResultContentBlock,
 };

 use commands::{
@@ -29,20 +29,13 @@ 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};

 const DEFAULT_MODEL: &str = "claude-opus-4-6";
-fn max_tokens_for_model(model: &str) -> u32 {
-    if model.contains("opus") {
-        32_000
-    } else {
-        64_000
-    }
-}
 const DEFAULT_DATE: &str = "2026-03-31";
 const DEFAULT_OAUTH_CALLBACK_PORT: u16 = 4545;
 const VERSION: &str = env!("CARGO_PKG_VERSION");
@@ -289,15 +282,6 @@ fn parse_args(args: &[String]) -> Result<CliAction, String> {
    }
 }

-fn resolve_model_alias(model: &str) -> &str {
-    match model {
-        "opus" => "claude-opus-4-6",
-        "sonnet" => "claude-sonnet-4-6",
-        "haiku" => "claude-haiku-4-5-20251213",
-        _ => model,
-    }
-}
-
 fn normalize_allowed_tools(values: &[String]) -> Result<Option<AllowedToolSet>, String> {
    if values.is_empty() {
        return Ok(None);
@@ -981,7 +965,7 @@ struct LiveCli {
    allowed_tools: Option<AllowedToolSet>,
    permission_mode: PermissionMode,
    system_prompt: Vec<String>,
-    runtime: ConversationRuntime<AnthropicRuntimeClient, CliToolExecutor>,
+    runtime: ConversationRuntime<ProviderRuntimeClient, CliToolExecutor>,
    session: SessionHandle,
 }

@@ -996,7 +980,6 @@ impl LiveCli {
        let session = create_managed_session_handle()?;
        let runtime = build_runtime(
            Session::new(),
-            session.id.clone(),
            model.clone(),
            system_prompt.clone(),
            enable_tools,
@@ -1052,14 +1035,13 @@ impl LiveCli {
        let mut permission_prompter = CliPermissionPrompter::new(self.permission_mode);
        let result = self.runtime.run_turn(input, Some(&mut permission_prompter));
        match result {
-            Ok(summary) => {
+            Ok(_) => {
                spinner.finish(
                    "✨ Done",
                    TerminalRenderer::new().color_theme(),
                    &mut stdout,
                )?;
                println!();
-                print_prompt_cache_events(&summary);
                self.persist_session()?;
                Ok(())
            }
@@ -1089,7 +1071,6 @@ impl LiveCli {
        let session = self.runtime.session().clone();
        let mut runtime = build_runtime(
            session,
-            self.session.id.clone(),
            self.model.clone(),
            self.system_prompt.clone(),
            true,
@@ -1109,7 +1090,6 @@ 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 +1217,6 @@ 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 +1260,6 @@ 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 +1285,6 @@ 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 +1320,6 @@ 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 +1392,6 @@ 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 +1422,6 @@ 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,
@@ -1923,31 +1897,24 @@ 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,
    emit_output: bool,
    allowed_tools: Option<AllowedToolSet>,
    permission_mode: PermissionMode,
-) -> Result<ConversationRuntime<AnthropicRuntimeClient, CliToolExecutor>, Box<dyn std::error::Error>>
+) -> Result<ConversationRuntime<ProviderRuntimeClient, CliToolExecutor>, Box<dyn std::error::Error>>
 {
+    let feature_config = build_runtime_feature_config()?;
    Ok(ConversationRuntime::new_with_features(
        session,
-        AnthropicRuntimeClient::new(
-            model,
-            enable_tools,
-            emit_output,
-            allowed_tools.clone(),
-            session_id,
-        )?,
+        ProviderRuntimeClient::new(model, enable_tools, emit_output, allowed_tools.clone())?,
        CliToolExecutor::new(allowed_tools, emit_output),
        permission_policy(permission_mode),
        system_prompt,
-        &build_runtime_feature_config()?,
+        &feature_config,
    ))
 }

@@ -1997,28 +1964,33 @@ impl runtime::PermissionPrompter for CliPermissionPrompter {
    }
 }

-struct AnthropicRuntimeClient {
+struct ProviderRuntimeClient {
    runtime: tokio::runtime::Runtime,
-    client: AnthropicClient,
+    client: ProviderClient,
    model: String,
    enable_tools: bool,
    emit_output: bool,
    allowed_tools: Option<AllowedToolSet>,
 }

-impl AnthropicRuntimeClient {
+impl ProviderRuntimeClient {
    fn new(
        model: String,
        enable_tools: bool,
        emit_output: bool,
        allowed_tools: Option<AllowedToolSet>,
-        session_id: impl Into<String>,
    ) -> Result<Self, Box<dyn std::error::Error>> {
+        let model = resolve_model_alias(&model).to_string();
+        let client = match detect_provider_kind(&model) {
+            ProviderKind::Anthropic => ProviderClient::from_model_with_anthropic_auth(
+                &model,
+                Some(resolve_cli_auth_source()?),
+            )?,
+            ProviderKind::Xai | ProviderKind::OpenAi => ProviderClient::from_model(&model)?,
+        };
        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)),
+            client,
            model,
            enable_tools,
            emit_output,
@@ -2037,7 +2009,7 @@ fn resolve_cli_auth_source() -> Result<AuthSource, Box<dyn std::error::Error>> {
    })?)
 }

-impl ApiClient for AnthropicRuntimeClient {
+impl ApiClient for ProviderRuntimeClient {
    #[allow(clippy::too_many_lines)]
    fn stream(&mut self, request: ApiRequest) -> Result<Vec<AssistantEvent>, RuntimeError> {
        let message_request = MessageRequest {
@@ -2075,7 +2047,7 @@ impl ApiClient for AnthropicRuntimeClient {
            let renderer = TerminalRenderer::new();
            let mut markdown_stream = MarkdownStreamState::default();
            let mut events = Vec::new();
-            let mut pending_tool: Option<(String, String, String)> = None;
+            let mut pending_tools: BTreeMap<u32, (String, String, String)> = BTreeMap::new();
            let mut saw_stop = false;

            while let Some(event) = stream
@@ -2086,15 +2058,23 @@ impl ApiClient for AnthropicRuntimeClient {
                match event {
                    ApiStreamEvent::MessageStart(start) => {
                        for block in start.message.content {
-                            push_output_block(block, out, &mut events, &mut pending_tool, true)?;
+                            push_output_block(
+                                block,
+                                0,
+                                out,
+                                &mut events,
+                                &mut pending_tools,
+                                true,
+                            )?;
                        }
                    }
                    ApiStreamEvent::ContentBlockStart(start) => {
                        push_output_block(
                            start.content_block,
+                            start.index,
                            out,
                            &mut events,
-                            &mut pending_tool,
+                            &mut pending_tools,
                            true,
                        )?;
                    }
@@ -2110,18 +2090,18 @@ impl ApiClient for AnthropicRuntimeClient {
                            }
                        }
                        ContentBlockDelta::InputJsonDelta { partial_json } => {
-                            if let Some((_, _, input)) = &mut pending_tool {
+                            if let Some((_, _, input)) = pending_tools.get_mut(&delta.index) {
                                input.push_str(&partial_json);
                            }
                        }
                    },
-                    ApiStreamEvent::ContentBlockStop(_) => {
+                    ApiStreamEvent::ContentBlockStop(stop) => {
                        if let Some(rendered) = markdown_stream.flush(&renderer) {
                            write!(out, "{rendered}")
                                .and_then(|()| out.flush())
                                .map_err(|error| RuntimeError::new(error.to_string()))?;
                        }
-                        if let Some((id, name, input)) = pending_tool.take() {
+                        if let Some((id, name, input)) = pending_tools.remove(&stop.index) {
                            // Display tool call now that input is fully accumulated
                            writeln!(out, "\n{}", format_tool_call_start(&name, &input))
                                .and_then(|()| out.flush())
@@ -2133,8 +2113,8 @@ 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 +2129,6 @@ 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 +2153,7 @@ 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 +2214,6 @@ 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()
@@ -2417,20 +2360,18 @@ 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())
    {
-        let _ = write!(lines[0], " backgrounded ({task_id})");
+        lines[0].push_str(&format!(" backgrounded ({task_id})"));
    } else if let Some(status) = parsed
        .get("returnCodeInterpretation")
        .and_then(|value| value.as_str())
        .filter(|status| !status.is_empty())
    {
-        let _ = write!(lines[0], " {status}");
+        lines[0].push_str(&format!(" {status}"));
    }

    if let Some(stdout) = parsed.get("stdout").and_then(|value| value.as_str()) {
@@ -2452,15 +2393,15 @@ fn format_read_result(icon: &str, parsed: &serde_json::Value) -> String {
    let path = extract_tool_path(file);
    let start_line = file
        .get("startLine")
-        .and_then(serde_json::Value::as_u64)
+        .and_then(|value| value.as_u64())
        .unwrap_or(1);
    let num_lines = file
        .get("numLines")
-        .and_then(serde_json::Value::as_u64)
+        .and_then(|value| value.as_u64())
        .unwrap_or(0);
    let total_lines = file
        .get("totalLines")
-        .and_then(serde_json::Value::as_u64)
+        .and_then(|value| value.as_u64())
        .unwrap_or(num_lines);
    let content = file
        .get("content")
@@ -2486,7 +2427,8 @@ fn format_write_result(icon: &str, parsed: &serde_json::Value) -> String {
    let line_count = parsed
        .get("content")
        .and_then(|value| value.as_str())
-        .map_or(0, |content| content.lines().count());
+        .map(|content| content.lines().count())
+        .unwrap_or(0);
    format!(
        "{icon} \x1b[1;32m✏️ {} {path}\x1b[0m \x1b[2m({line_count} lines)\x1b[0m",
        if kind == "create" { "Wrote" } else { "Updated" },
@@ -2517,7 +2459,7 @@ fn format_edit_result(icon: &str, parsed: &serde_json::Value) -> String {
    let path = extract_tool_path(parsed);
    let suffix = if parsed
        .get("replaceAll")
-        .and_then(serde_json::Value::as_bool)
+        .and_then(|value| value.as_bool())
        .unwrap_or(false)
    {
        " (replace all)"
@@ -2545,7 +2487,7 @@ fn format_edit_result(icon: &str, parsed: &serde_json::Value) -> String {
 fn format_glob_result(icon: &str, parsed: &serde_json::Value) -> String {
    let num_files = parsed
        .get("numFiles")
-        .and_then(serde_json::Value::as_u64)
+        .and_then(|value| value.as_u64())
        .unwrap_or(0);
    let filenames = parsed
        .get("filenames")
@@ -2569,11 +2511,11 @@ fn format_glob_result(icon: &str, parsed: &serde_json::Value) -> String {
 fn format_grep_result(icon: &str, parsed: &serde_json::Value) -> String {
    let num_matches = parsed
        .get("numMatches")
-        .and_then(serde_json::Value::as_u64)
+        .and_then(|value| value.as_u64())
        .unwrap_or(0);
    let num_files = parsed
        .get("numFiles")
-        .and_then(serde_json::Value::as_u64)
+        .and_then(|value| value.as_u64())
        .unwrap_or(0);
    let content = parsed
        .get("content")
@@ -2623,9 +2565,10 @@ fn truncate_for_summary(value: &str, limit: usize) -> String {

 fn push_output_block(
    block: OutputContentBlock,
+    block_index: u32,
    out: &mut (impl Write + ?Sized),
    events: &mut Vec<AssistantEvent>,
-    pending_tool: &mut Option<(String, String, String)>,
+    pending_tools: &mut BTreeMap<u32, (String, String, String)>,
    streaming_tool_input: bool,
 ) -> Result<(), RuntimeError> {
    match block {
@@ -2650,7 +2593,7 @@ fn push_output_block(
            } else {
                input.to_string()
            };
-            *pending_tool = Some((id, name, initial_input));
+            pending_tools.insert(block_index, (id, name, initial_input));
        }
    }
    Ok(())
@@ -2661,11 +2604,13 @@ fn response_to_events(
    out: &mut (impl Write + ?Sized),
 ) -> Result<Vec<AssistantEvent>, RuntimeError> {
    let mut events = Vec::new();
-    let mut pending_tool = None;
+    let mut pending_tools = BTreeMap::new();

-    for block in response.content {
-        push_output_block(block, out, &mut events, &mut pending_tool, false)?;
-        if let Some((id, name, input)) = pending_tool.take() {
+    for (index, block) in response.content.into_iter().enumerate() {
+        let index =
+            u32::try_from(index).map_err(|_| RuntimeError::new("response block index overflow"))?;
+        push_output_block(block, index, out, &mut events, &mut pending_tools, false)?;
+        if let Some((id, name, input)) = pending_tools.remove(&index) {
            events.push(AssistantEvent::ToolUse { id, name, input });
        }
    }
@@ -2680,26 +2625,6 @@ 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,
@@ -2911,6 +2836,7 @@ mod tests {
    use api::{MessageResponse, OutputContentBlock, Usage};
    use runtime::{AssistantEvent, ContentBlock, ConversationMessage, MessageRole, PermissionMode};
    use serde_json::json;
+    use std::collections::BTreeMap;
    use std::path::PathBuf;

    #[test]
@@ -2990,6 +2916,9 @@ mod tests {
        assert_eq!(resolve_model_alias("opus"), "claude-opus-4-6");
        assert_eq!(resolve_model_alias("sonnet"), "claude-sonnet-4-6");
        assert_eq!(resolve_model_alias("haiku"), "claude-haiku-4-5-20251213");
+        assert_eq!(resolve_model_alias("grok"), "grok-3");
+        assert_eq!(resolve_model_alias("grok-mini"), "grok-3-mini");
+        assert_eq!(resolve_model_alias("grok-2"), "grok-2");
        assert_eq!(resolve_model_alias("claude-opus"), "claude-opus");
    }

@@ -3457,15 +3386,16 @@ mod tests {
    fn push_output_block_renders_markdown_text() {
        let mut out = Vec::new();
        let mut events = Vec::new();
-        let mut pending_tool = None;
+        let mut pending_tools = BTreeMap::new();

        push_output_block(
            OutputContentBlock::Text {
                text: "# Heading".to_string(),
            },
+            0,
            &mut out,
            &mut events,
-            &mut pending_tool,
+            &mut pending_tools,
            false,
        )
        .expect("text block should render");
@@ -3479,7 +3409,7 @@ mod tests {
    fn push_output_block_skips_empty_object_prefix_for_tool_streams() {
        let mut out = Vec::new();
        let mut events = Vec::new();
-        let mut pending_tool = None;
+        let mut pending_tools = BTreeMap::new();

        push_output_block(
            OutputContentBlock::ToolUse {
@@ -3487,20 +3417,83 @@ mod tests {
                name: "read_file".to_string(),
                input: json!({}),
            },
+            1,
            &mut out,
            &mut events,
-            &mut pending_tool,
+            &mut pending_tools,
            true,
        )
        .expect("tool block should accumulate");

        assert!(events.is_empty());
        assert_eq!(
-            pending_tool,
+            pending_tools.remove(&1),
            Some(("tool-1".to_string(), "read_file".to_string(), String::new(),))
        );
    }

+    #[test]
+    fn pending_tools_preserve_multiple_streaming_tool_calls_by_index() {
+        let mut out = Vec::new();
+        let mut events = Vec::new();
+        let mut pending_tools = BTreeMap::new();
+
+        push_output_block(
+            OutputContentBlock::ToolUse {
+                id: "tool-1".to_string(),
+                name: "read_file".to_string(),
+                input: json!({}),
+            },
+            1,
+            &mut out,
+            &mut events,
+            &mut pending_tools,
+            true,
+        )
+        .expect("first tool should accumulate");
+        push_output_block(
+            OutputContentBlock::ToolUse {
+                id: "tool-2".to_string(),
+                name: "grep_search".to_string(),
+                input: json!({}),
+            },
+            2,
+            &mut out,
+            &mut events,
+            &mut pending_tools,
+            true,
+        )
+        .expect("second tool should accumulate");
+
+        pending_tools
+            .get_mut(&1)
+            .expect("first tool pending")
+            .2
+            .push_str("{\"path\":\"src/main.rs\"}");
+        pending_tools
+            .get_mut(&2)
+            .expect("second tool pending")
+            .2
+            .push_str("{\"pattern\":\"TODO\"}");
+
+        assert_eq!(
+            pending_tools.remove(&1),
+            Some((
+                "tool-1".to_string(),
+                "read_file".to_string(),
+                "{\"path\":\"src/main.rs\"}".to_string(),
+            ))
+        );
+        assert_eq!(
+            pending_tools.remove(&2),
+            Some((
+                "tool-2".to_string(),
+                "grep_search".to_string(),
+                "{\"pattern\":\"TODO\"}".to_string(),
+            ))
+        );
+    }
+
    #[test]
    fn response_to_events_preserves_empty_object_json_input_outside_streaming() {
        let mut out = Vec::new();
--- a/rust/crates/rusty-claude-cli/src/render.rs
+++ b/rust/crates/rusty-claude-cli/src/render.rs
@@ -286,7 +286,7 @@ impl TerminalRenderer {
    ) {
        match event {
            Event::Start(Tag::Heading { level, .. }) => {
-                Self::start_heading(state, level as u8, output);
+                self.start_heading(state, level as u8, output)
            }
            Event::End(TagEnd::Paragraph) => output.push_str("\n\n"),
            Event::Start(Tag::BlockQuote(..)) => self.start_quote(state, output),
@@ -426,7 +426,7 @@ impl TerminalRenderer {
        }
    }

-    fn start_heading(state: &mut RenderState, level: u8, output: &mut String) {
+    fn start_heading(&self, state: &mut RenderState, level: u8, output: &mut String) {
        state.heading_level = Some(level);
        if !output.is_empty() {
            output.push('\n');
--- a/rust/crates/tools/src/lib.rs
+++ b/rust/crates/tools/src/lib.rs
@@ -4,8 +4,8 @@ use std::process::Command;
 use std::time::{Duration, Instant};

 use api::{
-    read_base_url, AnthropicClient, ContentBlockDelta, InputContentBlock, InputMessage,
-    MessageRequest, MessageResponse, OutputContentBlock, PromptCache, PromptCacheRecord,
+    max_tokens_for_model, resolve_model_alias, ContentBlockDelta, InputContentBlock, InputMessage,
+    MessageRequest, MessageResponse, OutputContentBlock, ProviderClient,
    StreamEvent as ApiStreamEvent, ToolChoice, ToolDefinition, ToolResultContentBlock,
 };
 use reqwest::blocking::Client;
@@ -13,7 +13,7 @@ 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};
@@ -1459,15 +1459,14 @@ fn run_agent_job(job: &AgentJob) -> Result<(), String> {

 fn build_agent_runtime(
    job: &AgentJob,
-) -> Result<ConversationRuntime<AnthropicRuntimeClient, SubagentToolExecutor>, String> {
+) -> Result<ConversationRuntime<ProviderRuntimeClient, SubagentToolExecutor>, String> {
    let model = job
        .manifest
        .model
        .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 = ProviderRuntimeClient::new(model, allowed_tools.clone())?;
    let tool_executor = SubagentToolExecutor::new(allowed_tools);
    Ok(ConversationRuntime::new(
        Session::new(),
@@ -1636,23 +1635,17 @@ fn format_agent_terminal_output(status: &str, result: Option<&str>, error: Optio
    sections.join("")
 }

-struct AnthropicRuntimeClient {
+struct ProviderRuntimeClient {
    runtime: tokio::runtime::Runtime,
-    client: AnthropicClient,
+    client: ProviderClient,
    model: String,
    allowed_tools: BTreeSet<String>,
 }

-impl AnthropicRuntimeClient {
-    fn new(
-        model: String,
-        allowed_tools: BTreeSet<String>,
-        session_id: impl Into<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));
+impl ProviderRuntimeClient {
+    fn new(model: String, allowed_tools: BTreeSet<String>) -> Result<Self, String> {
+        let model = resolve_model_alias(&model).to_string();
+        let client = ProviderClient::from_model(&model).map_err(|error| error.to_string())?;
        Ok(Self {
            runtime: tokio::runtime::Runtime::new().map_err(|error| error.to_string())?,
            client,
@@ -1662,8 +1655,7 @@ impl AnthropicRuntimeClient {
    }
 }

-impl ApiClient for AnthropicRuntimeClient {
-    #[allow(clippy::too_many_lines)]
+impl ApiClient for ProviderRuntimeClient {
    fn stream(&mut self, request: ApiRequest) -> Result<Vec<AssistantEvent>, RuntimeError> {
        let tools = tool_specs_for_allowed_tools(Some(&self.allowed_tools))
            .into_iter()
@@ -1675,7 +1667,7 @@ impl ApiClient for AnthropicRuntimeClient {
            .collect::<Vec<_>>();
        let message_request = MessageRequest {
            model: self.model.clone(),
-            max_tokens: 32_000,
+            max_tokens: max_tokens_for_model(&self.model),
            messages: convert_messages(&request.messages),
            system: (!request.system_prompt.is_empty()).then(|| request.system_prompt.join("\n\n")),
            tools: (!tools.is_empty()).then_some(tools),
@@ -1690,7 +1682,7 @@ impl ApiClient for AnthropicRuntimeClient {
                .await
                .map_err(|error| RuntimeError::new(error.to_string()))?;
            let mut events = Vec::new();
-            let mut pending_tool: Option<(String, String, String)> = None;
+            let mut pending_tools: BTreeMap<u32, (String, String, String)> = BTreeMap::new();
            let mut saw_stop = false;

            while let Some(event) = stream
@@ -1701,14 +1693,15 @@ impl ApiClient for AnthropicRuntimeClient {
                match event {
                    ApiStreamEvent::MessageStart(start) => {
                        for block in start.message.content {
-                            push_output_block(block, &mut events, &mut pending_tool, true);
+                            push_output_block(block, 0, &mut events, &mut pending_tools, true);
                        }
                    }
                    ApiStreamEvent::ContentBlockStart(start) => {
                        push_output_block(
                            start.content_block,
+                            start.index,
                            &mut events,
-                            &mut pending_tool,
+                            &mut pending_tools,
                            true,
                        );
                    }
@@ -1719,13 +1712,13 @@ impl ApiClient for AnthropicRuntimeClient {
                            }
                        }
                        ContentBlockDelta::InputJsonDelta { partial_json } => {
-                            if let Some((_, _, input)) = &mut pending_tool {
+                            if let Some((_, _, input)) = pending_tools.get_mut(&delta.index) {
                                input.push_str(&partial_json);
                            }
                        }
                    },
-                    ApiStreamEvent::ContentBlockStop(_) => {
-                        if let Some((id, name, input)) = pending_tool.take() {
+                    ApiStreamEvent::ContentBlockStop(stop) => {
+                        if let Some((id, name, input)) = pending_tools.remove(&stop.index) {
                            events.push(AssistantEvent::ToolUse { id, name, input });
                        }
                    }
@@ -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))
        })
    }
 }
@@ -1850,8 +1839,9 @@ fn convert_messages(messages: &[ConversationMessage]) -> Vec<InputMessage> {

 fn push_output_block(
    block: OutputContentBlock,
+    block_index: u32,
    events: &mut Vec<AssistantEvent>,
-    pending_tool: &mut Option<(String, String, String)>,
+    pending_tools: &mut BTreeMap<u32, (String, String, String)>,
    streaming_tool_input: bool,
 ) {
    match block {
@@ -1869,18 +1859,19 @@ fn push_output_block(
            } else {
                input.to_string()
            };
-            *pending_tool = Some((id, name, initial_input));
+            pending_tools.insert(block_index, (id, name, initial_input));
        }
    }
 }

 fn response_to_events(response: MessageResponse) -> Vec<AssistantEvent> {
    let mut events = Vec::new();
-    let mut pending_tool = None;
+    let mut pending_tools = BTreeMap::new();

-    for block in response.content {
-        push_output_block(block, &mut events, &mut pending_tool, false);
-        if let Some((id, name, input)) = pending_tool.take() {
+    for (index, block) in response.content.into_iter().enumerate() {
+        let index = u32::try_from(index).expect("response block index overflow");
+        push_output_block(block, index, &mut events, &mut pending_tools, false);
+        if let Some((id, name, input)) = pending_tools.remove(&index) {
            events.push(AssistantEvent::ToolUse { id, name, input });
        }
    }
@@ -1895,26 +1886,6 @@ 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
@@ -2924,6 +2895,7 @@ fn parse_skill_description(contents: &str) -> Option<String> {

 #[cfg(test)]
 mod tests {
+    use std::collections::BTreeMap;
    use std::collections::BTreeSet;
    use std::fs;
    use std::io::{Read, Write};
@@ -2936,8 +2908,9 @@ mod tests {
    use super::{
        agent_permission_policy, allowed_tools_for_subagent, execute_agent_with_spawn,
        execute_tool, final_assistant_text, mvp_tool_specs, persist_agent_terminal_state,
-        AgentInput, AgentJob, SubagentToolExecutor,
+        push_output_block, AgentInput, AgentJob, SubagentToolExecutor,
    };
+    use api::OutputContentBlock;
    use runtime::{ApiRequest, AssistantEvent, ConversationRuntime, RuntimeError, Session};
    use serde_json::json;

@@ -3152,6 +3125,63 @@ mod tests {
        assert!(error.contains("relative URL without a base") || error.contains("empty host"));
    }

+    #[test]
+    fn pending_tools_preserve_multiple_streaming_tool_calls_by_index() {
+        let mut events = Vec::new();
+        let mut pending_tools = BTreeMap::new();
+
+        push_output_block(
+            OutputContentBlock::ToolUse {
+                id: "tool-1".to_string(),
+                name: "read_file".to_string(),
+                input: json!({}),
+            },
+            1,
+            &mut events,
+            &mut pending_tools,
+            true,
+        );
+        push_output_block(
+            OutputContentBlock::ToolUse {
+                id: "tool-2".to_string(),
+                name: "grep_search".to_string(),
+                input: json!({}),
+            },
+            2,
+            &mut events,
+            &mut pending_tools,
+            true,
+        );
+
+        pending_tools
+            .get_mut(&1)
+            .expect("first tool pending")
+            .2
+            .push_str("{\"path\":\"src/main.rs\"}");
+        pending_tools
+            .get_mut(&2)
+            .expect("second tool pending")
+            .2
+            .push_str("{\"pattern\":\"TODO\"}");
+
+        assert_eq!(
+            pending_tools.remove(&1),
+            Some((
+                "tool-1".to_string(),
+                "read_file".to_string(),
+                "{\"path\":\"src/main.rs\"}".to_string(),
+            ))
+        );
+        assert_eq!(
+            pending_tools.remove(&2),
+            Some((
+                "tool-2".to_string(),
+                "grep_search".to_string(),
+                "{\"pattern\":\"TODO\"}".to_string(),
+            ))
+        );
+    }
+
    #[test]
    fn todo_write_persists_and_returns_previous_state() {
        let _guard = env_lock()
Author	SHA1	Message	Date
Yeachan-Heo	40008b6513	wip: grok provider abstraction	2026-04-01 06:00:48 +00:00
Yeachan-Heo	f477dde4a6	feat: provider tests + grok integration	2026-04-01 05:45:27 +00:00
Yeachan-Heo	178934a9a0	feat: grok provider tests + cargo fmt	2026-04-01 04:20:15 +00:00
Yeachan-Heo	2a0f4b677a	feat: provider abstraction layer + Grok API support	2026-04-01 04:10:46 +00:00
Yeachan-Heo	cbc0a83059	auto: save WIP progress from rcc session	2026-04-01 04:01:37 +00:00