diff --git a/codex-rs/core/src/tools/code_mode/execute_handler.rs b/codex-rs/core/src/tools/code_mode/execute_handler.rs
index 3f77216c1674..c46c3e045854 100644
--- a/codex-rs/core/src/tools/code_mode/execute_handler.rs
+++ b/codex-rs/core/src/tools/code_mode/execute_handler.rs
@@ -1,5 +1,3 @@
-use async_trait::async_trait;
-
 use crate::function_tool::FunctionCallError;
 use crate::tools::context::FunctionToolOutput;
 use crate::tools::context::ToolInvocation;
@@ -53,7 +51,6 @@ impl CodeModeExecuteHandler {
     }
 }
 
-#[async_trait]
 impl ToolHandler for CodeModeExecuteHandler {
     type Output = FunctionToolOutput;
 
diff --git a/codex-rs/core/src/tools/code_mode/wait_handler.rs b/codex-rs/core/src/tools/code_mode/wait_handler.rs
index f319985a885e..8a9d24c1ffcc 100644
--- a/codex-rs/core/src/tools/code_mode/wait_handler.rs
+++ b/codex-rs/core/src/tools/code_mode/wait_handler.rs
@@ -1,4 +1,3 @@
-use async_trait::async_trait;
 use serde::Deserialize;
 
 use crate::function_tool::FunctionCallError;
@@ -39,7 +38,6 @@ where
     })
 }
 
-#[async_trait]
 impl ToolHandler for CodeModeWaitHandler {
     type Output = FunctionToolOutput;
 
diff --git a/codex-rs/core/src/tools/handlers/agent_jobs.rs b/codex-rs/core/src/tools/handlers/agent_jobs.rs
index c607730b8fd2..044e2072f9f3 100644
--- a/codex-rs/core/src/tools/handlers/agent_jobs.rs
+++ b/codex-rs/core/src/tools/handlers/agent_jobs.rs
@@ -13,7 +13,6 @@ use crate::tools::handlers::multi_agents::build_agent_spawn_config;
 use crate::tools::handlers::parse_arguments;
 use crate::tools::registry::ToolHandler;
 use crate::tools::registry::ToolKind;
-use async_trait::async_trait;
 use codex_protocol::ThreadId;
 use codex_protocol::protocol::AgentStatus;
 use codex_protocol::protocol::SessionSource;
@@ -178,7 +177,6 @@ impl JobProgressEmitter {
     }
 }
 
-#[async_trait]
 impl ToolHandler for BatchJobHandler {
     type Output = FunctionToolOutput;
 
diff --git a/codex-rs/core/src/tools/handlers/apply_patch.rs b/codex-rs/core/src/tools/handlers/apply_patch.rs
index 801cff56f381..00b1173aa4ac 100644
--- a/codex-rs/core/src/tools/handlers/apply_patch.rs
+++ b/codex-rs/core/src/tools/handlers/apply_patch.rs
@@ -21,7 +21,6 @@ use crate::tools::registry::ToolKind;
 use crate::tools::runtimes::apply_patch::ApplyPatchRequest;
 use crate::tools::runtimes::apply_patch::ApplyPatchRuntime;
 use crate::tools::sandboxing::ToolCtx;
-use async_trait::async_trait;
 use codex_apply_patch::ApplyPatchAction;
 use codex_apply_patch::ApplyPatchFileChange;
 use codex_protocol::models::FileSystemPermissions;
@@ -122,7 +121,6 @@ async fn effective_patch_permissions(
     )
 }
 
-#[async_trait]
 impl ToolHandler for ApplyPatchHandler {
     type Output = ApplyPatchToolOutput;
 
diff --git a/codex-rs/core/src/tools/handlers/dynamic.rs b/codex-rs/core/src/tools/handlers/dynamic.rs
index 23285bc9079d..5f73f096e28f 100644
--- a/codex-rs/core/src/tools/handlers/dynamic.rs
+++ b/codex-rs/core/src/tools/handlers/dynamic.rs
@@ -7,7 +7,6 @@ use crate::tools::context::ToolPayload;
 use crate::tools::handlers::parse_arguments;
 use crate::tools::registry::ToolHandler;
 use crate::tools::registry::ToolKind;
-use async_trait::async_trait;
 use codex_protocol::dynamic_tools::DynamicToolCallRequest;
 use codex_protocol::dynamic_tools::DynamicToolResponse;
 use codex_protocol::models::FunctionCallOutputContentItem;
@@ -20,7 +19,6 @@ use tracing::warn;
 
 pub struct DynamicToolHandler;
 
-#[async_trait]
 impl ToolHandler for DynamicToolHandler {
     type Output = FunctionToolOutput;
 
diff --git a/codex-rs/core/src/tools/handlers/js_repl.rs b/codex-rs/core/src/tools/handlers/js_repl.rs
index c5906abafcfb..cf8d0e862068 100644
--- a/codex-rs/core/src/tools/handlers/js_repl.rs
+++ b/codex-rs/core/src/tools/handlers/js_repl.rs
@@ -1,4 +1,3 @@
-use async_trait::async_trait;
 use serde_json::Value as JsonValue;
 use std::sync::Arc;
 use std::time::Duration;
@@ -92,7 +91,6 @@ async fn emit_js_repl_exec_end(
     };
     emitter.emit(ctx, stage).await;
 }
-#[async_trait]
 impl ToolHandler for JsReplHandler {
     type Output = FunctionToolOutput;
 
@@ -182,7 +180,6 @@ impl ToolHandler for JsReplHandler {
     }
 }
 
-#[async_trait]
 impl ToolHandler for JsReplResetHandler {
     type Output = FunctionToolOutput;
 
diff --git a/codex-rs/core/src/tools/handlers/list_dir.rs b/codex-rs/core/src/tools/handlers/list_dir.rs
index fd461e82e5d4..be4e356c5c91 100644
--- a/codex-rs/core/src/tools/handlers/list_dir.rs
+++ b/codex-rs/core/src/tools/handlers/list_dir.rs
@@ -4,7 +4,6 @@ use std::fs::FileType;
 use std::path::Path;
 use std::path::PathBuf;
 
-use async_trait::async_trait;
 use codex_utils_string::take_bytes_at_char_boundary;
 use serde::Deserialize;
 use tokio::fs;
@@ -45,7 +44,6 @@ struct ListDirArgs {
     depth: usize,
 }
 
-#[async_trait]
 impl ToolHandler for ListDirHandler {
     type Output = FunctionToolOutput;
 
diff --git a/codex-rs/core/src/tools/handlers/mcp.rs b/codex-rs/core/src/tools/handlers/mcp.rs
index 18e0df25c4ad..6eaccaf81a0c 100644
--- a/codex-rs/core/src/tools/handlers/mcp.rs
+++ b/codex-rs/core/src/tools/handlers/mcp.rs
@@ -1,4 +1,3 @@
-use async_trait::async_trait;
 use std::sync::Arc;
 
 use crate::function_tool::FunctionCallError;
@@ -10,7 +9,6 @@ use crate::tools::registry::ToolKind;
 use codex_protocol::mcp::CallToolResult;
 
 pub struct McpHandler;
-#[async_trait]
 impl ToolHandler for McpHandler {
     type Output = CallToolResult;
 
diff --git a/codex-rs/core/src/tools/handlers/mcp_resource.rs b/codex-rs/core/src/tools/handlers/mcp_resource.rs
index 158aee612b56..d0b7ddc5a816 100644
--- a/codex-rs/core/src/tools/handlers/mcp_resource.rs
+++ b/codex-rs/core/src/tools/handlers/mcp_resource.rs
@@ -3,7 +3,6 @@ use std::sync::Arc;
 use std::time::Duration;
 use std::time::Instant;
 
-use async_trait::async_trait;
 use codex_protocol::mcp::CallToolResult;
 use codex_protocol::models::function_call_output_content_items_to_text;
 use rmcp::model::ListResourceTemplatesResult;
@@ -178,7 +177,6 @@ struct ReadResourcePayload {
     result: ReadResourceResult,
 }
 
-#[async_trait]
 impl ToolHandler for McpResourceHandler {
     type Output = FunctionToolOutput;
 
diff --git a/codex-rs/core/src/tools/handlers/multi_agents.rs b/codex-rs/core/src/tools/handlers/multi_agents.rs
index 166dbd287d73..df66543da64c 100644
--- a/codex-rs/core/src/tools/handlers/multi_agents.rs
+++ b/codex-rs/core/src/tools/handlers/multi_agents.rs
@@ -17,7 +17,6 @@ pub(crate) use crate::tools::handlers::multi_agents_common::*;
 use crate::tools::handlers::parse_arguments;
 use crate::tools::registry::ToolHandler;
 use crate::tools::registry::ToolKind;
-use async_trait::async_trait;
 use codex_protocol::ThreadId;
 use codex_protocol::models::ResponseInputItem;
 use codex_protocol::openai_models::ReasoningEffort;
diff --git a/codex-rs/core/src/tools/handlers/multi_agents/close_agent.rs b/codex-rs/core/src/tools/handlers/multi_agents/close_agent.rs
index efc8ec378e32..779a85e19892 100644
--- a/codex-rs/core/src/tools/handlers/multi_agents/close_agent.rs
+++ b/codex-rs/core/src/tools/handlers/multi_agents/close_agent.rs
@@ -2,7 +2,6 @@ use super::*;
 
 pub(crate) struct Handler;
 
-#[async_trait]
 impl ToolHandler for Handler {
     type Output = CloseAgentResult;
 
diff --git a/codex-rs/core/src/tools/handlers/multi_agents/resume_agent.rs b/codex-rs/core/src/tools/handlers/multi_agents/resume_agent.rs
index 09526182f293..9991a90671b6 100644
--- a/codex-rs/core/src/tools/handlers/multi_agents/resume_agent.rs
+++ b/codex-rs/core/src/tools/handlers/multi_agents/resume_agent.rs
@@ -4,7 +4,6 @@ use std::sync::Arc;
 
 pub(crate) struct Handler;
 
-#[async_trait]
 impl ToolHandler for Handler {
     type Output = ResumeAgentResult;
 
diff --git a/codex-rs/core/src/tools/handlers/multi_agents/send_input.rs b/codex-rs/core/src/tools/handlers/multi_agents/send_input.rs
index 3c8527712b2e..4ae3240cb384 100644
--- a/codex-rs/core/src/tools/handlers/multi_agents/send_input.rs
+++ b/codex-rs/core/src/tools/handlers/multi_agents/send_input.rs
@@ -3,7 +3,6 @@ use crate::agent::control::render_input_preview;
 
 pub(crate) struct Handler;
 
-#[async_trait]
 impl ToolHandler for Handler {
     type Output = SendInputResult;
 
diff --git a/codex-rs/core/src/tools/handlers/multi_agents/spawn.rs b/codex-rs/core/src/tools/handlers/multi_agents/spawn.rs
index 308ec49d8564..8e4bfb5b594f 100644
--- a/codex-rs/core/src/tools/handlers/multi_agents/spawn.rs
+++ b/codex-rs/core/src/tools/handlers/multi_agents/spawn.rs
@@ -10,7 +10,6 @@ use crate::agent::next_thread_spawn_depth;
 
 pub(crate) struct Handler;
 
-#[async_trait]
 impl ToolHandler for Handler {
     type Output = SpawnAgentResult;
 
diff --git a/codex-rs/core/src/tools/handlers/multi_agents/wait.rs b/codex-rs/core/src/tools/handlers/multi_agents/wait.rs
index 2fe33f1edd3c..8102b9732968 100644
--- a/codex-rs/core/src/tools/handlers/multi_agents/wait.rs
+++ b/codex-rs/core/src/tools/handlers/multi_agents/wait.rs
@@ -14,7 +14,6 @@ use tokio::time::timeout_at;
 
 pub(crate) struct Handler;
 
-#[async_trait]
 impl ToolHandler for Handler {
     type Output = WaitAgentResult;
 
diff --git a/codex-rs/core/src/tools/handlers/multi_agents_v2.rs b/codex-rs/core/src/tools/handlers/multi_agents_v2.rs
index 44191ed85e8d..51b80e4a7bf7 100644
--- a/codex-rs/core/src/tools/handlers/multi_agents_v2.rs
+++ b/codex-rs/core/src/tools/handlers/multi_agents_v2.rs
@@ -11,7 +11,6 @@ use crate::tools::handlers::multi_agents_common::*;
 use crate::tools::handlers::parse_arguments;
 use crate::tools::registry::ToolHandler;
 use crate::tools::registry::ToolKind;
-use async_trait::async_trait;
 use codex_protocol::AgentPath;
 use codex_protocol::models::ResponseInputItem;
 use codex_protocol::openai_models::ReasoningEffort;
diff --git a/codex-rs/core/src/tools/handlers/multi_agents_v2/close_agent.rs b/codex-rs/core/src/tools/handlers/multi_agents_v2/close_agent.rs
index 2296ae5dd3ea..8074f7fe04a7 100644
--- a/codex-rs/core/src/tools/handlers/multi_agents_v2/close_agent.rs
+++ b/codex-rs/core/src/tools/handlers/multi_agents_v2/close_agent.rs
@@ -2,7 +2,6 @@ use super::*;
 
 pub(crate) struct Handler;
 
-#[async_trait]
 impl ToolHandler for Handler {
     type Output = CloseAgentResult;
 
diff --git a/codex-rs/core/src/tools/handlers/multi_agents_v2/followup_task.rs b/codex-rs/core/src/tools/handlers/multi_agents_v2/followup_task.rs
index d0f87f34268b..312e17a31604 100644
--- a/codex-rs/core/src/tools/handlers/multi_agents_v2/followup_task.rs
+++ b/codex-rs/core/src/tools/handlers/multi_agents_v2/followup_task.rs
@@ -6,7 +6,6 @@ use super::*;
 
 pub(crate) struct Handler;
 
-#[async_trait]
 impl ToolHandler for Handler {
     type Output = MessageToolResult;
 
diff --git a/codex-rs/core/src/tools/handlers/multi_agents_v2/list_agents.rs b/codex-rs/core/src/tools/handlers/multi_agents_v2/list_agents.rs
index b3b3f7160b7a..579c4419931b 100644
--- a/codex-rs/core/src/tools/handlers/multi_agents_v2/list_agents.rs
+++ b/codex-rs/core/src/tools/handlers/multi_agents_v2/list_agents.rs
@@ -3,7 +3,6 @@ use crate::agent::control::ListedAgent;
 
 pub(crate) struct Handler;
 
-#[async_trait]
 impl ToolHandler for Handler {
     type Output = ListAgentsResult;
 
diff --git a/codex-rs/core/src/tools/handlers/multi_agents_v2/send_message.rs b/codex-rs/core/src/tools/handlers/multi_agents_v2/send_message.rs
index a16aebd4c299..a490d1100dcd 100644
--- a/codex-rs/core/src/tools/handlers/multi_agents_v2/send_message.rs
+++ b/codex-rs/core/src/tools/handlers/multi_agents_v2/send_message.rs
@@ -6,7 +6,6 @@ use super::*;
 
 pub(crate) struct Handler;
 
-#[async_trait]
 impl ToolHandler for Handler {
     type Output = MessageToolResult;
 
diff --git a/codex-rs/core/src/tools/handlers/multi_agents_v2/spawn.rs b/codex-rs/core/src/tools/handlers/multi_agents_v2/spawn.rs
index 3dc8d7202464..9b3b818513ee 100644
--- a/codex-rs/core/src/tools/handlers/multi_agents_v2/spawn.rs
+++ b/codex-rs/core/src/tools/handlers/multi_agents_v2/spawn.rs
@@ -11,7 +11,6 @@ use codex_protocol::protocol::Op;
 
 pub(crate) struct Handler;
 
-#[async_trait]
 impl ToolHandler for Handler {
     type Output = SpawnAgentResult;
 
diff --git a/codex-rs/core/src/tools/handlers/multi_agents_v2/wait.rs b/codex-rs/core/src/tools/handlers/multi_agents_v2/wait.rs
index bf3ad8e93409..777fe1c2e764 100644
--- a/codex-rs/core/src/tools/handlers/multi_agents_v2/wait.rs
+++ b/codex-rs/core/src/tools/handlers/multi_agents_v2/wait.rs
@@ -6,7 +6,6 @@ use tokio::time::timeout_at;
 
 pub(crate) struct Handler;
 
-#[async_trait]
 impl ToolHandler for Handler {
     type Output = WaitAgentResult;
 
diff --git a/codex-rs/core/src/tools/handlers/plan.rs b/codex-rs/core/src/tools/handlers/plan.rs
index ce0b98b1cb93..fb1c708ada9c 100644
--- a/codex-rs/core/src/tools/handlers/plan.rs
+++ b/codex-rs/core/src/tools/handlers/plan.rs
@@ -6,7 +6,6 @@ use crate::tools::context::ToolOutput;
 use crate::tools::context::ToolPayload;
 use crate::tools::registry::ToolHandler;
 use crate::tools::registry::ToolKind;
-use async_trait::async_trait;
 use codex_protocol::config_types::ModeKind;
 use codex_protocol::models::FunctionCallOutputPayload;
 use codex_protocol::models::ResponseInputItem;
@@ -44,7 +43,6 @@ impl ToolOutput for PlanToolOutput {
     }
 }
 
-#[async_trait]
 impl ToolHandler for PlanHandler {
     type Output = PlanToolOutput;
 
diff --git a/codex-rs/core/src/tools/handlers/request_permissions.rs b/codex-rs/core/src/tools/handlers/request_permissions.rs
index e0755deac7a9..2590b9d7dd7e 100644
--- a/codex-rs/core/src/tools/handlers/request_permissions.rs
+++ b/codex-rs/core/src/tools/handlers/request_permissions.rs
@@ -1,4 +1,3 @@
-use async_trait::async_trait;
 use codex_protocol::request_permissions::RequestPermissionsArgs;
 use codex_sandboxing::policy_transforms::normalize_additional_permissions;
 
@@ -12,7 +11,6 @@ use crate::tools::registry::ToolKind;
 
 pub struct RequestPermissionsHandler;
 
-#[async_trait]
 impl ToolHandler for RequestPermissionsHandler {
     type Output = FunctionToolOutput;
 
diff --git a/codex-rs/core/src/tools/handlers/request_user_input.rs b/codex-rs/core/src/tools/handlers/request_user_input.rs
index f12defd0e7e9..dcc9445a948e 100644
--- a/codex-rs/core/src/tools/handlers/request_user_input.rs
+++ b/codex-rs/core/src/tools/handlers/request_user_input.rs
@@ -5,7 +5,6 @@ use crate::tools::context::ToolPayload;
 use crate::tools::handlers::parse_arguments;
 use crate::tools::registry::ToolHandler;
 use crate::tools::registry::ToolKind;
-use async_trait::async_trait;
 use codex_protocol::request_user_input::RequestUserInputArgs;
 use codex_tools::REQUEST_USER_INPUT_TOOL_NAME;
 use codex_tools::normalize_request_user_input_args;
@@ -15,7 +14,6 @@ pub struct RequestUserInputHandler {
     pub default_mode_request_user_input: bool,
 }
 
-#[async_trait]
 impl ToolHandler for RequestUserInputHandler {
     type Output = FunctionToolOutput;
 
diff --git a/codex-rs/core/src/tools/handlers/shell.rs b/codex-rs/core/src/tools/handlers/shell.rs
index 34cdd5b976e6..6f662ff493c7 100644
--- a/codex-rs/core/src/tools/handlers/shell.rs
+++ b/codex-rs/core/src/tools/handlers/shell.rs
@@ -1,4 +1,3 @@
-use async_trait::async_trait;
 use codex_protocol::ThreadId;
 use codex_protocol::models::ShellCommandToolCallParams;
 use codex_protocol::models::ShellToolCallParams;
@@ -178,7 +177,6 @@ impl From<ShellCommandBackendConfig> for ShellCommandHandler {
     }
 }
 
-#[async_trait]
 impl ToolHandler for ShellHandler {
     type Output = FunctionToolOutput;
 
@@ -279,7 +277,6 @@ impl ToolHandler for ShellHandler {
     }
 }
 
-#[async_trait]
 impl ToolHandler for ShellCommandHandler {
     type Output = FunctionToolOutput;
 
diff --git a/codex-rs/core/src/tools/handlers/test_sync.rs b/codex-rs/core/src/tools/handlers/test_sync.rs
index 2d6e351488c5..ad2647243a2a 100644
--- a/codex-rs/core/src/tools/handlers/test_sync.rs
+++ b/codex-rs/core/src/tools/handlers/test_sync.rs
@@ -4,7 +4,6 @@ use std::sync::Arc;
 use std::sync::OnceLock;
 use std::time::Duration;
 
-use async_trait::async_trait;
 use serde::Deserialize;
 use tokio::sync::Barrier;
 use tokio::time::sleep;
@@ -54,7 +53,6 @@ fn barrier_map() -> &'static tokio::sync::Mutex<HashMap<String, BarrierState>> {
     BARRIERS.get_or_init(|| tokio::sync::Mutex::new(HashMap::new()))
 }
 
-#[async_trait]
 impl ToolHandler for TestSyncHandler {
     type Output = FunctionToolOutput;
 
diff --git a/codex-rs/core/src/tools/handlers/tool_search.rs b/codex-rs/core/src/tools/handlers/tool_search.rs
index aa9d8e92f19e..dd203e93b5ef 100644
--- a/codex-rs/core/src/tools/handlers/tool_search.rs
+++ b/codex-rs/core/src/tools/handlers/tool_search.rs
@@ -4,7 +4,6 @@ use crate::tools::context::ToolPayload;
 use crate::tools::context::ToolSearchOutput;
 use crate::tools::registry::ToolHandler;
 use crate::tools::registry::ToolKind;
-use async_trait::async_trait;
 use bm25::Document;
 use bm25::Language;
 use bm25::SearchEngineBuilder;
@@ -25,7 +24,6 @@ impl ToolSearchHandler {
     }
 }
 
-#[async_trait]
 impl ToolHandler for ToolSearchHandler {
     type Output = ToolSearchOutput;
 
diff --git a/codex-rs/core/src/tools/handlers/tool_suggest.rs b/codex-rs/core/src/tools/handlers/tool_suggest.rs
index 45c77a350c3b..380aebd51baf 100644
--- a/codex-rs/core/src/tools/handlers/tool_suggest.rs
+++ b/codex-rs/core/src/tools/handlers/tool_suggest.rs
@@ -1,6 +1,5 @@
 use std::collections::HashSet;
 
-use async_trait::async_trait;
 use codex_app_server_protocol::AppInfo;
 use codex_mcp::mcp::CODEX_APPS_MCP_SERVER_NAME;
 use codex_rmcp_client::ElicitationAction;
@@ -28,7 +27,6 @@ use crate::tools::registry::ToolKind;
 
 pub struct ToolSuggestHandler;
 
-#[async_trait]
 impl ToolHandler for ToolSuggestHandler {
     type Output = FunctionToolOutput;
 
diff --git a/codex-rs/core/src/tools/handlers/unified_exec.rs b/codex-rs/core/src/tools/handlers/unified_exec.rs
index 98d7d717fced..dfe8c42752f5 100644
--- a/codex-rs/core/src/tools/handlers/unified_exec.rs
+++ b/codex-rs/core/src/tools/handlers/unified_exec.rs
@@ -22,7 +22,6 @@ use crate::unified_exec::ExecCommandRequest;
 use crate::unified_exec::UnifiedExecContext;
 use crate::unified_exec::UnifiedExecProcessManager;
 use crate::unified_exec::WriteStdinRequest;
-use async_trait::async_trait;
 use codex_features::Feature;
 use codex_otel::SessionTelemetry;
 use codex_otel::metrics::names::TOOL_CALL_UNIFIED_EXEC_METRIC;
@@ -86,7 +85,6 @@ fn default_tty() -> bool {
     false
 }
 
-#[async_trait]
 impl ToolHandler for UnifiedExecHandler {
     type Output = ExecCommandToolOutput;
 
diff --git a/codex-rs/core/src/tools/handlers/view_image.rs b/codex-rs/core/src/tools/handlers/view_image.rs
index e87638bba6ac..ec34fafb360d 100644
--- a/codex-rs/core/src/tools/handlers/view_image.rs
+++ b/codex-rs/core/src/tools/handlers/view_image.rs
@@ -1,4 +1,3 @@
-use async_trait::async_trait;
 use codex_protocol::models::FunctionCallOutputBody;
 use codex_protocol::models::FunctionCallOutputContentItem;
 use codex_protocol::models::FunctionCallOutputPayload;
@@ -37,7 +36,6 @@ enum ViewImageDetail {
     Original,
 }
 
-#[async_trait]
 impl ToolHandler for ViewImageHandler {
     type Output = ViewImageOutput;
 
diff --git a/codex-rs/core/src/tools/registry.rs b/codex-rs/core/src/tools/registry.rs
index f1ebb38c06c8..2723d8a9a445 100644
--- a/codex-rs/core/src/tools/registry.rs
+++ b/codex-rs/core/src/tools/registry.rs
@@ -13,7 +13,6 @@ use crate::tools::context::FunctionToolOutput;
 use crate::tools::context::ToolInvocation;
 use crate::tools::context::ToolOutput;
 use crate::tools::context::ToolPayload;
-use async_trait::async_trait;
 use codex_hooks::HookEvent;
 use codex_hooks::HookEventAfterToolUse;
 use codex_hooks::HookPayload;
@@ -26,6 +25,7 @@ use codex_protocol::protocol::SandboxPolicy;
 use codex_tools::ConfiguredToolSpec;
 use codex_tools::ToolSpec;
 use codex_utils_readiness::Readiness;
+use futures::future::BoxFuture;
 use serde_json::Value;
 use tracing::warn;
 
@@ -35,7 +35,6 @@ pub enum ToolKind {
     Mcp,
 }
 
-#[async_trait]
 pub trait ToolHandler: Send + Sync {
     type Output: ToolOutput + 'static;
 
@@ -54,8 +53,11 @@ pub trait ToolHandler: Send + Sync {
     /// user (through file system, OS operations, ...).
     /// This function must remains defensive and return `true` if a doubt exist on the
     /// exact effect of a ToolInvocation.
-    async fn is_mutating(&self, _invocation: &ToolInvocation) -> bool {
-        false
+    fn is_mutating(
+        &self,
+        _invocation: &ToolInvocation,
+    ) -> impl std::future::Future<Output = bool> + Send {
+        async { false }
     }
 
     fn pre_tool_use_payload(&self, _invocation: &ToolInvocation) -> Option<PreToolUsePayload> {
@@ -73,7 +75,10 @@ pub trait ToolHandler: Send + Sync {
 
     /// Perform the actual [ToolInvocation] and returns a [ToolOutput] containing
     /// the final output to return to the model.
-    async fn handle(&self, invocation: ToolInvocation) -> Result<Self::Output, FunctionCallError>;
+    fn handle(
+        &self,
+        invocation: ToolInvocation,
+    ) -> impl std::future::Future<Output = Result<Self::Output, FunctionCallError>> + Send;
 }
 
 pub(crate) struct AnyToolResult {
@@ -112,11 +117,10 @@ pub(crate) struct PostToolUsePayload {
     pub(crate) tool_response: Value,
 }
 
-#[async_trait]
 trait AnyToolHandler: Send + Sync {
     fn matches_kind(&self, payload: &ToolPayload) -> bool;
 
-    async fn is_mutating(&self, invocation: &ToolInvocation) -> bool;
+    fn is_mutating<'a>(&'a self, invocation: &'a ToolInvocation) -> BoxFuture<'a, bool>;
 
     fn pre_tool_use_payload(&self, invocation: &ToolInvocation) -> Option<PreToolUsePayload>;
 
@@ -127,13 +131,12 @@ trait AnyToolHandler: Send + Sync {
         result: &dyn ToolOutput,
     ) -> Option<PostToolUsePayload>;
 
-    async fn handle_any(
-        &self,
+    fn handle_any<'a>(
+        &'a self,
         invocation: ToolInvocation,
-    ) -> Result<AnyToolResult, FunctionCallError>;
+    ) -> BoxFuture<'a, Result<AnyToolResult, FunctionCallError>>;
 }
 
-#[async_trait]
 impl<T> AnyToolHandler for T
 where
     T: ToolHandler,
@@ -142,8 +145,8 @@ where
         ToolHandler::matches_kind(self, payload)
     }
 
-    async fn is_mutating(&self, invocation: &ToolInvocation) -> bool {
-        ToolHandler::is_mutating(self, invocation).await
+    fn is_mutating<'a>(&'a self, invocation: &'a ToolInvocation) -> BoxFuture<'a, bool> {
+        Box::pin(ToolHandler::is_mutating(self, invocation))
     }
 
     fn pre_tool_use_payload(&self, invocation: &ToolInvocation) -> Option<PreToolUsePayload> {
@@ -159,17 +162,19 @@ where
         ToolHandler::post_tool_use_payload(self, call_id, payload, result)
     }
 
-    async fn handle_any(
-        &self,
+    fn handle_any<'a>(
+        &'a self,
         invocation: ToolInvocation,
-    ) -> Result<AnyToolResult, FunctionCallError> {
-        let call_id = invocation.call_id.clone();
-        let payload = invocation.payload.clone();
-        let output = self.handle(invocation).await?;
-        Ok(AnyToolResult {
-            call_id,
-            payload,
-            result: Box::new(output),
+    ) -> BoxFuture<'a, Result<AnyToolResult, FunctionCallError>> {
+        Box::pin(async move {
+            let call_id = invocation.call_id.clone();
+            let payload = invocation.payload.clone();
+            let output = self.handle(invocation).await?;
+            Ok(AnyToolResult {
+                call_id,
+                payload,
+                result: Box::new(output),
+            })
         })
     }
 }
diff --git a/codex-rs/core/src/tools/registry_tests.rs b/codex-rs/core/src/tools/registry_tests.rs
index 687364872c96..287996d7d870 100644
--- a/codex-rs/core/src/tools/registry_tests.rs
+++ b/codex-rs/core/src/tools/registry_tests.rs
@@ -1,10 +1,8 @@
 use super::*;
-use async_trait::async_trait;
 use pretty_assertions::assert_eq;
 
 struct TestHandler;
 
-#[async_trait]
 impl ToolHandler for TestHandler {
     type Output = crate::tools::context::FunctionToolOutput;