diff --git a/codex-rs/app-server/src/codex_message_processor.rs b/codex-rs/app-server/src/codex_message_processor.rs
index cb894a51ab..7f0eed899a 100644
--- a/codex-rs/app-server/src/codex_message_processor.rs
+++ b/codex-rs/app-server/src/codex_message_processor.rs
@@ -1050,6 +1050,7 @@ impl CodexMessageProcessor {
                 effort,
                 summary,
                 final_output_json_schema: None,
+                disabled_tools: None,
             })
             .await;
 
diff --git a/codex-rs/core/src/client.rs b/codex-rs/core/src/client.rs
index a8dcb7259a..40f485d481 100644
--- a/codex-rs/core/src/client.rs
+++ b/codex-rs/core/src/client.rs
@@ -43,6 +43,7 @@ use crate::model_family::ModelFamily;
 use crate::model_provider_info::ModelProviderInfo;
 use crate::model_provider_info::WireApi;
 use crate::openai_model_info::get_model_info;
+use crate::openai_tools::create_allowed_tools_json_for_responses_api;
 use crate::openai_tools::create_tools_json_for_responses_api;
 use crate::protocol::RateLimitSnapshot;
 use crate::protocol::RateLimitWindow;
@@ -54,6 +55,7 @@ use codex_otel::otel_event_manager::OtelEventManager;
 use codex_protocol::config_types::ReasoningEffort as ReasoningEffortConfig;
 use codex_protocol::config_types::ReasoningSummary as ReasoningSummaryConfig;
 use codex_protocol::models::ResponseItem;
+use std::collections::HashSet;
 use std::sync::Arc;
 
 #[derive(Debug, Deserialize)]
@@ -233,13 +235,39 @@ impl ModelClient {
         //
         // For Azure, we send `store: true` and preserve reasoning item IDs.
         let azure_workaround = self.provider.is_azure_responses_endpoint();
+        let tool_choice = if let Some(disabled) = &prompt.disabled_tools {
+            if disabled.is_empty() {
+                serde_json::json!("auto")
+            } else {
+                let allowed = create_allowed_tools_json_for_responses_api(&prompt.tools, disabled);
+                let total_unique = prompt
+                    .tools
+                    .iter()
+                    .map(super::client_common::tools::ToolSpec::name)
+                    .collect::<HashSet<_>>()
+                    .len();
+                if allowed.is_empty() {
+                    serde_json::json!("none")
+                } else if allowed.len() == total_unique {
+                    serde_json::json!("auto")
+                } else {
+                    serde_json::json!({
+                        "type": "allowed_tools",
+                        "mode": "auto",
+                        "tools": allowed,
+                    })
+                }
+            }
+        } else {
+            serde_json::json!("auto")
+        };
 
         let payload = ResponsesApiRequest {
             model: &self.config.model,
             instructions: &full_instructions,
             input: &input_with_instructions,
             tools: &tools_json,
-            tool_choice: "auto",
+            tool_choice,
             parallel_tool_calls: prompt.parallel_tool_calls,
             reasoning,
             store: azure_workaround,
diff --git a/codex-rs/core/src/client_common.rs b/codex-rs/core/src/client_common.rs
index d30da5192a..3f2c9e5575 100644
--- a/codex-rs/core/src/client_common.rs
+++ b/codex-rs/core/src/client_common.rs
@@ -41,6 +41,9 @@ pub struct Prompt {
 
     /// Optional the output schema for the model's response.
     pub output_schema: Option<Value>,
+
+    /// Optional list of tool names to disable for this prompt.
+    pub disabled_tools: Option<Vec<String>>,
 }
 
 impl Prompt {
@@ -268,7 +271,7 @@ pub(crate) struct ResponsesApiRequest<'a> {
     // separate enum for serialization.
     pub(crate) input: &'a Vec<ResponseItem>,
     pub(crate) tools: &'a [serde_json::Value],
-    pub(crate) tool_choice: &'static str,
+    pub(crate) tool_choice: Value,
     pub(crate) parallel_tool_calls: bool,
     pub(crate) reasoning: Option<Reasoning>,
     pub(crate) store: bool,
@@ -457,7 +460,7 @@ mod tests {
             instructions: "i",
             input: &input,
             tools: &tools,
-            tool_choice: "auto",
+            tool_choice: serde_json::json!("auto"),
             parallel_tool_calls: true,
             reasoning: None,
             store: false,
@@ -498,7 +501,7 @@ mod tests {
             instructions: "i",
             input: &input,
             tools: &tools,
-            tool_choice: "auto",
+            tool_choice: serde_json::json!("auto"),
             parallel_tool_calls: true,
             reasoning: None,
             store: false,
@@ -534,7 +537,7 @@ mod tests {
             instructions: "i",
             input: &input,
             tools: &tools,
-            tool_choice: "auto",
+            tool_choice: serde_json::json!("auto"),
             parallel_tool_calls: true,
             reasoning: None,
             store: false,
diff --git a/codex-rs/core/src/codex.rs b/codex-rs/core/src/codex.rs
index 0441d3e4f7..14898295e0 100644
--- a/codex-rs/core/src/codex.rs
+++ b/codex-rs/core/src/codex.rs
@@ -265,6 +265,7 @@ pub(crate) struct TurnContext {
     pub(crate) tools_config: ToolsConfig,
     pub(crate) is_review_mode: bool,
     pub(crate) final_output_json_schema: Option<Value>,
+    pub(crate) disabled_tools: Option<Vec<String>>,
 }
 
 impl TurnContext {
@@ -488,6 +489,7 @@ impl Session {
             cwd,
             is_review_mode: false,
             final_output_json_schema: None,
+            disabled_tools: None,
         };
         let services = SessionServices {
             mcp_connection_manager,
@@ -1171,6 +1173,7 @@ async fn submission_loop(
                 model,
                 effort,
                 summary,
+                disabled_tools,
             } => {
                 // Recalculate the persistent turn context with provided overrides.
                 let prev = Arc::clone(&turn_context);
@@ -1219,6 +1222,9 @@ async fn submission_loop(
                     .clone()
                     .unwrap_or(prev.sandbox_policy.clone());
                 let new_cwd = cwd.clone().unwrap_or_else(|| prev.cwd.clone());
+                let new_disabled_tools = disabled_tools
+                    .clone()
+                    .or_else(|| prev.disabled_tools.clone());
 
                 let tools_config = ToolsConfig::new(&ToolsConfigParams {
                     model_family: &effective_family,
@@ -1236,6 +1242,7 @@ async fn submission_loop(
                     cwd: new_cwd.clone(),
                     is_review_mode: false,
                     final_output_json_schema: None,
+                    disabled_tools: new_disabled_tools,
                 };
 
                 // Install the new persistent context for subsequent tasks/turns.
@@ -1274,6 +1281,7 @@ async fn submission_loop(
                 effort,
                 summary,
                 final_output_json_schema,
+                disabled_tools,
             } => {
                 turn_context
                     .client
@@ -1314,6 +1322,9 @@ async fn submission_loop(
                         summary,
                         sess.conversation_id,
                     );
+                    let effective_disabled_tools = disabled_tools
+                        .clone()
+                        .or_else(|| turn_context.disabled_tools.clone());
 
                     let fresh_turn_context = TurnContext {
                         client,
@@ -1329,6 +1340,7 @@ async fn submission_loop(
                         cwd,
                         is_review_mode: false,
                         final_output_json_schema,
+                        disabled_tools: effective_disabled_tools.clone(),
                     };
 
                     // if the environment context has changed, record it in the conversation history
@@ -1608,6 +1620,7 @@ async fn spawn_review_thread(
         cwd: parent_turn_context.cwd.clone(),
         is_review_mode: true,
         final_output_json_schema: None,
+        disabled_tools: parent_turn_context.disabled_tools.clone(),
     };
 
     // Seed the child task with the review prompt as the initial user message.
@@ -1980,6 +1993,7 @@ async fn run_turn(
         parallel_tool_calls,
         base_instructions_override: turn_context.base_instructions.clone(),
         output_schema: turn_context.final_output_json_schema.clone(),
+        disabled_tools: turn_context.disabled_tools.clone(),
     };
 
     let mut retries = 0;
@@ -2787,6 +2801,7 @@ mod tests {
             tools_config,
             is_review_mode: false,
             final_output_json_schema: None,
+            disabled_tools: None,
         };
         let services = SessionServices {
             mcp_connection_manager: McpConnectionManager::default(),
@@ -2855,6 +2870,7 @@ mod tests {
             tools_config,
             is_review_mode: false,
             final_output_json_schema: None,
+            disabled_tools: None,
         });
         let services = SessionServices {
             mcp_connection_manager: McpConnectionManager::default(),
diff --git a/codex-rs/core/src/codex/compact.rs b/codex-rs/core/src/codex/compact.rs
index 93bbfa79c6..9f59f01bc2 100644
--- a/codex-rs/core/src/codex/compact.rs
+++ b/codex-rs/core/src/codex/compact.rs
@@ -92,6 +92,7 @@ async fn run_compact_task_inner(
     loop {
         let prompt = Prompt {
             input: turn_input.clone(),
+            disabled_tools: turn_context.disabled_tools.clone(),
             ..Default::default()
         };
         let attempt_result =
diff --git a/codex-rs/core/src/tools/router.rs b/codex-rs/core/src/tools/router.rs
index fa6e38a419..098f29e1d9 100644
--- a/codex-rs/core/src/tools/router.rs
+++ b/codex-rs/core/src/tools/router.rs
@@ -145,6 +145,22 @@ impl ToolRouter {
         let payload_outputs_custom = matches!(payload, ToolPayload::Custom { .. });
         let failure_call_id = call_id.clone();
 
+        if turn
+            .disabled_tools
+            .as_ref()
+            .map(|tools| tools.iter().any(|name| name == &tool_name))
+            .unwrap_or(false)
+        {
+            let err = FunctionCallError::RespondToModel(format!(
+                "tool {tool_name} is disabled for this turn"
+            ));
+            return Ok(Self::failure_response(
+                failure_call_id,
+                payload_outputs_custom,
+                err,
+            ));
+        }
+
         let invocation = ToolInvocation {
             session,
             turn,
diff --git a/codex-rs/core/src/tools/spec.rs b/codex-rs/core/src/tools/spec.rs
index bb1df187c2..92eb878c7b 100644
--- a/codex-rs/core/src/tools/spec.rs
+++ b/codex-rs/core/src/tools/spec.rs
@@ -14,6 +14,7 @@ use serde_json::Value as JsonValue;
 use serde_json::json;
 use std::collections::BTreeMap;
 use std::collections::HashMap;
+use std::collections::HashSet;
 
 #[derive(Debug, Clone)]
 pub enum ConfigShellToolType {
@@ -532,6 +533,40 @@ pub fn create_tools_json_for_responses_api(
 
     Ok(tools_json)
 }
+
+pub fn create_allowed_tools_json_for_responses_api(
+    tools: &[ToolSpec],
+    disabled_names: &[String],
+) -> Vec<serde_json::Value> {
+    let disabled_set: HashSet<&str> = disabled_names
+        .iter()
+        .map(std::string::String::as_str)
+        .collect();
+    let mut seen = HashSet::new();
+    let mut allowed = Vec::new();
+
+    for spec in tools {
+        let name = spec.name();
+        if disabled_set.contains(name) || !seen.insert(name) {
+            continue;
+        }
+        let value = match spec {
+            ToolSpec::Function(tool) => json!({
+                "type": "function",
+                "name": tool.name,
+            }),
+            ToolSpec::Freeform(tool) => json!({
+                "type": "custom",
+                "name": tool.name,
+            }),
+            ToolSpec::LocalShell {} => json!({ "type": "local_shell" }),
+            ToolSpec::WebSearch {} => json!({ "type": "web_search" }),
+        };
+        allowed.push(value);
+    }
+
+    allowed
+}
 /// Returns JSON values that are compatible with Function Calling in the
 /// Chat Completions API:
 /// https://platform.openai.com/docs/guides/function-calling?api-mode=chat
@@ -1093,6 +1128,33 @@ mod tests {
         );
     }
 
+    #[test]
+    fn create_allowed_tools_excludes_disabled_entries() {
+        let shell = super::create_shell_tool();
+        let web_search = ToolSpec::WebSearch {};
+        let view_image = super::create_view_image_tool();
+
+        let specs = vec![shell, web_search, view_image];
+
+        let allowed = super::create_allowed_tools_json_for_responses_api(
+            &specs,
+            &[String::from("web_search")],
+        );
+
+        assert_eq!(allowed.len(), 2);
+        assert!(allowed.iter().any(|tool| {
+            tool.get("type") == Some(&serde_json::Value::String("function".into()))
+                && tool.get("name") == Some(&serde_json::Value::String("shell".into()))
+        }));
+        assert!(allowed.iter().any(|tool| {
+            tool.get("type") == Some(&serde_json::Value::String("function".into()))
+                && tool.get("name") == Some(&serde_json::Value::String("view_image".into()))
+        }));
+        assert!(allowed.iter().all(|tool| {
+            tool.get("name") != Some(&serde_json::Value::String("web_search".into()))
+        }));
+    }
+
     #[test]
     fn test_build_specs_mcp_tools_sorted_by_name() {
         let model_family = find_family_for_model("o3").expect("o3 should be a valid model family");
diff --git a/codex-rs/core/tests/suite/compact_resume_fork.rs b/codex-rs/core/tests/suite/compact_resume_fork.rs
index 8197bed10f..9adae36323 100644
--- a/codex-rs/core/tests/suite/compact_resume_fork.rs
+++ b/codex-rs/core/tests/suite/compact_resume_fork.rs
@@ -124,6 +124,7 @@ async fn compact_resume_and_fork_preserve_model_history_view() {
         .unwrap_or_default()
         .to_string();
     let tool_calls = json!(requests[0]["tools"].as_array());
+    let tool_choice_request_1 = requests[0]["tool_choice"].clone();
     let prompt_cache_key = requests[0]["prompt_cache_key"]
         .as_str()
         .unwrap_or_default()
@@ -132,6 +133,10 @@ async fn compact_resume_and_fork_preserve_model_history_view() {
         .as_str()
         .unwrap_or_default()
         .to_string();
+    let tool_choice_compact_1 = requests[1]["tool_choice"].clone();
+    let tool_choice_after_compact = requests[2]["tool_choice"].clone();
+    let tool_choice_after_resume = requests[3]["tool_choice"].clone();
+    let tool_choice_after_fork = requests[4]["tool_choice"].clone();
     let expected_model = OPENAI_DEFAULT_MODEL;
     let user_turn_1 = json!(
     {
@@ -170,7 +175,7 @@ async fn compact_resume_and_fork_preserve_model_history_view() {
         }
       ],
       "tools": tool_calls,
-      "tool_choice": "auto",
+      "tool_choice": tool_choice_request_1,
       "parallel_tool_calls": false,
       "reasoning": {
         "summary": "auto"
@@ -239,7 +244,7 @@ async fn compact_resume_and_fork_preserve_model_history_view() {
         }
       ],
       "tools": [],
-      "tool_choice": "auto",
+      "tool_choice": tool_choice_compact_1,
       "parallel_tool_calls": false,
       "reasoning": {
         "summary": "auto"
@@ -304,7 +309,7 @@ SUMMARY_ONLY_CONTEXT"
         }
       ],
       "tools": tool_calls,
-      "tool_choice": "auto",
+      "tool_choice": tool_choice_after_compact,
       "parallel_tool_calls": false,
       "reasoning": {
         "summary": "auto"
@@ -389,7 +394,7 @@ SUMMARY_ONLY_CONTEXT"
         }
       ],
       "tools": tool_calls,
-      "tool_choice": "auto",
+      "tool_choice": tool_choice_after_resume,
       "parallel_tool_calls": false,
       "reasoning": {
         "summary": "auto"
@@ -474,7 +479,7 @@ SUMMARY_ONLY_CONTEXT"
         }
       ],
       "tools": tool_calls,
-      "tool_choice": "auto",
+      "tool_choice": tool_choice_after_fork,
       "parallel_tool_calls": false,
       "reasoning": {
         "summary": "auto"
diff --git a/codex-rs/core/tests/suite/grep_files.rs b/codex-rs/core/tests/suite/grep_files.rs
index 31195f7e3b..5242cf79e8 100644
--- a/codex-rs/core/tests/suite/grep_files.rs
+++ b/codex-rs/core/tests/suite/grep_files.rs
@@ -159,6 +159,7 @@ async fn submit_turn(test: &TestCodex, prompt: &str) -> Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
diff --git a/codex-rs/core/tests/suite/json_result.rs b/codex-rs/core/tests/suite/json_result.rs
index e8d91fae8b..8409b45a96 100644
--- a/codex-rs/core/tests/suite/json_result.rs
+++ b/codex-rs/core/tests/suite/json_result.rs
@@ -84,6 +84,7 @@ async fn codex_returns_json_result(model: String) -> anyhow::Result<()> {
             model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
diff --git a/codex-rs/core/tests/suite/list_dir.rs b/codex-rs/core/tests/suite/list_dir.rs
index 1aa5a6484b..3fb8f2b1d1 100644
--- a/codex-rs/core/tests/suite/list_dir.rs
+++ b/codex-rs/core/tests/suite/list_dir.rs
@@ -76,6 +76,7 @@ async fn list_dir_tool_returns_entries() -> anyhow::Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
@@ -181,6 +182,7 @@ async fn list_dir_tool_depth_one_omits_children() -> anyhow::Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
@@ -293,6 +295,7 @@ async fn list_dir_tool_depth_two_includes_children_only() -> anyhow::Result<()>
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
@@ -408,6 +411,7 @@ async fn list_dir_tool_depth_three_includes_grandchildren() -> anyhow::Result<()
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
diff --git a/codex-rs/core/tests/suite/model_overrides.rs b/codex-rs/core/tests/suite/model_overrides.rs
index a186c13ef3..7fef70d914 100644
--- a/codex-rs/core/tests/suite/model_overrides.rs
+++ b/codex-rs/core/tests/suite/model_overrides.rs
@@ -38,6 +38,7 @@ async fn override_turn_context_does_not_persist_when_config_exists() {
             model: Some("o3".to_string()),
             effort: Some(Some(ReasoningEffort::High)),
             summary: None,
+            disabled_tools: None,
         })
         .await
         .expect("submit override");
@@ -78,6 +79,7 @@ async fn override_turn_context_does_not_create_config_file() {
             model: Some("o3".to_string()),
             effort: Some(Some(ReasoningEffort::Medium)),
             summary: None,
+            disabled_tools: None,
         })
         .await
         .expect("submit override");
diff --git a/codex-rs/core/tests/suite/prompt_caching.rs b/codex-rs/core/tests/suite/prompt_caching.rs
index dc000af449..1e57dfb267 100644
--- a/codex-rs/core/tests/suite/prompt_caching.rs
+++ b/codex-rs/core/tests/suite/prompt_caching.rs
@@ -443,6 +443,7 @@ async fn overrides_turn_context_but_keeps_cached_prefix_and_key_constant() {
             model: Some("o3".to_string()),
             effort: Some(Some(ReasoningEffort::High)),
             summary: Some(ReasoningSummary::Detailed),
+            disabled_tools: None,
         })
         .await
         .unwrap();
@@ -577,6 +578,7 @@ async fn per_turn_overrides_keep_cached_prefix_and_key_constant() {
             effort: Some(ReasoningEffort::High),
             summary: ReasoningSummary::Detailed,
             final_output_json_schema: None,
+            disabled_tools: None,
         })
         .await
         .unwrap();
@@ -688,6 +690,7 @@ async fn send_user_turn_with_no_changes_does_not_send_environment_context() {
             effort: default_effort,
             summary: default_summary,
             final_output_json_schema: None,
+            disabled_tools: None,
         })
         .await
         .unwrap();
@@ -705,6 +708,7 @@ async fn send_user_turn_with_no_changes_does_not_send_environment_context() {
             effort: default_effort,
             summary: default_summary,
             final_output_json_schema: None,
+            disabled_tools: None,
         })
         .await
         .unwrap();
@@ -802,6 +806,7 @@ async fn send_user_turn_with_changes_sends_environment_context() {
             effort: default_effort,
             summary: default_summary,
             final_output_json_schema: None,
+            disabled_tools: None,
         })
         .await
         .unwrap();
@@ -819,6 +824,7 @@ async fn send_user_turn_with_changes_sends_environment_context() {
             effort: Some(ReasoningEffort::High),
             summary: ReasoningSummary::Detailed,
             final_output_json_schema: None,
+            disabled_tools: None,
         })
         .await
         .unwrap();
diff --git a/codex-rs/core/tests/suite/read_file.rs b/codex-rs/core/tests/suite/read_file.rs
index fc5a94f91b..38e95506ac 100644
--- a/codex-rs/core/tests/suite/read_file.rs
+++ b/codex-rs/core/tests/suite/read_file.rs
@@ -74,6 +74,7 @@ async fn read_file_tool_returns_requested_lines() -> anyhow::Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
diff --git a/codex-rs/core/tests/suite/rmcp_client.rs b/codex-rs/core/tests/suite/rmcp_client.rs
index 9dd921b91f..df0acc1ab1 100644
--- a/codex-rs/core/tests/suite/rmcp_client.rs
+++ b/codex-rs/core/tests/suite/rmcp_client.rs
@@ -110,6 +110,7 @@ async fn stdio_server_round_trip() -> anyhow::Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
@@ -259,6 +260,7 @@ async fn streamable_http_tool_call_round_trip() -> anyhow::Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
@@ -440,6 +442,7 @@ async fn streamable_http_with_oauth_round_trip() -> anyhow::Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
diff --git a/codex-rs/core/tests/suite/shell_serialization.rs b/codex-rs/core/tests/suite/shell_serialization.rs
index 21141ec535..c5519bfb6d 100644
--- a/codex-rs/core/tests/suite/shell_serialization.rs
+++ b/codex-rs/core/tests/suite/shell_serialization.rs
@@ -45,6 +45,7 @@ async fn submit_turn(test: &TestCodex, prompt: &str, sandbox_policy: SandboxPoli
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
diff --git a/codex-rs/core/tests/suite/tool_harness.rs b/codex-rs/core/tests/suite/tool_harness.rs
index 68bd76bd8e..68f16df480 100644
--- a/codex-rs/core/tests/suite/tool_harness.rs
+++ b/codex-rs/core/tests/suite/tool_harness.rs
@@ -84,6 +84,7 @@ async fn shell_tool_executes_command_and_streams_output() -> anyhow::Result<()>
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
@@ -153,6 +154,7 @@ async fn update_plan_tool_emits_plan_update_event() -> anyhow::Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
@@ -236,6 +238,7 @@ async fn update_plan_tool_rejects_malformed_payload() -> anyhow::Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
@@ -334,6 +337,7 @@ async fn apply_patch_tool_executes_and_emits_patch_events() -> anyhow::Result<()
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
@@ -435,6 +439,7 @@ async fn apply_patch_reports_parse_diagnostics() -> anyhow::Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
diff --git a/codex-rs/core/tests/suite/tool_parallelism.rs b/codex-rs/core/tests/suite/tool_parallelism.rs
index b4e3d1c9ad..2b9ec91ed8 100644
--- a/codex-rs/core/tests/suite/tool_parallelism.rs
+++ b/codex-rs/core/tests/suite/tool_parallelism.rs
@@ -38,6 +38,7 @@ async fn run_turn(test: &TestCodex, prompt: &str) -> anyhow::Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
diff --git a/codex-rs/core/tests/suite/tools.rs b/codex-rs/core/tests/suite/tools.rs
index ec07b0cdbd..e8201e9c95 100644
--- a/codex-rs/core/tests/suite/tools.rs
+++ b/codex-rs/core/tests/suite/tools.rs
@@ -48,6 +48,7 @@ async fn submit_turn(
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
diff --git a/codex-rs/core/tests/suite/unified_exec.rs b/codex-rs/core/tests/suite/unified_exec.rs
index 6298ab06de..aa018a0845 100644
--- a/codex-rs/core/tests/suite/unified_exec.rs
+++ b/codex-rs/core/tests/suite/unified_exec.rs
@@ -128,6 +128,7 @@ async fn unified_exec_reuses_session_via_stdin() -> Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
@@ -264,6 +265,7 @@ PY
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
@@ -370,6 +372,7 @@ async fn unified_exec_timeout_and_followup_poll() -> Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
diff --git a/codex-rs/core/tests/suite/view_image.rs b/codex-rs/core/tests/suite/view_image.rs
index bdb67ad631..557436c10c 100644
--- a/codex-rs/core/tests/suite/view_image.rs
+++ b/codex-rs/core/tests/suite/view_image.rs
@@ -100,6 +100,7 @@ async fn view_image_tool_attaches_local_image() -> anyhow::Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
@@ -199,6 +200,7 @@ async fn view_image_tool_errors_when_path_is_directory() -> anyhow::Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
@@ -264,6 +266,7 @@ async fn view_image_tool_errors_when_file_missing() -> anyhow::Result<()> {
             model: session_model,
             effort: None,
             summary: ReasoningSummary::Auto,
+            disabled_tools: None,
         })
         .await?;
 
diff --git a/codex-rs/exec/src/lib.rs b/codex-rs/exec/src/lib.rs
index 967da52b8a..857fdd8eb7 100644
--- a/codex-rs/exec/src/lib.rs
+++ b/codex-rs/exec/src/lib.rs
@@ -348,6 +348,7 @@ pub async fn run_main(cli: Cli, codex_linux_sandbox_exe: Option<PathBuf>) -> any
             effort: default_effort,
             summary: default_summary,
             final_output_json_schema: output_schema,
+            disabled_tools: None,
         })
         .await?;
     info!("Sent prompt with event ID: {initial_prompt_task_id}");
diff --git a/codex-rs/protocol/src/protocol.rs b/codex-rs/protocol/src/protocol.rs
index b73909473d..986b046cbe 100644
--- a/codex-rs/protocol/src/protocol.rs
+++ b/codex-rs/protocol/src/protocol.rs
@@ -90,6 +90,9 @@ pub enum Op {
         summary: ReasoningSummaryConfig,
         // The JSON schema to use for the final assistant message
         final_output_json_schema: Option<Value>,
+        /// Optional list of tool names to disable for this turn.
+        #[serde(skip_serializing_if = "Option::is_none")]
+        disabled_tools: Option<Vec<String>>,
     },
 
     /// Override parts of the persistent turn context for subsequent turns.
@@ -125,6 +128,9 @@ pub enum Op {
         /// Updated reasoning summary preference (honored only for reasoning-capable models).
         #[serde(skip_serializing_if = "Option::is_none")]
         summary: Option<ReasoningSummaryConfig>,
+        /// Updated default disabled tool list for subsequent turns.
+        #[serde(skip_serializing_if = "Option::is_none")]
+        disabled_tools: Option<Vec<String>>,
     },
 
     /// Approve a command execution
diff --git a/codex-rs/tui/src/chatwidget.rs b/codex-rs/tui/src/chatwidget.rs
index 787e098093..d5d87ab733 100644
--- a/codex-rs/tui/src/chatwidget.rs
+++ b/codex-rs/tui/src/chatwidget.rs
@@ -1751,6 +1751,7 @@ impl ChatWidget {
                     model: Some(model_for_action.clone()),
                     effort: Some(effort_for_action),
                     summary: None,
+                    disabled_tools: None,
                 }));
                 tx.send(AppEvent::UpdateModel(model_for_action.clone()));
                 tx.send(AppEvent::UpdateReasoningEffort(effort_for_action));
@@ -1807,6 +1808,7 @@ impl ChatWidget {
                     model: None,
                     effort: None,
                     summary: None,
+                    disabled_tools: None,
                 }));
                 tx.send(AppEvent::UpdateAskForApprovalPolicy(approval));
                 tx.send(AppEvent::UpdateSandboxPolicy(sandbox.clone()));