feat(cli): show raw reasoning content

codex-rs/config.md

@@ -452,6 +452,16 @@ Setting `hide_agent_reasoning` to `true` suppresses these events in **both** the
 hide_agent_reasoning = true   # defaults to false
 ```
 
+## show_reasoning_content
+
+When enabled, Codex will display the raw chain-of-thought text returned by the
+model for reasoning events. This content is not moderated and may contain
+hallucinations or other undesirable text, so it is disabled by default.
+
+```toml
+show_reasoning_content = true   # defaults to false
+```
+
 ## model_context_window
 
 The size of the context window for the model, in tokens.

codex-rs/core/src/codex.rs

@@ -56,12 +56,14 @@ use crate::mcp_tool_call::handle_mcp_tool_call;
 use crate::models::ContentItem;
 use crate::models::FunctionCallOutputPayload;
 use crate::models::LocalShellAction;
+use crate::models::ReasoningItemContent;
 use crate::models::ReasoningItemReasoningSummary;
 use crate::models::ResponseInputItem;
 use crate::models::ResponseItem;
 use crate::models::ShellToolCallParams;
 use crate::project_doc::get_user_instructions;
 use crate::protocol::AgentMessageEvent;
+use crate::protocol::AgentReasoningContentEvent;
 use crate::protocol::AgentReasoningEvent;
 use crate::protocol::ApplyPatchApprovalRequestEvent;
 use crate::protocol::AskForApproval;
@@ -1196,7 +1198,7 @@ async fn handle_response_item(
             }
             None
         }
-        ResponseItem::Reasoning { id: _, summary } => {
+        ResponseItem::Reasoning { id: _, summary, content } => {
             for item in summary {
                 let text = match item {
                     ReasoningItemReasoningSummary::SummaryText { text } => text,
@@ -1207,6 +1209,16 @@ async fn handle_response_item(
                 };
                 sess.tx_event.send(event).await.ok();
             }
+            for item in content {
+                let text = match item {
+                    ReasoningItemContent::ReasoningText { text } => text,
+                };
+                let event = Event {
+                    id: sub_id.to_string(),
+                    msg: EventMsg::AgentReasoningContent(AgentReasoningContentEvent { text }),
+                };
+                sess.tx_event.send(event).await.ok();
+            }
             None
         }
         ResponseItem::FunctionCall {

codex-rs/core/src/config.rs

@@ -57,6 +57,10 @@ pub struct Config {
     /// users are only interested in the final agent responses.
     pub hide_agent_reasoning: bool,
 
+    /// When `true`, the raw chain-of-thought text from reasoning events will be
+    /// displayed in the UI in addition to the reasoning summaries.
+    pub show_reasoning_content: bool,
+
     /// Disable server-side response storage (sends the full conversation
     /// context with every request). Currently necessary for OpenAI customers
     /// who have opted into Zero Data Retention (ZDR).
@@ -313,6 +317,10 @@ pub struct ConfigToml {
     /// UI/output. Defaults to `false`.
     pub hide_agent_reasoning: Option<bool>,
 
+    /// When set to `true`, raw chain-of-thought text from reasoning events will
+    /// be shown in the UI.
+    pub show_reasoning_content: Option<bool>,
+
     pub model_reasoning_effort: Option<ReasoningEffort>,
     pub model_reasoning_summary: Option<ReasoningSummary>,
 
@@ -477,6 +485,7 @@ impl Config {
             codex_linux_sandbox_exe,
 
             hide_agent_reasoning: cfg.hide_agent_reasoning.unwrap_or(false),
+            show_reasoning_content: cfg.show_reasoning_content.unwrap_or(false),
             model_reasoning_effort: config_profile
                 .model_reasoning_effort
                 .or(cfg.model_reasoning_effort)
@@ -796,6 +805,7 @@ disable_response_storage = true
                 tui: Tui::default(),
                 codex_linux_sandbox_exe: None,
                 hide_agent_reasoning: false,
+                show_reasoning_content: false,
                 model_reasoning_effort: ReasoningEffort::High,
                 model_reasoning_summary: ReasoningSummary::Detailed,
                 model_supports_reasoning_summaries: false,
@@ -842,6 +852,7 @@ disable_response_storage = true
             tui: Tui::default(),
             codex_linux_sandbox_exe: None,
             hide_agent_reasoning: false,
+            show_reasoning_content: false,
             model_reasoning_effort: ReasoningEffort::default(),
             model_reasoning_summary: ReasoningSummary::default(),
             model_supports_reasoning_summaries: false,
@@ -903,6 +914,7 @@ disable_response_storage = true
             tui: Tui::default(),
             codex_linux_sandbox_exe: None,
             hide_agent_reasoning: false,
+            show_reasoning_content: false,
             model_reasoning_effort: ReasoningEffort::default(),
             model_reasoning_summary: ReasoningSummary::default(),
             model_supports_reasoning_summaries: false,

codex-rs/core/src/models.rs

@@ -43,6 +43,8 @@ pub enum ResponseItem {
     Reasoning {
         id: String,
         summary: Vec<ReasoningItemReasoningSummary>,
+        #[serde(default)]
+        content: Vec<ReasoningItemContent>,
     },
     LocalShellCall {
         /// Set when using the chat completions API.
@@ -128,6 +130,12 @@ pub enum ReasoningItemReasoningSummary {
     SummaryText { text: String },
 }
 
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(tag = "type", rename_all = "snake_case")]
+pub enum ReasoningItemContent {
+    ReasoningText { text: String },
+}
+
 impl From<Vec<InputItem>> for ResponseInputItem {
     fn from(items: Vec<InputItem>) -> Self {
         Self::Message {

codex-rs/core/src/protocol.rs

@@ -282,9 +282,12 @@ pub enum EventMsg {
     /// Agent text output message
     AgentMessage(AgentMessageEvent),
 
-    /// Reasoning event from agent.
+    /// Reasoning summary from agent.
     AgentReasoning(AgentReasoningEvent),
 
+    /// Raw chain-of-thought from agent.
+    AgentReasoningContent(AgentReasoningContentEvent),
+
     /// Ack the client's configure message.
     SessionConfigured(SessionConfiguredEvent),
 
@@ -345,6 +348,11 @@ pub struct AgentReasoningEvent {
     pub text: String,
 }
 
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct AgentReasoningContentEvent {
+    pub text: String,
+}
+
 #[derive(Debug, Clone, Deserialize, Serialize)]
 pub struct McpToolCallBeginEvent {
     /// Identifier so this can be paired with the McpToolCallEnd event.

codex-rs/exec/src/event_processor.rs

@@ -15,6 +15,7 @@ use codex_core::protocol::McpToolCallBeginEvent;
 use codex_core::protocol::McpToolCallEndEvent;
 use codex_core::protocol::PatchApplyBeginEvent;
 use codex_core::protocol::PatchApplyEndEvent;
+use codex_core::protocol::AgentReasoningContentEvent;
 use codex_core::protocol::SessionConfiguredEvent;
 use codex_core::protocol::TokenUsage;
 use owo_colors::OwoColorize;
@@ -50,10 +51,15 @@ pub(crate) struct EventProcessor {
 
     /// Whether to include `AgentReasoning` events in the output.
     show_agent_reasoning: bool,
+    show_agent_reasoning_content: bool,
 }
 
 impl EventProcessor {
-    pub(crate) fn create_with_ansi(with_ansi: bool, show_agent_reasoning: bool) -> Self {
+    pub(crate) fn create_with_ansi(
+        with_ansi: bool,
+        show_agent_reasoning: bool,
+        show_agent_reasoning_content: bool,
+    ) -> Self {
         let call_id_to_command = HashMap::new();
         let call_id_to_patch = HashMap::new();
         let call_id_to_tool_call = HashMap::new();
@@ -71,6 +77,7 @@ impl EventProcessor {
                 cyan: Style::new().cyan(),
                 call_id_to_tool_call,
                 show_agent_reasoning,
+                show_agent_reasoning_content,
             }
         } else {
             Self {
@@ -85,6 +92,7 @@ impl EventProcessor {
                 cyan: Style::new(),
                 call_id_to_tool_call,
                 show_agent_reasoning,
+                show_agent_reasoning_content,
             }
         }
     }
@@ -449,6 +457,16 @@ impl EventProcessor {
                     );
                 }
             }
+            EventMsg::AgentReasoningContent(agent_reasoning_event) => {
+                if self.show_agent_reasoning && self.show_agent_reasoning_content {
+                    ts_println!(
+                        self,
+                        "{}\n{}",
+                        "thinking".style(self.italic).style(self.magenta),
+                        agent_reasoning_event.text
+                    );
+                }
+            }
             EventMsg::SessionConfigured(session_configured_event) => {
                 let SessionConfiguredEvent {
                     session_id,

codex-rs/exec/src/lib.rs

@@ -115,8 +115,11 @@ pub async fn run_main(cli: Cli, codex_linux_sandbox_exe: Option<PathBuf>) -> any
     };
 
     let config = Config::load_with_cli_overrides(cli_kv_overrides, overrides)?;
-    let mut event_processor =
-        EventProcessor::create_with_ansi(stdout_with_ansi, !config.hide_agent_reasoning);
+    let mut event_processor = EventProcessor::create_with_ansi(
+        stdout_with_ansi,
+        !config.hide_agent_reasoning,
+        config.show_reasoning_content,
+    );
     // Print the effective configuration and prompt so users can see what Codex
     // is using.
     event_processor.print_config_summary(&config, &prompt);

codex-rs/mcp-server/src/codex_tool_runner.rs

@@ -175,6 +175,7 @@ pub async fn run_codex_tool_session(
                     | EventMsg::TaskStarted
                     | EventMsg::TokenCount(_)
                     | EventMsg::AgentReasoning(_)
+                    | EventMsg::AgentReasoningContent(_)
                     | EventMsg::McpToolCallBegin(_)
                     | EventMsg::McpToolCallEnd(_)
                     | EventMsg::ExecCommandBegin(_)

codex-rs/tui/src/chatwidget.rs

@@ -4,6 +4,7 @@ use std::sync::Arc;
 use codex_core::codex_wrapper::init_codex;
 use codex_core::config::Config;
 use codex_core::protocol::AgentMessageEvent;
+use codex_core::protocol::AgentReasoningContentEvent;
 use codex_core::protocol::AgentReasoningEvent;
 use codex_core::protocol::ApplyPatchApprovalRequestEvent;
 use codex_core::protocol::ErrorEvent;
@@ -251,6 +252,13 @@ impl ChatWidget<'_> {
                     self.request_redraw();
                 }
             }
+            EventMsg::AgentReasoningContent(AgentReasoningContentEvent { text }) => {
+                if !self.config.hide_agent_reasoning && self.config.show_reasoning_content {
+                    self.conversation_history
+                        .add_agent_reasoning(&self.config, text);
+                    self.request_redraw();
+                }
+            }
             EventMsg::TaskStarted => {
                 self.bottom_pane.clear_ctrl_c_quit_hint();
                 self.bottom_pane.set_task_running(true);