codex/codex-rs/core/src/tools/context.rs

use crate::original_image_detail::sanitize_original_image_detail;
use crate::session::session::Session;
use crate::session::step_context::StepContext;
use crate::session::turn_context::TurnContext;
use crate::turn_diff_tracker::TurnDiffTracker;
use crate::unified_exec::format_output_omission_marker;
use crate::unified_exec::resolve_max_tokens;
use codex_protocol::ResponseItemId;
use codex_protocol::mcp::CallToolResult;
use codex_protocol::models::FunctionCallOutputBody;
use codex_protocol::models::FunctionCallOutputContentItem;
use codex_protocol::models::FunctionCallOutputPayload;
use codex_protocol::models::ResponseInputItem;
use codex_protocol::models::ResponseItem;
use codex_protocol::models::function_call_output_content_items_to_text;
use codex_tools::LoadableToolSpec;
use codex_tools::ToolName;
use codex_utils_audio::estimate_audio_token_count;
use codex_utils_output_truncation::TruncationPolicy;
use codex_utils_output_truncation::approx_token_count;
use codex_utils_output_truncation::formatted_truncate_text;
use codex_utils_output_truncation::truncate_function_output_payload;
use codex_utils_output_truncation::truncate_text;
use serde::Serialize;
use serde_json::Value as JsonValue;
use std::num::NonZeroUsize;
use std::sync::Arc;
use std::time::Duration;
use tokio::sync::Mutex;
use tokio_util::sync::CancellationToken;

pub use codex_tools::ToolOutput;
pub use codex_tools::ToolPayload;

pub(crate) fn boxed_tool_output<T>(output: T) -> Box<dyn ToolOutput>
where
    T: ToolOutput + 'static,
{
    Box::new(output)
}

pub type SharedTurnDiffTracker = Arc<Mutex<TurnDiffTracker>>;

#[derive(Clone, Debug, Eq, PartialEq)]
pub enum ToolCallSource {
    Direct,
    DirectPlaintextMessage,
    CodeMode {
        /// Runtime cell that issued the nested tool request.
        cell_id: String,
        /// Code-mode's per-cell tool invocation id. This is useful for
        /// debugging the JS/runtime bridge, but it is not the Codex tool call id
        /// because the runtime id only needs to be unique within one cell.
        runtime_tool_call_id: String,
    },
}

#[derive(Clone)]
pub struct ToolInvocation {
    pub session: Arc<Session>,
    // TODO(sayan): Remove this compatibility field once handlers use `step_context.turn`.
    pub turn: Arc<TurnContext>,
    pub(crate) step_context: Arc<StepContext>,
    pub cancellation_token: CancellationToken,
    pub tracker: SharedTurnDiffTracker,
    pub call_id: String,
    pub tool_name: ToolName,
    pub source: ToolCallSource,
    pub payload: ToolPayload,
}

impl ToolInvocation {
    /// Returns the Responses item that requested this call or started its code-mode cell.
    pub(crate) async fn originating_item_id(&self) -> Option<ResponseItemId> {
        if let ToolCallSource::CodeMode { cell_id, .. } = &self.source {
            return self
                .session
                .services
                .code_mode_service
                .cell_originating_item_id(&codex_code_mode::CellId::new(cell_id.clone()));
        }

        self.session
            .clone_history()
            .await
            .raw_items()
            .rev()
            .find_map(|item| match item {
                ResponseItem::FunctionCall { id, call_id, .. }
                | ResponseItem::CustomToolCall { id, call_id, .. }
                    if call_id == &self.call_id =>
                {
                    id.clone()
                }
                _ => None,
            })
    }
}

#[derive(Clone, Debug)]
pub struct McpToolOutput {
    pub result: CallToolResult,
    pub tool_input: JsonValue,
    pub wall_time: Duration,
    pub original_image_detail_supported: bool,
    pub truncation_policy: TruncationPolicy,
}

impl ToolOutput for McpToolOutput {
    fn log_output(&self) -> String {
        // Logging has its own budget; do not first apply the model-context budget.
        let output = self.result.log_output();
        let wall_time_seconds = self.wall_time.as_secs_f64();
        let header = format!("Wall time: {wall_time_seconds:.4} seconds\nOutput:");
        if output.is_empty() {
            header
        } else {
            format!("{header}\n{output}")
        }
    }

    fn success_for_logging(&self) -> bool {
        self.result.success()
    }

    fn fallback_token_limit_override(&self) -> Option<usize> {
        Some((self.truncation_policy * 1.2).token_budget())
    }

    fn to_response_item(&self, call_id: &str, _payload: &ToolPayload) -> ResponseInputItem {
        ResponseInputItem::FunctionCallOutput {
            call_id: call_id.to_string(),
            output: self.response_payload(),
        }
    }

    fn code_mode_result(&self, payload: &ToolPayload) -> JsonValue {
        self.result.code_mode_result(payload)
    }

    fn post_tool_use_input(&self, _payload: &ToolPayload) -> Option<JsonValue> {
        Some(self.tool_input.clone())
    }

    fn post_tool_use_response(&self, _call_id: &str, _payload: &ToolPayload) -> Option<JsonValue> {
        serde_json::to_value(&self.result).ok()
    }
}

impl McpToolOutput {
    fn response_payload(&self) -> FunctionCallOutputPayload {
        let mut payload = self.result.as_function_call_output_payload();
        if let Some(items) = payload.content_items_mut() {
            sanitize_original_image_detail(self.original_image_detail_supported, items);
        }

        let wall_time_seconds = self.wall_time.as_secs_f64();
        let header = format!("Wall time: {wall_time_seconds:.4} seconds\nOutput:");

        match &mut payload.body {
            FunctionCallOutputBody::Text(text) => {
                if text.is_empty() {
                    *text = header;
                } else {
                    *text = format!("{header}\n{text}");
                }
            }
            FunctionCallOutputBody::ContentItems(items) => {
                items.insert(0, FunctionCallOutputContentItem::InputText { text: header });
            }
        }

        // History receives this budget in tokens. Code Mode keeps the raw result.
        truncate_function_output_payload(
            &mut payload,
            self.truncation_policy * 1.2,
            estimate_audio_token_count,
        );
        payload
    }
}

#[derive(Clone)]
pub struct ToolSearchOutput {
    pub tools: Vec<LoadableToolSpec>,
}

impl ToolOutput for ToolSearchOutput {
    fn log_output(&self) -> String {
        let tools = self
            .tools
            .iter()
            .map(|tool| {
                serde_json::to_value(tool).unwrap_or_else(|err| {
                    JsonValue::String(format!("failed to serialize tool_search output: {err}"))
                })
            })
            .collect();
        JsonValue::Array(tools).to_string()
    }

    fn success_for_logging(&self) -> bool {
        true
    }

    fn to_response_item(&self, call_id: &str, _payload: &ToolPayload) -> ResponseInputItem {
        ResponseInputItem::ToolSearchOutput {
            call_id: call_id.to_string(),
            status: "completed".to_string(),
            execution: "client".to_string(),
            tools: self
                .tools
                .iter()
                .map(|tool| {
                    serde_json::to_value(tool).unwrap_or_else(|err| {
                        JsonValue::String(format!("failed to serialize tool_search output: {err}"))
                    })
                })
                .collect(),
        }
    }
}

pub struct FunctionToolOutput {
    pub body: Vec<FunctionCallOutputContentItem>,
    pub success: Option<bool>,
    pub post_tool_use_response: Option<JsonValue>,
}

impl FunctionToolOutput {
    pub fn from_text(text: String, success: Option<bool>) -> Self {
        Self {
            body: vec![FunctionCallOutputContentItem::InputText { text }],
            success,
            post_tool_use_response: None,
        }
    }

    pub fn from_content(
        content: Vec<FunctionCallOutputContentItem>,
        success: Option<bool>,
    ) -> Self {
        Self {
            body: content,
            success,
            post_tool_use_response: None,
        }
    }

    pub fn into_text(self) -> String {
        function_call_output_content_items_to_text(&self.body).unwrap_or_default()
    }
}

impl ToolOutput for FunctionToolOutput {
    fn log_output(&self) -> String {
        function_call_output_content_items_to_text(&self.body).unwrap_or_default()
    }

    fn success_for_logging(&self) -> bool {
        self.success.unwrap_or(true)
    }

    fn to_response_item(&self, call_id: &str, payload: &ToolPayload) -> ResponseInputItem {
        function_tool_response(call_id, payload, self.body.clone(), self.success)
    }

    fn post_tool_use_response(&self, _call_id: &str, _payload: &ToolPayload) -> Option<JsonValue> {
        self.post_tool_use_response.clone()
    }
}

pub struct ApplyPatchToolOutput {
    pub text: String,
}

impl ApplyPatchToolOutput {
    pub fn from_text(text: String) -> Self {
        Self { text }
    }
}

impl ToolOutput for ApplyPatchToolOutput {
    fn log_output(&self) -> String {
        self.text.clone()
    }

    fn success_for_logging(&self) -> bool {
        true
    }

    fn to_response_item(&self, call_id: &str, payload: &ToolPayload) -> ResponseInputItem {
        function_tool_response(
            call_id,
            payload,
            vec![FunctionCallOutputContentItem::InputText {
                text: self.text.clone(),
            }],
            Some(true),
        )
    }

    fn post_tool_use_response(&self, _call_id: &str, _payload: &ToolPayload) -> Option<JsonValue> {
        Some(JsonValue::String(self.text.clone()))
    }

    fn code_mode_result(&self, _payload: &ToolPayload) -> JsonValue {
        JsonValue::Object(serde_json::Map::new())
    }
}

pub struct AbortedToolOutput {
    pub message: String,
}

impl ToolOutput for AbortedToolOutput {
    fn log_output(&self) -> String {
        self.message.clone()
    }

    fn success_for_logging(&self) -> bool {
        false
    }

    fn to_response_item(&self, call_id: &str, payload: &ToolPayload) -> ResponseInputItem {
        match payload {
            ToolPayload::ToolSearch { .. } => ResponseInputItem::ToolSearchOutput {
                call_id: call_id.to_string(),
                status: "completed".to_string(),
                execution: "client".to_string(),
                tools: Vec::new(),
            },
            _ => function_tool_response(
                call_id,
                payload,
                vec![FunctionCallOutputContentItem::InputText {
                    text: self.message.clone(),
                }],
                /*success*/ None,
            ),
        }
    }
}

#[derive(Debug, Clone, PartialEq)]
pub struct ExecCommandToolOutput {
    pub event_call_id: String,
    pub chunk_id: String,
    pub wall_time: Duration,
    /// Raw bytes returned for this unified exec call before any truncation.
    pub raw_output: Vec<u8>,
    pub truncation_policy: TruncationPolicy,
    pub max_output_tokens: Option<usize>,
    pub process_id: Option<i32>,
    pub exit_code: Option<i32>,
    pub original_token_count: Option<usize>,
    /// Bytes omitted by the output collection cap before model-facing truncation.
    pub output_omitted_bytes: Option<NonZeroUsize>,
    pub hook_command: Option<String>,
}

impl ToolOutput for ExecCommandToolOutput {
    fn log_output(&self) -> String {
        // The telemetry budget must not inherit the model's output-token limit.
        let mut output = String::from_utf8_lossy(&self.raw_output).into_owned();
        if let Some(omitted_bytes) = self.output_omitted_bytes {
            let marker = format_output_omission_marker(omitted_bytes.get());
            if !output.contains(&marker) {
                output = format!("{marker}\n{output}");
            }
        }
        format!("{}\n{output}", self.response_header())
    }

    fn success_for_logging(&self) -> bool {
        true
    }

    fn to_response_item(&self, call_id: &str, payload: &ToolPayload) -> ResponseInputItem {
        function_tool_response(
            call_id,
            payload,
            vec![FunctionCallOutputContentItem::InputText {
                text: self.response_text(),
            }],
            Some(true),
        )
    }

    fn post_tool_use_id(&self, call_id: &str) -> String {
        if self.event_call_id.is_empty() {
            call_id.to_string()
        } else {
            self.event_call_id.clone()
        }
    }

    fn post_tool_use_input(&self, _payload: &ToolPayload) -> Option<JsonValue> {
        self.hook_command
            .as_ref()
            .map(|command| serde_json::json!({ "command": command }))
    }

    fn post_tool_use_response(&self, _call_id: &str, _payload: &ToolPayload) -> Option<JsonValue> {
        if self.process_id.is_some() || self.hook_command.is_none() {
            return None;
        }

        Some(JsonValue::String(
            self.truncated_output_with_policy(self.model_output_policy()),
        ))
    }

    fn code_mode_result(&self, _payload: &ToolPayload) -> JsonValue {
        #[derive(Serialize)]
        struct UnifiedExecCodeModeResult {
            #[serde(skip_serializing_if = "Option::is_none")]
            chunk_id: Option<String>,
            wall_time_seconds: f64,
            #[serde(skip_serializing_if = "Option::is_none")]
            exit_code: Option<i32>,
            #[serde(skip_serializing_if = "Option::is_none")]
            session_id: Option<i32>,
            #[serde(skip_serializing_if = "Option::is_none")]
            original_token_count: Option<usize>,
            output: String,
        }

        let result = UnifiedExecCodeModeResult {
            chunk_id: (!self.chunk_id.is_empty()).then(|| self.chunk_id.clone()),
            wall_time_seconds: self.wall_time.as_secs_f64(),
            exit_code: self.exit_code,
            session_id: self.process_id,
            original_token_count: self.original_token_count,
            output: match self.max_output_tokens {
                Some(max_tokens) => self.truncated_output(max_tokens),
                None => String::from_utf8_lossy(&self.raw_output).to_string(),
            },
        };

        serde_json::to_value(result).unwrap_or_else(|err| {
            JsonValue::String(format!("failed to serialize exec result: {err}"))
        })
    }
}

impl ExecCommandToolOutput {
    fn model_output_policy(&self) -> TruncationPolicy {
        let requested_policy = TruncationPolicy::Tokens(resolve_max_tokens(self.max_output_tokens));
        if requested_policy.byte_budget() < self.truncation_policy.byte_budget() {
            requested_policy
        } else {
            self.truncation_policy
        }
    }

    pub(crate) fn truncated_output(&self, max_tokens: usize) -> String {
        self.truncated_output_with_policy(TruncationPolicy::Tokens(max_tokens))
    }

    fn truncated_output_with_policy(&self, policy: TruncationPolicy) -> String {
        let text = String::from_utf8_lossy(&self.raw_output).to_string();
        let Some(omitted_bytes) = self.output_omitted_bytes else {
            return formatted_truncate_text(&text, policy);
        };

        let marker = format_output_omission_marker(omitted_bytes.get());
        if text.len() <= policy.byte_budget() {
            return if text.contains(&marker) {
                text
            } else {
                format!("{marker}\n{text}")
            };
        }

        let original_token_count = self
            .original_token_count
            .unwrap_or_else(|| approx_token_count(&text));
        let truncated = truncate_text(&text, policy);
        let omission_notice = if truncated.contains(&marker) {
            String::new()
        } else {
            format!("{marker}\n")
        };
        format!(
            "Warning: truncated output (original token count: {original_token_count})\n{omission_notice}\n{truncated}"
        )
    }

    fn response_header(&self) -> String {
        let mut sections = Vec::new();

        if !self.chunk_id.is_empty() {
            sections.push(format!("Chunk ID: {}", self.chunk_id));
        }

        let wall_time_seconds = self.wall_time.as_secs_f64();
        sections.push(format!("Wall time: {wall_time_seconds:.4} seconds"));

        if let Some(exit_code) = self.exit_code {
            sections.push(format!("Process exited with code {exit_code}"));
        }

        if let Some(process_id) = &self.process_id {
            sections.push(format!("Process running with session ID {process_id}"));
        }

        if let Some(original_token_count) = self.original_token_count {
            sections.push(format!("Original token count: {original_token_count}"));
        }

        sections.push("Output:".to_string());
        sections.join("\n")
    }

    fn response_text(&self) -> String {
        let header = self.response_header();
        let output_budget = (self.truncation_policy * 1.2)
            .byte_budget()
            .saturating_sub(header.len().saturating_add(/*rhs*/ 1));
        let mut policy = self.model_output_policy();
        let mut output = self.truncated_output_with_policy(policy);

        // History applies this same serialization budget to the complete response.
        // Reserve room for metadata, warning headers, and the truncation marker so
        // it does not truncate an already-truncated output a second time.
        while output.len() > output_budget && policy.byte_budget() > 0 {
            let excess_bytes = output.len() - output_budget;
            policy = match policy {
                TruncationPolicy::Bytes(bytes) => {
                    TruncationPolicy::Bytes(bytes.saturating_sub(excess_bytes))
                }
                TruncationPolicy::Tokens(tokens) => TruncationPolicy::Tokens(
                    tokens.saturating_sub(TruncationPolicy::Bytes(excess_bytes).token_budget()),
                ),
            };
            output = self.truncated_output_with_policy(policy);
        }

        format!("{header}\n{output}")
    }
}

fn function_tool_response(
    call_id: &str,
    payload: &ToolPayload,
    body: Vec<FunctionCallOutputContentItem>,
    success: Option<bool>,
) -> ResponseInputItem {
    let body = match body.as_slice() {
        [FunctionCallOutputContentItem::InputText { text }] => {
            FunctionCallOutputBody::Text(text.clone())
        }
        _ => FunctionCallOutputBody::ContentItems(body),
    };

    if matches!(payload, ToolPayload::Custom { .. }) {
        return ResponseInputItem::CustomToolCallOutput {
            call_id: call_id.to_string(),
            name: None,
            output: FunctionCallOutputPayload { body, success },
        };
    }

    ResponseInputItem::FunctionCallOutput {
        call_id: call_id.to_string(),
        output: FunctionCallOutputPayload { body, success },
    }
}

#[cfg(test)]
#[path = "context_tests.rs"]
mod tests;