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[codex] Emit MCP tool calls as turn items #20677

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Merged
pakrym-oai merged 6 commits into from
May 4, 2026
Merged

[codex] Emit MCP tool calls as turn items #20677

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d5db19f
Emit MCP tool calls as turn items
pakrym-oai May 1, 2026
98aa9f2
Align MCP tool call items with v2 shape
pakrym-oai May 1, 2026
69a3655
codex: fix CI failure on PR #20677
pakrym-oai May 1, 2026
26225c2
codex: allow large MCP turn item variant
pakrym-oai May 1, 2026
b69ebea
Remove legacy MCP event v2 mapping
pakrym-oai May 1, 2026
e3adc72
Merge branch 'main' into pakrym/mcp-tool-call-turn-item
pakrym-oai May 3, 2026
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241 changes: 0 additions & 241 deletions codex-rs/app-server-protocol/src/protocol/event_mapping.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -12,9 +12,6 @@ use crate::protocol::v2::DynamicToolCallStatus;
use crate::protocol::v2::FileChangePatchUpdatedNotification;
use crate::protocol::v2::ItemCompletedNotification;
use crate::protocol::v2::ItemStartedNotification;
use crate::protocol::v2::McpToolCallError;
use crate::protocol::v2::McpToolCallResult;
use crate::protocol::v2::McpToolCallStatus;
use crate::protocol::v2::PlanDeltaNotification;
use crate::protocol::v2::ReasoningSummaryPartAddedNotification;
use crate::protocol::v2::ReasoningSummaryTextDeltaNotification;
Expand All @@ -23,7 +20,6 @@ use crate::protocol::v2::TerminalInteractionNotification;
use crate::protocol::v2::ThreadItem;
use codex_protocol::dynamic_tools::DynamicToolCallOutputContentItem as CoreDynamicToolCallOutputContentItem;
use codex_protocol::protocol::EventMsg;
use serde_json::Value as JsonValue;
use std::collections::HashMap;

/// Build the v2 app-server notification that directly corresponds to a single core event.
Expand Down Expand Up @@ -75,64 +71,6 @@ pub fn item_event_to_server_notification(
item,
})
}
EventMsg::McpToolCallBegin(begin_event) => {
let item = ThreadItem::McpToolCall {
id: begin_event.call_id,
server: begin_event.invocation.server,
tool: begin_event.invocation.tool,
status: McpToolCallStatus::InProgress,
arguments: begin_event.invocation.arguments.unwrap_or(JsonValue::Null),
mcp_app_resource_uri: begin_event.mcp_app_resource_uri,
result: None,
error: None,
duration_ms: None,
};
ServerNotification::ItemStarted(ItemStartedNotification {
thread_id,
turn_id,
item,
})
}
EventMsg::McpToolCallEnd(end_event) => {
let status = if end_event.is_success() {
McpToolCallStatus::Completed
} else {
McpToolCallStatus::Failed
};
let duration_ms = i64::try_from(end_event.duration.as_millis()).ok();
let (result, error) = match &end_event.result {
Ok(value) => (
Some(Box::new(McpToolCallResult {
content: value.content.clone(),
structured_content: value.structured_content.clone(),
meta: value.meta.clone(),
})),
None,
),
Err(message) => (
None,
Some(McpToolCallError {
message: message.clone(),
}),
),
};
let item = ThreadItem::McpToolCall {
id: end_event.call_id,
server: end_event.invocation.server,
tool: end_event.invocation.tool,
status,
arguments: end_event.invocation.arguments.unwrap_or(JsonValue::Null),
mcp_app_resource_uri: end_event.mcp_app_resource_uri,
result,
error,
duration_ms,
};
ServerNotification::ItemCompleted(ItemCompletedNotification {
thread_id,
turn_id,
item,
})
}
EventMsg::CollabAgentSpawnBegin(begin_event) => {
let item = ThreadItem::CollabAgentToolCall {
id: begin_event.call_id,
Expand Down Expand Up @@ -500,17 +438,11 @@ pub fn item_event_to_server_notification(
mod tests {
use super::*;
use codex_protocol::ThreadId;
use codex_protocol::mcp::CallToolResult;
use codex_protocol::protocol::CollabResumeBeginEvent;
use codex_protocol::protocol::CollabResumeEndEvent;
use codex_protocol::protocol::ExecCommandOutputDeltaEvent;
use codex_protocol::protocol::ExecOutputStream;
use codex_protocol::protocol::McpInvocation;
use codex_protocol::protocol::McpToolCallBeginEvent;
use codex_protocol::protocol::McpToolCallEndEvent;
use pretty_assertions::assert_eq;
use rmcp::model::Content;
use std::time::Duration;

fn assert_item_started_server_notification(
notification: ServerNotification,
Expand Down Expand Up @@ -621,179 +553,6 @@ mod tests {
);
}

#[test]
fn mcp_tool_call_begin_maps_to_item_started_notification_with_args() {
let begin_event = McpToolCallBeginEvent {
call_id: "call_123".to_string(),
invocation: McpInvocation {
server: "codex".to_string(),
tool: "list_mcp_resources".to_string(),
arguments: Some(serde_json::json!({"server": ""})),
},
mcp_app_resource_uri: Some("ui://widget/list-resources.html".to_string()),
};

let notification = item_event_to_server_notification(
EventMsg::McpToolCallBegin(begin_event.clone()),
"thread-1",
"turn_1",
);
assert_item_started_server_notification(
notification,
ItemStartedNotification {
thread_id: "thread-1".to_string(),
turn_id: "turn_1".to_string(),
item: ThreadItem::McpToolCall {
id: begin_event.call_id,
server: begin_event.invocation.server,
tool: begin_event.invocation.tool,
status: McpToolCallStatus::InProgress,
arguments: serde_json::json!({"server": ""}),
mcp_app_resource_uri: Some("ui://widget/list-resources.html".to_string()),
result: None,
error: None,
duration_ms: None,
},
},
);
}

#[test]
fn mcp_tool_call_begin_maps_to_item_started_notification_without_args() {
let begin_event = McpToolCallBeginEvent {
call_id: "call_456".to_string(),
invocation: McpInvocation {
server: "codex".to_string(),
tool: "list_mcp_resources".to_string(),
arguments: None,
},
mcp_app_resource_uri: None,
};

let notification = item_event_to_server_notification(
EventMsg::McpToolCallBegin(begin_event.clone()),
"thread-2",
"turn_2",
);
assert_item_started_server_notification(
notification,
ItemStartedNotification {
thread_id: "thread-2".to_string(),
turn_id: "turn_2".to_string(),
item: ThreadItem::McpToolCall {
id: begin_event.call_id,
server: begin_event.invocation.server,
tool: begin_event.invocation.tool,
status: McpToolCallStatus::InProgress,
arguments: JsonValue::Null,
mcp_app_resource_uri: None,
result: None,
error: None,
duration_ms: None,
},
},
);
}

#[test]
fn mcp_tool_call_end_maps_to_item_completed_notification_on_success() {
let content = vec![
serde_json::to_value(Content::text("{\"resources\":[]}"))
.expect("content should serialize"),
];
let result = CallToolResult {
content: content.clone(),
is_error: Some(false),
structured_content: None,
meta: Some(serde_json::json!({
"ui/resourceUri": "ui://widget/list-resources.html"
})),
};

let end_event = McpToolCallEndEvent {
call_id: "call_789".to_string(),
invocation: McpInvocation {
server: "codex".to_string(),
tool: "list_mcp_resources".to_string(),
arguments: Some(serde_json::json!({"server": ""})),
},
mcp_app_resource_uri: Some("ui://widget/list-resources.html".to_string()),
duration: Duration::from_nanos(92708),
result: Ok(result),
};

let notification = item_event_to_server_notification(
EventMsg::McpToolCallEnd(end_event.clone()),
"thread-3",
"turn_3",
);
assert_item_completed_server_notification(
notification,
ItemCompletedNotification {
thread_id: "thread-3".to_string(),
turn_id: "turn_3".to_string(),
item: ThreadItem::McpToolCall {
id: end_event.call_id,
server: end_event.invocation.server,
tool: end_event.invocation.tool,
status: McpToolCallStatus::Completed,
arguments: serde_json::json!({"server": ""}),
mcp_app_resource_uri: Some("ui://widget/list-resources.html".to_string()),
result: Some(Box::new(McpToolCallResult {
content,
structured_content: None,
meta: Some(serde_json::json!({
"ui/resourceUri": "ui://widget/list-resources.html"
})),
})),
error: None,
duration_ms: Some(0),
},
},
);
}

#[test]
fn mcp_tool_call_end_maps_to_item_completed_notification_on_error() {
let end_event = McpToolCallEndEvent {
call_id: "call_err".to_string(),
invocation: McpInvocation {
server: "codex".to_string(),
tool: "list_mcp_resources".to_string(),
arguments: None,
},
mcp_app_resource_uri: None,
duration: Duration::from_millis(1),
result: Err("boom".to_string()),
};

let notification = item_event_to_server_notification(
EventMsg::McpToolCallEnd(end_event.clone()),
"thread-4",
"turn_4",
);
assert_item_completed_server_notification(
notification,
ItemCompletedNotification {
thread_id: "thread-4".to_string(),
turn_id: "turn_4".to_string(),
item: ThreadItem::McpToolCall {
id: end_event.call_id,
server: end_event.invocation.server,
tool: end_event.invocation.tool,
status: McpToolCallStatus::Failed,
arguments: JsonValue::Null,
mcp_app_resource_uri: None,
result: None,
error: Some(McpToolCallError {
message: "boom".to_string(),
}),
duration_ms: Some(1),
},
},
);
}

#[test]
fn exec_command_output_delta_maps_to_command_execution_output_delta() {
let notification = item_event_to_server_notification(
Expand Down
2 changes: 2 additions & 0 deletions codex-rs/app-server-protocol/src/protocol/thread_history.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -359,6 +359,7 @@ impl ThreadHistoryBuilder {
| codex_protocol::items::TurnItem::ImageView(_)
| codex_protocol::items::TurnItem::ImageGeneration(_)
| codex_protocol::items::TurnItem::FileChange(_)
| codex_protocol::items::TurnItem::McpToolCall(_)
| codex_protocol::items::TurnItem::ContextCompaction(_) => {}
}
}
Expand All @@ -382,6 +383,7 @@ impl ThreadHistoryBuilder {
| codex_protocol::items::TurnItem::ImageView(_)
| codex_protocol::items::TurnItem::ImageGeneration(_)
| codex_protocol::items::TurnItem::FileChange(_)
| codex_protocol::items::TurnItem::McpToolCall(_)
| codex_protocol::items::TurnItem::ContextCompaction(_) => {}
}
}
Expand Down
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