Anton Panasenko

This commit provides a **fix** and **refactoring** within the **`core` module** to standardize name sanitization logic. It introduces a new `sanitize_slug` function in `codex-rs/core/src/connectors.rs` and updates the existing `sanitize_name` to consistently replace all hyphens with underscores. This ensures that all generated identifiers, such as connector slugs and tool names, uniformly use underscores. Consequently, redundant `.replace('-', '_')` calls are removed from `codex-rs/core/src/mcp_connection_manager.rs`, simplifying the codebase and preventing potential naming inconsistencies.

This commit introduces a **new capability** to precisely control the **`search_tool`'s availability** by gating its inclusion on a dedicated `supports_search_tool` field within the `ModelInfo` struct. The **`core` tool specification logic** in `codex-rs/core/src/tools/spec.rs` now explicitly checks this model-specific boolean, replacing the previous reliance on a broader feature flag. This **refactoring** of the `search_tool`'s enablement allows for more granular, per-model configuration, ensuring the tool is only offered when a model explicitly declares support. The **`protocol`'s `ModelInfo` definition** has been updated to include this new field, and numerous **`test` suites** across the `app-server` and `core` modules have been adjusted to accommodate and validate this change.

This commit addresses a **snapshot parity issue** for **Rust `insta` tests** within the **Bazel build system**, specifically for `rust_test` targets derived from `tests/*.rs` files. It **modifies the `codex_rust_crate` macro** in `defs.bzl` to ensure these tests adopt Cargo-style crate names and utilize a Bazel runfiles-compatible workspace root. Additionally, a new function in `codex-rs/core/tests/common/lib.rs` now dynamically configures the `INSTA_WORKSPACE_ROOT` environment variable based on package depth, guaranteeing `insta` correctly resolves committed snapshots even when Bazel runfiles are disabled. This **bug fix** and **maintenance** effort ensures **consistent snapshot resolution** and **parity with Cargo's naming conventions**, preventing test failures due to environment discrepancies.

This commit introduces a **new capability** to **persist and restore Codex app's tool selections** after a search, ensuring they survive across turns and upon session resumption or forking. It achieves this by removing the per-turn selection reset and implementing logic within `core/src/codex.rs` to parse `search_tool_bm25` outputs from rollout history, recovering `active_selected_tools`. This enhancement to the **Codex application core logic** and **session state management** (`core/src/state/session.rs`) significantly improves the user experience by maintaining tool context. Users will now find that search-activated tools remain active, additional searches union into the selection, and the selection is reliably restored, making the **Codex app tools** more consistent and intelligent.

This commit **refactors** the **tool discovery mechanism** within the `core` module, specifically for `search_tool_bm25`. It **limits** the `search_tool_bm25` to exclusively index and discover **`codex_apps` tools**, preventing non-Apps MCP servers from being found through this path. Concurrently, the commit **clarifies discovery guidance** by embedding detailed usage instructions directly into the `search_tool_bm25` tool description via `tool_description.md`, advising users on when to leverage the search tool for Apps-backed systems versus direct tool calls. This change also includes **dead code removal** from `codex.rs` and `mcp_connection_manager.rs` and updates `search_tool` tests to validate the new Apps-only behavior and improved guidance.

This commit **refactors** the feature management system by **consolidating** the `SearchTool` feature into the broader `Apps` feature. It **removes** the standalone `Feature::SearchTool` and its associated configuration key, instead gating the exposure of `search_tool_bm25` and the search tool's behavior selection within the **Model-Controller-Processor (MCP) logic** under `Feature::Apps`. This change impacts the **core feature registry**, **tool specification** in `core/src/tools/spec.rs`, and **MCP selection logic** in `core/src/codex.rs`, simplifying the feature flag landscape. Consequently, the `core/tests/suite/search_tool.rs` test suite has been updated to enable `Feature::Apps`, ensuring continued coverage for this now-integrated capability.

This commit **enhances the WebSocket client** by introducing a robust mechanism for injecting and managing request headers. It adds a new `merge_request_headers` utility within the **`codex-api` module** to combine various header sources, including default client headers, during WebSocket connection establishment. The **`codex-core` module** is updated to pass these default headers to the WebSocket connection, with the logic for generating them now centralized in a new `default_headers` function. This **new capability** ensures that critical `originator` and `residency` headers are consistently applied to WebSocket requests, improving client identification and routing.

This commit introduces an **experimental `search_tool` feature** to enhance **MCP tool management** by reducing context pollution and improving relevance. It implements a **new capability** that forces an explicit tool discovery step, where the model must call the `search_tool_bm25` handler to select relevant tools before they are exposed. This change significantly impacts the **core tool handling logic**, **session state**, and **configuration**, ensuring that only explicitly selected tools are available for subsequent model calls. The feature includes updated **developer instructions** and comprehensive E2E tests, aiming to lower prompt clutter and improve the model's focus.

This commit primarily introduces **premessage-deflate support for websockets** within the `codex-api` module, enhancing data transfer efficiency. Concurrently, it performs a significant **refactoring** by **migrating the TLS implementation from `rama-tls-boring` to `rama-tls-rustls`** across the **websocket connections**, **HTTP proxy**, and **upstream network components**. This critical dependency change was driven by linker errors encountered with `rama-tls-boring` during `tokio-tungstenite` upgrades, particularly affecting `x86_64-unknown-linux-musl` builds. The migration ensures more robust and compatible TLS handling, supported by necessary **build system adjustments** and **dependency updates** to `MODULE.bazel` and related scripts.

This commit introduces a **new capability** to expose detailed engine IAPI and service TTFT/TBT timing metrics within the system. It extends the **OpenTelemetry (OTel) metrics collection** to capture these new duration metrics from responses via `OtelManager` and store them in `RuntimeMetricsSummary`. The most significant impact is on the **Terminal User Interface (TUI)**, where the `ChatWidget` and `history_cell` are updated to accumulate, format, and display these granular performance insights to the user. This enhancement provides deeper visibility into the performance characteristics of websocket interactions, with new test assertions verifying their correct collection and display.

This commit introduces a **new capability** to collect and display detailed WebSocket timing metrics, specifically for Responses API overhead and inference time. It modifies the **`codex-rs/core`** client to conditionally request these metrics via a new header in WebSocket connections. The **`codex-rs/otel`** module is significantly enhanced to define, parse, and record these timing durations from incoming WebSocket events into the `RuntimeMetricsSummary`. This provides users with deeper insights into WebSocket performance, with the **`codex-rs/tui`** updated to visualize these new metrics.

This commit **introduces comprehensive telemetry for websocket interactions**, enabling detailed monitoring of request durations and event processing. It defines a new `WebsocketTelemetry` trait within the **`codex-api`** and integrates it into the **`core` client's `ModelClientSession`**, allowing the **`otel` telemetry system** to record specific websocket metrics via `OtelManager`. As a direct impact, the **`history` UI** (TUI) is updated to **display these new websocket call and event metrics**, providing enhanced observability into runtime performance. This **new capability** significantly improves the ability to track and understand websocket-driven operations, with new tests ensuring correct reporting and summary updates.

This commit introduces a **new feature** to collect and display **runtime metrics** within the application, controlled by a `runtime_metrics` feature flag. It enables on-demand snapshotting of performance data via **OpenTelemetry**, tracking key activities such as tool calls, API requests, and SSE/streaming events. The `core` module defines the feature flag and configuration, while the `otel` module handles the intricate metric collection, snapshotting, and summarization logic. Finally, the **terminal user interface (TUI)** is updated to display a summary of these metrics in the final message separator, providing users with valuable insights into session performance and activity.

This commit introduces **proxy support for WebSocket connections**, enhancing the network capabilities of the `codex-api` module. As a **new feature**, it reworks the core WebSocket connection and message sending logic, particularly within the `connect_websocket` and `run_websocket_response_stream` functions in `codex-rs/codex-api/src/endpoint/responses_websocket.rs`. These modifications ensure compatibility through updated string references and type conversions, enabling connections via a proxy. Correspondingly, test helper functions in `codex-rs/core/tests/common/responses.rs` were updated to use the new `into()` conversion for message payloads, ensuring robust testing of the enhanced WebSocket functionality.

This commit introduces **proxy support for WebSocket connections**, a **new capability** that significantly enhances network connectivity for the `codex-rs` project. It primarily involves configuring the `reqwest` client within the **`codex-rs/core` module** to explicitly use `rustls` for TLS, enabling proxy functionality via the `build_reqwest_client` function. The **`codex-rs/codex-api` module** was **refactored** in `responses_websocket.rs` to adapt to these client changes, specifically in how URLs are passed and text messages are sent over the websocket stream. This feature temporarily relies on a custom `tokio-tungstenite` build until upstream proxy support is officially integrated.

This commit introduces a **new capability** to track and display the origin of forked sessions within the system. It extends the **`codex-rs/protocol`** by adding a `forked_from_id` field to `SessionMeta` and `SessionConfiguredEvent`, which is then extracted during session creation in `codex-rs/core` and persisted by the **`RolloutRecorder`**. As a result, the **`/status` endpoint** in both the `codex-rs/tui` and `codex-rs/tui2` user interfaces now explicitly displays the ID of the session from which the current session was forked. This enhancement provides users with improved session traceability and context, making it easier to understand the lineage of active sessions.

This commit introduces a **new capability** for the `/fork` slash command, enabling it to directly duplicate the **current chat session** without first presenting a session picker. This **refactoring** impacts both the **TUI** and **TUI2** applications, where the `OpenForkPicker` application event has been replaced by `ForkCurrentSession` in the event handling system. The `chatwidget.rs` module now dispatches this new event, streamlining the fork process. Consequently, all related documentation, tooltips, and tests have been updated to accurately reflect this immediate branching behavior, providing a more direct user experience.

This commit introduces a **bug fix** and **refactoring** to correctly manage and apply tracing contexts, particularly for session-related operations. It **refactors** the **`OpenTelemetry` integration** by removing the internal `session_span` from `OtelManager` and introducing `apply_traceparent_parent` for dynamic span context application. Concurrently, the **`core` task execution logic** in `codex-rs/core/src/tasks/regular.rs` is adjusted to ensure the `run_turn` tracing span is correctly parented and its context is properly applied. This change resolves issues where session spans were not correctly dropped or parented, leading to improved **trace correlation** and accurate representation of task execution within tracing systems.

This commit introduces a **new capability** to **fork existing sessions** within the Codex application, allowing users to create new sessions based on previous ones. It integrates a `codex fork` subcommand into the **CLI** and a `/fork` slash command into both the **TUI** and **TUI2** interactive interfaces. The existing session picker (`resume_picker.rs`) has been **refactored** to dynamically support both 'resume' and 'fork' actions, providing a unified and intuitive user experience. This enhancement significantly improves session management flexibility across all interactive modes, complete with new test coverage for the `/fork` command.

This commit introduces a **new capability** to **fork conversations and threads**, allowing users to create new conversational branches from existing ones. It extends the `app-server-protocol` by defining new `ThreadFork` and `ForkConversation` endpoints for both v1 and v2 APIs, and implements the core handling logic within the `app-server`'s `codex_message_processor.rs` using the `thread_manager`. The `core` module's `rollout/truncation` logic is also enhanced to support full history inheritance, ensuring forked threads can maintain complete context. Comprehensive **test suites** are added for both `thread/fork` and `forkConversation` functionality, alongside updated **documentation** in the `README.md`, to fully support and explain this significant feature. This enables more flexible management of conversational flows by allowing users to branch off at any point.