## Why The `non_prefixed_mcp_tool_names` feature should be applied where MCP tools become model-visible, not by remapping names later in core. Keeping the decision in `McpConnectionManager` construction makes `ToolInfo` the single shaped view that spec building, deferred tool search, routing, and unavailable-tool placeholders can consume directly. This also preserves the existing external behavior while the feature is off, and keeps the feature-on behavior for code mode and hooks explicit at the manager boundary. ## What Changed - Add `McpToolNameMode` to `codex-mcp` and flow it through `McpConfig` into `McpConnectionManager::new`. - Normalize MCP `ToolInfo` names in the manager using either legacy-prefixed namespaces or non-prefixed namespaces; the legacy path adds `mcp__` without restoring the old trailing namespace suffix. - Remove the core-side MCP name remapping path so specs, tool search, session resolution, and unavailable-tool placeholder construction use the manager-provided `ToolName` values directly. - Keep code mode flattening on the `__` namespace separator. - Preserve hook compatibility by giving non-prefixed MCP hook names legacy `mcp__...` matcher aliases. - Add/adjust integration and unit coverage for non-prefixed code-mode behavior, hook matching with the feature on and off, and manager-level legacy prefixing. ## Testing - `cargo test -p codex-mcp --lib` - `cargo test -p codex-core --lib tools::spec::tests -- --nocapture` - `cargo test -p codex-core --lib mcp_tools -- --nocapture` - `cargo test -p codex-core --lib mcp_tool_exposure -- --nocapture` - `cargo test -p codex-core --test all mcp_tool -- --nocapture` - `cargo test -p codex-core --test all search_tool -- --nocapture` - `cargo test -p codex-core --test all hooks_mcp -- --nocapture` - `cargo test -p codex-core --test all code_mode_uses_non_prefixed_mcp_tool_names_when_feature_enabled -- --nocapture` - `cargo test -p codex-tools` - `cargo test -p codex-features`
codex-tools
codex-tools is the shared support crate for building, adapting, and executing
model-visible tools outside codex-core.
Today this crate owns the host-facing tool models and helpers that no longer
need to live in core/src/tools/spec.rs or core/src/client_common.rs:
- aggregate host models such as
ToolSpec,ConfiguredToolSpec,LoadableToolSpec,ResponsesApiNamespace, andResponsesApiNamespaceTool - host discovery models used while assembling tool sets, including discoverable-tool models and request-plugin-install helpers
- host adapters such as schema sanitization, MCP/dynamic conversion, code-mode augmentation, and image-detail normalization
- shared executable-tool contracts such as
ToolExecutor,ToolCall, andToolOutput
That extraction is the first step in a longer migration. The goal is not to
move all of core/src/tools into this crate in one shot. Instead, the plan is
to peel off reusable pieces in reviewable increments while keeping
compatibility-sensitive orchestration in codex-core until the surrounding
boundaries are ready.
Vision
Over time, this crate should hold host-side tool machinery that is shared by multiple consumers, for example:
- host-visible aggregate tool models
- tool-set planning and discovery helpers
- MCP and dynamic-tool adaptation into Responses API shapes
- code-mode compatibility shims that do not depend on
codex-core - other narrowly scoped host utilities that multiple crates need
The corresponding non-goals are just as important:
- do not move
codex-coreorchestration here prematurely - do not pull
Session/TurnContext/ approval flow / runtime execution logic into this crate unless those dependencies have first been split into stable shared interfaces - do not turn this crate into a grab-bag for unrelated helper code
Migration approach
The expected migration shape is:
- Keep extension-owned executable-tool authoring in
codex-extension-api. - Move host-side planning/adaptation helpers here when they no longer need to
stay coupled to
codex-core. - Leave compatibility-sensitive adapters in
codex-corewhile downstream call sites are updated. - Only extract higher-level host infrastructure after the crate boundaries are clear and independently testable.
Crate conventions
This crate should start with stricter structure than core/src/tools so it
stays easy to grow:
src/lib.rsshould remain exports-only.- Business logic should live in named module files such as
foo.rs. - Unit tests for
foo.rsshould live in a siblingfoo_tests.rs. - The implementation file should wire tests with:
#[cfg(test)]
#[path = "foo_tests.rs"]
mod tests;
If this crate starts accumulating code that needs runtime state from
codex-core, that is a sign to revisit the extraction boundary before adding
more here.