# How to Type-Check a Specific OpenLogi Crate: Fast Verification for Multi-Crate Workspaces > Learn how to type-check a specific OpenLogi crate using cargo check -p. Quickly verify individual crates in multi-crate workspaces without full compilation. - Repository: [Xuan Zhang/OpenLogi](https://github.com/AprilNEA/OpenLogi) - Tags: how-to-guide - Published: 2026-08-22 --- **Run `cargo check -p ` from the repository root to quickly type-check any individual OpenLogi crate without compiling the entire workspace or generating binaries.** OpenLogi organizes its Rust codebase as a multi-crate workspace, with each component residing beneath the `crates/` directory. When iterating on specific functionality—whether the **openlogi-core** protocol library or the **openlogi-ui** front-end—you need targeted verification that skips the overhead of full workspace compilation while ensuring type safety. ## Locate the Target Crate in the Workspace Each crate in OpenLogi declares its package name in its respective [`Cargo.toml`](https://github.com/AprilNEA/OpenLogi/blob/main/Cargo.toml) file under the `crates/` directory. The primary library is **openlogi-core**, defined in [`crates/openlogi-core/Cargo.toml`](https://github.com/AprilNEA/OpenLogi/blob/main/crates/openlogi-core/Cargo.toml), while the GPUI-based GUI front-end lives in **openlogi-ui** at [`crates/openlogi-ui/Cargo.toml`](https://github.com/AprilNEA/OpenLogi/blob/main/crates/openlogi-ui/Cargo.toml). Other key crates include **openlogi-hidpp** for HID++ protocol implementation and **openlogi-agent** for the background service. To identify the correct name for the `-p` flag, inspect the `package.name` field within the target crate’s [`Cargo.toml`](https://github.com/AprilNEA/OpenLogi/blob/main/Cargo.toml). ## Execute Fast Type-Checking with Cargo According to the OpenLogi developer guide in [`AGENTS.md`](https://github.com/AprilNEA/OpenLogi/blob/main/AGENTS.md) (lines 62-64), the recommended "fast-path verification step" uses `cargo check` with the `-p` (package) flag. This command performs semantic analysis, type-checking, and borrow-checking without producing binaries or running code generation, making it significantly faster than `cargo build`. From the repository root, execute: ```bash cargo check -p openlogi-core ``` This validates **openlogi-core** and its local dependencies while ignoring unrelated workspace members. The command exits with compilation errors, type mismatches, or dependency resolution failures if present. ### Verify Platform-Specific Code Paths Crates such as `openlogi-agent` contain `#[cfg(target_os = …)]` blocks for cross-platform compatibility. Running `cargo check` on Linux only validates Linux-specific code paths. To verify Windows-specific implementations without switching hosts, specify the target triple: ```bash cargo check -p openlogi-agent --target x86_64-pc-windows-msvc ``` ## Integrate Targeted Checks into Your Development Workflow The OpenLogi development workflow documented in [`AGENTS.md`](https://github.com/AprilNEA/OpenLogi/blob/main/AGENTS.md) (lines 77-81) describes this approach as the "inner loop"—rapid iteration on a single crate followed by comprehensive workspace validation once changes stabilize. This methodology appears in automation scripts like [`xtask/src/commands/release/changelog.rs`](https://github.com/AprilNEA/OpenLogi/blob/main/xtask/src/commands/release/changelog.rs), which runs `cargo check` on specific crates before generating release documentation to ensure changelog generation only proceeds when the target code compiles. For test-driven verification, remember that `cargo test -p ` also type-checks the code it touches before execution, though `cargo check` remains the fastest pure verification method. ## Practical Type-Checking Examples Use these commands to verify specific OpenLogi components: ```bash # Type-check the core protocol library cargo check -p openlogi-core # Type-check the GPUI-based UI front-end cargo check -p openlogi-ui # Type-check the HID++ protocol implementation cargo check -p openlogi-hidpp # Type-check Windows tray code (requires Windows target or cross-compilation setup) cargo check -p openlogi-agent --target x86_64-pc-windows-msvc ``` ## Summary - **Use `cargo check -p `** to validate a single OpenLogi crate without building the entire workspace. - **Crate names** derive from `package.name` in each crate’s [`Cargo.toml`](https://github.com/AprilNEA/OpenLogi/blob/main/Cargo.toml) located under `crates//`. - **Performance**: Type-checking skips binary generation, offering faster feedback than `cargo build`. - **Cross-platform validation** requires the `--target` flag to check platform-specific `#[cfg]` blocks for non-host operating systems. - **Workflow integration** follows the "inner loop" pattern described in [`AGENTS.md`](https://github.com/AprilNEA/OpenLogi/blob/main/AGENTS.md) for efficient iterative development. ## Frequently Asked Questions ### What is the difference between `cargo check` and `cargo build` when working with OpenLogi? `cargo check` performs type-checking, borrow-checking, and macro expansion without producing binaries or optimizing code generation, making it roughly 2-3x faster than `cargo build`. Use `cargo check` for rapid verification during development, and reserve `cargo build` for producing release artifacts or when you need to execute the compiled code. ### How do I type-check an OpenLogi crate for a different operating system? Append the `--target` flag to your `cargo check -p` command with the appropriate target triple, such as `--target x86_64-pc-windows-msvc` for Windows or `--target aarch64-unknown-linux-gnu` for ARM64 Linux. This forces the compiler to evaluate `#[cfg(target_os = "...")]` blocks for the specified platform rather than your host system. ### Can I run tests on a single OpenLogi crate without checking the entire workspace? Yes. Use `cargo test -p ` to compile and execute tests for a specific crate only. This command implicitly type-checks the code paths touched by the test suite before running them. For even finer granularity, filter specific tests with `cargo test -p --lib `. ### Where does OpenLogi define the crate names used with the `-p` flag? Each crate defines its package name in the `[package]` section of its [`Cargo.toml`](https://github.com/AprilNEA/OpenLogi/blob/main/Cargo.toml) file. For example, [`crates/openlogi-core/Cargo.toml`](https://github.com/AprilNEA/OpenLogi/blob/main/crates/openlogi-core/Cargo.toml) declares `name = "openlogi-core"`, which becomes the identifier for the `-p` flag. The workspace-wide configuration in the root [`Cargo.toml`](https://github.com/AprilNEA/OpenLogi/blob/main/Cargo.toml) lists these crates as members, enabling Cargo to resolve them by name.