---

title: C description: "Configure C language support in Zed, including language servers, formatting, and debugging." #

C #

C support is available natively in Zed.

• Tree-sitter: tree-sitter/tree-sitter-c
• Language Server: clangd/clangd
• Debug Adapter: CodeLLDB (primary), GDB (secondary, not available on Apple silicon)

Clangd: Force detect as C #

Clangd out of the box assumes mixed C++/C projects. If you have a C-only project you may wish to instruct clangd to treat all files as C using the -xc flag. To do this, create a .clangd file in the root of your project with the following:

# yaml-language-server: $schema=https://json.schemastore.org/clangd.json
CompileFlags:
  Add: [-xc]

By default clang and gcc will recognize *.C and *.H (uppercase extensions) as C++ and not C and so Zed too follows this convention. If you are working with a C-only project (perhaps one with legacy uppercase pathing like FILENAME.C) you can override this behavior by adding this to your settings:

{
  "file_types": {
    "C": ["C", "H"]
  }
}

Formatting #

By default Zed will use the clangd language server for formatting C code like the clang-format CLI tool. To configure this you can add a .clang-format file. For example:

# yaml-language-server: $schema=https://json.schemastore.org/clang-format-21.x.json
---
BasedOnStyle: GNU
IndentWidth: 2
---

See Clang-Format Style Options for a complete list of options.

You can trigger formatting via {#kb editor::Format} or the {#action editor::Format} action from the command palette or by enabling format on save.

Configure formatting in Settings ({#kb zed::OpenSettings}) under Languages > C, or add to your settings file:

  "languages": {
    "C": {
      "format_on_save": "on",
      "tab_size": 2
    }
  }

Compile Commands #

For some projects Clangd requires a compile_commands.json file to properly analyze your project. This file contains the compilation database that tells clangd how your project should be built.

CMake Compile Commands #

With CMake, you can generate compile_commands.json automatically by adding the following line to your CMakeLists.txt:

set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

After building your project, CMake will generate the compile_commands.json file in the build directory and clangd will automatically pick it up.

Debugging #

You can use CodeLLDB or GDB to debug native binaries. (Make sure that your build process passes -g to the C compiler, so that debug information is included in the resulting binary.) See below for examples of debug configurations that you can add to .zed/debug.json.

• CodeLLDB configuration documentation
• GDB configuration documentation

Build and Debug Binary #

[
  {
    "label": "Debug native binary",
    "build": {
      "command": "make",
      "args": ["-j8"],
      "cwd": "$ZED_WORKTREE_ROOT"
    },
    "program": "$ZED_WORKTREE_ROOT/build/prog",
    "request": "launch",
    "adapter": "CodeLLDB"
  }
]