# Toolchains (/pipeline-sdk/toolchains)



A toolchain wraps three things: installing the runtime, warming the dependency
cache, and the common build/test/lint commands. You call one factory, then
attach the actions you want. Each action forks off the shared install step, so
adding a check costs you the action — never the install.

## Rust [#rust]

`hm.rust.toolchain()` installs the toolchain; the action methods build, test,
lint, and format.

<DslSignature name="rust.toolchain" />

**Python**

```python
import harmont as hm

@hm.pipeline("ci")
def ci() -> tuple[hm.Step, ...]:
    project = hm.rust.toolchain(path=".")
    return (project.build(), project.test(), project.clippy(), project.fmt())
```

**TypeScript**

```typescript
import { pipeline, type PipelineDefinition } from "@harmont/hm";
import { rust } from "@harmont/hm/toolchains";

const project = rust.toolchain({ path: "." });

const pipelines: PipelineDefinition[] = [
  { slug: "ci", pipeline: pipeline([project.build(), project.test(), project.clippy(), project.fmt()]) },
];
export default pipelines;
```

## CMake (C / C++) [#cmake-c--c]

`hm.cmake()` configures and builds with CMake. Pass `compiler`, `defines`, a
`generator`, or a `preset`; the action methods run CTest, clang-format, and
clang-tidy.

<DslSignature name="cmake" />

**Python**

```python
import harmont as hm

@hm.pipeline("ci")
def ci() -> tuple[hm.Step, ...]:
    project = hm.cmake(
        path=".",
        compiler="clang-18",
        defines={"CMAKE_BUILD_TYPE": "Release", "CMAKE_CXX_STANDARD": "20"},
    )
    return (project.test(), project.lint(), project.fmt())
```

**TypeScript**

```typescript
import { pipeline, type PipelineDefinition } from "@harmont/hm";
import { cmake } from "@harmont/hm/toolchains";

const project = cmake({
  path: ".",
  compiler: "clang-18",
  defines: { CMAKE_BUILD_TYPE: "Release", CMAKE_CXX_STANDARD: "20" },
});

const pipelines: PipelineDefinition[] = [
  { slug: "ci", pipeline: pipeline([project.test(), project.lint(), project.fmt()]) },
];
export default pipelines;
```

## Every toolchain [#every-toolchain]

Harmont ships toolchains for **Rust**, **Python**, **Go**, **JavaScript/TypeScript**
(`js`/`ts`, with npm, pnpm, yarn, and Bun), **CMake** (C/C++), **Elixir**,
and **Zig**. Each one's full method list lives in the
[toolchains reference](/pipeline-sdk/reference/toolchains).