> ## Documentation Index > Fetch the complete documentation index at: https://site.aspect.build/llms.txt > Use this file to discover all available pages before exploring further. # Env `function` **Env.arch**

        
          def Env.arch() -> str

Returns the CPU architecture. Returns a string describing the CPU architecture, such as "x86\_64", "aarch64", etc. `function` **Env.aspect\_cli\_version**

        
          def Env.aspect\_cli\_version() -> str

Returns the version of the Aspect CLI. `function` **Env.aspect\_root\_dir**

        
          def Env.aspect\_root\_dir() -> str

Returns the Aspect project root directory — the anchor for axl / config loading. Found by walking upwards from the current working directory looking for an `.aspect/version.axl` or `MODULE.aspect` marker. Falls back to the deepest Bazel workspace marker (`MODULE.bazel`, `WORKSPACE`, etc.) so a pure-Bazel monorepo still resolves to a sane project anchor, and finally to the current working directory if no marker exists anywhere. Distinct from the Bazel workspace root — bazelrc discovery and `bazel info workspace` use the deepest Bazel marker, which can differ when a Bazel sub-workspace sits under an Aspect root. `function` **Env.bazel\_root\_dir**

        
          def Env.bazel\_root\_dir() -> str

Returns the Bazel workspace root directory — the anchor for bazelrc discovery, `bazel info workspace`, and BES output paths. Found by walking upwards from the current working directory looking for a `MODULE.bazel` / `WORKSPACE` marker. Falls back to the deepest `.aspect/version.axl` or `MODULE.aspect` marker so a pure-Aspect workspace still resolves, and finally to the current working directory if no marker exists anywhere. Distinct from the Aspect project root — axl / config loading uses the deepest `.aspect/` marker, which can differ when a Bazel sub-workspace sits under an Aspect root. `function` **Env.current\_dir**

        
          def Env.current\_dir() -> str

Returns the current working directory as a path. **Platform**-specific behavior This function currently corresponds to the `getcwd` function on Unix and the `GetCurrentDirectoryW` function on Windows. **Errors** Fails if the current working directory value is invalid. Possible cases: * Current directory does not exist. * There are insufficient permissions to access the current directory. `function` **Env.current\_exe**

        
          def Env.current\_exe() -> str

`function` **Env.git\_root\_dir**

        
          def Env.git\_root\_dir() -> None | str

Returns the git repository root — the directory containing `.git` — or `None` when not inside a git repository. `function` **Env.home\_dir**

        
          def Env.home\_dir() -> None | str

Returns the path of the current user's home directory if known. This may return `None` if getting the directory fails or if the platform does not have user home directories. For storing user data and configuration it is often preferable to use more specific directories. For example, [XDG Base Directories] on Unix or the `LOCALAPPDATA` and `APPDATA` environment variables on Windows. [XDG Base Directories]: https://specifications.freedesktop.org/basedir-spec/latest/ **Unix** * Returns the value of the 'HOME' environment variable if it is set (including to an empty string). * Otherwise, it tries to determine the home directory by invoking the `getpwuid_r` function using the UID of the current user. An empty home directory field returned from the `getpwuid_r` function is considered to be a valid value. * Returns `None` if the current user has no entry in the /etc/passwd file. **Windows** * Returns the value of the 'USERPROFILE' environment variable if it is set, and is not an empty string. * Otherwise, [`GetUserProfileDirectory`][msdn] is used to return the path. This may change in the future. [msdn]: https://docs.microsoft.com/en-us/windows/win32/api/userenv/nf-userenv-getuserprofiledirectorya In UWP (Universal Windows Platform) targets this function is unimplemented and always returns `None`. `function` **Env.os**

        
          def Env.os() -> str

Returns the operating system name. Returns a string describing the operating system in use, such as "linux", "macos", "windows", etc. `function` **Env.remove\_var**

        
          def Env.remove\_var(
          key: str,
          /
          ) -> None

Removes an environment variable from the current process. Has no effect if the variable is not set. Subsequent `var()` calls will return `None` for the removed variable. `function` **Env.set\_var**

        
          def Env.set\_var(
          key: str,
          value: str,
          /
          ) -> None

Sets an environment variable for the current process. This affects all subsequent `var()` calls and any child processes spawned after this call. Use with care — environment variables are global process state. `function` **Env.temp\_dir**

        
          def Env.temp\_dir() -> str

Returns the path of a temporary directory. The temporary directory may be shared among users, or between processes with different privileges; thus, the creation of any files or directories in the temporary directory must use a secure method to create a uniquely named file. Creating a file or directory with a fixed or predictable name may result in "insecure temporary file" security vulnerabilities. Consider using a crate that securely creates temporary files or directories. Note that the returned value may be a symbolic link, not a directory. **Platform**-specific behavior On Unix, returns the value of the `TMPDIR` environment variable if it is set, otherwise the value is OS-specific: * On Darwin-based OSes (macOS, iOS, etc) it returns the directory provided by `confstr(_CS_DARWIN_USER_TEMP_DIR, ...)`, as recommended by [Apple's security guidelines][appledoc]. * On all other unix-based OSes, it returns `/tmp`. On Windows, the behavior is equivalent to that of [`GetTempPath2`][GetTempPath2] / [`GetTempPath`][GetTempPath], which this function uses internally. [GetTempPath2]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-gettemppath2a [GetTempPath]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-gettemppatha [appledoc]: https://developer.apple.com/library/archive/documentation/Security/Conceptual/SecureCodingGuide/Articles/RaceConditions.html#//apple_ref/doc/uid/TP40002585-SW10 `function` **Env.var**

        
          def Env.var(
          key: str,
          /
          ) -> None | str

Fetches the environment variable key from the current process. `function` **Env.vars**

              
          def Env.vars() -> list\[tuple\[str, ...]]

Returns an iterator of (variable, value) pairs of strings, for all the environment variables of the current process. The returned iterator contains a snapshot of the process's environment variables at the time of this invocation. Modifications to environment variables afterwards will not be reflected in the returned iterator.