Core Actions are primitives implemented by the Dagger Engine itself. They can be combined into higher-level composite actions. Their definitions can be imported in the `dagger.io/dagger/core` package.
| `#Copy` | [fs.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/fs.cue) | Copy files between two filesystem trees |
| `#Diff` | [fs.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/fs.cue) | Extract the difference between two filesystems as its own file system |
| `#Merge` | [fs.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/fs.cue) | Merge multiple filesystem trees |
| `#Mkdir` | [fs.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/fs.cue) | Create a directory in a filesystem tree |
| `#ReadFile` | [fs.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/fs.cue) | Read a file from a filesystem tree |
| `#Scratch` | [fs.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/fs.cue) | Create an empty filesystem tree |
| `#Source` | [fs.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/fs.cue) | Access the source for the current CUE package |
| `#Subdir` | [fs.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/fs.cue) | Read a subdirectory from a filesystem tree |
| `#WriteFile` | [fs.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/fs.cue) | Write a file to a filesystem tree |
## Core Actions related to secrets
| Definition | File | Description |
| :-- | :-- | :-- |
| `#DecodeSecret` | [secrets.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/secrets.cue) | Decode a secret without leaking its contents |
| `#NewSecret` | [secrets.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/secrets.cue) | Create a new a secret from a filesystem tree |
| `#TrimSecret` | [secrets.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/secrets.cue) | Trim leading and trailing space characters from a secret |
## Core Actions related to containers
| Definition | File | Description |
| :-- | :-- | :-- |
| `#Dockerfile` | [image.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/image.cue) | Build a container image using a Dockerfile |
| `#Exec` | [exec.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/exec.cue) | Execute a command in a docker-compatible container |
| `#Export` | [image.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/image.cue) | Export a docker image as a tar archive |
| `#Pull` | [image.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/image.cue) | Download an image from a docker registry |
| `#Push` | [image.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/image.cue) | Upload an image to a docker registry |
| `#GitPull` | [git.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/git.cue) | Download a repository from a remote git server |
| `#HTTPFetch` | [http.cue](https://github.com/dagger/dagger/blob/v0.2.4/pkg/dagger.io/dagger/core/http.cue) | Get a file from an HTTP server |
