While other remotes store the contents of annexed files somewhere,
this special remote uses a program to compute the contents of annexed
files.

To add a file to a compute special remote, use the [[git-annex-addcomputed]]
command. Once a file has been added to a compute special remote, commands
like `git-annex get` will use it to compute the content of the file.

To enable an instance of this special remote:

    # git-annex initremote myremote type=compute program=git-annex-compute-foo

The `program` parameter is the only required parameter. It is the name of the
program to use to compute the contents of annexed files. It must start with
"git-annex-compute-". The program needs to be installed somewhere in the
`PATH`.

Any program can be passed to `git-annex initremote`. However, when enabling
a compute special remote later with `git-annex enableremote` or due to
"autoenable=true", the program must be listed in the git config
`annex.security.allowed-compute-programs`.

All other "field=value" parameters passed to `initremote` will be passed
to the program when running [[git-annex-addcomputed]]. Note that when the
program takes a dashed option, it can be provided after "--":

    # git-annex initremote myremote type=compute program=git-annex-compute-foo -- --level=9

See [[tips/computing_annexed_files]] for more documentation.

## compute programs

To write programs used by the compute special remote, see the 
[[design/compute_special_remote_interface]].

Have you written a generally useful (and secure) compute program?
List it here with an example!

* [[compute/git-annex-compute-imageconvert]]  
  Uses imagemagick to convert between image formats

  `git-annex addcomputed --to=imageconvert foo.jpeg foo.gif`

* [[compute/git-annex-compute-singularity]]
  Uses [Singularity](https://sylabs.io/) to run a container, which is
  checked into the git-annex repository, to compute other files in the
  repository. Amoung other things, this can run other compute programs
  inside a singularity container. 
  [[Examples here|compute/git-annex-compute-singularity-examples]]

* [[compute/git-annex-compute-wasmedge]]  
  Uses [WasmEdge](https://WasmEdge.org/) to run WASM programs that are
  checked into the git-annex repository, to compute other files in the
  repository. [[Examples here|compute/git-annex-compute-wasmedge-examples]]