Servers

A session can run its notebook on another computer, such as a lab server with more memory or with your data on it. Endeavor connects to it with SSH, the standard way to sign in to another computer from a terminal.

Only Julia and the notebook run on the server. Endeavor and Claude stay on your Mac, and nothing Claude-related is installed on the server.

To run notebooks as jobs on a shared cluster, see Clusters instead.

What you need

• You can already sign in to the server from Terminal on your Mac, for example with ssh lab-server. Endeavor uses the same ssh program, so your ~/.ssh/config, your keys and any jump hosts work the same way.
• The server runs Linux (on Intel or ARM processors), or macOS on the same kind of processor as your Mac.

If the server asks for a password or a two-factor code, Endeavor shows the prompt in a dialog. If an answer doesn’t work, the dialog says so and asks again. A server gives you only so long to answer (two minutes, unless its administrator changed it). If you take longer, the dialog closes and Endeavor says the server stopped waiting. Connect again to sign in.

Add a server

1. Open the Where chip on the Start a session screen, and click Add server…. You can also add one in Settings, under Where notebooks run.
2. Fill in the fields:
   • SSH host: an alias from your ~/.ssh/config, or user@host. Add :port if the server doesn’t use port 22. Aliases from your ~/.ssh/config are listed under the field. Click one to use it.
   • Name: what Endeavor calls the server. Leave it empty to use the SSH host, numbered (“lab 2”) if another server already has that name. Each server needs its own name.
   • How to get Julia: see Julia on the server. You can leave it empty.
   • How to get R, for R notebooks: see R on the server.
   • Stop idle notebooks after: how long a notebook nobody uses keeps running. The default follows Settings.
3. Click Test connection. Endeavor connects, installs what it needs, finds Julia and starts it once. Each step shows as it happens. When all is well, it says the server “works with Endeavor”.
4. Click Add.

To change a server later, click the gear next to it in the Where chip or in Settings. Remove server… makes Endeavor forget it. Anything still running there keeps running.

Start a session on the server

On the Start a session screen, pick the server in the Where chip. Then pick a folder on the server with the folder chip. Browse… shows the server’s folders. The notebook and the files the session makes are saved in that folder on the server.

What Endeavor installs on the server

Everything goes in ~/.cache/endeavor/ in your home folder on the server:

• a small program, endeavor, that relays between your Mac and Julia, with the files Julia needs to run the notebook, in a folder named after Endeavor’s version;
• the notebook’s state, in state/;
• Julia’s packages, in depot/;
• Julia itself, only if Endeavor has to download it.

Endeavor installs over the same SSH connection it uses to connect, so you sign in once. Nothing needs administrator rights.

Julia on the server

How to get Julia takes one of three things:

• nothing: Endeavor uses the julia it finds when you sign in. If there is none, or it’s older than 1.11, Endeavor downloads its own Julia 1.12.6 into ~/.cache/endeavor/;
• the path to a julia program, such as /opt/julia-1.12/bin/julia;
• a shell line that makes julia available, such as module load julia.

Endeavor needs Julia 1.11 or newer.

R on the server

How to get R works the same way. Left empty, it uses the Rscript your login shell finds. It also takes the path to an Rscript program, or a shell line such as module load R. Endeavor never installs R on a server. The first R notebook installs Ember, the R package that runs R notebooks, which takes a few minutes that one time.

What Claude can do on a server

In a server session, Claude’s own tools for your Mac’s files and commands are switched off, because they would look at the wrong computer. Instead, Claude can list folders, read files and run commands on the server. In Manual and Ask to run, each command asks first, with a card such as “Run a command on lab-server?” that shows the command and the folder it runs in.

Notebooks keep running

A notebook on a server keeps running when you quit Endeavor or lose the connection. When you come back, Endeavor reconnects to it. A long calculation goes on while your laptop is closed.

A notebook stops when:

• you stop it: Stop notebook in its ⋮ menu, or Stop next to the server in Settings, under Where notebooks run;
• nobody has used it for the time set in Stop idle notebooks after, 48 hours unless you changed it.

The notebook’s file stays on the server either way. Start runs it again.

Only one computer can be connected to a server’s Julia at a time. If you connect from another Mac, that one takes over, and the first says “Another connection took over Julia on lab-server.” with a Reconnect button.

Servers that are clusters

If the server is a cluster’s login node, Endeavor notices when you start a session and asks: “This looks like a cluster’s login node. Clusters stop long-running programs here. Add it as a cluster instead?”. Choose Add as cluster to run the notebook in a cluster job. See Clusters.

When the server can’t be reached

See Can’t reach a server.