The "open" command:

Usage: fossil open REPOSITORY ?VERSION? ?OPTIONS?

Open a new connection to the repository name REPOSITORY. A check-out for the repository is created with its root at the current working directory, or in DIR if the "--workdir DIR" is used. If VERSION is specified then that version is checked out. Otherwise the most recent check-in on the main branch (usually "trunk") is used.

REPOSITORY can be the filename for a repository that already exists on the local machine or it can be a URI for a remote repository. If REPOSITORY is a URI in one of the formats recognized by the clone command, the remote repo is first cloned, then the clone is opened. The clone will be stored in the current directory, or in DIR if the "--repodir DIR" option is used. The name of the clone will be taken from the last term of the URI. For "http:" and "https:" URIs, you can append an extra term to the end of the URI to get any repository name you like. For example:

fossil open https://fossil-scm.org/home/new-name

The base URI for cloning is "https://fossil-scm.org/home". The extra "new-name" term means that the cloned repository will be called "new-name.fossil".

Options:

--empty
Initialize check-out as being empty, but still connected with the local repository. If you commit this check-out, it will become a new "initial" commit in the repository.
-f|--force
Continue with the open even if the working directory is not empty, or if auto-sync fails.
--force-missing
Force opening a repository with missing content
-k|--keep
Only modify the manifest file(s)
--nested
Allow opening a repository inside an opened check-out
--nosync
Do not auto-sync the repository prior to opening even if the autosync setting is on.
--proxy PROXY
Use PROXY as http proxy during sync operation
--reopen REPO
"Reopen" an existing checkout to use a different repository file REPO. Useful to reconnect an existing checkout to a repository after the original repository file is moved. CAUTION: may lose stash and bisect history.
--repodir DIR
If REPOSITORY is a URI that will be cloned, store the clone in DIR rather than in "."
--setmtime
Set timestamps of all files to match their SCM-side times (the timestamp of the last check-in which modified them).
--verbose
If passed a URI then this flag is passed on to the clone operation, otherwise it has no effect
--workdir DIR
Use DIR as the working directory instead of ".". The DIR directory is created if it does not exist.