GIT-REMOTE-HELPERS(1)                                    GIT-REMOTE-HELPERS(1)



NAME
       git-remote-helpers - Helper programs to interact with remote
       repositories

SYNOPSIS
       git remote-<transport> <repository> [<URL>]


DESCRIPTION
       Remote helper programs are normally not used directly by end users, but
       they are invoked by git when it needs to interact with remote
       repositories git does not support natively. A given helper will
       implement a subset of the capabilities documented here. When git needs
       to interact with a repository using a remote helper, it spawns the
       helper as an independent process, sends commands to the helper&#8217;s
       standard input, and expects results from the helper&#8217;s standard
       output. Because a remote helper runs as an independent process from
       git, there is no need to re-link git to add a new helper, nor any need
       to link the helper with the implementation of git.


       Every helper must support the "capabilities" command, which git will
       use to determine what other commands the helper will accept. Other
       commands generally concern facilities like discovering and updating
       remote refs, transporting objects between the object database and the
       remote repository, and updating the local object store.


       Helpers supporting the fetch capability can discover refs from the
       remote repository and transfer objects reachable from those refs to the
       local object store. Helpers supporting the push capability can transfer
       local objects to the remote repository and update remote refs.


       Git comes with a "curl" family of remote helpers, that handle various
       transport protocols, such as git-remote-http, git-remote-https,
       git-remote-ftp and git-remote-ftps. They implement the capabilities
       fetch, option, and push.


INVOCATION
       Remote helper programs are invoked with one or (optionally) two
       arguments. The first argument specifies a remote repository as in git;
       it is either the name of a configured remote or a URL. The second
       argument specifies a URL; it is usually of the form
       <transport>://<address>, but any arbitrary string is possible.


       When git encounters a URL of the form <transport>://<address>, where
       <transport> is a protocol that it cannot handle natively, it
       automatically invokes git remote-<transport> with the full URL as the
       second argument. If such a URL is encountered directly on the command
       line, the first argument is the same as the second, and if it is
       encountered in a configured remote, the first argument is the name of
       that remote.


       A URL of the form <transport>::<address> explicitly instructs git to
       invoke git remote-<transport> with <address> as the second argument. If
       such a URL is encountered directly on the command line, the first
       argument is <address>, and if it is encountered in a configured remote,
       the first argument is the name of that remote.


       Additionally, when a configured remote has remote.<name>.vcs set to
       <transport>, git explicitly invokes git remote-<transport> with <name>
       as the first argument. If set, the second argument is
       remote.<name>.url; otherwise, the second argument is omitted.


COMMANDS
       Commands are given by the caller on the helper&#8217;s standard input,
       one per line.


       capabilities
              Lists the capabilities of the helper, one per line, ending with
              a blank line. Each capability may be preceded with *, which
              marks them mandatory for git version using the remote helper to
              understand (unknown mandatory capability is fatal error).


       list   Lists the refs, one per line, in the format "<value> <name>
              [<attr> ...]". The value may be a hex sha1 hash, "@<dest>" for a
              symref, or "?" to indicate that the helper could not get the
              value of the ref. A space-separated list of attributes follows
              the name; unrecognized attributes are ignored. The list ends
              with a blank line.

              If push is supported this may be called as list for-push to
              obtain the current refs prior to sending one or more push
              commands to the helper.


       option <name> <value>
              Sets the transport helper option <name> to <value>. Outputs a
              single line containing one of ok (option successfully set),
              unsupported (option not recognized) or error <msg> (option
              <name> is supported but <value> is not valid for it). Options
              should be set before other commands, and may influence the
              behavior of those commands.

              Supported if the helper has the "option" capability.


       fetch <sha1> <name>
              Fetches the given object, writing the necessary objects to the
              database. Fetch commands are sent in a batch, one per line,
              terminated with a blank line. Outputs a single blank line when
              all fetch commands in the same batch are complete. Only objects
              which were reported in the ref list with a sha1 may be fetched
              this way.

              Optionally may output a lock <file> line indicating a file under
              GIT_DIR/objects/pack which is keeping a pack until refs can be
              suitably updated.

              Supported if the helper has the "fetch" capability.


       push +<src>:<dst>
              Pushes the given local <src> commit or branch to the remote
              branch described by <dst>. A batch sequence of one or more push
              commands is terminated with a blank line.

              Zero or more protocol options may be entered after the last push
              command, before the batch&#8217;s terminating blank line.

              When the push is complete, outputs one or more ok <dst> or error
              <dst> <why>? lines to indicate success or failure of each pushed
              ref. The status report output is terminated by a blank line. The
              option field <why> may be quoted in a C style string if it
              contains an LF.

              Supported if the helper has the "push" capability.


       import <name>
              Produces a fast-import stream which imports the current value of
              the named ref. It may additionally import other refs as needed
              to construct the history efficiently. The script writes to a
              helper-specific private namespace. The value of the named ref
              should be written to a location in this namespace derived by
              applying the refspecs from the "refspec" capability to the name
              of the ref.

              Especially useful for interoperability with a foreign versioning
              system.

              Supported if the helper has the "import" capability.


       connect <service>
              Connects to given service. Standard input and standard output of
              helper are connected to specified service (git prefix is
              included in service name so e.g. fetching uses git-upload-pack
              as service) on remote side. Valid replies to this command are
              empty line (connection established), fallback (no smart
              transport support, fall back to dumb transports) and just
              exiting with error message printed (can&#8217;t connect,
              don&#8217;t bother trying to fall back). After line feed
              terminating the positive (empty) response, the output of service
              starts. After the connection ends, the remote helper exits.

              Supported if the helper has the "connect" capability.


              If a fatal error occurs, the program writes the error message to
              stderr and exits. The caller should expect that a suitable error
              message has been printed if the child closes the connection
              without completing a valid response for the current command.


              Additional commands may be supported, as may be determined from
              capabilities reported by the helper.


CAPABILITIES
       fetch, option, push, import, connect
              This helper supports the corresponding command with the same
              name.


       refspec spec
              When using the import command, expect the source ref to have
              been written to the destination ref. The earliest applicable
              refspec takes precedence. For example
              "refs/heads/*:refs/svn/origin/branches/*" means that, after an
              "import refs/heads/name", the script has written to
              refs/svn/origin/branches/name. If this capability is used at
              all, it must cover all refs reported by the list command; if it
              is not used, it is effectively "*:*"


REF LIST ATTRIBUTES
       for-push
              The caller wants to use the ref list to prepare push commands. A
              helper might chose to acquire the ref list by opening a
              different type of connection to the destination.


       unchanged
              This ref is unchanged since the last import or fetch, although
              the helper cannot necessarily determine what value that
              produced.


OPTIONS
       option verbosity <n>
              Changes the verbosity of messages displayed by the helper. A
              value of 0 for <n> means that processes operate quietly, and the
              helper produces only error output. 1 is the default level of
              verbosity, and higher values of <n> correspond to the number of
              -v flags passed on the command line.


       option progress {true|false}
              Enables (or disables) progress messages displayed by the
              transport helper during a command.


       option depth <depth>
              Deepens the history of a shallow repository.


       option followtags {true|false}
              If enabled the helper should automatically fetch annotated tag
              objects if the object the tag points at was transferred during
              the fetch command. If the tag is not fetched by the helper a
              second fetch command will usually be sent to ask for the tag
              specifically. Some helpers may be able to use this option to
              avoid a second network connection.


              option dry-run {true|false}: If true, pretend the operation
              completed successfully, but don&#8217;t actually change any
              repository data. For most helpers this only applies to the push,
              if supported.


       option servpath <c-style-quoted-path>
              Sets service path (--upload-pack, --receive-pack etc.) for next
              connect. Remote helper may support this option, but must not
              rely on this option being set before connect request occurs.


SEE ALSO
       git-remote(1)


GIT
       Part of the git(1) suite




                                                         GIT-REMOTE-HELPERS(1)
