NAME

       mu-server - the mu backend for the mu4e e-mail client

SYNOPSIS

       mu [COMMON-OPTIONS] server

DESCRIPTION

       mu server starts a simple shell in which one can query and manipulate the mu database. The output uses s-
       expressions.  mu  server  is  not  meant for use by humans, except for debugging purposes. Instead, it is
       designed specifically for the mu4e e-mail client.

              (<command-name> :param1 value1 :param2 value2)

       For example, to view a certain message, the command would be:

              (view :docid 12345)

       Parameters can be sent in any order; they must be of the correct  type  though.   See  lib/utils/mu-sexp-
       parser.hh and lib/utils/mu-sexp-parser.cc in source-tree for the details.

OUTPUT FORMAT

       mu server accepts a number of commands, and delivers its results in the form:

              \\376<length>\\377<s-expr>

       \376  (one  byte  0xfe),  followed  by the length of the s-expression expressed as an hexadecimal number,
       followed by another \377 (one byte 0xff), followed by the actual s-expression.

       By prefixing the expression with its length, it can be processed more efficiently. The \376 and \377 were
       chosen since they never occur in valid UTF-8 (in which the s-expressions are encoded).

SERVER OPTIONS

   --commands
       List available commands (and try with --verbose).

   --eval expression
       Evaluate a mu4e server s-expression.

   --allow-temp-file
       If set, allow for the output of some commands to use temp-files rather than directly  through  the  emacs
       process  input/output.  This  is  noticeably  faster for commands with a lot of output, esp. when the the
       temp-file uses a in-memory file-system.

PERFORMANCE

       As an indication for the relative performance, we can simulate something mu4e does; we take overall  time
       of 50 such requests:

              time build/mu/mu server --allow-temp-file --eval '(find :query "\"\"" :include-related t :threads t :maxnum 50000)' >/dev/null

       (and --allow-temp-file for 1.11)

                                            ┌────────────────────────────┐
                                            │       release   time (sec) │
                                            ├────────────────────────────┤
                                            │           1.8   8.6s       │
                                            │          1.10   5.7s       │
                                            │ 1.11 (master)   2.8s       │
                                            └────────────────────────────┘

   --muhome
       Use a non-default directory to store and read the database, write the logs, etc.  By default, mu uses the
       XDG  Base  Directory  Specification  (e.g.  on  GNU/Linux this defaults to ~/.cache/mu and ~/.config/mu).
       Earlier versions of mu defaulted to ~/.mu, which now requires --muhome=~/.mu.

       The environment variable MUHOME can be used as an alternative to --muhome. The latter has precedence.

COMMON OPTIONS

   -d, --debug
       Makes mu generate extra debug information, useful for debugging the  program  itself.  Debug  information
       goes to the standard logging location; see mu(1).

   -q, --quiet
       Causes  mu  not to output informational messages and progress information to standard output, but only to
       the log file. Error messages will still be sent to standard error. Note that mu index is much faster with
       --quiet, so it is recommended you use this option when using mu from scripts etc.

   --log-stderr
       Causes mu to not output log messages to standard error, in addition  to  sending  them  to  the  standard
       logging location.

   --nocolor
       Do not use ANSI colors. The environment variable NO_COLOR can be used as an alternative to --nocolor.

   -V, --version
       Prints mu version and copyright information.

   -h, --help
       Lists the various command line options.

REPORTING BUGS

       Please report bugs at https://github.com/djcb/mu/issues.

AUTHOR

       Dirk-Jan C. Binnema <djcb@djcbsoftware.nl>

COPYRIGHT

       This manpage is part of mu 1.12.9.

       Copyright   ©   2008-2025   Dirk-Jan   C.   Binnema.   License   GPLv3+:  GNU  GPL  version  3  or  later
       https://gnu.org/licenses/gpl.html. This is free software: you are free to  change  and  redistribute  it.
       There is NO WARRANTY, to the extent permitted by law.

SEE ALSO

       mu(1)

                                                                                                    MU-SERVER(1)