Manage external services from within Emacs
Emacs Lisp Gherkin Other


Manage external services from within Emacs

I came up with the idea when I got to work one Monday morning and before I could start working I had to manually start ten or so services.

To get rid of this tedious work, I started working on this Emacs plugin, which provides a nice and simple GUI to manage services.



Add prodigy to your Cask file:

(depends-on "prodigy")

If you are on a Mac, disable nap mode for Emacs, otherwise requests will be very slow when Emacs enters nap mode:

$ defaults write org.gnu.Emacs NSAppSleepDisabled -bool YES


Start Prodigy with M-x prodigy. You should see a list of all defined services.


Services can be defined in a few different ways. See doc-string for information about available properties to specify: M-x describe-variable RET prodigy-services.

Properties that accepts a function as argument all get a property list as argument, for example:

  :command (lambda (&rest args)
             (let ((service (plist-get args :service)))
               ;; ...

You can also use the prodigy-callback macro to simplify the argument handling.

  :command (prodigy-callback (service)
             ;; ...

Depending on property, the args list contain various properties.

prodigy-define-service (&rest args)

Services can be defined using the function prodigy-define-service:

(prodigy-define-service :prop value ...)


Services can be defined by setting the variable prodigy-services:

(setq prodigy-services
 '((:prop value ...)
   (:prop value ...)))

Viewing process output

In the prodigy window, you can see a process' output with the $ key. Process output buffers use the prodigy-view-mode and do some special pre-processing to the process output. The buffer output will be tailed (à la tail -f) if the point is at the buffer end. There are two significant variables that influence process output:

  • prodigy-output-filters is a list of filters to apply to the output (currently, the process will be ansi-colorized and ^M literals will be stripped). Filter functions should take a single argument, the output string, and should return a string.
  • prodigy-process-on-output-hook is a hook that runs on process output. Each function in the hook takes two arguments, service (the service data structure) and output (the service's output).


Services can have any number of tags. Tags does not have to be pre defined. If they are, the service will inherit all the tags properties. Tags can also have tags. A service will inherit all tags recursively.

See doc-string for information about available properties to specify: M-x describe-variable RET prodigy-tags.

prodigy-define-tag (&rest args)

Tags can be defined using the function prodigy-define-tag:

(prodigy-define-tag :prop value ...)


Tags can be defined by setting the variable prodigy-tags:

(setq prodigy-tags
 '((:prop value ...)
   (:prop value ...)))


Filters is a way to show only specific services in the Prodigy buffer. For example services with specific tag or with a name matching a string.

prodigy-add-filter (&rest args)

To add a filter, use prodigy-add-filter:

(prodigy-add-filter :tag 'foo)
(prodigy-add-filter :name "bar")


You can also set the variable prodigy-filters directly:

(setq prodigy-filters
      '((:tag foo)
        (:name "bar")))


Each service is associated with a status. The built in statuses are:

  • stopped (default) - The process is not running.
  • running - The process is running. If the process status is run, this status will be used.
  • ready - The process is "actually" ready. This will be set when the service outputs a message that matches its ready-message property, or it can be set manually.
  • stopping - Set when a service is stopping.
  • failed - The process failed. A service has this status if:
    • It is not started within prodigy-start-tryouts seconds.
    • Or, it is not stopped within prodigy-stop-tryouts seconds.
    • Or, if the process exit code is non zero.

The only way Prodigy has an idea of the service status, is to look at the process status (note the difference between service and process status). The process status is however not always a very good indication of the service "actual" status. For example, it takes about five seconds to start a Rails server, but the process status will be run almost instantly after started.

To improve the service status, there is a function called prodigy-set-status, that can change the status of a service. The function takes two arguments: The service and the status-id. The status id has to be one of the statuses in prodigy-status-list.

You can create your own status with the function prodigy-define-status. See doc-string for information about available properties to specify: M-x describe-variable RET prodigy-status-list.

For more information, see status example below!


Python Simple HTTP Server

This service start a Python Simple HTTP Server on port 6001. When stopping the service, the sigkill signal is used.

  :name "Python app"
  :command "python"
  :args '("-m" "SimpleHTTPServer" "6001")
  :cwd "/path/to/my/project"
  :tags '(work)
  :stop-signal 'sigkill
  :kill-process-buffer-on-stop t)

Nodemon Server

This service starts a Nodemon serveron port 6002. The project is using NVM (Node Version Manager), so before the process starts, NVM is set up.

  :name "Node app"
  :command "nodemon"
  :cwd "/path/to/my/project"
  :args '("")
  :port 6002
  :tags '(work node)
  :init-async (lambda (done)
                (nvm-use-for "/path/to/my/project" done)))

Sinatra Server

This service starts a Sinatra server on port 6003. The project is using RVM (Ruby Version Manager), so before the process starts, RVM is set up.

  :name "Sinatra"
  :command "server"
  :cwd "/path/to/my/project"
  :path '("/path/to/my/project/bin")
  :port 6003
  :tags '(work ruby)
  :init-async (lambda (done)
                (rvm-activate-ruby-for "/path/to/my/project" done)))


Prodigy also works with Foreman.

  :name "Foreman"
  :command "foreman"
  :args '("start")
  :cwd "/path/to/my/project")

Tag inheritance

If a service has a tag and that tag is defined (see prodigy-define-tag), the service inherits the tag properties. The inheritance is recursive, so if any of the service tags has tags itself, the service will inherit those tag properties as well.

This is best illustrated with an example. Rails can run with many different servers. Each server indicate that it's ready with a different log message. In the example code below, a tag is defined for each server and one for Rails that inherits all those servers.

That means that a service that is tagged with rails, will be set to ready if it uses any of the three servers. But since there is a tag for each server, a non Rails service that uses any of the servers can simply use that tag.

  :name 'thin
  :ready-message "Listening on 0\\.0\\.0\\.0:[0-9]+, CTRL\\+C to stop")

  :name 'webrick
  :ready-message "WEBrick::HTTPServer#start: pid=[0-9]+ port=[0-9]+")

  :name 'mongrel
  :ready-message "Ctrl-C to shutdown server")

  :name 'rails
  :tags '(thin mongrel webrick))

  :name "Rails Project"
  :command "bundle"
  :args '("exec" "rails" "server")
  :cwd "/path/to/my/project"
  :tags '(rails))

  :name "Thin Project"
  :command "bundle"
  :args '("exec" "thin" "start")
  :cwd "/path/to/my/project"
  :tags '(thin))

Fine Tuning Status

Prodigy can only look at the process status to determine the service status. To make status even more useful, you can set status manually. Prodigy provides the function prodigy-set-status for this. In this example, we create a tag rails that will set the status to ready when the server is actually ready.

The services that are tagged with rails will all inherit this.

  :name 'rails
  :on-output (lambda (&rest args)
               (let ((output (plist-get args :output))
                     (service (plist-get args :service)))
                 (when (or (s-matches? "Listening on 0\.0\.0\.0:[0-9]+, CTRL\\+C to stop" output)
                           (s-matches? "Ctrl-C to shutdown server" output))
                   (prodigy-set-status service 'ready)))))

  :name "Rails"
  :command "bundle"
  :args '("exec" "rails" "server")
  :cwd "/path/to/my/project"
  :tags '(rvm rails))

  :name "Sinatra"
  :command "bundle"
  :args '("exec" "rackup")
  :cwd "/path/to/my/project"
  :tags '(rvm rails))



For some unknown reason, Jekyll fail with this error:

error: invalid byte sequence in US-ASCII. Use --trace to view backtrace

This can be solved by adding a jekyll tag, like this:

  :name 'jekyll
  :env '(("LANG" "en_US.UTF-8")
         ("LC_ALL" "en_US.UTF-8")))

Then tag your services with the jekyll tag.


This is a short summary of changes between versions.


  • Tail process buffer if the point is at the end
  • Misc bug fixes


  • Adding new function prodigy-callback, allowing for some syntactic sugar using property lambdas (that take plist as argument).
  • For some properties that accepts a lambda as argument, the lambda arguments is now a plist. Breaking change!


  • New property :ready-message used to set the process status to ready when matching output appears.
  • Clear process buffer contents using k


  • Do not require current working directory (see :cwd property).
  • Improved test suite.
  • Process output buffer has major mode prodigy-view-mode.
  • Font lock automatically enabled in view mode.
  • Truncate process output buffer (see variables prodigy-view-buffer-maximum-size, prodigy-view-truncate-by-default and :truncate-output property).
  • Fix bug when restarting a service cleared buffer contents.
  • Jump between services with status with M-n and M-p.


  • Tag inheritance (see prodigy-define-tag).
  • On process output hook (see :on-output property).
  • Improved status handling (see prodigy-set-status).
  • Using hl-line.
  • Updated status colors.
  • Url property can be a list of urls (see :url property).
  • Async restarts.
  • Force kill process (using prefix argument to prodigy-stop).
  • Service path can be string, list or lambda (see :path property).
  • Service command can be string or lambda (see :command property).
  • Service args can be list or lambda (see :args property).
  • Hidden tags (see :hide property).


Contribution is much welcome!

If your contribution is a bug fix, create your topic branch from master. If it is a new feature, check if there exists a WIP branch (vMAJOR.MINOR-wip). If it does, use that branch, otherwise use master.

Install Cask if you haven't already, then:

$ cd /path/to/prodigy.el
$ cask

Run all tests with:

$ make