#plugin #launcher #desktop #front-end #pop-launcher #ipc #json


Library for writing plugins and frontends for pop-launcher

2 stable releases

1.2.4 Feb 14, 2024
1.2.3 Jan 22, 2024

#604 in Web programming

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Used in 3 crates

MPL-2.0 license

218 lines

Onagre launcher

This repository is a fork of pop-launcher which gets read of all the PopOs specific and dependencies.

Modular IPC-based desktop launcher service, written in Rust. Desktop launchers may interface with this service via spawning the pop-launcher process and communicating to it via JSON IPC over the stdin and stdout pipes. The launcher service will also spawn plugins found in plugin directories on demand, based on the queries sent to the service.

Using IPC enables each plugin to isolate their data from other plugin processes and frontends that are interacting with them. If a plugin crashes, the launcher will continue functioning normally, gracefully cleaning up after the crashed process. Frontends and plugins may also be written in any language. The pop-launcher will do its part to schedule the execution of these plugins in parallel, on demand.


Requires the following dependencies:

And then must be used with a compatible pop-launcher frontend

just build-release # Build
just install # Install locally

If you are packaging, run just vendor outside of your build chroot, then use just build-vendored inside the build-chroot. Then you can specify a custom root directory and prefix.

# Outside build chroot
just vendor

# Inside build chroot
just build-vendored
sudo just rootdir=debian/tmp prefix=/usr install

Want to install specific plugins? Remove the plugins you don't want:

just plugins="calc desktop_entries files find pop_shell pulse recent scripts terminal web" install

Plugin Directories

  • User-local plugins: ~/.local/share/pop-launcher/plugins/{plugin}/
  • System-wide install for system administrators: /etc/pop-launcher/plugins/{plugin}/
  • Distribution packaging: /usr/lib/pop-launcher/plugins/{plugin}/

Plugin Config

A plugin's metadata is defined pop-launcher/plugins/{plugin}/plugin.ron.

    name: "PluginName",
    description: "Plugin Description: Example",
    bin: (
        path: "name-of-executable-in-plugin-folder",
    icon: Name("icon-name-or-path"),
    // Optional
    query: (
        // Optional -- if we should isolate this plugin when the regex matches
        isolate: true,
        // Optional -- Plugin which searches on empty queries
        persistent: true,
        // Optional -- avoid sorting results from this plugin
        no_sort: true,
        // Optional -- pattern that a query must have to be sent to plugin
        regex: "pattern",
        // Optional -- the launcher should keep a history for this plugin
        history: true,

Script Directories

  • User-local scripts: ~/.local/share/pop-launcher/scripts
  • System-wide install for system administrators: /etc/pop-launcher/scripts
  • Distribution packaging: /usr/lib/pop-launcher/scripts

Example script

# name: Connect to VPN
# icon: network-vpn
# description: Start VPN
# keywords: vpn start connect

nmcli connection up "vpn-name"


Whether implementing a frontend or a plugin, the JSON codec used by pop-launcher is line-based. Every line will contain a single JSON message That will be serialized or decoded as a Request, PluginResponse, or Response. These types can be referenced in docs.rs. IPC is based on standard input/output streams, so you should take care not to write logs to stdout.

Frontend JSON IPC

The frontend will send Requests to the pop-launcher service through the stdin pipe. The stdout pipe will respond with Responses. It is ideal to design your frontend to accept responses asynchronously. Sending Interrupt or Search will cancel any active searches being performed, if the plugins that are still actively searching support cancellation.


Plugins will receive Requests from pop-launcher through their stdin pipe. They should respond with PluginResponse messages.


If you are writing a frontend, you are sending these events to the pop-launcher stdin pipe. If you are writing a plugin, the plugin will be receiving these events from its stdin.

pub enum Request {
    /// Activate on the selected item
    /// Activate a context item on an item.
    ActivateContext { id: Indice, context: Indice },
    /// Perform a tab completion from the selected item
    /// Request for any context options this result may have.
    /// Request to end the service
    /// Requests to cancel any active searches
    /// Request to close the selected item
    /// Perform a search in our database

JSON Equivalent

  • { "Activate": number }
  • { "ActivateContext": { "id": number, "context": id }}
  • { "Complete": number }
  • { "Context": number }
  • "Exit"
  • "Interrupt"
  • { "Quit": number }
  • { "Search": string }


If you are writing a plugin, you should send these events to your stdout.

pub enum PluginResponse {
    /// Append a new search item to the launcher
    /// Clear all results in the launcher list
    /// Close the launcher
    // Additional options for launching a certain item
    Context {
        id: Indice,
        options: Vec<ContextOption>,
    // Notifies that a .desktop entry should be launched by the frontend.
    DesktopEntry {
        path: PathBuf,
        gpu_preference: GpuPreference,
    /// Update the text in the launcher
    /// Indicates that a plugin is finished with its queries

JSON Equivalent

  • { "Append": PluginSearchResult },
  • "Clear",
  • "Close",
  • { "Context": { "id": number, "options": Array<ContextOption> }}
  • { "DesktopEntry": { "path": string, "gpu_preference": GpuPreference }}
  • { "Fill": string }
  • "Finished"

Where PluginSearchResult is:

    id: number,
    name: string,
    description: string,
    keywords?: Array<string>,
    icon?: IconSource,
    exec?: string,
    window?: [number, number],

ContextOption is:

    id: number,
    name: string

GpuPreference is:

"Default" | "NonDefault"

And IconSource is either:

  • { "Name": string }, where the name is a system icon, or an icon referred to by path
  • { "Mime": string }, where the mime is a mime essence string, to display file-based icons


Those implementing frontends should listen for these events:

pub enum Response {
    // An operation was performed and the frontend may choose to exit its process.
    // Additional options for launching a certain item
    Context {
        id: Indice,
        options: Vec<ContextOption>,
    // Notifies that a .desktop entry should be launched by the frontend.
    DesktopEntry {
        path: PathBuf,
        gpu_preference: GpuPreference,
    // The frontend should clear its search results and display a new list
    // An item was selected that resulted in a need to autofill the launcher

JSON Equivalent

  • "Close"
  • { "DesktopEntry": string }
  • { "Update": Array<SearchResult>}
  • { "Fill": string }

Where SearchResult is:

    id: number,
    name: string,
    description: string,
    icon?: IconSource,
    category_icon?: IconSource,
    window?: [number, number]


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