cli: add json output

book/AGENTS.md

@@ -61,6 +61,12 @@ A third review pass fixed:
 - `outputs.md`: VRR variant3 description said "describes its content as"
   instead of the correct protocol term "describes its content type as".
 
+A fourth update documented the new `--json` and `--all-json-fields` global
+CLI flags, which enable machine-readable JSONL output from all query/status
+subcommands. A new "JSON Output" section was added to `cli.md` listing all
+supported commands, the JSONL format, field omission behavior, and `jq`
+usage examples.
+
 **Future work might include:**
 
 - Keeping the book in sync as Jay adds new features or changes behavior.

book/src/cli.md

@@ -20,6 +20,79 @@ Every subcommand accepts a global `--log-level` option (`trace`, `debug`,
 
 ---
 
+## JSON Output
+
+Most query and status commands can output machine-readable JSON instead of
+human-readable text. Pass the global `--json` flag before the subcommand:
+
+```shell
+~$ jay --json randr
+~$ jay --json clients
+~$ jay --json idle
+```
+
+Each command prints one or more JSON objects, one per line (JSONL format). This
+makes it easy to process with tools like `jq`:
+
+```shell
+~$ jay --json randr | jq '.drm_devices[].connectors[].name'
+~$ jay --json clients | jq 'select(.pid != null) | .pid'
+```
+
+By default, fields that are empty arrays, `null`, or `false` are omitted from
+the output to reduce noise. To include every field, pass `--all-json-fields`:
+
+```shell
+~$ jay --all-json-fields --json randr
+```
+
+### Supported Commands
+
+The following commands support `--json`:
+
+`jay clients`
+: One JSON object per client.
+
+`jay color-management status`
+: Color management enabled/available status.
+
+`jay config path`
+: The config file path as a JSON string.
+
+`jay idle status`
+: Idle interval, grace period, and inhibitors.
+
+`jay input show`, `jay input seat <seat> show`, `jay input device <id> show`
+: Seats and input devices with all properties.
+
+`jay log --path`
+: The log file path as a JSON string.
+
+`jay pid`
+: The compositor PID as a JSON number.
+
+`jay randr show`
+: DRM devices, connectors, outputs, modes, and display properties.
+
+`jay seat-test`
+: Streaming JSONL -- one JSON object per input event (key, pointer, touch,
+  gesture, tablet, switch).
+
+`jay tree query`
+: One JSON object per root node, with children nested recursively.
+
+`jay version`
+: The version string as a JSON value.
+
+`jay xwayland status`
+: Xwayland scaling mode and implied scale.
+
+> [!TIP]
+> Mutating commands (e.g., `jay idle set`, `jay randr output ... enable`)
+> produce no output, so `--json` has no effect on them.
+
+---
+
 ## Running
 
 ### `jay run`

book/src/features.md

@@ -42,7 +42,8 @@ There is a small but growing integration test suite that is used to ensure this.
 ## Command-Line Interface
 
 Jay has a comprehensive CLI that can be used to inspect and configure the
-compositor at runtime:
+compositor at runtime. All query commands support `--json` for machine-readable
+output:
 
 ```
 ~$ jay
@@ -77,7 +78,9 @@ Commands:
 
 Options:
       --log-level <LOG_LEVEL>  The log level [default: info] [possible values: trace, debug, info, warn, error, off]
-  -h, --help                   Print help
+      --json                   Output data as JSONL
+      --all-json-fields        Print all fields in JSON output
+  -h, --help                   Print help (see more with '--help')
 ```
 
 See the full [Command-Line Interface](cli.md) reference for details.

src/cli.rs

@@ -8,6 +8,7 @@ mod duration;
 mod generate;
 mod idle;
 mod input;
+mod json;
 mod log;
 mod pid;
 mod quit;
@@ -27,8 +28,9 @@ use {
     crate::{
         cli::{
             clients::ClientsArgs, color_management::ColorManagementArgs, config::ConfigArgs,
-            damage_tracking::DamageTrackingArgs, idle::IdleCmd, input::InputArgs, randr::RandrArgs,
+            damage_tracking::DamageTrackingArgs, idle::IdleCmd, input::InputArgs,
-            reexec::ReexecArgs, run_tagged::RunTaggedArgs, tree::TreeArgs, xwayland::XwaylandArgs,
+            json::VERBOSE_JSON, randr::RandrArgs, reexec::ReexecArgs, run_tagged::RunTaggedArgs,
+            tree::TreeArgs, xwayland::XwaylandArgs,
         },
         compositor::{LogLevel, start_compositor},
         format::{Format, ref_formats},
@@ -37,6 +39,7 @@ use {
     },
     clap::{Args, Parser, Subcommand, ValueEnum, ValueHint, builder::PossibleValue},
     clap_complete::Shell,
+    std::sync::atomic::Ordering::Relaxed,
 };
 
 /// A wayland compositor.
@@ -53,6 +56,14 @@ pub struct GlobalArgs {
     /// The log level.
     #[clap(value_enum, long, default_value_t)]
     pub log_level: LogLevel,
+    /// Output data as JSONL.
+    #[clap(long)]
+    pub json: bool,
+    /// Print all fields in JSON output.
+    ///
+    /// By default, some fields that are empty arrays, null, or false are omitted.
+    #[clap(long)]
+    pub all_json_fields: bool,
 }
 
 #[derive(Subcommand, Debug)]
@@ -225,6 +236,9 @@ pub fn main() {
     if not_matches!(cli.command, Cmd::Run(_)) {
         drop_all_pr_caps();
     }
+    if cli.global.all_json_fields {
+        VERBOSE_JSON.store(true, Relaxed);
+    }
     match cli.command {
         Cmd::Run(a) => start_compositor(cli.global, a),
         Cmd::GenerateCompletion(g) => generate::main(g),

src/cli/clients.rs

@@ -1,6 +1,9 @@
 use {
     crate::{
-        cli::GlobalArgs,
+        cli::{
+            GlobalArgs,
+            json::{JsonClient, jsonl},
+        },
         tools::tool_client::{Handle, ToolClient, with_tool_client},
         wire::{JayClientQueryId, jay_client_query, jay_compositor},
     },
@@ -69,7 +72,7 @@ struct KillIdArgs {
 pub fn main(global: GlobalArgs, clients_args: ClientsArgs) {
     with_tool_client(global.log_level, |tc| async move {
         let clients = Rc::new(Clients { tc: tc.clone() });
-        clients.run(clients_args).await;
+        clients.run(&global, clients_args).await;
     });
 }
 
@@ -78,7 +81,7 @@ struct Clients {
 }
 
 impl Clients {
-    async fn run(&self, args: ClientsArgs) {
+    async fn run(&self, global: &GlobalArgs, args: ClientsArgs) {
         let tc = &self.tc;
         let comp = tc.jay_compositor().await;
         let cmd = args
@@ -113,13 +116,20 @@ impl Clients {
                 let clients = handle_client_query(tc, id).await;
                 let mut clients = clients.values().collect::<Vec<_>>();
                 clients.sort_by_key(|c| c.id);
-                let mut prefix = "    ".to_string();
+                if global.json {
-                let mut printer = ClientPrinter {
+                    for client in clients {
-                    prefix: &mut prefix,
+                        let client = make_json_client(client);
-                };
+                        jsonl(&client);
-                for client in clients {
+                    }
-                    println!("- client:");
+                } else {
-                    printer.print_client(client);
+                    let mut prefix = "    ".to_string();
+                    let mut printer = ClientPrinter {
+                        prefix: &mut prefix,
+                    };
+                    for client in clients {
+                        println!("- client:");
+                        printer.print_client(client);
+                    }
                 }
             }
             ClientsCmd::Kill(a) => match a.cmd {
@@ -246,3 +256,19 @@ impl ClientPrinter<'_> {
         opt!(tag, "tag");
     }
 }
+
+pub fn make_json_client(client: &Client) -> JsonClient<'_> {
+    JsonClient {
+        client_id: client.id,
+        sandboxed: client.sandboxed,
+        sandbox_engine: client.sandbox_engine.as_deref(),
+        sandbox_app_id: client.sandbox_app_id.as_deref(),
+        sandbox_instance_id: client.sandbox_instance_id.as_deref(),
+        uid: client.uid,
+        pid: client.pid,
+        is_xwayland: client.is_xwayland,
+        comm: client.comm.as_deref(),
+        exe: client.exe.as_deref(),
+        tag: client.tag.as_deref(),
+    }
+}

src/cli/color_management.rs

@@ -1,6 +1,9 @@
 use {
     crate::{
-        cli::GlobalArgs,
+        cli::{
+            GlobalArgs,
+            json::{JsonColorManagementStatus, jsonl},
+        },
         tools::tool_client::{Handle, ToolClient, with_tool_client},
         wire::{JayColorManagementId, jay_color_management, jay_compositor},
     },
@@ -28,7 +31,7 @@ pub enum ColorManagementCmd {
 pub fn main(global: GlobalArgs, args: ColorManagementArgs) {
     with_tool_client(global.log_level, |tc| async move {
         let cm = ColorManagement { tc: tc.clone() };
-        cm.run(args).await;
+        cm.run(&global, args).await;
     });
 }
 
@@ -37,19 +40,19 @@ struct ColorManagement {
 }
 
 impl ColorManagement {
-    async fn run(self, args: ColorManagementArgs) {
+    async fn run(self, global: &GlobalArgs, args: ColorManagementArgs) {
         let tc = &self.tc;
         let comp = tc.jay_compositor().await;
         let id = tc.id();
         tc.send(jay_compositor::GetColorManagement { self_id: comp, id });
         match args.command.unwrap_or_default() {
-            ColorManagementCmd::Status => self.status(id).await,
+            ColorManagementCmd::Status => self.status(global, id).await,
             ColorManagementCmd::Enable => self.set_enabled(id, true).await,
             ColorManagementCmd::Disable => self.set_enabled(id, false).await,
         }
     }
 
-    async fn status(self, id: JayColorManagementId) {
+    async fn status(self, global: &GlobalArgs, id: JayColorManagementId) {
         let tc = &self.tc;
         tc.send(jay_color_management::Get { self_id: id });
         let enabled = Rc::new(Cell::new(false));
@@ -61,14 +64,21 @@ impl ColorManagement {
             iv.set(msg.available != 0);
         });
         tc.round_trip().await;
-        if enabled.get() {
+        if global.json {
-            print!("Enabled");
+            jsonl(&JsonColorManagementStatus {
-            if !available.get() {
+                enabled: enabled.get(),
-                print!(" (Unavailable)");
+                available: available.get(),
-            }
+            });
-            println!();
         } else {
-            println!("Disabled");
+            if enabled.get() {
+                print!("Enabled");
+                if !available.get() {
+                    print!(" (Unavailable)");
+                }
+                println!();
+            } else {
+                println!("Disabled");
+            }
         }
     }
 

src/cli/config.rs

@@ -1,5 +1,10 @@
 use {
-    crate::{cli::GlobalArgs, compositor::config_dir, logger::Logger, utils::errorfmt::ErrorFmt},
+    crate::{
+        cli::{GlobalArgs, json::jsonl},
+        compositor::config_dir,
+        logger::Logger,
+        utils::errorfmt::ErrorFmt,
+    },
     clap::{Args, Subcommand},
     jay_toml_config::CONFIG_TOML,
     std::path::Path,
@@ -87,7 +92,12 @@ pub fn main(global: GlobalArgs, args: ConfigArgs) {
         ConfigCmd::Path => {
             let dir = dir();
             let toml_path = Path::new(&dir).join(CONFIG_TOML);
-            println!("{}", toml_path.display());
+            if global.json {
+                let path = toml_path.display().to_string();
+                jsonl(&path);
+            } else {
+                println!("{}", toml_path.display());
+            }
         }
         ConfigCmd::OpenDir => {
             const XDG_OPEN: &str = "xdg-open";

src/cli/idle.rs

@@ -1,6 +1,10 @@
 use {
     crate::{
-        cli::{GlobalArgs, IdleArgs, duration::parse_duration},
+        cli::{
+            GlobalArgs, IdleArgs,
+            duration::parse_duration,
+            json::{JsonIdle, JsonIdleInhibitor, jsonl},
+        },
         tools::tool_client::{Handle, ToolClient, with_tool_client},
         utils::stack::Stack,
         wire::{JayIdleId, WlSurfaceId, jay_compositor, jay_idle},
@@ -53,7 +57,7 @@ pub struct IdleSetGracePeriodArgs {
 pub fn main(global: GlobalArgs, args: IdleArgs) {
     with_tool_client(global.log_level, |tc| async move {
         let idle = Idle { tc: tc.clone() };
-        idle.run(args).await;
+        idle.run(&global, args).await;
     });
 }
 
@@ -62,7 +66,7 @@ struct Idle {
 }
 
 impl Idle {
-    async fn run(self, args: IdleArgs) {
+    async fn run(self, global: &GlobalArgs, args: IdleArgs) {
         let tc = &self.tc;
         let comp = tc.jay_compositor().await;
         let idle = tc.id();
@@ -71,13 +75,13 @@ impl Idle {
             id: idle,
         });
         match args.command.unwrap_or_default() {
-            IdleCmd::Status => self.status(idle).await,
+            IdleCmd::Status => self.status(global, idle).await,
             IdleCmd::Set(args) => self.set(idle, args).await,
             IdleCmd::SetGracePeriod(args) => self.set_grace_period(idle, args).await,
         }
     }
 
-    async fn status(self, idle: JayIdleId) {
+    async fn status(self, global: &GlobalArgs, idle: JayIdleId) {
         let tc = &self.tc;
         tc.send(jay_idle::GetStatus { self_id: idle });
         let timeout = Rc::new(Cell::new(0u64));
@@ -90,7 +94,7 @@ impl Idle {
         });
         struct Inhibitor {
             surface: WlSurfaceId,
-            _client_id: u64,
+            client_id: u64,
             pid: u64,
             comm: String,
         }
@@ -98,47 +102,63 @@ impl Idle {
         jay_idle::Inhibitor::handle(tc, idle, inhibitors.clone(), |iv, msg| {
             iv.push(Inhibitor {
                 surface: msg.surface,
-                _client_id: msg.client_id,
+                client_id: msg.client_id,
                 pid: msg.pid,
                 comm: msg.comm.to_string(),
             });
         });
         tc.round_trip().await;
-        let interval = |iv: u64| {
-            fmt::from_fn(move |f| {
-                let minutes = iv / 60;
-                let seconds = iv % 60;
-                if minutes == 0 && seconds == 0 {
-                    write!(f, " disabled")?;
-                } else {
-                    if minutes > 0 {
-                        write!(f, " {} minute", minutes)?;
-                        if minutes > 1 {
-                            write!(f, "s")?;
-                        }
-                    }
-                    if seconds > 0 {
-                        write!(f, " {} second", seconds)?;
-                        if seconds > 1 {
-                            write!(f, "s")?;
-                        }
-                    }
-                }
-                Ok(())
-            })
-        };
-        println!("Interval:{}", interval(timeout.get()));
-        println!("Grace period:{}", interval(grace.get()));
         let mut inhibitors = inhibitors.take();
-        inhibitors.sort_by_key(|i| i.pid);
+        inhibitors.sort_by_key(|i| (i.pid, i.surface));
-        inhibitors.sort_by_key(|i| i.surface);
+        if global.json {
-        if inhibitors.len() > 0 {
+            let mut json = JsonIdle {
-            println!("Inhibitors:");
+                idle_sec: timeout.get(),
-            for inhibitor in inhibitors {
+                grace_sec: grace.get(),
-                println!(
+                inhibitors: vec![],
-                    "  {}, surface {}, pid {}",
+            };
-                    inhibitor.comm, inhibitor.surface, inhibitor.pid
+            for inhibitor in &inhibitors {
-                );
+                json.inhibitors.push(JsonIdleInhibitor {
+                    surface: inhibitor.surface.raw(),
+                    client_id: inhibitor.client_id,
+                    pid: inhibitor.pid,
+                    comm: &inhibitor.comm,
+                });
+            }
+            jsonl(&json);
+        } else {
+            let interval = |iv: u64| {
+                fmt::from_fn(move |f| {
+                    let minutes = iv / 60;
+                    let seconds = iv % 60;
+                    if minutes == 0 && seconds == 0 {
+                        write!(f, " disabled")?;
+                    } else {
+                        if minutes > 0 {
+                            write!(f, " {} minute", minutes)?;
+                            if minutes > 1 {
+                                write!(f, "s")?;
+                            }
+                        }
+                        if seconds > 0 {
+                            write!(f, " {} second", seconds)?;
+                            if seconds > 1 {
+                                write!(f, "s")?;
+                            }
+                        }
+                    }
+                    Ok(())
+                })
+            };
+            println!("Interval:{}", interval(timeout.get()));
+            println!("Grace period:{}", interval(grace.get()));
+            if inhibitors.len() > 0 {
+                println!("Inhibitors:");
+                for inhibitor in inhibitors {
+                    println!(
+                        "  {}, surface {}, pid {}",
+                        inhibitor.comm, inhibitor.surface, inhibitor.pid
+                    );
+                }
             }
         }
     }

src/cli/input.rs

@@ -1,7 +1,10 @@
 use {
     crate::{
         backend::{InputDeviceAccelProfile, InputDeviceCapability, InputDeviceClickMethod},
-        cli::GlobalArgs,
+        cli::{
+            GlobalArgs,
+            json::{JsonInputData, JsonInputDevice, JsonSeat, jsonl},
+        },
         clientmem::ClientMem,
         libinput::consts::{
             ConfigClickMethod, LIBINPUT_CONFIG_ACCEL_PROFILE_ADAPTIVE,
@@ -326,7 +329,7 @@ pub struct UseHardwareCursorArgs {
 pub fn main(global: GlobalArgs, args: InputArgs) {
     with_tool_client(global.log_level, |tc| async move {
         let idle = Rc::new(Input { tc: tc.clone() });
-        idle.run(args).await;
+        idle.run(&global, args).await;
     });
 }
 
@@ -372,7 +375,7 @@ struct Input {
 }
 
 impl Input {
-    async fn run(self: &Rc<Self>, args: InputArgs) {
+    async fn run(self: &Rc<Self>, global: &GlobalArgs, args: InputArgs) {
         let tc = &self.tc;
         let comp = tc.jay_compositor().await;
         let input = tc.id();
@@ -381,9 +384,9 @@ impl Input {
             id: input,
         });
         match args.command.unwrap_or_default() {
-            InputCmd::Show(args) => self.show(input, args).await,
+            InputCmd::Show(args) => self.show(global, input, args).await,
-            InputCmd::Seat(args) => self.seat(input, args).await,
+            InputCmd::Seat(args) => self.seat(global, input, args).await,
-            InputCmd::Device(args) => self.device(input, args).await,
+            InputCmd::Device(args) => self.device(global, input, args).await,
         }
     }
 
@@ -436,7 +439,7 @@ impl Input {
         data.take()
     }
 
-    async fn seat(self: &Rc<Self>, input: JayInputId, args: SeatArgs) {
+    async fn seat(self: &Rc<Self>, global: &GlobalArgs, input: JayInputId, args: SeatArgs) {
         let tc = &self.tc;
         match args.command.unwrap_or_default() {
             SeatCommand::Show(a) => {
@@ -448,7 +451,11 @@ impl Input {
                     name: &args.seat,
                 });
                 let data = self.get(input).await;
-                self.print_data(data, a.verbose);
+                if global.json {
+                    self.print_data_json(data);
+                } else {
+                    self.print_data(data, a.verbose);
+                }
             }
             SeatCommand::SetRepeatRate(a) => {
                 self.handle_error(input, |e| {
@@ -543,7 +550,7 @@ impl Input {
         tc.round_trip().await;
     }
 
-    async fn device(self: &Rc<Self>, input: JayInputId, args: DeviceArgs) {
+    async fn device(self: &Rc<Self>, global: &GlobalArgs, input: JayInputId, args: DeviceArgs) {
         let tc = &self.tc;
         match args.command.unwrap_or_default() {
             DeviceCommand::Show => {
@@ -555,8 +562,12 @@ impl Input {
                     id: args.device,
                 });
                 let data = self.get(input).await;
-                for device in &data.input_device {
+                if global.json {
-                    self.print_device("", true, device);
+                    self.print_data_json(data);
+                } else {
+                    for device in &data.input_device {
+                        self.print_device("", true, device);
+                    }
                 }
             }
             DeviceCommand::SetAccelProfile(a) => {
@@ -779,10 +790,14 @@ impl Input {
         tc.round_trip().await;
     }
 
-    async fn show(self: &Rc<Self>, input: JayInputId, args: ShowArgs) {
+    async fn show(self: &Rc<Self>, global: &GlobalArgs, input: JayInputId, args: ShowArgs) {
         self.tc.send(jay_input::GetAll { self_id: input });
         let data = self.get(input).await;
-        self.print_data(data, args.verbose);
+        if global.json {
+            self.print_data_json(data);
+        } else {
+            self.print_data(data, args.verbose);
+        }
     }
 
     fn print_data(self: &Rc<Self>, mut data: Data, verbose: bool) {
@@ -911,6 +926,38 @@ impl Input {
         }
     }
 
+    fn print_data_json(&self, mut data: Data) {
+        data.seats.sort_by(|l, r| l.name.cmp(&r.name));
+        data.input_device.sort_by_key(|l| l.id);
+        let mut seats = Vec::new();
+        for seat in &data.seats {
+            let devices = data
+                .input_device
+                .iter()
+                .filter(|c| c.seat.as_ref() == Some(&seat.name))
+                .map(make_json_device)
+                .collect();
+            seats.push(JsonSeat {
+                name: &seat.name,
+                repeat_rate: seat.repeat_rate,
+                repeat_delay: seat.repeat_delay,
+                hardware_cursor: seat.hardware_cursor,
+                devices,
+            });
+        }
+        let detached_devices = data
+            .input_device
+            .iter()
+            .filter(|c| c.seat.is_none())
+            .map(make_json_device)
+            .collect();
+        let json = JsonInputData {
+            seats,
+            detached_devices,
+        };
+        jsonl(&json);
+    }
+
     async fn get(self: &Rc<Self>, input: JayInputId) -> Data {
         let tc = &self.tc;
         let data = Rc::new(RefCell::new(Data::default()));
@@ -1018,3 +1065,27 @@ impl Input {
         data.borrow_mut().clone()
     }
 }
+
+fn make_json_device(device: &InputDevice) -> JsonInputDevice<'_> {
+    JsonInputDevice {
+        input_device_id: device.id,
+        name: &device.name,
+        seat: device.seat.as_deref(),
+        syspath: device.syspath.as_deref(),
+        devnode: device.devnode.as_deref(),
+        capabilities: device.capabilities.iter().map(|c| c.text()).collect(),
+        accel_profile: device.accel_profile.as_ref().map(|v| v.text()),
+        accel_speed: device.accel_speed,
+        tap_enabled: device.tap_enabled,
+        tap_drag_enabled: device.tap_drag_enabled,
+        tap_drag_lock_enabled: device.tap_drag_lock_enabled,
+        left_handed: device.left_handed,
+        natural_scrolling: device.natural_scrolling_enabled,
+        px_per_wheel_scroll: device.px_per_wheel_scroll,
+        transform_matrix: device.transform_matrix,
+        output: device.output.as_deref(),
+        calibration_matrix: device.calibration_matrix,
+        click_method: device.click_method.as_ref().map(|v| v.text()),
+        middle_button_emulation: device.middle_button_emulation_enabled,
+    }
+}

src/cli/json.rs

@@ -0,0 +1,606 @@
+use {
+    crate::ifs::jay_tree_query::{
+        TREE_TY_CONTAINER, TREE_TY_DISPLAY, TREE_TY_FLOAT, TREE_TY_LAYER_SURFACE,
+        TREE_TY_LOCK_SURFACE, TREE_TY_OUTPUT, TREE_TY_PLACEHOLDER, TREE_TY_WORKSPACE,
+        TREE_TY_X_WINDOW, TREE_TY_XDG_POPUP, TREE_TY_XDG_TOPLEVEL,
+    },
+    jay_config::video::{TearingMode, VrrMode},
+    num_traits::Zero,
+    serde::{Serialize, Serializer},
+    std::{
+        io::{Write, stdout},
+        sync::atomic::{AtomicBool, Ordering::Relaxed},
+    },
+    uapi::c,
+};
+
+pub static VERBOSE_JSON: AtomicBool = AtomicBool::new(false);
+
+fn quiet() -> bool {
+    !VERBOSE_JSON.load(Relaxed)
+}
+
+fn is_none<T>(t: &Option<T>) -> bool {
+    quiet() && t.is_none()
+}
+
+fn is_empty<T>(t: &[T]) -> bool {
+    quiet() && t.is_empty()
+}
+
+fn is_false(v: &bool) -> bool {
+    quiet() && !*v
+}
+
+fn is_zero(v: &impl Zero) -> bool {
+    quiet() && v.is_zero()
+}
+
+pub fn jsonl<T>(value: &T)
+where
+    T: ?Sized + Serialize,
+{
+    let mut writer = stdout().lock();
+    serde_json::to_writer(&mut writer, value).unwrap();
+    writer.write_all(b"\n").unwrap();
+}
+
+#[derive(Serialize)]
+pub struct JsonClient<'a> {
+    pub client_id: u64,
+    #[serde(skip_serializing_if = "is_false")]
+    pub sandboxed: bool,
+    #[serde(skip_serializing_if = "is_none")]
+    pub sandbox_engine: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub sandbox_app_id: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub sandbox_instance_id: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub uid: Option<c::uid_t>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub pid: Option<c::pid_t>,
+    #[serde(skip_serializing_if = "is_false")]
+    pub is_xwayland: bool,
+    #[serde(skip_serializing_if = "is_none")]
+    pub comm: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub exe: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub tag: Option<&'a str>,
+}
+
+#[derive(Serialize)]
+pub struct JsonColorManagementStatus {
+    pub enabled: bool,
+    pub available: bool,
+}
+
+#[derive(Serialize)]
+pub struct JsonIdle<'a> {
+    pub idle_sec: u64,
+    #[serde(skip_serializing_if = "is_zero")]
+    pub grace_sec: u64,
+    #[serde(skip_serializing_if = "is_empty")]
+    pub inhibitors: Vec<JsonIdleInhibitor<'a>>,
+}
+
+#[derive(Serialize)]
+pub struct JsonIdleInhibitor<'a> {
+    pub client_id: u64,
+    pub surface: u32,
+    pub pid: u64,
+    pub comm: &'a str,
+}
+
+#[derive(Serialize)]
+pub struct JsonRandrData<'a> {
+    #[serde(skip_serializing_if = "is_empty")]
+    pub drm_devices: Vec<JsonDrmDevice<'a>>,
+    #[serde(skip_serializing_if = "is_empty")]
+    pub unbound_connectors: Vec<JsonConnector<'a>>,
+}
+
+#[derive(Serialize)]
+pub struct JsonDrmDevice<'a> {
+    pub devnode: &'a str,
+    pub syspath: &'a str,
+    pub vendor: u32,
+    pub vendor_name: &'a str,
+    pub model: u32,
+    pub model_name: &'a str,
+    pub gfx_api: &'a str,
+    #[serde(skip_serializing_if = "is_false")]
+    pub render_device: bool,
+    #[serde(skip_serializing_if = "is_empty")]
+    pub connectors: Vec<JsonConnector<'a>>,
+}
+
+#[derive(Serialize)]
+pub struct JsonConnector<'a> {
+    pub name: &'a str,
+    pub enabled: bool,
+    #[serde(skip_serializing_if = "is_none")]
+    pub output: Option<JsonOutput<'a>>,
+}
+
+pub struct JsonVrrMode(pub VrrMode);
+
+impl Serialize for JsonVrrMode {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let s = match self.0 {
+            VrrMode::NEVER => "never",
+            VrrMode::ALWAYS => "always",
+            VrrMode::VARIANT_1 => "variant1",
+            VrrMode::VARIANT_2 => "variant2",
+            VrrMode::VARIANT_3 => "variant3",
+            n => return serializer.serialize_u32(n.0),
+        };
+        serializer.serialize_str(s)
+    }
+}
+
+pub struct JsonTearingMode(pub TearingMode);
+
+impl Serialize for JsonTearingMode {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let s = match self.0 {
+            TearingMode::NEVER => "never",
+            TearingMode::ALWAYS => "always",
+            TearingMode::VARIANT_1 => "variant1",
+            TearingMode::VARIANT_2 => "variant2",
+            TearingMode::VARIANT_3 => "variant3",
+            n => return serializer.serialize_u32(n.0),
+        };
+        serializer.serialize_str(s)
+    }
+}
+
+#[derive(Serialize)]
+pub struct JsonOutput<'a> {
+    pub product: &'a str,
+    pub manufacturer: &'a str,
+    pub serial_number: &'a str,
+    #[serde(skip_serializing_if = "is_zero")]
+    pub width_mm: i32,
+    #[serde(skip_serializing_if = "is_zero")]
+    pub height_mm: i32,
+    #[serde(skip_serializing_if = "is_false")]
+    pub non_desktop: bool,
+    pub scale: f64,
+    pub x: i32,
+    pub y: i32,
+    pub width: i32,
+    pub height: i32,
+    pub transform: &'static str,
+    #[serde(skip_serializing_if = "is_none")]
+    pub mode: Option<JsonMode>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub format: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_false")]
+    pub vrr_capable: bool,
+    #[serde(skip_serializing_if = "is_false")]
+    pub vrr_enabled: bool,
+    pub vrr_mode: JsonVrrMode,
+    #[serde(skip_serializing_if = "is_none")]
+    pub vrr_cursor_hz: Option<f64>,
+    pub tearing_mode: JsonTearingMode,
+    #[serde(skip_serializing_if = "is_none")]
+    pub flip_margin_ns: Option<u64>,
+    #[serde(skip_serializing_if = "is_empty")]
+    pub supported_color_spaces: Vec<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub current_color_space: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_empty")]
+    pub supported_eotfs: Vec<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub current_eotf: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub min_brightness: Option<f64>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub max_brightness: Option<f64>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub brightness: Option<f64>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub blend_space: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub native_gamut: Option<JsonPrimaries>,
+    #[serde(skip_serializing_if = "is_false")]
+    pub use_native_gamut: bool,
+    #[serde(skip_serializing_if = "is_false")]
+    pub arbitrary_modes: bool,
+    #[serde(skip_serializing_if = "is_empty")]
+    pub modes: Vec<JsonMode>,
+    #[serde(skip_serializing_if = "is_empty")]
+    pub formats: Vec<&'a str>,
+}
+
+#[derive(Serialize)]
+pub struct JsonMode {
+    pub width: i32,
+    pub height: i32,
+    pub refresh_rate_millihz: u32,
+    #[serde(skip_serializing_if = "is_false")]
+    pub current: bool,
+}
+
+#[derive(Serialize)]
+pub struct JsonPrimaries {
+    pub r_x: f64,
+    pub r_y: f64,
+    pub g_x: f64,
+    pub g_y: f64,
+    pub b_x: f64,
+    pub b_y: f64,
+    pub w_x: f64,
+    pub w_y: f64,
+}
+
+#[derive(Serialize)]
+pub struct JsonInputData<'a> {
+    #[serde(skip_serializing_if = "is_empty")]
+    pub seats: Vec<JsonSeat<'a>>,
+    #[serde(skip_serializing_if = "is_empty")]
+    pub detached_devices: Vec<JsonInputDevice<'a>>,
+}
+
+#[derive(Serialize)]
+pub struct JsonSeat<'a> {
+    pub name: &'a str,
+    pub repeat_rate: i32,
+    pub repeat_delay: i32,
+    #[serde(skip_serializing_if = "is_false")]
+    pub hardware_cursor: bool,
+    #[serde(skip_serializing_if = "is_empty")]
+    pub devices: Vec<JsonInputDevice<'a>>,
+}
+
+#[derive(Serialize)]
+pub struct JsonInputDevice<'a> {
+    pub input_device_id: u32,
+    pub name: &'a str,
+    #[serde(skip_serializing_if = "is_none")]
+    pub seat: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub syspath: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub devnode: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_empty")]
+    pub capabilities: Vec<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub accel_profile: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub accel_speed: Option<f64>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub tap_enabled: Option<bool>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub tap_drag_enabled: Option<bool>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub tap_drag_lock_enabled: Option<bool>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub left_handed: Option<bool>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub natural_scrolling: Option<bool>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub px_per_wheel_scroll: Option<f64>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub transform_matrix: Option<[[f64; 2]; 2]>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub output: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub calibration_matrix: Option<[[f32; 3]; 2]>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub click_method: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub middle_button_emulation: Option<bool>,
+}
+
+pub struct JsonTreeNodeType(pub u32);
+
+impl Serialize for JsonTreeNodeType {
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        let s = match self.0 {
+            TREE_TY_DISPLAY => "display",
+            TREE_TY_OUTPUT => "output",
+            TREE_TY_WORKSPACE => "workspace",
+            TREE_TY_FLOAT => "float",
+            TREE_TY_CONTAINER => "container",
+            TREE_TY_PLACEHOLDER => "placeholder",
+            TREE_TY_XDG_TOPLEVEL => "xdg-toplevel",
+            TREE_TY_X_WINDOW => "x-window",
+            TREE_TY_XDG_POPUP => "xdg-popup",
+            TREE_TY_LAYER_SURFACE => "layer-surface",
+            TREE_TY_LOCK_SURFACE => "lock-surface",
+            n => return serializer.serialize_u32(n),
+        };
+        serializer.serialize_str(s)
+    }
+}
+
+#[derive(Serialize)]
+pub struct JsonTreeNode<'a> {
+    #[serde(rename = "type")]
+    pub ty: JsonTreeNodeType,
+    #[serde(skip_serializing_if = "is_none")]
+    pub output: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub workspace: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub toplevel_id: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub placeholder_for: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub position: Option<JsonRect>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub client: Option<JsonClient<'a>>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub title: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub app_id: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub tag: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub content_type: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub x_class: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub x_instance: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub x_role: Option<&'a str>,
+    #[serde(skip_serializing_if = "is_false")]
+    pub floating: bool,
+    #[serde(skip_serializing_if = "is_false")]
+    pub visible: bool,
+    #[serde(skip_serializing_if = "is_false")]
+    pub urgent: bool,
+    #[serde(skip_serializing_if = "is_false")]
+    pub fullscreen: bool,
+    #[serde(skip_serializing_if = "is_empty")]
+    pub children: Vec<JsonTreeNode<'a>>,
+}
+
+#[derive(Serialize)]
+pub struct JsonRect {
+    pub x1: i32,
+    pub y1: i32,
+    pub x2: i32,
+    pub y2: i32,
+    pub width: i32,
+    pub height: i32,
+}
+
+#[derive(Serialize)]
+pub struct JsonXwaylandStatus<'a> {
+    pub scaling_mode: &'a str,
+    #[serde(skip_serializing_if = "is_none")]
+    pub implied_scale: Option<f64>,
+}
+
+#[derive(Serialize)]
+#[serde(tag = "type")]
+#[serde(rename_all = "snake_case")]
+pub enum JsonSeatEvent<'a> {
+    Key {
+        seat: &'a str,
+        time_usec: u64,
+        key: u32,
+        state: u32,
+    },
+    Modifiers {
+        seat: &'a str,
+        modifiers: u32,
+        group: u32,
+    },
+    PointerAbs {
+        seat: &'a str,
+        time_usec: u64,
+        x: f64,
+        y: f64,
+    },
+    PointerRel {
+        seat: &'a str,
+        time_usec: u64,
+        x: f64,
+        y: f64,
+        dx: f64,
+        dy: f64,
+        dx_unaccelerated: f64,
+        dy_unaccelerated: f64,
+    },
+    Button {
+        seat: &'a str,
+        time_usec: u64,
+        button: u32,
+        state: u32,
+    },
+    Axis {
+        seat: &'a str,
+        time_usec: u64,
+        #[serde(skip_serializing_if = "is_none")]
+        source: Option<&'a str>,
+        #[serde(skip_serializing_if = "is_none")]
+        horizontal: Option<JsonAxisData>,
+        #[serde(skip_serializing_if = "is_none")]
+        vertical: Option<JsonAxisData>,
+    },
+    SwipeBegin {
+        seat: &'a str,
+        time_usec: u64,
+        fingers: u32,
+    },
+    SwipeUpdate {
+        seat: &'a str,
+        time_usec: u64,
+        dx: f64,
+        dy: f64,
+        dx_unaccelerated: f64,
+        dy_unaccelerated: f64,
+    },
+    SwipeEnd {
+        seat: &'a str,
+        time_usec: u64,
+        cancelled: bool,
+    },
+    PinchBegin {
+        seat: &'a str,
+        time_usec: u64,
+        fingers: u32,
+    },
+    PinchUpdate {
+        seat: &'a str,
+        time_usec: u64,
+        dx: f64,
+        dy: f64,
+        dx_unaccelerated: f64,
+        dy_unaccelerated: f64,
+        scale: f64,
+        rotation: f64,
+    },
+    PinchEnd {
+        seat: &'a str,
+        time_usec: u64,
+        cancelled: bool,
+    },
+    HoldBegin {
+        seat: &'a str,
+        time_usec: u64,
+        fingers: u32,
+    },
+    HoldEnd {
+        seat: &'a str,
+        time_usec: u64,
+        cancelled: bool,
+    },
+    Switch {
+        seat: &'a str,
+        time_usec: u64,
+        input_device: u32,
+        event: &'a str,
+    },
+    TabletTool {
+        seat: &'a str,
+        time_usec: u64,
+        input_device: u32,
+        tool: u32,
+        #[serde(skip_serializing_if = "is_false")]
+        proximity_in: bool,
+        #[serde(skip_serializing_if = "is_false")]
+        proximity_out: bool,
+        #[serde(skip_serializing_if = "is_false")]
+        down: bool,
+        #[serde(skip_serializing_if = "is_false")]
+        up: bool,
+        #[serde(skip_serializing_if = "is_none")]
+        x: Option<f64>,
+        #[serde(skip_serializing_if = "is_none")]
+        y: Option<f64>,
+        #[serde(skip_serializing_if = "is_none")]
+        pressure: Option<f64>,
+        #[serde(skip_serializing_if = "is_none")]
+        distance: Option<f64>,
+        #[serde(skip_serializing_if = "is_none")]
+        tilt_x: Option<f64>,
+        #[serde(skip_serializing_if = "is_none")]
+        tilt_y: Option<f64>,
+        #[serde(skip_serializing_if = "is_none")]
+        rotation: Option<f64>,
+        #[serde(skip_serializing_if = "is_none")]
+        slider: Option<f64>,
+        #[serde(skip_serializing_if = "is_none")]
+        wheel_degrees: Option<f64>,
+        #[serde(skip_serializing_if = "is_none")]
+        wheel_clicks: Option<i32>,
+        #[serde(skip_serializing_if = "is_none")]
+        button: Option<u32>,
+        #[serde(skip_serializing_if = "is_none")]
+        button_state: Option<&'a str>,
+    },
+    TabletPadModeSwitch {
+        seat: &'a str,
+        time_usec: u64,
+        input_device: u32,
+        mode: u32,
+    },
+    TabletPadButton {
+        seat: &'a str,
+        time_usec: u64,
+        input_device: u32,
+        button: u32,
+        state: &'a str,
+    },
+    TabletPadStrip {
+        seat: &'a str,
+        time_usec: u64,
+        input_device: u32,
+        strip: u32,
+        source: &'a str,
+        #[serde(skip_serializing_if = "is_none")]
+        position: Option<f64>,
+        #[serde(skip_serializing_if = "is_false")]
+        stop: bool,
+    },
+    TabletPadRing {
+        seat: &'a str,
+        time_usec: u64,
+        input_device: u32,
+        ring: u32,
+        source: &'a str,
+        #[serde(skip_serializing_if = "is_none")]
+        degrees: Option<f64>,
+        #[serde(skip_serializing_if = "is_false")]
+        stop: bool,
+    },
+    TabletPadDial {
+        seat: &'a str,
+        time_usec: u64,
+        input_device: u32,
+        dial: u32,
+        #[serde(skip_serializing_if = "is_none")]
+        delta120: Option<i32>,
+    },
+    TouchDown {
+        seat: &'a str,
+        time_usec: u64,
+        id: i32,
+        x: f64,
+        y: f64,
+    },
+    TouchUp {
+        seat: &'a str,
+        time_usec: u64,
+        id: i32,
+    },
+    TouchMotion {
+        seat: &'a str,
+        time_usec: u64,
+        id: i32,
+        x: f64,
+        y: f64,
+    },
+    TouchCancel {
+        seat: &'a str,
+        time_usec: u64,
+        id: i32,
+    },
+}
+
+#[derive(Serialize)]
+pub struct JsonAxisData {
+    #[serde(skip_serializing_if = "is_none")]
+    pub px: Option<f64>,
+    #[serde(skip_serializing_if = "is_none")]
+    pub v120: Option<i32>,
+    #[serde(skip_serializing_if = "is_false")]
+    pub stop: bool,
+    #[serde(skip_serializing_if = "is_false")]
+    pub natural_scrolling: bool,
+}

src/cli/log.rs

@@ -1,6 +1,6 @@
 use {
     crate::{
-        cli::{GlobalArgs, LogArgs},
+        cli::{GlobalArgs, LogArgs, json::jsonl},
         tools::tool_client::{Handle, ToolClient, with_tool_client},
         utils::errorfmt::ErrorFmt,
         wire::{jay_compositor, jay_log_file},
@@ -24,7 +24,7 @@ pub fn main(global: GlobalArgs, args: LogArgs) {
             path: RefCell::new(None),
             args,
         });
-        run(logger).await;
+        run(&global, logger).await;
     });
 }
 
@@ -34,7 +34,7 @@ struct Log {
     args: LogArgs,
 }
 
-async fn run(log: Rc<Log>) {
+async fn run(global: &GlobalArgs, log: Rc<Log>) {
     let tc = &log.tc;
     let comp = tc.jay_compositor().await;
     let log_file = tc.id();
@@ -52,7 +52,12 @@ async fn run(log: Rc<Log>) {
         _ => fatal!("Server did not send the path of the log file"),
     };
     if log.args.path {
-        println!("{}", path);
+        if global.json {
+            let path = path.to_string();
+            jsonl(&path);
+        } else {
+            println!("{}", path);
+        }
         process::exit(0);
     }
     let mut command = Command::new("less");

src/cli/pid.rs

@@ -1,6 +1,6 @@
 use {
     crate::{
-        cli::GlobalArgs,
+        cli::{GlobalArgs, json::jsonl},
         tools::tool_client::{Handle, ToolClient, with_tool_client},
         wire::jay_compositor::{GetPid, Pid},
     },
@@ -10,7 +10,7 @@ use {
 pub fn main(global: GlobalArgs) {
     with_tool_client(global.log_level, |tc| async move {
         let pid = Rc::new(P { tc: tc.clone() });
-        run(pid).await;
+        run(&global, pid).await;
     });
 }
 
@@ -18,12 +18,17 @@ struct P {
     tc: Rc<ToolClient>,
 }
 
-async fn run(p: Rc<P>) {
+async fn run(global: &GlobalArgs, p: Rc<P>) {
     let tc = &p.tc;
     let comp = tc.jay_compositor().await;
     tc.send(GetPid { self_id: comp });
-    Pid::handle(tc, comp, (), |_, pid| {
+    let json = global.json;
-        println!("{}", pid.pid);
+    Pid::handle(tc, comp, (), move |_, pid| {
+        if json {
+            jsonl(&pid.pid);
+        } else {
+            println!("{}", pid.pid);
+        }
     });
     tc.round_trip().await;
 }

src/cli/randr.rs

@@ -1,14 +1,20 @@
 use {
     crate::{
         backend::{BackendColorSpace, BackendEotfs},
-        cli::GlobalArgs,
+        cli::{
+            GlobalArgs,
+            json::{
+                JsonConnector, JsonDrmDevice, JsonMode, JsonOutput, JsonPrimaries, JsonRandrData,
+                JsonTearingMode, JsonVrrMode, jsonl,
+            },
+        },
         cmm::cmm_primaries::Primaries,
         format::{Format, XRGB8888},
         ifs::wl_output::BlendSpace,
         scale::Scale,
         tools::tool_client::{Handle, ToolClient, with_tool_client},
         tree::Transform,
-        utils::{errorfmt::ErrorFmt, ordered_float::F64},
+        utils::{errorfmt::ErrorFmt, ordered_float::F64, static_text::StaticText},
         wire::{JayRandrId, jay_compositor, jay_randr},
     },
     clap::{
@@ -496,7 +502,7 @@ pub struct RemoveVirtualOutputArgs {
 pub fn main(global: GlobalArgs, args: RandrArgs) {
     with_tool_client(global.log_level, |tc| async move {
         let idle = Rc::new(Randr { tc: tc.clone() });
-        idle.run(args).await;
+        idle.run(&global, args).await;
     });
 }
 
@@ -596,7 +602,7 @@ struct Randr {
 }
 
 impl Randr {
-    async fn run(self: &Rc<Self>, args: RandrArgs) {
+    async fn run(self: &Rc<Self>, global: &GlobalArgs, args: RandrArgs) {
         let tc = &self.tc;
         let comp = tc.jay_compositor().await;
         let randr = tc.id();
@@ -605,7 +611,7 @@ impl Randr {
             id: randr,
         });
         match args.command.unwrap_or_default() {
-            RandrCmd::Show(args) => self.show(randr, args).await,
+            RandrCmd::Show(args) => self.show(global, randr, args).await,
             RandrCmd::Card(args) => self.card(randr, args).await,
             RandrCmd::Output(args) => self.output(randr, args).await,
             RandrCmd::VirtualOutput(args) => self.virtual_output(randr, args).await,
@@ -957,9 +963,51 @@ impl Randr {
         tc.round_trip().await;
     }
 
-    async fn show(self: &Rc<Self>, randr: JayRandrId, args: ShowArgs) {
+    async fn show(self: &Rc<Self>, global: &GlobalArgs, randr: JayRandrId, args: ShowArgs) {
         let mut data = self.get(randr).await;
         data.drm_devices.sort_by(|l, r| l.devnode.cmp(&r.devnode));
+        if global.json {
+            self.show_json(&data);
+        } else {
+            self.show_text(&data, &args);
+        }
+    }
+
+    fn show_json(&self, data: &Data) {
+        let mut drm_devices = Vec::new();
+        for dev in &data.drm_devices {
+            let mut connectors: Vec<_> = data
+                .connectors
+                .iter()
+                .filter(|c| c.drm_device == Some(dev.id))
+                .collect();
+            connectors.sort_by_key(|c| &c.name);
+            drm_devices.push(JsonDrmDevice {
+                devnode: &dev.devnode,
+                syspath: &dev.syspath,
+                vendor: dev.vendor,
+                vendor_name: &dev.vendor_name,
+                model: dev.model,
+                model_name: &dev.model_name,
+                gfx_api: &dev.gfx_api,
+                render_device: dev.render_device,
+                connectors: connectors.into_iter().map(make_json_connector).collect(),
+            });
+        }
+        let mut unbound: Vec<_> = data
+            .connectors
+            .iter()
+            .filter(|c| c.drm_device.is_none())
+            .collect();
+        unbound.sort_by_key(|c| &c.name);
+        let json = JsonRandrData {
+            drm_devices,
+            unbound_connectors: unbound.into_iter().map(make_json_connector).collect(),
+        };
+        jsonl(&json);
+    }
+
+    fn show_text(&self, data: &Data, args: &ShowArgs) {
         if data.drm_devices.is_not_empty() {
             println!("drm devices:");
         }
@@ -1077,17 +1125,7 @@ impl Randr {
             println!("        scale: {}", o.scale);
         }
         if o.transform != Transform::None {
-            let name = match o.transform {
+            println!("        transform: {}", o.transform.text());
-                Transform::None => "none",
-                Transform::Rotate90 => "rotate-90",
-                Transform::Rotate180 => "rotate-180",
-                Transform::Rotate270 => "rotate-270",
-                Transform::Flip => "flip",
-                Transform::FlipRotate90 => "flip-rotate-90",
-                Transform::FlipRotate180 => "flip-rotate-180",
-                Transform::FlipRotate270 => "flip-rotate-270",
-            };
-            println!("        transform: {}", name);
         }
         if let Some(flip_margin_ns) = o.flip_margin_ns {
             println!(
@@ -1361,3 +1399,77 @@ impl Randr {
         data.borrow_mut().clone()
     }
 }
+
+fn make_json_connector(c: &Connector) -> JsonConnector<'_> {
+    let output = c.output.as_ref().map(|o| {
+        let modes = o
+            .modes
+            .iter()
+            .map(|m| JsonMode {
+                width: m.width,
+                height: m.height,
+                refresh_rate_millihz: m.refresh_rate_millihz,
+                current: m.current,
+            })
+            .collect();
+        let formats = o.formats.iter().map(|f| f.as_str()).collect();
+        JsonOutput {
+            product: &o.product,
+            manufacturer: &o.manufacturer,
+            serial_number: &o.serial_number,
+            width_mm: o.width_mm,
+            height_mm: o.height_mm,
+            non_desktop: o.non_desktop,
+            scale: o.scale,
+            x: o.x,
+            y: o.y,
+            width: o.width,
+            height: o.height,
+            transform: o.transform.text(),
+            mode: o.current_mode.map(|m| JsonMode {
+                width: m.width,
+                height: m.height,
+                refresh_rate_millihz: m.refresh_rate_millihz,
+                current: m.current,
+            }),
+            format: o.format.as_deref(),
+            vrr_capable: o.vrr_capable,
+            vrr_enabled: o.vrr_enabled,
+            vrr_mode: JsonVrrMode(o.vrr_mode),
+            vrr_cursor_hz: o.vrr_cursor_hz,
+            tearing_mode: JsonTearingMode(o.tearing_mode),
+            flip_margin_ns: o.flip_margin_ns,
+            supported_color_spaces: o
+                .supported_color_spaces
+                .iter()
+                .map(|s| s.as_str())
+                .collect(),
+            current_color_space: o.current_color_space.as_deref(),
+            supported_eotfs: o.supported_eotfs.iter().map(|s| s.as_str()).collect(),
+            current_eotf: o.current_eotf.as_deref(),
+            min_brightness: o.brightness_range.map(|(min, _)| min),
+            max_brightness: o.brightness_range.map(|(_, max)| max),
+            brightness: o.brightness,
+            blend_space: o.blend_space.as_deref(),
+            native_gamut: o.native_gamut.as_ref().map(|p| JsonPrimaries {
+                r_x: p.r.0.0,
+                r_y: p.r.1.0,
+                g_x: p.g.0.0,
+                g_y: p.g.1.0,
+                b_x: p.b.0.0,
+                b_y: p.b.1.0,
+                w_x: p.wp.0.0,
+                w_y: p.wp.1.0,
+            }),
+            use_native_gamut: o.use_native_gamut,
+            arbitrary_modes: o.arbitrary_modes,
+            modes,
+            formats,
+        }
+    });
+    JsonConnector {
+        name: &c.name,
+        enabled: c.enabled,
+        output,
+    }
+}

src/cli/tree.rs

@@ -2,7 +2,8 @@ use {
     crate::{
         cli::{
             GlobalArgs,
-            clients::{Client, ClientPrinter, handle_client_query},
+            clients::{Client, ClientPrinter, handle_client_query, make_json_client},
+            json::{JsonRect, JsonTreeNode, JsonTreeNodeType, jsonl},
         },
         ifs::jay_tree_query::{
             TREE_TY_CONTAINER, TREE_TY_DISPLAY, TREE_TY_FLOAT, TREE_TY_LAYER_SURFACE,
@@ -68,7 +69,7 @@ pub fn main(global: GlobalArgs, tree_args: TreeArgs) {
             tc: tc.clone(),
             comp,
         });
-        tree.run(tree_args).await;
+        tree.run(&global, tree_args).await;
     });
 }
 
@@ -78,13 +79,13 @@ struct Tree {
 }
 
 impl Tree {
-    async fn run(&self, args: TreeArgs) {
+    async fn run(&self, global: &GlobalArgs, args: TreeArgs) {
         match &args.cmd {
-            TreeCmd::Query(a) => self.query(a).await,
+            TreeCmd::Query(a) => self.query(global, a).await,
         }
     }
 
-    async fn query(&self, args: &QueryArgs) {
+    async fn query(&self, global: &GlobalArgs, args: &QueryArgs) {
         let id = self.tc.id();
         self.tc.send(jay_compositor::CreateTreeQuery {
             self_id: self.comp,
@@ -95,7 +96,7 @@ impl Tree {
             tc: &self.tc,
             id,
         };
-        query.run(args).await;
+        query.run(global, args).await;
     }
 }
 
@@ -137,7 +138,7 @@ struct Node {
 }
 
 impl Query<'_> {
-    async fn run(&mut self, args: &QueryArgs) {
+    async fn run(&mut self, global: &GlobalArgs, args: &QueryArgs) {
         match &args.cmd {
             QueryCmd::Root => {
                 self.tc.send(SetRootDisplay { self_id: self.id });
@@ -296,20 +297,68 @@ impl Query<'_> {
             tl.send(Execute { self_id: id });
             handle_client_query(tl, id).await
         };
-        let mut printer = Printer {
+        if global.json {
-            clients,
+            for node in &d.borrow().roots {
-            printed_clients: Default::default(),
+                let node = make_json_tree_node(&clients, node);
-            verbose: args.all_clients,
+                jsonl(&node);
-            prefix: "".to_string(),
+            }
-            output_depth: 0,
+        } else {
-            workspace_depth: 0,
+            let mut printer = Printer {
-        };
+                clients,
-        for node in &d.borrow().roots {
+                printed_clients: Default::default(),
-            printer.print(node);
+                verbose: args.all_clients,
+                prefix: "".to_string(),
+                output_depth: 0,
+                workspace_depth: 0,
+            };
+            for node in &d.borrow().roots {
+                printer.print(node);
+            }
         }
     }
 }
 
+fn make_json_tree_node<'b>(clients: &'b AHashMap<u64, Client>, node: &'b Node) -> JsonTreeNode<'b> {
+    let position = node.position.map(|r| JsonRect {
+        x1: r.x1(),
+        y1: r.y1(),
+        x2: r.x2(),
+        y2: r.y2(),
+        width: r.width(),
+        height: r.height(),
+    });
+    let client = node
+        .client
+        .and_then(|client_id| clients.get(&client_id))
+        .map(make_json_client);
+    let children = node
+        .children
+        .iter()
+        .map(|c| make_json_tree_node(clients, c))
+        .collect();
+    JsonTreeNode {
+        ty: JsonTreeNodeType(node.ty),
+        output: node.output.as_deref(),
+        workspace: node.workspace.as_deref(),
+        toplevel_id: node.toplevel_id.as_deref(),
+        placeholder_for: node.placeholder_for.as_deref(),
+        position,
+        client,
+        title: node.title.as_deref(),
+        app_id: node.app_id.as_deref(),
+        tag: node.tag.as_deref(),
+        content_type: node.content_type.as_deref(),
+        x_class: node.x_class.as_deref(),
+        x_instance: node.x_instance.as_deref(),
+        x_role: node.x_role.as_deref(),
+        floating: node.floating,
+        visible: node.visible,
+        urgent: node.urgent,
+        fullscreen: node.fullscreen,
+        children,
+    }
+}
+
 struct Printer {
     clients: AHashMap<u64, Client>,
     printed_clients: AHashSet<u64>,

src/cli/version.rs

@@ -1,5 +1,12 @@
-use crate::{cli::GlobalArgs, version::VERSION};
+use crate::{
+    cli::{GlobalArgs, json::jsonl},
+    version::VERSION,
+};
 
-pub fn main(_global: GlobalArgs) {
+pub fn main(global: GlobalArgs) {
-    println!("{VERSION}");
+    if global.json {
+        jsonl(&VERSION);
+    } else {
+        println!("{VERSION}");
+    }
 }

src/cli/xwayland.rs

@@ -1,6 +1,9 @@
 use {
     crate::{
-        cli::GlobalArgs,
+        cli::{
+            GlobalArgs,
+            json::{JsonXwaylandStatus, jsonl},
+        },
         tools::tool_client::{Handle, ToolClient, with_tool_client},
         wire::{JayXwaylandId, jay_compositor, jay_xwayland},
     },
@@ -41,7 +44,7 @@ pub enum CliScalingMode {
 pub fn main(global: GlobalArgs, args: XwaylandArgs) {
     with_tool_client(global.log_level, |tc| async move {
         let xwayland = Xwayland { tc: tc.clone() };
-        xwayland.run(args).await;
+        xwayland.run(&global, args).await;
     });
 }
 
@@ -50,7 +53,7 @@ struct Xwayland {
 }
 
 impl Xwayland {
-    async fn run(self, args: XwaylandArgs) {
+    async fn run(self, global: &GlobalArgs, args: XwaylandArgs) {
         let tc = &self.tc;
         let comp = tc.jay_compositor().await;
         let xwayland = tc.id();
@@ -59,12 +62,12 @@ impl Xwayland {
             id: xwayland,
         });
         match args.command.unwrap_or_default() {
-            XwaylandCmd::Status => self.status(xwayland).await,
+            XwaylandCmd::Status => self.status(global, xwayland).await,
             XwaylandCmd::SetScalingMode(args) => self.set_scaling_mode(xwayland, args).await,
         }
     }
 
-    async fn status(self, xwayland: JayXwaylandId) {
+    async fn status(self, global: &GlobalArgs, xwayland: JayXwaylandId) {
         let tc = &self.tc;
         tc.send(jay_xwayland::GetScaling { self_id: xwayland });
         let mode = Rc::new(Cell::new(0));
@@ -85,9 +88,16 @@ impl Xwayland {
                 &mode_str
             }
         };
-        println!("scaling mode: {}", mode);
+        if global.json {
-        if let Some(scale) = scale.get() {
+            jsonl(&JsonXwaylandStatus {
-            println!("implied scale: {}", scale);
+                scaling_mode: mode,
+                implied_scale: scale.get().map(|s| s as f64),
+            });
+        } else {
+            println!("scaling mode: {}", mode);
+            if let Some(scale) = scale.get() {
+                println!("implied scale: {}", scale);
+            }
         }
     }
 

src/control_center/cc_outputs.rs

@@ -21,7 +21,7 @@ use {
         scale::{SCALE_BASE, SCALE_BASEF, Scale},
         state::State,
         tree::{TearingMode, Transform, VrrMode},
-        utils::errorfmt::ErrorFmt,
+        utils::{errorfmt::ErrorFmt, static_text::StaticText},
     },
     ahash::AHashMap,
     egui::{
@@ -1166,18 +1166,8 @@ fn show_transform(ui: &mut Ui, m: &HeadState, t: &mut Option<HeadState>) -> bool
     grid_label(ui, "Transform");
     let mut v = effective!(m, t).transform;
     let mut changed = false;
-    let transform_name = |t: Transform| match t {
-        Transform::None => "none",
-        Transform::Rotate90 => "rotate-90",
-        Transform::Rotate180 => "rotate-180",
-        Transform::Rotate270 => "rotate-270",
-        Transform::Flip => "flip",
-        Transform::FlipRotate90 => "flip-rotate-90",
-        Transform::FlipRotate180 => "flip-rotate-180",
-        Transform::FlipRotate270 => "flip-rotate-270",
-    };
     ComboBox::from_id_salt("transform")
-        .selected_text(transform_name(v))
+        .selected_text(v.text())
         .show_ui(ui, |ui| {
             let transforms = [
                 Transform::None,
@@ -1190,7 +1180,7 @@ fn show_transform(ui: &mut Ui, m: &HeadState, t: &mut Option<HeadState>) -> bool
                 Transform::FlipRotate270,
             ];
             for s in transforms {
-                changed |= ui.selectable_value(&mut v, s, transform_name(s)).changed();
+                changed |= ui.selectable_value(&mut v, s, s.text()).changed();
             }
         });
     if changed {
@@ -1200,7 +1190,7 @@ fn show_transform(ui: &mut Ui, m: &HeadState, t: &mut Option<HeadState>) -> bool
     }
     let diff = m.transform != v;
     if diff {
-        ui.label(transform_name(m.transform));
+        ui.label(m.transform.text());
     }
     diff
 }

src/tree.rs

@@ -101,6 +101,21 @@ pub enum Transform {
     FlipRotate270,
 }
 
+impl StaticText for Transform {
+    fn text(&self) -> &'static str {
+        match self {
+            Transform::None => "none",
+            Transform::Rotate90 => "rotate-90",
+            Transform::Rotate180 => "rotate-180",
+            Transform::Rotate270 => "rotate-270",
+            Transform::Flip => "flip",
+            Transform::FlipRotate90 => "flip-rotate-90",
+            Transform::FlipRotate180 => "flip-rotate-180",
+            Transform::FlipRotate270 => "flip-rotate-270",
+        }
+    }
+}
+
 impl From<ConfigTransform> for Transform {
     fn from(value: ConfigTransform) -> Self {
         match value {