feat(commandline): autocomplete suggestions + inventory-based registry

Type-as-you-go suggestion popup above the input that filters known
command names by substring (so `LEADER` surfaces both LEADER and
MLEADER). Up / Down navigates the list, Enter dispatches the
highlighted entry, clicking a row dispatches directly. Esc on a
non-empty input clears the buffer instead of escalating to
command-cancel.

The name corpus comes from `inventory::submit!` blocks placed next
to each `CadCommand` impl rather than a hand-maintained static list.
Adding a new interactive command means dropping one `inventory::submit!`
line in its own module file — the autocomplete picks it up at the
next compile. 98 submissions seeded across 60 module files;
`command::all_registered_command_names()` flattens them at runtime.

One-shot dispatch arms in `app/commands.rs` (NEW, OPEN, SAVE, UNDO,
…) don't have a `CadCommand` impl and are therefore absent from
autocomplete by design.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Cargo.lock

@@ -12,6 +12,7 @@ dependencies = [
  "glam 0.33.0",
  "iced",
  "image",
+ "inventory",
  "open",
  "printpdf",
  "rayon",
@@ -2311,6 +2312,15 @@ dependencies = [
  "syn 2.0.117",
 ]
 
+[[package]]
+name = "inventory"
+version = "0.3.24"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a4f0c30c76f2f4ccee3fe55a2435f691ca00c0e4bd87abe4f4a851b1d4dac39b"
+dependencies = [
+ "rustversion",
+]
+
 [[package]]
 name = "is-docker"
 version = "0.2.0"

Cargo.toml

@@ -19,6 +19,7 @@ flate2 = "1"
 image = { version = "0.25", default-features = false, features = ["png", "jpeg", "bmp", "tiff"] }
 rayon = "1"
 ureq = { version = "3", default-features = false, features = ["rustls"] }
+inventory = "0.3"
 
 [target.'cfg(target_os = "windows")'.dependencies]
 windows-sys = { version = "0.61", features = ["Win32_UI_Shell", "Win32_UI_WindowsAndMessaging"] }

src/app/mod.rs

@@ -357,6 +357,9 @@ pub enum Message {
     CommandHistoryNext,
     /// Toggle the dropdown listing the full command-line history.
     CommandHistoryToggle,
+    /// User clicked an autocomplete suggestion — fill the input with
+    /// the chosen command name and dispatch it.
+    CommandSuggestionPick(String),
     ToggleLayers,
     LayerToggleVisible(usize),
     LayerToggleLock(usize),

src/app/update.rs

@@ -824,6 +824,9 @@ impl OpenCADStudio {
                     return Task::done(Message::CommandSubmit);
                 }
                 self.command_line.input = s;
+                // Typing invalidates the previous arrow-key cursor —
+                // the matches list has likely changed.
+                self.command_line.autocomplete_cursor = None;
                 Task::none()
             }
 
@@ -833,20 +836,36 @@ impl OpenCADStudio {
                 if s.chars().all(|c| !c.is_control()) {
                     self.command_line.input.push_str(&s);
                 }
+                self.command_line.autocomplete_cursor = None;
                 self.focus_cmd_input()
             }
 
             Message::CommandBackspace => {
                 self.command_line.input.pop();
+                self.command_line.autocomplete_cursor = None;
                 self.focus_cmd_input()
             }
 
             Message::CommandHistoryPrev => {
+                // While autocomplete is showing suggestions, ↑ walks up
+                // that list. Otherwise it falls back to recall history.
+                let i = self.active_tab;
+                if self.tabs[i].active_cmd.is_none()
+                    && self.command_line.autocomplete_prev()
+                {
+                    return Task::none();
+                }
                 self.command_line.history_prev();
                 Task::none()
             }
 
             Message::CommandHistoryNext => {
+                let i = self.active_tab;
+                if self.tabs[i].active_cmd.is_none()
+                    && self.command_line.autocomplete_next()
+                {
+                    return Task::none();
+                }
                 self.command_line.history_next();
                 Task::none()
             }
@@ -856,11 +875,29 @@ impl OpenCADStudio {
                 Task::none()
             }
 
+            Message::CommandSuggestionPick(cmd) => {
+                self.command_line.input.clear();
+                self.command_line.close_history();
+                self.dispatch_command(&cmd)
+            }
+
             Message::CommandSubmit => {
                 // Submitting a command implicitly dismisses the history
                 // dropdown so the dispatched command's new prompt is
                 // immediately visible on the overlay.
                 self.command_line.close_history();
+                // If the user navigated the autocomplete list with the
+                // arrow keys, Enter dispatches the highlighted command
+                // rather than the partial text actually in the buffer.
+                let i_tab = self.active_tab;
+                if self.tabs[i_tab].active_cmd.is_none() {
+                    if let Some(picked) = self.command_line.selected_suggestion() {
+                        let cmd = picked.to_string();
+                        self.command_line.input.clear();
+                        self.command_line.autocomplete_cursor = None;
+                        return self.dispatch_command(&cmd);
+                    }
+                }
                 let i = self.active_tab;
                 if self.tabs[i].active_cmd.is_some() {
                     let text = self.command_line.input.trim().to_string();
@@ -971,6 +1008,16 @@ impl OpenCADStudio {
                 {
                     return Task::none();
                 }
+                // Typed text on the command line cancels first — one
+                // Esc empties the buffer, a second Esc then escalates
+                // to whatever the current mode would otherwise do
+                // (cancel command / exit viewport / deselect).
+                if !self.command_line.input.is_empty() {
+                    self.command_line.input.clear();
+                    self.command_line.autocomplete_cursor = None;
+                    self.command_line.close_history();
+                    return Task::none();
+                }
                 let i = self.active_tab;
                 if self.tabs[i].active_cmd.is_some() {
                     let result = self.tabs[i].active_cmd.as_mut().map(|c| c.on_escape());

src/app/view.rs

@@ -508,7 +508,10 @@ impl OpenCADStudio {
         // viewport stack rather than as a separate row in the main
         // column — frees up vertical space when no command is active
         // and keeps the input close to where the cursor is drawing.
-        let command_line_overlay = iced::widget::container(self.command_line.view())
+        // Autocomplete shows only when no command is collecting its
+        // own input (otherwise typed prefixes are coordinates / values).
+        let allow_autocomplete = tab.active_cmd.is_none();
+        let command_line_overlay = iced::widget::container(self.command_line.view(allow_autocomplete))
             .width(Fill)
             .height(Fill)
             .align_x(iced::alignment::Horizontal::Center)

src/command/mod.rs

@@ -317,3 +317,29 @@ pub trait CadCommand: Send {
     /// Default: no-op.
     fn inject_picked_entity(&mut self, _entity: acadrust::EntityType) {}
 }
+
+// ── Autocomplete registry ─────────────────────────────────────────────────
+//
+// Every `impl CadCommand for Foo` module submits the names it answers to
+// at compile time via `inventory::submit!`. The command-line autocomplete
+// then iterates the resulting collection at runtime — no central list to
+// keep in sync.
+//
+// Non-interactive one-shot dispatch arms (NEW, OPEN, SAVE, …) live in
+// `app/commands.rs` and don't have a `CadCommand` impl; they're absent
+// from autocomplete by design. Add an explicit `inventory::submit!` next
+// to their dispatch arm if you want them surfaced.
+
+pub struct CommandRegistration {
+    pub names: &'static [&'static str],
+}
+
+inventory::collect!(CommandRegistration);
+
+/// All registered command names, including aliases.
+pub fn all_registered_command_names() -> Vec<&'static str> {
+    inventory::iter::<CommandRegistration>
+        .into_iter()
+        .flat_map(|r| r.names.iter().copied())
+        .collect()
+}

src/modules/annotate/aligned_dim.rs

@@ -149,3 +149,7 @@ fn preview_aligned(p1: Vec3, p2: Vec3, dim_pt: Vec3) -> WireModel {
         fill_tris: vec![],
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DAL", "DIMALIGNED"] });  // AlignedDimensionCommand

src/modules/annotate/angular_dim.rs

@@ -173,3 +173,7 @@ fn angular_preview(vertex: Vec3, first: Vec3, second: Vec3, arc_pt: Vec3) -> Vec
     }
     points
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DIMANGULAR"] });  // AngularDimensionCommand

src/modules/annotate/diameter_dim.rs

@@ -112,3 +112,7 @@ fn preview_line(a: Vec3, b: Vec3) -> WireModel {
         fill_tris: vec![],
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DDI", "DIMDIAMETER"] });  // DiameterDimensionCommand

src/modules/annotate/dim_baseline.rs

@@ -177,3 +177,7 @@ impl CadCommand for DimBaselineCommand {
 fn v3(p: Vec3) -> Vector3 {
     Vector3::new(p.x as f64, p.y as f64, p.z as f64)
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DBA", "DIMBASELINE"] });  // DimBaselineCommand

src/modules/annotate/dim_continue.rs

@@ -158,3 +158,7 @@ impl CadCommand for DimContinueCommand {
 fn v3(p: Vec3) -> Vector3 {
     Vector3::new(p.x as f64, p.y as f64, p.z as f64)
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DCO", "DIMCONTINUE"] });  // DimContinueCommand

src/modules/annotate/dimbreak.rs

@@ -97,3 +97,7 @@ impl CadCommand for DimBreakCommand {
         CmdResult::Cancel
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DBR", "DIMBREAK"] });  // DimBreakCommand

src/modules/annotate/dimedit.rs

@@ -85,3 +85,7 @@ impl CadCommand for DimEditCommand {
         CmdResult::Cancel
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DED", "DIMEDIT"] });  // DimEditCommand

src/modules/annotate/dimjogline.rs

@@ -108,3 +108,7 @@ impl CadCommand for DimJogLineCommand {
         })
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DIMJOGLINE", "DJL"] });  // DimJogLineCommand

src/modules/annotate/dimspace.rs

@@ -125,3 +125,7 @@ impl CadCommand for DimSpaceCommand {
         }
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DIMSPACE", "DSPACE"] });  // DimSpaceCommand

src/modules/annotate/dimtedit.rs

@@ -128,3 +128,7 @@ impl CadCommand for DimTeditCommand {
         }
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DIMTED", "DIMTEDIT"] });  // DimTeditCommand

src/modules/annotate/leader_cmd.rs

@@ -252,3 +252,7 @@ pub fn arrowhead_wings(tip: Vec3, next: Vec3, size: f32) -> [Vec3; 2] {
         ),
     ]
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["LE", "LEADER"] });  // LeaderCommand

src/modules/annotate/linear_dim.rs

@@ -163,3 +163,7 @@ fn linear_text_pos(first: Vec3, second: Vec3, def: Vec3) -> Vec3 {
     let d2 = second + perp * offset;
     (d1 + d2) * 0.5 + perp * 0.15
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DIMLINEAR"] });  // LinearDimensionCommand

src/modules/annotate/mleader_cmd.rs

@@ -199,3 +199,7 @@ fn arrowhead_wings(tip: Vec3, next: Vec3, size: f32) -> [Vec3; 2] {
         ),
     ]
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["MLD", "MLEADER"] });  // MLeaderCommand

src/modules/annotate/mleader_edit.rs

@@ -476,3 +476,10 @@ fn preview_wire(pts: &[Vec3]) -> WireModel {
 
 // Silence unused-import warning for MultiLeader and LeaderLine if not used in all paths
 fn _uses_ml_types(_ml: &MultiLeader, _ll: &LeaderLine) {}
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["MLA", "MLEADERADD"] });  // MLeaderAddCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["MLAL", "MLEADERALIGN"] });  // MLeaderAlignCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["MLC", "MLEADERCOLLECT"] });  // MLeaderCollectCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["MLEADERREMOVE", "MLR"] });  // MLeaderRemoveCommand

src/modules/annotate/mtext.rs

@@ -91,3 +91,7 @@ impl CadCommand for MTextCommand {
         None
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["MT", "MTEXT"] });  // MTextCommand

src/modules/annotate/ordinate_dim.rs

@@ -86,3 +86,7 @@ impl CadCommand for OrdinateDimCommand {
 fn v3(p: Vec3) -> Vector3 {
     Vector3::new(p.x as f64, 0.0, p.z as f64)
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DIMORDINATE", "DOR"] });  // OrdinateDimCommand

src/modules/annotate/qdim.rs

@@ -128,3 +128,7 @@ pub fn make_linear_dim(p1: Vec3, p2: Vec3, dim_pt: Vec3) -> EntityType {
     dim.base.actual_measurement = dim.measurement();
     EntityType::Dimension(Dimension::Linear(dim))
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["QDIM"] });  // QdimCommand

src/modules/annotate/radius_dim.rs

@@ -117,3 +117,7 @@ fn preview_wire(points: Vec<Vec3>) -> WireModel {
         fill_tris: vec![],
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DIMRADIUS"] });  // RadiusDimensionCommand

src/modules/annotate/table_cmd.rs

@@ -169,3 +169,7 @@ impl CadCommand for TableCommand {
         }
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["TABLE"] });  // TableCommand

src/modules/annotate/text.rs

@@ -86,3 +86,7 @@ impl CadCommand for TextCommand {
         None
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DT", "T", "TEXT"] });  // TextCommand

src/modules/annotate/tolerance_cmd.rs

@@ -108,3 +108,7 @@ impl CadCommand for ToleranceCommand {
         })
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["TOL", "TOLERANCE"] });  // ToleranceCommand

src/modules/home/clipboard/paste.rs

@@ -58,3 +58,7 @@ impl CadCommand for PasteCommand {
         self.wires.iter().map(|w| w.translated(delta)).collect()
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["PASTECLIP", "PC"] });  // PasteCommand

src/modules/home/draw/arc.rs

@@ -1102,3 +1102,16 @@ impl CadCommand for ArcCSLCommand {
         }
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["ARC_3P"] });  // Arc3PCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["ARC_CSA"] });  // ArcCSACommand
+inventory::submit!(crate::command::CommandRegistration { names: &["ARC_CSL"] });  // ArcCSLCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["A", "ARC"] });  // ArcCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["ARC_SCA"] });  // ArcSCACommand
+inventory::submit!(crate::command::CommandRegistration { names: &["ARC_SCE"] });  // ArcSCECommand
+inventory::submit!(crate::command::CommandRegistration { names: &["ARC_SCL"] });  // ArcSCLCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["ARC_SEA"] });  // ArcSEACommand
+inventory::submit!(crate::command::CommandRegistration { names: &["ARC_SED"] });  // ArcSEDCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["ARC_SER"] });  // ArcSERCommand

src/modules/home/draw/attdef.rs

@@ -184,3 +184,7 @@ impl CadCommand for AttdefCommand {
         })
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["ATTDEF"] });  // AttdefCommand

src/modules/home/draw/circle.rs

@@ -910,3 +910,12 @@ impl CadCommand for CircleTTTCommand {
         None
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["CIRCLE_2P"] });  // Circle2PCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["CIRCLE_3P"] });  // Circle3PCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["CIRCLE_CD"] });  // CircleCDCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["C", "CIRCLE"] });  // CircleCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["CIRCLE_TTR"] });  // CircleTTRCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["CIRCLE_TTT"] });  // CircleTTTCommand

src/modules/home/draw/donut.rs

@@ -132,3 +132,7 @@ fn make_donut(cx: f64, cy: f64, inner_r: f64, outer_r: f64) -> EntityType {
     p.vertices = vec![v0, v1];
     EntityType::LwPolyline(p)
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DO", "DONUT"] });  // DonutCommand

src/modules/home/draw/ellipse.rs

@@ -532,3 +532,9 @@ fn line_wire(from: Vec3, to: Vec3) -> WireModel {
         fill_tris: vec![],
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["ELLIPSE_ARC"] });  // EllipseArcCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["ELLIPSE_AXIS"] });  // EllipseAxisCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["EL", "ELLIPSE"] });  // EllipseCommand

src/modules/home/draw/hatch.rs

@@ -423,3 +423,9 @@ impl CadCommand for BoundaryCommand {
         CmdResult::Cancel
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["BOUNDARY"] });  // BoundaryCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["GRADIENT"] });  // GradientCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["H", "HATCH"] });  // HatchCommand

src/modules/home/draw/hatchedit.rs

@@ -161,3 +161,7 @@ impl CadCommand for HatcheditCommand {
         CmdResult::Cancel
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["HATCHEDIT", "HE"] });  // HatcheditCommand

src/modules/home/draw/line.rs

@@ -94,3 +94,7 @@ impl CadCommand for LineCommand {
         })
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["L", "LINE"] });  // LineCommand

src/modules/home/draw/mline.rs

@@ -157,3 +157,7 @@ fn build_mline(pts: &[Vec3], scale: f64, closed: bool, style_name: &str) -> Enti
     mline.style_name = style_name.to_string();
     EntityType::MLine(mline)
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["ML", "MLINE"] });  // MlineCommand

src/modules/home/draw/point.rs

@@ -55,3 +55,7 @@ impl CadCommand for PointCommand {
         None
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["PO", "POINT"] });  // PointCommand

src/modules/home/draw/polyline.rs

@@ -321,3 +321,7 @@ impl CadCommand for PlineCommand {
         ))
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["PL", "PLINE"] });  // PlineCommand

src/modules/home/draw/ray.rs

@@ -173,3 +173,8 @@ impl CadCommand for XLineCommand {
         })
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["RAY"] });  // RayCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["CONSTRUCTIONLINE", "XL", "XLINE"] });  // XLineCommand

src/modules/home/draw/revcloud.rs

@@ -133,3 +133,7 @@ fn make_revcloud(pts: &[Vec3], arc_len: f64) -> EntityType {
     p.vertices = vertices;
     EntityType::LwPolyline(p)
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["REVCLOUD"] });  // RevCloudCommand

src/modules/home/draw/shapes.rs

@@ -633,3 +633,12 @@ fn edge_poly_params(a: Vec3, b: Vec3, sides: u32) -> Option<(Vec3, f32, f32)> {
     let sa = angle_xy(center, a);
     Some((center, vr, sa))
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["POLY_C"] });  // PolyCCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["POL", "POLY", "POLYGON"] });  // PolyCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["POLY_E"] });  // PolyECommand
+inventory::submit!(crate::command::CommandRegistration { names: &["RECT_CEN"] });  // RectCenCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["REC", "RECT", "RECTANG"] });  // RectCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["RECT_ROT"] });  // RectRotCommand

src/modules/home/draw/spline.rs

@@ -118,3 +118,7 @@ impl CadCommand for SplineCommand {
         ))
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["SPL", "SPLINE"] });  // SplineCommand

src/modules/home/groups/ungroup.rs

@@ -59,3 +59,7 @@ impl CadCommand for UngroupCommand {
         vec![]
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["UG", "UNGROUP"] });  // UngroupCommand

src/modules/home/inquiry/area.rs

@@ -82,3 +82,7 @@ impl CadCommand for AreaCommand {
         })
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["AREA"] });  // AreaCommand

src/modules/home/inquiry/dist.rs

@@ -77,3 +77,7 @@ impl CadCommand for DistCommand {
         })
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DI", "DIST"] });  // DistCommand

src/modules/home/inquiry/divide.rs

@@ -295,3 +295,8 @@ fn arc_span_rad(start: f64, end: f64) -> f64 {
         span
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["DIV", "DIVIDE"] });  // DivideCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["ME", "MEASURE"] });  // MeasureCommand

src/modules/home/inquiry/id.rs

@@ -34,3 +34,7 @@ impl CadCommand for IdCommand {
         CmdResult::Cancel
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["ID"] });  // IdCommand

src/modules/home/layers/match_layer.rs

@@ -79,3 +79,7 @@ impl CadCommand for LayMatchCommand {
         vec![]
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["LAYMATCH", "LAYMCH"] });  // LayMatchCommand

src/modules/home/modify/align.rs

@@ -189,3 +189,7 @@ impl AlignCommand {
         }
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["AL", "ALIGN"] });  // AlignCommand

src/modules/home/modify/break_cmd.rs

@@ -467,3 +467,8 @@ impl CadCommand for BreakAtPointCommand {
         CmdResult::Cancel
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["BAP", "BREAKATPOINT"] });  // BreakAtPointCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["BR", "BREAK"] });  // BreakInteractiveCommand

src/modules/home/modify/fillet.rs

@@ -1706,3 +1706,8 @@ impl CadCommand for ChamferCommand {
         CmdResult::Cancel
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["CHA", "CHAMFER"] });  // ChamferCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["F", "FILLET"] });  // FilletCommand

src/modules/home/modify/join.rs

@@ -237,3 +237,7 @@ fn try_join_arcs(arcs: &[&(Handle, &EntityType)]) -> Option<(Vec<Handle>, Vec<En
 fn vec3_xz_to_v3(v: Vec3, z: f64) -> Vector3 {
     Vector3::new(v.x as f64, v.y as f64, z)
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["J", "JOIN"] });  // JoinCommand

src/modules/home/modify/lengthen.rs

@@ -500,3 +500,7 @@ fn lengthen_spline(spl: &SplineEnt, pick_pt: Vec3, mode: &LenMode) -> Option<Ent
         Some(EntityType::Spline(bspline_to_spline(&right, spl)))
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["LEN", "LENGTHEN"] });  // LengthenCommand

src/modules/home/modify/offset.rs

@@ -714,3 +714,7 @@ impl CadCommand for OffsetCommand {
         CmdResult::Cancel
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["O", "OFFSET"] });  // OffsetCommand

src/modules/home/modify/pedit.rs

@@ -138,3 +138,7 @@ pub fn apply_pedit(entity: &mut EntityType, op: &PeditOp) -> bool {
         },
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["PE", "PEDIT"] });  // PeditCommand

src/modules/home/modify/refedit.rs

@@ -206,3 +206,8 @@ pub fn apply_insert_inverse_transform(entity: &mut EntityType, session: &RefEdit
         );
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["REFCLOSE"] });  // RefCloseCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["REFEDIT"] });  // RefEditPickCommand

src/modules/home/modify/splinedit.rs

@@ -200,3 +200,7 @@ pub fn apply_spline_op(doc: &mut acadrust::CadDocument, handle: acadrust::Handle
         _ => {}
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["SPE", "SPLINEDIT"] });  // SplineditCommand

src/modules/home/modify/trim.rs

@@ -2457,3 +2457,8 @@ impl CadCommand for ExtendCommand {
         CmdResult::Cancel
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["EX", "EXTEND"] });  // ExtendCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["TR", "TRIM"] });  // TrimCommand

src/modules/home/properties/match_prop.rs

@@ -89,3 +89,7 @@ impl CadCommand for MatchPropCommand {
         vec![]
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["MA", "MATCHPROP"] });  // MatchPropCommand

src/modules/home/select.rs

@@ -60,3 +60,7 @@ impl CadCommand for SelectObjectsCommand {
         vec![]
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["AR", "ARRAY", "ARRAYPATH", "ARRAYPOLAR", "ARRAYRECT", "BLOCK", "CC", "CO", "COPY", "COPYCLIP", "CUTCLIP", "CX", "E", "ERASE", "EXPLODE", "G", "GROUP", "LAYFRZ", "LAYLCK", "LAYMCUR", "LAYOFF", "LAYULK", "M", "MI", "MIRROR", "MOVE", "RO", "ROTATE", "SC", "SCALE", "SS", "STRETCH", "X"] });  // SelectObjectsCommand

src/modules/insert/insert_block.rs

@@ -210,3 +210,7 @@ impl InsertBlockCommand {
         }
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["INSERT"] });  // InsertBlockCommand

src/modules/insert/solid3d_cmds.rs

@@ -658,3 +658,13 @@ impl CadCommand for LoftCommand {
 pub fn empty_solid3d() -> EntityType {
     EntityType::Solid3D(Solid3D::new())
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["BOX"] });  // BoxCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["CYLINDER"] });  // CylinderCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["EXT", "EXTRUDE"] });  // ExtrudeCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["LOFT"] });  // LoftCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["REV", "REVOLVE"] });  // RevolveCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["SPHERE"] });  // SphereCommand
+inventory::submit!(crate::command::CommandRegistration { names: &["SWEEP"] });  // SweepCommand

src/modules/layout/mview.rs

@@ -104,3 +104,7 @@ impl CadCommand for MviewCommand {
         })
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["MV", "MVIEW"] });  // MviewCommand

src/modules/layout/vplayer.rs

@@ -106,3 +106,7 @@ impl CadCommand for VplayerCommand {
         None
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["VPLAYER"] });  // VplayerCommand

src/modules/view/plot_window.rs

@@ -75,3 +75,7 @@ impl CadCommand for PlotWindowCommand {
         })
     }
 }
+
+
+// ── Autocomplete registry ─────────────────────────────────
+inventory::submit!(crate::command::CommandRegistration { names: &["PLOTWINDOW", "PW"] });  // PlotWindowCommand

src/ui/command_line.rs

@@ -12,6 +12,9 @@ pub const CMD_INPUT_ID: &str = "cmd_input";
 /// out. Picking the full archive happens through the dropdown button.
 const HISTORY_VISIBLE_SECS: f32 = 3.0;
 
+/// How many autocomplete matches the suggestion popup shows at once.
+const AUTOCOMPLETE_LIMIT: usize = 8;
+
 fn cmd_input_id() -> iced::widget::Id {
     iced::widget::Id::new(CMD_INPUT_ID)
 }
@@ -30,6 +33,10 @@ pub struct CommandLine {
     recall_draft: String,
     /// When `true`, the dropdown showing the full backlog is open.
     pub history_open: bool,
+    /// Index of the currently-highlighted autocomplete suggestion, or
+    /// `None` when the user hasn't yet started navigating with the
+    /// arrow keys. Reset on every keystroke.
+    pub autocomplete_cursor: Option<usize>,
 }
 
 #[derive(Clone, Debug)]
@@ -152,7 +159,74 @@ impl CommandLine {
         self.history_open = false;
     }
 
-    pub fn view(&self) -> Element<'_, Message> {
+    /// Move the autocomplete highlight up one entry. Wraps to the last
+    /// match. Returns `true` when there was a list to navigate.
+    pub fn autocomplete_prev(&mut self) -> bool {
+        let len = self.autocomplete_matches().len();
+        if len == 0 {
+            return false;
+        }
+        let next = match self.autocomplete_cursor {
+            None => len - 1,
+            Some(0) => len - 1,
+            Some(i) => i - 1,
+        };
+        self.autocomplete_cursor = Some(next);
+        true
+    }
+
+    /// Move the autocomplete highlight down one entry. Wraps to the
+    /// first match. Returns `true` when there was a list to navigate.
+    pub fn autocomplete_next(&mut self) -> bool {
+        let len = self.autocomplete_matches().len();
+        if len == 0 {
+            return false;
+        }
+        let next = match self.autocomplete_cursor {
+            None => 0,
+            Some(i) if i + 1 < len => i + 1,
+            Some(_) => 0,
+        };
+        self.autocomplete_cursor = Some(next);
+        true
+    }
+
+    /// The command name the user has currently highlighted in the
+    /// autocomplete popup, if any.
+    pub fn selected_suggestion(&self) -> Option<&'static str> {
+        let matches = self.autocomplete_matches();
+        self.autocomplete_cursor
+            .and_then(|i| matches.get(i).copied())
+    }
+
+    /// Autocomplete suggestions for the current input, capped at
+    /// [`AUTOCOMPLETE_LIMIT`]. Match is substring-anywhere (typing
+    /// `LEADER` surfaces `LEADER` and `MLEADER` and `QLEADER`); the
+    /// list is sorted so prefix matches come first.
+    ///
+    /// Names come from `crate::command::all_registered_command_names()`
+    /// which collects every `inventory::submit!` block placed next to a
+    /// `CadCommand` impl — no central list to maintain.
+    pub fn autocomplete_matches(&self) -> Vec<&'static str> {
+        let typed = self.input.trim();
+        if typed.is_empty() {
+            return Vec::new();
+        }
+        let needle = typed.to_uppercase();
+        let mut matches: Vec<&'static str> = crate::command::all_registered_command_names()
+            .into_iter()
+            .filter(|cmd| cmd.contains(&needle))
+            .collect();
+        matches.sort();
+        matches.dedup();
+        // Prefix matches rank above mid-string ones, then alphabetical
+        // so the order is stable as the user keeps typing.
+        matches.sort_by_key(|cmd| (!cmd.starts_with(&needle), *cmd));
+        matches.truncate(AUTOCOMPLETE_LIMIT);
+        matches
+    }
+
+    pub fn view(&self, show_autocomplete: bool) -> Element<'_, Message> {
         // Only the most recent entries pushed within the last few
         // seconds show on the overlay. The dropdown button keeps the
         // full backlog reachable when the user actually wants it.
@@ -207,6 +281,67 @@ impl CommandLine {
             })
             .size(11)
             .padding([4, 6]);
+        // Autocomplete suggestions panel, shown above the input row
+        // when the user has typed a prefix that matches at least one
+        // command. Each row is a button — clicking it dispatches the
+        // command directly.
+        let autocomplete: Element<'_, Message> = if show_autocomplete {
+            let matches = self.autocomplete_matches();
+            if matches.is_empty() {
+                container(column![]).height(0).into()
+            } else {
+                let cursor = self.autocomplete_cursor;
+                let mut col = column![].spacing(0).width(Length::Fill);
+                for (idx, cmd) in matches.iter().enumerate() {
+                    let is_selected = cursor == Some(idx);
+                    let row = button(text(*cmd).size(11).color(CMD_COLOR))
+                        .on_press(Message::CommandSuggestionPick(cmd.to_string()))
+                        .width(Length::Fill)
+                        .padding([2, 8])
+                        .style(move |_: &Theme, status| {
+                            let bg = if is_selected {
+                                Color {
+                                    r: 0.28,
+                                    g: 0.40,
+                                    b: 0.56,
+                                    a: 1.0,
+                                }
+                            } else if matches!(status, button::Status::Hovered) {
+                                Color {
+                                    r: 0.22,
+                                    g: 0.30,
+                                    b: 0.42,
+                                    a: 1.0,
+                                }
+                            } else {
+                                PANEL_BG
+                            };
+                            button::Style {
+                                background: Some(Background::Color(bg)),
+                                text_color: Color::WHITE,
+                                border: Border::default(),
+                                ..Default::default()
+                            }
+                        });
+                    col = col.push(row);
+                }
+                container(col)
+                    .style(|_: &Theme| container::Style {
+                        background: Some(Background::Color(PANEL_BG)),
+                        border: Border {
+                            color: BORDER_COLOR,
+                            width: 1.0,
+                            radius: 4.0.into(),
+                        },
+                        ..Default::default()
+                    })
+                    .width(Length::Fill)
+                    .into()
+            }
+        } else {
+            container(column![]).height(0).into()
+        };
+
         // Dropdown trigger next to the input. Clicking it pops up the
         // full backlog (everything pushed since the app started) so the
         // user can recover anything that has already faded off the
@@ -275,6 +410,7 @@ impl CommandLine {
         };
 
         container(column![
+            autocomplete,
             dropdown,
             container(history_rows)
                 .style(|_: &Theme| container::Style {
@@ -369,3 +505,4 @@ const INFO_COLOR: Color = Color {
     b: 0.90,
     a: 1.0,
 };
+