diff --git a/ATTRIBUTION.md b/ATTRIBUTION.md
index 6e23b06e..ec7442d1 100644
--- a/ATTRIBUTION.md
+++ b/ATTRIBUTION.md
@@ -69,6 +69,8 @@ Screenshots of EffectCraft itself, rendered headlessly, showing only procedurall
   `crates/engine/scripts/Sort Layers by In Point.jsx`, `crates/engine/scripts/Create Null at Selected Layers.jsx`,
   `crates/engine/scripts/Render Queue Batch.jsx`, `crates/engine/scripts/ScriptUI Panels/Layer Tools.jsx`
   (sidecars `.attribution`).
+- Bundled extension (ScriptUI panel) with its twelve built-in ease presets:
+  `extensions/scriptui-panels/Ease Presets.jsx` (sidecar `.attribution`).
 - Example effect plug-in: `examples/plugins/posterize-bands` (plug-in API v1, WebAssembly).
 
 ## Trained models (optional downloads, not bundled)
diff --git a/crates/engine/src/commands/frontend.rs b/crates/engine/src/commands/frontend.rs
index b65d7666..296160d1 100644
--- a/crates/engine/src/commands/frontend.rs
+++ b/crates/engine/src/commands/frontend.rs
@@ -86,7 +86,7 @@ pub fn specs() -> Vec<CommandSpec> {
             "Show Panel",
             [],
             None,
-            "{panel: project|effectControls|composition|layer|timeline|info|audio|preview|effectsPresets|properties|character|paragraph|align|tracker|wiggler|smoother|motionSketch|paint|brushes|renderQueue|flowchart|history|markers|tools|lumetriScopes|footage|mediaBrowser|metadata|progress|contentAwareFill|createNullsFromPaths|vrCompEditor|easePresets}",
+            "{panel: project|effectControls|composition|layer|timeline|info|audio|preview|effectsPresets|properties|character|paragraph|align|tracker|wiggler|smoother|motionSketch|paint|brushes|renderQueue|flowchart|history|markers|tools|lumetriScopes|footage|mediaBrowser|metadata|progress|contentAwareFill|createNullsFromPaths|vrCompEditor}",
             always
         ),
         fe!(
diff --git a/crates/engine/src/commands/mod.rs b/crates/engine/src/commands/mod.rs
index b8d626ba..423aaea2 100644
--- a/crates/engine/src/commands/mod.rs
+++ b/crates/engine/src/commands/mod.rs
@@ -204,7 +204,6 @@ pub fn command_specs() -> &'static [CommandSpec] {
         v.extend(crate::storage::specs());
         v.extend(crate::learn::specs());
         v.extend(crate::templates::specs());
-        v.extend(crate::ease_presets::specs());
         v.extend(crate::preview::specs());
         v
     })
diff --git a/crates/engine/src/commands/scripts.rs b/crates/engine/src/commands/scripts.rs
index b3847b6b..e6951c37 100644
--- a/crates/engine/src/commands/scripts.rs
+++ b/crates/engine/src/commands/scripts.rs
@@ -3,11 +3,15 @@
 //! * **Installed scripts** live in the settings store under `Scripts/` (File ▸ Scripts ▸ Install
 //!   Script File…) and `Scripts/ScriptUI Panels/` (Install ScriptUI Panel…), next to the
 //!   settings on the desktop, so dropping `.jsx` files in those folders works too. File ▸ Scripts
-//!   lists them with the bundled sample scripts ([`SAMPLES`]) and runs them by name; ScriptUI
+//!   lists them with the bundled sample scripts and extensions ([`BUNDLED`]) and runs them by name; ScriptUI
 //!   panels appear at the bottom of the Window menu and open as dockable panels
 //!   (`window.scriptPanel`), running with `this` = the panel as in After Effects.
 //! * **ScriptUI windows** (`scriptui.*`): list the open script windows, read their control
 //!   trees, click buttons and set values like a user, close them (see [`crate::scriptui`]).
+//! * **Script settings** (`script.settings.*`): After Effects' `app.settings`, string values by
+//!   section and key that last between runs ([`SCRIPT_SETTINGS_FILE`]).
+
+use std::collections::BTreeMap;
 
 use serde::Serialize;
 use serde_json::{Value, json};
@@ -20,14 +24,88 @@ pub const SCRIPTS_DIR: &str = "Scripts";
 pub const PANELS_DIR: &str = "Scripts/ScriptUI Panels";
 /// The ScriptUI panels open when EffectCraft last quit (settings store), reopened at launch.
 pub const OPEN_PANELS_FILE: &str = "scriptui_panels.json";
+/// Scripts' `app.settings` in the settings store: `{section: {key: value}}`, as After Effects
+/// keeps them in its preferences.
+pub const SCRIPT_SETTINGS_FILE: &str = "script_settings.json";
+/// User presets of the core Ease Presets panel of v0.6.0 (#254) and where the Ease Presets
+/// ScriptUI panel that replaced it keeps them: (file, section, key). The file's text moves there
+/// unchanged (the panel reads the same JSON) the first time settings load.
+const LEGACY_EASE_PRESETS: (&str, &str, &str) = ("ease_presets.json", "Ease Presets", "userPresets");
+/// Longest section, key and value a script may store (characters / bytes).
+const MAX_SETTING_NAME: usize = 256;
+const MAX_SETTING_VALUE: usize = 1 << 20;
 
-/// Sample scripts that ship with EffectCraft (original work): (file name, ScriptUI panel, code).
-pub const SAMPLES: &[(&str, bool, &str)] = &[
-    ("Create Null at Selected Layers.jsx", false, include_str!("../../scripts/Create Null at Selected Layers.jsx")),
-    ("Rename Layers.jsx", false, include_str!("../../scripts/Rename Layers.jsx")),
-    ("Render Queue Batch.jsx", false, include_str!("../../scripts/Render Queue Batch.jsx")),
-    ("Sort Layers by In Point.jsx", false, include_str!("../../scripts/Sort Layers by In Point.jsx")),
-    ("Layer Tools.jsx", true, include_str!("../../scripts/ScriptUI Panels/Layer Tools.jsx")),
+/// Scripts' `app.settings`: values by section and key.
+pub type ScriptSettings = BTreeMap<String, BTreeMap<String, String>>;
+
+/// Load scripts' settings from the settings store (a corrupt file gives none), moving user ease
+/// presets saved before Ease Presets became a ScriptUI panel into its section.
+pub(crate) fn load_script_settings(s: &mut Session) {
+    let Some(cfg) = s.config.clone() else { return };
+    s.script_settings = cfg
+        .read(SCRIPT_SETTINGS_FILE)
+        .and_then(|t| serde_json::from_str(&t).map_err(|e| log::warn!("{SCRIPT_SETTINGS_FILE} is not valid ({e}); scripts start without their settings")).ok())
+        .unwrap_or_default();
+    let (file, section, key) = LEGACY_EASE_PRESETS;
+    if let Some(text) = cfg.read(file)
+        && !s.script_settings.get(section).is_some_and(|m| m.contains_key(key))
+    {
+        s.script_settings.entry(section.into()).or_default().insert(key.into(), text);
+        if let Err(e) = store_script_settings(s) {
+            log::warn!("cannot move {file} into the Ease Presets panel's settings: {e}");
+        }
+    }
+}
+
+fn store_script_settings(s: &Session) -> Result<()> {
+    let Some(cfg) = &s.config else { return Ok(()) };
+    let text = serde_json::to_string_pretty(&s.script_settings).map_err(|e| EngineError::Other(format!("script settings: {e}")))?;
+    cfg.write(SCRIPT_SETTINGS_FILE, &text).map_err(|e| EngineError::Other(format!("cannot save script settings: {e}")))
+}
+
+fn setting_name<'a>(p: &'a Value, k: &str, c: &str) -> Result<&'a str> {
+    let v = str_p(p, k).ok_or_else(|| bad(c, format!("missing `{k}`")))?;
+    if v.chars().count() > MAX_SETTING_NAME {
+        return Err(bad(c, format!("`{k}` is longer than {MAX_SETTING_NAME} characters")));
+    }
+    Ok(v)
+}
+
+/// `script.settings.get {section, key}` → `{have, value}` (`value` "" when there is none).
+fn settings_get(s: &mut Session, p: &Value) -> Result<Value> {
+    const C: &str = "script.settings.get";
+    let (section, key) = (setting_name(p, "section", C)?, setting_name(p, "key", C)?);
+    let v = s.script_settings.get(section).and_then(|m| m.get(key));
+    Ok(json!({"have": v.is_some(), "value": v.cloned().unwrap_or_default()}))
+}
+
+/// `script.settings.save {section, key, value}`: kept in the settings store.
+fn settings_save(s: &mut Session, p: &Value) -> Result<Value> {
+    const C: &str = "script.settings.save";
+    let (section, key) = (setting_name(p, "section", C)?, setting_name(p, "key", C)?);
+    let value = match p.get("value") {
+        Some(Value::String(v)) => v.clone(),
+        Some(v) if !v.is_null() => v.to_string(),
+        _ => return Err(bad(C, "missing `value`")),
+    };
+    if value.len() > MAX_SETTING_VALUE {
+        return Err(bad(C, format!("`value` is larger than {MAX_SETTING_VALUE} bytes")));
+    }
+    s.script_settings.entry(section.into()).or_default().insert(key.into(), value);
+    store_script_settings(s)?;
+    Ok(Value::Null)
+}
+
+/// Scripts that ship with EffectCraft (original work): (file name, ScriptUI panel, source, code).
+/// `sample`s show how to script EffectCraft; `extension`s (in `extensions/`) are optional tools
+/// built on the public scripting API, outside the core, like third-party scripts in After Effects.
+pub const BUNDLED: &[(&str, bool, &str, &str)] = &[
+    ("Create Null at Selected Layers.jsx", false, "sample", include_str!("../../scripts/Create Null at Selected Layers.jsx")),
+    ("Rename Layers.jsx", false, "sample", include_str!("../../scripts/Rename Layers.jsx")),
+    ("Render Queue Batch.jsx", false, "sample", include_str!("../../scripts/Render Queue Batch.jsx")),
+    ("Sort Layers by In Point.jsx", false, "sample", include_str!("../../scripts/Sort Layers by In Point.jsx")),
+    ("Layer Tools.jsx", true, "sample", include_str!("../../scripts/ScriptUI Panels/Layer Tools.jsx")),
+    ("Ease Presets.jsx", true, "extension", include_str!("../../../../extensions/scriptui-panels/Ease Presets.jsx")),
 ];
 
 /// A script File ▸ Scripts (or the Window menu, for panels) offers.
@@ -37,7 +115,7 @@ pub struct ScriptEntry {
     pub name: String,
     /// In the ScriptUI Panels folder: opens as a dockable panel.
     pub panel: bool,
-    /// `installed` or `sample`.
+    /// `installed`, `sample` or `extension` (bundled, see [`BUNDLED`]).
     pub source: &'static str,
 }
 
@@ -46,7 +124,7 @@ fn is_script(name: &str) -> bool {
     l.ends_with(".jsx") || l.ends_with(".js")
 }
 
-/// Installed scripts and panels, then the samples not shadowed by an installed one, by name.
+/// Installed scripts and panels, then the bundled ones not shadowed by an installed one, by name.
 pub fn scripts(s: &Session) -> Vec<ScriptEntry> {
     let mut v: Vec<ScriptEntry> = vec![];
     if let Some(cfg) = &s.config {
@@ -56,16 +134,16 @@ pub fn scripts(s: &Session) -> Vec<ScriptEntry> {
             }
         }
     }
-    for (name, panel, _) in SAMPLES {
+    for (name, panel, source, _) in BUNDLED {
         if !v.iter().any(|e| e.name == *name && e.panel == *panel) {
-            v.push(ScriptEntry { name: name.to_string(), panel: *panel, source: "sample" });
+            v.push(ScriptEntry { name: name.to_string(), panel: *panel, source });
         }
     }
     v.sort_by(|a, b| a.panel.cmp(&b.panel).then(a.name.to_lowercase().cmp(&b.name.to_lowercase())));
     v
 }
 
-/// The code of an installed or sample script / panel.
+/// The code of an installed or bundled script / panel.
 pub fn script_code(s: &Session, name: &str, panel: Option<bool>) -> Option<(bool, String)> {
     if let Some(cfg) = &s.config {
         for (dir, is_panel) in [(SCRIPTS_DIR, false), (PANELS_DIR, true)] {
@@ -77,7 +155,7 @@ pub fn script_code(s: &Session, name: &str, panel: Option<bool>) -> Option<(bool
             }
         }
     }
-    SAMPLES.iter().find(|(n, p, _)| *n == name && panel.is_none_or(|w| w == *p)).map(|(_, p, c)| (*p, c.to_string()))
+    BUNDLED.iter().find(|(n, p, ..)| *n == name && panel.is_none_or(|w| w == *p)).map(|(_, p, _, c)| (*p, c.to_string()))
 }
 
 fn install(s: &mut Session, p: &Value, panel: bool) -> Result<Value> {
@@ -120,10 +198,10 @@ fn uninstall(s: &mut Session, p: &Value) -> Result<Value> {
     if removed { Ok(json!({"removed": name})) } else { Err(bad(c, format!("`{name}` is not installed"))) }
 }
 
-/// Run an installed or sample script by name (File ▸ Scripts ▸ <name>). A ScriptUI panel run
+/// Run an installed or bundled script by name (File ▸ Scripts ▸ <name>). A ScriptUI panel run
 /// this way gets `this` = a floating palette-like panel window.
 pub(crate) fn run_named(s: &mut Session, name: &str) -> Result<Value> {
-    let (panel, code) = script_code(s, name, None).ok_or_else(|| bad("file.runScript", format!("no installed or sample script `{name}`")))?;
+    let (panel, code) = script_code(s, name, None).ok_or_else(|| bad("file.runScript", format!("no installed or bundled script `{name}`")))?;
     if panel {
         return open_panel(s, &json!({"name": name}));
     }
@@ -241,7 +319,7 @@ pub fn specs() -> Vec<CommandSpec> {
             |s, p| install(s, p, true)
         ),
         cmd!("file.uninstallScript", "Uninstall Script", [], None, "{name}", always, uninstall),
-        crate::query!("file.scripts.list", "List Scripts", "{} → [{name, panel, source: installed|sample}]", list),
+        crate::query!("file.scripts.list", "List Scripts", "{} → [{name, panel, source: installed|sample|extension}]", list),
         cmd!(
             "window.scriptPanel",
             "ScriptUI Panel",
@@ -260,6 +338,16 @@ pub fn specs() -> Vec<CommandSpec> {
             always,
             restore_panels
         ),
+        crate::query!("script.settings.get", "Get Script Setting", "{section, key} → {have, value} (app.settings.haveSetting / getSetting)", settings_get),
+        cmd!(
+            "script.settings.save",
+            "Save Script Setting",
+            [],
+            None,
+            "{section, key, value (text)} → kept in the settings store (app.settings.saveSetting)",
+            always,
+            settings_save
+        ),
         crate::query!("scriptui.list", "List Script Windows", "{} → [{window, title, kind: dialog|palette|window|panel, script, modal, size}]", scriptui::list),
         crate::query!(
             "scriptui.get",
diff --git a/crates/engine/src/ease_presets.rs b/crates/engine/src/ease_presets.rs
deleted file mode 100644
index f7be97d2..00000000
--- a/crates/engine/src/ease_presets.rs
+++ /dev/null
@@ -1,272 +0,0 @@
-//! Ease presets (Window ▸ Ease Presets): easing curves kept by name and applied to pairs of
-//! keyframes. A few original built-in curves ship with EffectCraft; user presets live in the config
-//! store (`ease_presets.json`), read leniently: a corrupt file or entry is skipped, never fatal.
-//!
-//! Commands: `keys.easePreset.apply {preset | curve}` eases every pair of neighbouring selected
-//! keyframes of each property (one undo step), `keys.easePreset.capture` reads the curve between
-//! the first selected pair, `keys.easePreset.save {name, curve?}`, `keys.easePreset.list`,
-//! `keys.easePreset.rename {name, newName}` and `keys.easePreset.delete {name}`.
-
-use std::collections::BTreeMap;
-
-use effectcraft_keyframe::{EaseCurve, key_at};
-use effectcraft_project::{LayerId, Uid};
-use serde::{Deserialize, Serialize};
-use serde_json::{Value, json};
-
-use crate::commands::{CommandSpec, always, bad, has_keys, str_p};
-use crate::{EngineError, Result, Session, cmd, query};
-
-/// User presets in the config store.
-pub const EASE_PRESETS_FILE: &str = "ease_presets.json";
-/// Longest preset name, in characters.
-const MAX_NAME: usize = 64;
-const NEED_PAIR: &str = "select two or more neighbouring keyframes of a property";
-
-/// A user preset.
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-pub struct EasePreset {
-    pub name: String,
-    pub curve: EaseCurve,
-}
-
-const fn curve(out_influence: f64, out_speed: f64, in_influence: f64, in_speed: f64) -> EaseCurve {
-    EaseCurve { out_influence, out_speed, in_influence, in_speed }
-}
-
-/// Built-in presets (our own values). "Accelerate" starts slowly and "Decelerate" settles slowly.
-const BUILT_IN: [(&str, EaseCurve); 12] = [
-    ("Linear", EaseCurve::LINEAR),
-    ("Smooth", curve(40.0, 0.25, 40.0, 0.25)),
-    ("Ease In-Out Soft", curve(25.0, 0.0, 25.0, 0.0)),
-    ("Ease In-Out", curve(50.0, 0.0, 50.0, 0.0)),
-    ("Ease In-Out Strong", curve(75.0, 0.0, 75.0, 0.0)),
-    ("Accelerate", curve(50.0, 0.0, 20.0, 1.5)),
-    ("Accelerate Strong", curve(80.0, 0.0, 15.0, 2.5)),
-    ("Decelerate", curve(20.0, 1.5, 50.0, 0.0)),
-    ("Decelerate Strong", curve(15.0, 2.5, 80.0, 0.0)),
-    ("Expo In-Out", curve(88.0, 0.0, 88.0, 0.0)),
-    ("Expo Accelerate", curve(75.0, 0.0, 12.0, 7.0)),
-    ("Expo Decelerate", curve(12.0, 7.0, 75.0, 0.0)),
-];
-
-/// Every preset: (name, curve, built in), the built-in ones first.
-pub fn presets(s: &Session) -> impl Iterator<Item = (&str, EaseCurve, bool)> {
-    BUILT_IN.iter().map(|(n, c)| (*n, *c, true)).chain(s.ease_presets.iter().map(|p| (p.name.as_str(), p.curve, false)))
-}
-
-/// A preset's curve by name (any case).
-pub fn find(s: &Session, name: &str) -> Option<EaseCurve> {
-    presets(s).find(|(n, ..)| n.eq_ignore_ascii_case(name)).map(|(_, c, _)| c)
-}
-
-fn is_built_in(name: &str) -> bool {
-    BUILT_IN.iter().any(|(n, _)| n.eq_ignore_ascii_case(name))
-}
-
-/// Pairs of neighbouring selected keyframes of the active comp: (layer, property, index of the
-/// earlier key), by property and time.
-pub fn selected_pairs(s: &Session) -> Vec<(LayerId, Uid, usize)> {
-    let Some(comp) = s.active_comp() else { return vec![] };
-    let mut groups: BTreeMap<(LayerId, Uid), Vec<usize>> = BTreeMap::new();
-    for k in &s.state.selected_keys {
-        let Some(pr) = comp.layer(k.layer).and_then(|l| l.props.find(k.prop)).filter(|pr| pr.value.interpolates()) else { continue };
-        if let Some(i) = key_at(&pr.keys, k.time) {
-            groups.entry((k.layer, k.prop)).or_default().push(i);
-        }
-    }
-    let mut out = vec![];
-    for ((lid, uid), mut idx) in groups {
-        idx.sort_unstable();
-        idx.dedup();
-        out.extend(idx.windows(2).filter_map(|w| match *w {
-            [a, b] if b == a + 1 => Some((lid, uid, a)),
-            _ => None,
-        }));
-    }
-    out
-}
-
-/// Read user presets: entries that don't parse, have no usable name or repeat a name are
-/// skipped (and logged); a file that isn't JSON gives none.
-pub fn parse(text: &str) -> Vec<EasePreset> {
-    let doc: Value = serde_json::from_str(text).unwrap_or_else(|e| {
-        log::warn!("{EASE_PRESETS_FILE} is not valid JSON ({e}); no user ease presets loaded");
-        Value::Null
-    });
-    let mut out: Vec<EasePreset> = vec![];
-    for entry in doc.get("presets").and_then(Value::as_array).into_iter().flatten() {
-        let preset = serde_json::from_value::<EasePreset>(entry.clone())
-            .ok()
-            .and_then(|p| Some(EasePreset { name: clean_name(&p.name)?, curve: p.curve.sanitized()? }))
-            .filter(|p| !is_built_in(&p.name) && !out.iter().any(|q| q.name.eq_ignore_ascii_case(&p.name)));
-        match preset {
-            Some(p) => out.push(p),
-            None => log::warn!("{EASE_PRESETS_FILE}: skipped the unusable entry {entry}"),
-        }
-    }
-    out
-}
-
-/// The file as written.
-#[derive(Serialize)]
-struct PresetFile<'a> {
-    version: u32,
-    presets: &'a [EasePreset],
-}
-
-/// Write `list` to the config store, then make it the session's user presets.
-fn store(s: &mut Session, list: Vec<EasePreset>) -> Result<()> {
-    if let Some(cfg) = &s.config {
-        let text = serde_json::to_string_pretty(&PresetFile { version: 1, presets: &list }).map_err(|e| EngineError::Other(format!("ease presets: {e}")))?;
-        cfg.write(EASE_PRESETS_FILE, &text).map_err(|e| EngineError::Other(format!("cannot save ease presets: {e}")))?;
-    }
-    s.ease_presets = list;
-    Ok(())
-}
-
-fn clean_name(name: &str) -> Option<String> {
-    let name = name.trim();
-    (!name.is_empty() && name.chars().count() <= MAX_NAME).then(|| name.to_string())
-}
-
-fn name_p(p: &Value, key: &str, c: &str) -> Result<String> {
-    let raw = str_p(p, key).ok_or_else(|| bad(c, format!("missing `{key}`")))?;
-    clean_name(raw).ok_or_else(|| bad(c, format!("`{key}` must be 1–{MAX_NAME} characters")))
-}
-
-/// `curve`: `{outInfluence, outSpeed, inInfluence, inSpeed}` or handles `[x1, y1, x2, y2]`.
-fn curve_v(v: &Value, c: &str) -> Result<EaseCurve> {
-    let parsed = match v.as_array() {
-        Some(a) => {
-            let h: Option<Vec<f64>> = a.iter().map(Value::as_f64).collect();
-            let h: [f64; 4] = h.and_then(|h| h.try_into().ok()).ok_or_else(|| bad(c, "`curve` handles are four numbers [x1, y1, x2, y2]"))?;
-            EaseCurve::from_handles(h)
-        }
-        None => serde_json::from_value::<EaseCurve>(v.clone()).map_err(|e| bad(c, format!("`curve`: {e}")))?.sanitized(),
-    };
-    parsed.ok_or_else(|| bad(c, "`curve` numbers must be finite"))
-}
-
-/// The curve between the first selected pair of keyframes.
-fn captured(s: &Session, c: &str) -> Result<EaseCurve> {
-    let comp = s.active_comp().ok_or(EngineError::NoComp)?;
-    let (lid, uid, i) = selected_pairs(s).into_iter().next().ok_or_else(|| bad(c, NEED_PAIR))?;
-    let pr = comp.layer(lid).and_then(|l| l.props.find(uid)).ok_or_else(|| bad(c, "no property"))?;
-    EaseCurve::measure(&pr.keys, i, pr.spatial).ok_or_else(|| bad(c, "the selected keyframes have no curve to keep (a hold, or no change in value)"))
-}
-
-fn apply(s: &mut Session, p: &Value) -> Result<Value> {
-    const C: &str = "keys.easePreset.apply";
-    let curve = match (str_p(p, "preset"), p.get("curve")) {
-        (Some(name), _) => find(s, name).ok_or_else(|| bad(C, format!("no ease preset `{name}` (see keys.easePreset.list)")))?,
-        (None, Some(v)) => curve_v(v, C)?,
-        (None, None) => return Err(bad(C, "pass `preset` (a name) or `curve`")),
-    };
-    let pairs = selected_pairs(s);
-    if pairs.is_empty() {
-        return Err(bad(C, NEED_PAIR));
-    }
-    let cid = s.active_comp_id().ok_or(EngineError::NoComp)?;
-    let n = s.edit("Apply Ease Preset", None, |proj, _| {
-        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        let mut n = 0;
-        for (lid, uid, i) in &pairs {
-            if let Some(pr) = comp.layer_mut(*lid).and_then(|l| l.props.find_mut(*uid))
-                && curve.apply(&mut pr.keys, *i, pr.spatial)
-            {
-                n += 1;
-            }
-        }
-        Ok(n)
-    })?;
-    Ok(json!({"pairs": n, "curve": curve}))
-}
-
-fn capture(s: &mut Session, _: &Value) -> Result<Value> {
-    Ok(json!(captured(s, "keys.easePreset.capture")?))
-}
-
-fn save(s: &mut Session, p: &Value) -> Result<Value> {
-    const C: &str = "keys.easePreset.save";
-    let name = name_p(p, "name", C)?;
-    if is_built_in(&name) {
-        return Err(bad(C, format!("`{name}` is a built-in preset; choose another name")));
-    }
-    let curve = match p.get("curve") {
-        Some(v) => curve_v(v, C)?,
-        None => captured(s, C)?,
-    };
-    let preset = EasePreset { name, curve };
-    let mut list = s.ease_presets.clone();
-    // Saving under an existing name replaces that preset.
-    match list.iter_mut().find(|q| q.name.eq_ignore_ascii_case(&preset.name)) {
-        Some(q) => *q = preset.clone(),
-        None => list.push(preset.clone()),
-    }
-    store(s, list)?;
-    Ok(json!(preset))
-}
-
-/// Index of the user preset `name`; built-in presets can't be changed.
-fn user_preset(s: &Session, name: &str, c: &str) -> Result<usize> {
-    s.ease_presets.iter().position(|q| q.name.eq_ignore_ascii_case(name)).ok_or_else(|| {
-        if is_built_in(name) { bad(c, format!("`{name}` is a built-in preset and can't be changed")) } else { bad(c, format!("no user ease preset `{name}`")) }
-    })
-}
-
-fn rename(s: &mut Session, p: &Value) -> Result<Value> {
-    const C: &str = "keys.easePreset.rename";
-    let (name, new_name) = (name_p(p, "name", C)?, name_p(p, "newName", C)?);
-    let i = user_preset(s, &name, C)?;
-    if is_built_in(&new_name) || s.ease_presets.iter().enumerate().any(|(j, q)| j != i && q.name.eq_ignore_ascii_case(&new_name)) {
-        return Err(bad(C, format!("an ease preset named `{new_name}` exists")));
-    }
-    let mut list = s.ease_presets.clone();
-    if let Some(q) = list.get_mut(i) {
-        q.name = new_name.clone();
-    }
-    store(s, list)?;
-    Ok(json!({"name": new_name}))
-}
-
-fn delete(s: &mut Session, p: &Value) -> Result<Value> {
-    const C: &str = "keys.easePreset.delete";
-    let name = name_p(p, "name", C)?;
-    user_preset(s, &name, C)?;
-    let mut list = s.ease_presets.clone();
-    list.retain(|q| !q.name.eq_ignore_ascii_case(&name));
-    store(s, list)?;
-    Ok(json!({"deleted": name}))
-}
-
-fn list(s: &mut Session, _: &Value) -> Result<Value> {
-    Ok(presets(s).map(|(name, curve, built_in)| json!({"name": name, "builtIn": built_in, "curve": curve})).collect())
-}
-
-pub fn specs() -> Vec<CommandSpec> {
-    vec![
-        cmd!(
-            "keys.easePreset.apply",
-            "Apply Ease Preset",
-            [],
-            None,
-            "{preset (name) | curve: {outInfluence (%), outSpeed, inInfluence (%), inSpeed} | [x1, y1, x2, y2]} — eases every pair of neighbouring selected keyframes; speeds are relative to the segment's average speed",
-            has_keys,
-            apply
-        ),
-        cmd!(
-            "keys.easePreset.save",
-            "Save Ease Preset",
-            [],
-            None,
-            "{name, curve? (as for apply; default: the curve between the first selected pair of keyframes)} — replaces a user preset of that name",
-            always,
-            save
-        ),
-        cmd!("keys.easePreset.rename", "Rename Ease Preset", [], None, "{name, newName}", always, rename),
-        cmd!("keys.easePreset.delete", "Delete Ease Preset", [], None, "{name}", always, delete),
-        query!("keys.easePreset.list", "Ease Presets", "{} — [{name, builtIn, curve}]", list),
-        query!("keys.easePreset.capture", "Ease Curve of Selected Keyframes", "{} — the curve between the first selected pair of keyframes", capture),
-    ]
-}
diff --git a/crates/engine/src/lib.rs b/crates/engine/src/lib.rs
index b38a84ee..24ccf1af 100644
--- a/crates/engine/src/lib.rs
+++ b/crates/engine/src/lib.rs
@@ -15,7 +15,6 @@ pub mod camera_track;
 pub mod commands;
 pub mod config;
 pub mod demo;
-pub mod ease_presets;
 pub mod footage_check;
 pub mod guard;
 pub mod history;
@@ -406,8 +405,9 @@ pub struct Session {
     pub config: Option<Arc<dyn config::ConfigStore>>,
     /// Keyboard shortcut presets.
     pub keymaps: shortcuts::Keymaps,
-    /// User ease presets (Window ▸ Ease Presets; the built-in ones are in [`ease_presets`]).
-    pub ease_presets: Vec<ease_presets::EasePreset>,
+    /// Scripts' `app.settings`, kept in the settings store (see
+    /// [`commands::scripts::SCRIPT_SETTINGS_FILE`]).
+    pub script_settings: commands::scripts::ScriptSettings,
     /// Frontend-only commands offered for binding.
     pub ui_commands: Vec<shortcuts::UiCommand>,
     /// Cache of the resolved active preset (read it with [`Session::shortcuts`]).
@@ -521,7 +521,7 @@ impl Default for Session {
             prefs_revision: 0,
             config: None,
             keymaps: shortcuts::Keymaps::default(),
-            ease_presets: vec![],
+            script_settings: Default::default(),
             ui_commands: vec![],
             shortcut_table: std::sync::OnceLock::new(),
             autosave: autosave::AutoSaveState::default(),
@@ -1008,8 +1008,6 @@ mod tests_color_view;
 #[cfg(test)]
 mod tests_disk_cache;
 #[cfg(test)]
-mod tests_ease_presets;
-#[cfg(test)]
 mod tests_effects;
 #[cfg(test)]
 mod tests_essential;
diff --git a/crates/engine/src/menus.rs b/crates/engine/src/menus.rs
index 38636936..c5830828 100644
--- a/crates/engine/src/menus.rs
+++ b/crates/engine/src/menus.rs
@@ -1200,7 +1200,6 @@ Window
   @dynamic:openViewers
   ---
   Create Nulls From Paths | window.panel {"panel":"createNullsFromPaths"}
-  Ease Presets | window.panel {"panel":"easePresets"}
   VR Comp Editor | window.panel {"panel":"vrCompEditor"}
   @dynamic:scriptPanels
 Help
diff --git a/crates/engine/src/session_settings.rs b/crates/engine/src/session_settings.rs
index 88e1ce18..34f24786 100644
--- a/crates/engine/src/session_settings.rs
+++ b/crates/engine/src/session_settings.rs
@@ -3,13 +3,13 @@
 use std::path::Path;
 
 use crate::autosave::{self, Sentinel};
-use crate::ease_presets::EASE_PRESETS_FILE;
 use crate::prefs::{PREFS_FILE, Prefs};
 use crate::shortcuts::{Keymaps, SHORTCUTS_FILE, ShortcutTable, UiCommand};
 use crate::{EngineError, Result, Session};
 
 impl Session {
-    /// Load settings, shortcut and ease presets from the config store and apply them.
+    /// Load settings, shortcut presets and scripts' settings from the config store and apply
+    /// them.
     pub fn load_settings(&mut self) {
         if let Some(c) = &self.config {
             if let Some(t) = c.read(PREFS_FILE) {
@@ -18,10 +18,8 @@ impl Session {
             if let Some(t) = c.read(SHORTCUTS_FILE) {
                 self.keymaps = Keymaps::from_json(&t);
             }
-            if let Some(t) = c.read(EASE_PRESETS_FILE) {
-                self.ease_presets = crate::ease_presets::parse(&t);
-            }
         }
+        crate::commands::scripts::load_script_settings(self);
         self.prefs_changed();
         self.shortcuts_changed();
     }
diff --git a/crates/engine/src/tests_ease_presets.rs b/crates/engine/src/tests_ease_presets.rs
deleted file mode 100644
index 5f064181..00000000
--- a/crates/engine/src/tests_ease_presets.rs
+++ /dev/null
@@ -1,164 +0,0 @@
-//! Ease presets (#254): a saved curve applied to every pair of neighbouring selected keyframes
-//! (one undo step), save / rename / delete persisted through the config store, and lenient loading
-//! of a corrupt presets file.
-
-use std::sync::Arc;
-
-use effectcraft_keyframe::{Ease, Interp, ease_progress};
-use effectcraft_time::Tick;
-use serde_json::{Value, json};
-
-use crate::Session;
-use crate::config::{ConfigStore, MemoryConfig};
-use crate::ease_presets::EASE_PRESETS_FILE;
-use crate::tests_timeline::{animate, prop, setup};
-
-fn close(a: f64, b: f64, tol: f64) -> bool {
-    (a - b).abs() < tol
-}
-
-fn user_names(s: &mut Session) -> Vec<String> {
-    let list = s.execute("keys.easePreset.list", json!({})).unwrap();
-    list.as_array().unwrap().iter().filter(|p| p["builtIn"] == false).map(|p| p["name"].as_str().unwrap().to_string()).collect()
-}
-
-#[test]
-fn a_preset_eases_every_selected_pair_in_one_undo_step() {
-    let (mut s, l) = setup();
-    animate(&mut s, l, "transform/opacity", &[(0.0, json!(0)), (1.0, json!(100)), (3.0, json!(20))]);
-    animate(&mut s, l, "transform/rotation", &[(0.0, json!(0)), (2.0, json!(90))]);
-    s.execute("prop.select", json!({"layer": l, "path": "transform/opacity"})).unwrap();
-    s.execute("prop.select", json!({"layer": l, "path": "transform/rotation", "add": true})).unwrap();
-    let steps = s.history.undo.len();
-    let r = s.execute("keys.easePreset.apply", json!({"preset": "Ease In-Out"})).unwrap();
-    assert_eq!(r["pairs"], 3, "two opacity segments and one rotation segment");
-    assert_eq!(s.history.undo.len(), steps + 1, "one undo step");
-    let eased = Ease { speed: 0.0, influence: 0.5 };
-    let op = prop(&s, l, "transform/opacity");
-    assert_eq!((op.keys[0].out_interp, op.keys[0].out_ease.clone()), (Interp::Bezier, vec![eased]));
-    assert_eq!((op.keys[1].in_ease.clone(), op.keys[1].out_ease.clone()), (vec![eased], vec![eased]));
-    assert_eq!((op.keys[2].in_interp, op.keys[2].in_ease.clone()), (Interp::Bezier, vec![eased]));
-    // The first key's in side and the last key's out side are not part of a pair.
-    assert_eq!((op.keys[0].in_interp, op.keys[2].out_interp), (Interp::Linear, Interp::Linear));
-    // A symmetric curve passes the middle value at mid-time, slow near the keys.
-    assert!(close(op.value_at(Tick::from_seconds_f64(2.0)).as_f64(), 60.0, 1e-6));
-    let quarter = op.value_at(Tick::from_seconds_f64(1.5)).as_f64();
-    assert!(close(quarter, 100.0 - 80.0 * ease_progress(0.0, 0.5, 0.0, 0.5, 0.25), 1e-6), "{quarter}");
-    assert!(prop(&s, l, "transform/rotation").keys[1].in_interp == Interp::Bezier);
-    s.execute("edit.undo", json!({})).unwrap();
-    assert_eq!(s.history.redo.last().map(|(label, _)| label.as_str()), Some("Apply Ease Preset"));
-    let op = prop(&s, l, "transform/opacity");
-    assert!(op.keys.iter().all(|k| k.in_interp == Interp::Linear && k.out_interp == Interp::Linear));
-    assert!(close(op.value_at(Tick::from_seconds_f64(1.5)).as_f64(), 80.0, 1e-6));
-}
-
-#[test]
-fn a_curve_scales_to_each_dimension_and_follows_motion_paths() {
-    let (mut s, l) = setup();
-    animate(&mut s, l, "transform/scale", &[(0.0, json!([100, 100])), (1.0, json!([200, 50]))]);
-    animate(&mut s, l, "transform/position", &[(0.0, json!([0, 0])), (2.0, json!([300, 400]))]);
-    s.execute("prop.select", json!({"layer": l, "path": "transform/scale"})).unwrap();
-    let curve = json!({"outInfluence": 60, "outSpeed": 0, "inInfluence": 20, "inSpeed": 2});
-    s.execute("keys.easePreset.apply", json!({"curve": curve})).unwrap();
-    let sc = prop(&s, l, "transform/scale");
-    // X rises 100/s and Y falls 50/s: the in speed (2× average) is per dimension.
-    assert_eq!(sc.keys[1].in_ease[..2], [Ease { speed: 200.0, influence: 0.2 }, Ease { speed: -100.0, influence: 0.2 }]);
-    let f = ease_progress(0.0, 0.6, 2.0, 0.2, 0.5);
-    let v = sc.value_at(Tick::from_seconds_f64(0.5)).as_vec2();
-    assert!(close(v[0], 100.0 + 100.0 * f, 1e-6) && close(v[1], 100.0 - 50.0 * f, 1e-6), "{v:?}");
-    // Handles [x1, y1, x2, y2] on Position: the speed is along the 500 px path.
-    s.execute("prop.select", json!({"layer": l, "path": "transform/position"})).unwrap();
-    s.execute("keys.easePreset.apply", json!({"curve": [0.25, 0.1, 0.25, 1.0]})).unwrap();
-    let pos = prop(&s, l, "transform/position");
-    assert!(pos.keys[0].out_ease.iter().all(|e| close(e.speed, 0.4 * 250.0, 1e-6) && close(e.influence, 0.25, 1e-9)), "{:?}", pos.keys[0].out_ease);
-    let f = ease_progress(0.4, 0.25, 0.0, 0.75, 0.5);
-    let p = pos.value_at(Tick::from_seconds_f64(1.0)).as_vec2();
-    assert!(close(p[0], 300.0 * f, 0.05) && close(p[1], 400.0 * f, 0.05), "{p:?} {f}");
-    // The captured curve is the applied one.
-    let c = s.execute("keys.easePreset.capture", json!({})).unwrap();
-    assert!(close(c["inInfluence"].as_f64().unwrap(), 75.0, 1e-6) && close(c["outSpeed"].as_f64().unwrap(), 0.4, 1e-6), "{c}");
-}
-
-#[test]
-fn apply_needs_neighbouring_keys_and_a_known_curve() {
-    let (mut s, l) = setup();
-    animate(&mut s, l, "transform/opacity", &[(0.0, json!(0)), (1.0, json!(100)), (2.0, json!(0))]);
-    let key = |t: f64| json!({"layer": l, "path": "transform/opacity", "time": t});
-    // Keys 1 and 3 aren't neighbours.
-    s.execute("keys.select", json!({"keys": [key(0.0), key(2.0)]})).unwrap();
-    let steps = s.history.undo.len();
-    let e = s.execute("keys.easePreset.apply", json!({"preset": "Linear"})).unwrap_err().to_string();
-    assert!(e.contains("neighbouring"), "{e}");
-    assert_eq!(s.history.undo.len(), steps, "nothing changed");
-    s.execute("keys.select", json!({"keys": [key(0.0), key(1.0)]})).unwrap();
-    for bad in
-        [json!({"preset": "Nope"}), json!({"curve": [0.1, 0.2]}), json!({"curve": [0.1, "a", 0.3, 0.4]}), json!({"curve": {"outInfluence": 50}}), json!({})]
-    {
-        assert!(s.execute("keys.easePreset.apply", bad.clone()).is_err(), "{bad}");
-    }
-    // Names are matched in any case.
-    assert_eq!(s.execute("keys.easePreset.apply", json!({"preset": "expo in-out"})).unwrap()["pairs"], 1);
-}
-
-#[test]
-fn user_presets_save_rename_delete_and_persist() {
-    let store = Arc::new(MemoryConfig::default());
-    let (mut s, l) = setup();
-    s.config = Some(store.clone());
-    animate(&mut s, l, "transform/opacity", &[(0.0, json!(0)), (1.0, json!(100))]);
-    s.execute("prop.select", json!({"layer": l, "path": "transform/opacity"})).unwrap();
-    s.execute("keys.easePreset.apply", json!({"preset": "Decelerate"})).unwrap();
-    // Without a curve, save keeps the one between the selected keys.
-    let saved = s.execute("keys.easePreset.save", json!({"name": "  Settle "})).unwrap();
-    assert_eq!(saved["name"], "Settle");
-    assert!(close(saved["curve"]["outSpeed"].as_f64().unwrap(), 1.5, 1e-9) && close(saved["curve"]["inInfluence"].as_f64().unwrap(), 50.0, 1e-9), "{saved}");
-    s.execute("keys.easePreset.save", json!({"name": "Snap", "curve": [0.1, 0.5, 0.2, 1.0]})).unwrap();
-    assert_eq!(user_names(&mut s), ["Settle", "Snap"]);
-    // Built-in names and existing names are refused; built-in presets can't change.
-    assert!(s.execute("keys.easePreset.save", json!({"name": "linear", "curve": [0.3, 0.3, 0.7, 0.7]})).is_err());
-    assert!(s.execute("keys.easePreset.save", json!({"name": "   "})).is_err());
-    assert!(s.execute("keys.easePreset.rename", json!({"name": "Settle", "newName": "snap"})).is_err());
-    assert!(s.execute("keys.easePreset.rename", json!({"name": "Linear", "newName": "Straight"})).is_err());
-    assert!(s.execute("keys.easePreset.delete", json!({"name": "Ease In-Out"})).is_err());
-    s.execute("keys.easePreset.rename", json!({"name": "settle", "newName": "Soft Landing"})).unwrap();
-    // Saving under an existing name replaces that preset.
-    s.execute("keys.easePreset.save", json!({"name": "SNAP", "curve": [0.2, 0.5, 0.2, 1.0]})).unwrap();
-    assert_eq!(user_names(&mut s), ["Soft Landing", "SNAP"]);
-    s.execute("keys.easePreset.delete", json!({"name": "snap"})).unwrap();
-    assert!(s.execute("keys.easePreset.delete", json!({"name": "snap"})).is_err());
-    // A new session reads them back from the store.
-    let mut s2 = Session { config: Some(store.clone()), ..Default::default() };
-    s2.load_settings();
-    assert_eq!(user_names(&mut s2), ["Soft Landing"]);
-    let c = crate::ease_presets::find(&s2, "soft landing").unwrap();
-    assert!(close(c.out_influence, 20.0, 1e-9) && close(c.out_speed, 1.5, 1e-9) && close(c.in_speed, 0.0, 1e-9), "{c:?}");
-}
-
-#[test]
-fn a_corrupt_presets_file_loads_what_it_can() {
-    let store = Arc::new(MemoryConfig::default());
-    store.write(EASE_PRESETS_FILE, "{\"presets\": [ not json").unwrap();
-    let mut s = Session { config: Some(store.clone()), ..Default::default() };
-    s.load_settings();
-    assert!(s.ease_presets.is_empty());
-    assert_eq!(s.execute("keys.easePreset.list", json!({})).unwrap().as_array().unwrap().len(), 12, "the built-in presets");
-    let c = json!({"outInfluence": 30, "outSpeed": 0, "inInfluence": 30, "inSpeed": 0});
-    let doc = json!({"version": 1, "presets": [
-        {"name": "Good", "curve": c},
-        {"name": "Linear", "curve": c},
-        {"name": "", "curve": c},
-        {"name": "No curve"},
-        {"name": "good", "curve": c},
-        42,
-        {"name": "Wild", "curve": {"outInfluence": 1e9, "outSpeed": -1e9, "inInfluence": -5, "inSpeed": 0}},
-    ]});
-    store.write(EASE_PRESETS_FILE, &doc.to_string()).unwrap();
-    s.load_settings();
-    assert_eq!(s.ease_presets.iter().map(|p| p.name.as_str()).collect::<Vec<_>>(), ["Good", "Wild"]);
-    let wild = s.ease_presets[1].curve;
-    assert_eq!((wild.out_influence, wild.out_speed, wild.in_influence), (100.0, -100.0, 0.1));
-    // Saving rewrites a clean file.
-    s.execute("keys.easePreset.delete", json!({"name": "Wild"})).unwrap();
-    let text: Value = serde_json::from_str(&store.read(EASE_PRESETS_FILE).unwrap()).unwrap();
-    assert_eq!(text["presets"].as_array().unwrap().len(), 1);
-}
diff --git a/crates/keyframe/src/ease_curve.rs b/crates/keyframe/src/ease_curve.rs
deleted file mode 100644
index 25b5cdee..00000000
--- a/crates/keyframe/src/ease_curve.rs
+++ /dev/null
@@ -1,226 +0,0 @@
-//! Ease curves: the temporal ease of one keyframe segment, independent of its duration and values,
-//! so it can be kept as a preset and applied to any pair of keyframes.
-//!
-//! A curve is the out side of the first key and the in side of the second, in the Keyframe Velocity
-//! dialog's terms: influence in percent of the segment, and speed relative to the segment's average
-//! speed (1 = linear, 0 = at rest). In the normalised value graph (time and value 0 → 1) its handles
-//! are the points (x1, y1) = (out influence, out speed × out influence) and
-//! (x2, y2) = (1 − in influence, 1 − in speed × in influence).
-
-use serde::{Deserialize, Serialize};
-
-use crate::{Ease, Interp, Keyframe, Value, effective_ease, secs, spatial_segment_length};
-
-/// Smallest influence (percent), as in the Keyframe Velocity dialog.
-const MIN_INFLUENCE: f64 = 0.1;
-/// Relative speeds are kept within ± this (a handle 100 times steeper than linear).
-const MAX_SPEED: f64 = 100.0;
-
-#[derive(Clone, Copy, Debug, PartialEq, Serialize, Deserialize)]
-#[serde(rename_all = "camelCase")]
-pub struct EaseCurve {
-    pub out_influence: f64,
-    pub out_speed: f64,
-    pub in_influence: f64,
-    pub in_speed: f64,
-}
-
-impl EaseCurve {
-    /// Constant speed: both handles a third of the way along the straight line.
-    pub const LINEAR: EaseCurve = EaseCurve { out_influence: 100.0 / 3.0, out_speed: 1.0, in_influence: 100.0 / 3.0, in_speed: 1.0 };
-
-    /// The curve with influences in 0.1–100 % and speeds within ±100; `None` when a number isn't
-    /// finite.
-    pub fn sanitized(self) -> Option<EaseCurve> {
-        if ![self.out_influence, self.out_speed, self.in_influence, self.in_speed].iter().all(|v| v.is_finite()) {
-            return None;
-        }
-        let inf = |v: f64| v.clamp(MIN_INFLUENCE, 100.0);
-        let speed = |v: f64| v.clamp(-MAX_SPEED, MAX_SPEED);
-        Some(EaseCurve {
-            out_influence: inf(self.out_influence),
-            out_speed: speed(self.out_speed),
-            in_influence: inf(self.in_influence),
-            in_speed: speed(self.in_speed),
-        })
-    }
-
-    /// Handles in the normalised value graph: `[x1, y1, x2, y2]`.
-    pub fn handles(&self) -> [f64; 4] {
-        let (o, i) = (self.out_influence / 100.0, self.in_influence / 100.0);
-        [o, self.out_speed * o, 1.0 - i, 1.0 - self.in_speed * i]
-    }
-
-    /// The curve with handles `[x1, y1, x2, y2]` (each influence at least 0.1 %); `None` when a
-    /// number isn't finite.
-    pub fn from_handles([x1, y1, x2, y2]: [f64; 4]) -> Option<EaseCurve> {
-        let o = x1.clamp(MIN_INFLUENCE / 100.0, 1.0);
-        let i = (1.0 - x2).clamp(MIN_INFLUENCE / 100.0, 1.0);
-        EaseCurve { out_influence: o * 100.0, out_speed: y1 / o, in_influence: i * 100.0, in_speed: (1.0 - y2) / i }.sanitized()
-    }
-
-    /// Ease segment `i` → `i + 1` with this curve: the out side of key `i` and the in side of key
-    /// `i + 1` become Bezier, scaled to the segment per dimension (along the motion path for
-    /// spatial values, as overall progress for paths and gradients), as Easy Ease shapes them.
-    /// Auto-Bezier keys keep their other side as it plays. False when there is no such segment or
-    /// its values don't interpolate.
-    pub fn apply(&self, keys: &mut [Keyframe], i: usize, spatial: bool) -> bool {
-        let Some(slopes) = segment_slopes(keys, i, spatial) else { return false };
-        let side = |influence: f64, speed: f64| -> Vec<Ease> { slopes.iter().map(|s| Ease { speed: speed * s, influence: influence / 100.0 }).collect() };
-        let (out, inn) = (side(self.out_influence, self.out_speed), side(self.in_influence, self.in_speed));
-        freeze_auto(keys, i, spatial);
-        freeze_auto(keys, i + 1, spatial);
-        if let Some(a) = keys.get_mut(i) {
-            a.out_interp = Interp::Bezier;
-            a.out_ease = out;
-        }
-        if let Some(b) = keys.get_mut(i + 1) {
-            b.in_interp = Interp::Bezier;
-            b.in_ease = inn;
-        }
-        true
-    }
-
-    /// The curve segment `i` → `i + 1` plays (a linear side counts as speed 1 at 33.3 %), measured
-    /// on the dimension that changes most. `None` for hold segments, values that don't
-    /// interpolate and segments whose value doesn't change.
-    pub fn measure(keys: &[Keyframe], i: usize, spatial: bool) -> Option<EaseCurve> {
-        let slopes = segment_slopes(keys, i, spatial)?;
-        let (a, b) = (keys.get(i)?, keys.get(i + 1)?);
-        if a.out_interp == Interp::Hold {
-            return None;
-        }
-        let (d, slope) = slopes.iter().copied().enumerate().max_by(|x, y| x.1.abs().total_cmp(&y.1.abs()))?;
-        if slope.abs() < 1e-12 {
-            return None;
-        }
-        let is_spatial = is_spatial(&a.value, spatial);
-        let d = if is_spatial { 0 } else { d };
-        let side =
-            |k: usize, bezier: bool, out: bool| if bezier { effective_ease(keys, k, d, is_spatial, out) } else { Ease { speed: slope, influence: 1.0 / 3.0 } };
-        let out = side(i, a.out_interp == Interp::Bezier, true);
-        let inn = side(i + 1, b.in_interp == Interp::Bezier, false);
-        EaseCurve { out_influence: out.influence * 100.0, out_speed: out.speed / slope, in_influence: inn.influence * 100.0, in_speed: inn.speed / slope }
-            .sanitized()
-    }
-}
-
-fn is_spatial(v: &Value, spatial: bool) -> bool {
-    spatial && matches!(v, Value::Vec2(_) | Value::Vec3(_))
-}
-
-/// Average speed of segment `i` → `i + 1` for each ease entry of its keys: per dimension, along
-/// the motion path (spatial), or 1 / duration (paths and gradients ease their overall progress).
-fn segment_slopes(keys: &[Keyframe], i: usize, spatial: bool) -> Option<Vec<f64>> {
-    let (a, b) = (keys.get(i)?, keys.get(i.checked_add(1)?)?);
-    let dur = secs(b.time) - secs(a.time);
-    if !a.value.interpolates() || !dur.is_finite() || dur <= 0.0 {
-        return None;
-    }
-    let n = a.value.dims().max(1);
-    let (ca, cb) = (a.value.components(), b.value.components());
-    Some(if is_spatial(&a.value, spatial) {
-        vec![spatial_segment_length(keys, i) / dur; n]
-    } else if ca.is_empty() || ca.len() != cb.len() {
-        vec![1.0 / dur; n]
-    } else {
-        ca.iter().zip(&cb).map(|(x, y)| (y - x) / dur).collect()
-    })
-}
-
-/// Store the eases an Auto-Bezier key `k` plays and turn Auto-Bezier off, so editing one side
-/// leaves the other as it was.
-fn freeze_auto(keys: &mut [Keyframe], k: usize, spatial: bool) {
-    let Some(key) = keys.get(k).filter(|key| key.auto_bezier) else { return };
-    let is_spatial = is_spatial(&key.value, spatial);
-    let n = key.value.dims().max(1);
-    let side = |out: bool| -> Vec<Ease> { (0..n).map(|d| effective_ease(keys, k, if is_spatial { 0 } else { d }, is_spatial, out)).collect() };
-    let (inn, out) = (side(false), side(true));
-    if let Some(key) = keys.get_mut(k) {
-        key.in_ease = inn;
-        key.out_ease = out;
-        key.auto_bezier = false;
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use effectcraft_time::Tick;
-
-    use super::*;
-    use crate::{ease_progress, evaluate};
-
-    fn s(x: f64) -> Tick {
-        Tick::from_seconds_f64(x)
-    }
-
-    const CURVE: EaseCurve = EaseCurve { out_influence: 60.0, out_speed: 0.0, in_influence: 20.0, in_speed: 2.0 };
-
-    #[test]
-    fn handles_round_trip_and_reject_non_finite_numbers() {
-        let h = CURVE.handles();
-        assert!(h.iter().zip([0.6, 0.0, 0.8, 0.6]).all(|(a, b)| (a - b).abs() < 1e-12), "{h:?}");
-        let back = EaseCurve::from_handles(h).unwrap();
-        for (a, b) in [(back.out_influence, 60.0), (back.out_speed, 0.0), (back.in_influence, 20.0), (back.in_speed, 2.0)] {
-            assert!((a - b).abs() < 1e-9, "{back:?}");
-        }
-        // Influences stay ≥ 0.1 % even with a handle on the key.
-        assert!((EaseCurve::from_handles([0.0, 0.0, 1.0, 1.0]).unwrap().out_influence - MIN_INFLUENCE).abs() < 1e-12);
-        assert!(EaseCurve::from_handles([f64::NAN, 0.0, 0.5, 1.0]).is_none());
-        assert!(EaseCurve { out_speed: f64::INFINITY, ..CURVE }.sanitized().is_none());
-        assert_eq!(EaseCurve { in_speed: 1e9, ..CURVE }.sanitized().unwrap().in_speed, MAX_SPEED);
-    }
-
-    #[test]
-    fn applied_curve_scales_to_each_dimension_and_measures_back() {
-        let mut keys = vec![Keyframe::new(s(1.0), Value::Vec2([0.0, 100.0])), Keyframe::new(s(3.0), Value::Vec2([200.0, 50.0]))];
-        assert!(CURVE.apply(&mut keys, 0, false));
-        assert_eq!((keys[0].out_interp, keys[1].in_interp), (Interp::Bezier, Interp::Bezier));
-        // X goes 200 in 2 s (100/s), Y −50 (−25/s): speeds are relative to those.
-        assert_eq!(keys[1].in_ease, vec![Ease { speed: 200.0, influence: 0.2 }, Ease { speed: -50.0, influence: 0.2 }]);
-        // Every dimension follows the curve's progress.
-        let p = evaluate(&keys, s(2.0), false).unwrap().as_vec2();
-        let f = ease_progress(0.0, 0.6, 2.0, 0.2, 0.5);
-        assert!((p[0] - 200.0 * f).abs() < 1e-6 && (p[1] - (100.0 - 50.0 * f)).abs() < 1e-6, "{p:?}");
-        let m = EaseCurve::measure(&keys, 0, false).unwrap();
-        assert!((m.out_influence - 60.0).abs() < 1e-9 && (m.in_speed - 2.0).abs() < 1e-9, "{m:?}");
-        // No such segment / nothing to ease.
-        assert!(!CURVE.apply(&mut keys, 1, false));
-        let mut held = vec![Keyframe::new(s(0.0), Value::Bool(false)), Keyframe::new(s(1.0), Value::Bool(true))];
-        assert!(!CURVE.apply(&mut held, 0, false));
-    }
-
-    #[test]
-    fn spatial_curve_follows_the_motion_path() {
-        let mut keys = vec![Keyframe::new(s(0.0), Value::Vec2([0.0, 0.0])), Keyframe::new(s(1.0), Value::Vec2([300.0, 400.0]))];
-        assert!(CURVE.apply(&mut keys, 0, true));
-        // 500 px along the path in 1 s.
-        assert!(keys[1].in_ease.iter().all(|e| (e.speed - 1000.0).abs() < 1e-6), "{:?}", keys[1].in_ease);
-        let p = evaluate(&keys, s(0.5), true).unwrap().as_vec2();
-        let f = ease_progress(0.0, 0.6, 2.0, 0.2, 0.5);
-        // (within the arc-length table's precision)
-        assert!((p[0] - 300.0 * f).abs() < 0.05 && (p[1] - 400.0 * f).abs() < 0.05, "{p:?} {f}");
-    }
-
-    #[test]
-    fn linear_and_auto_bezier_sides_measure_as_they_play() {
-        let keys = vec![Keyframe::new(s(0.0), Value::Scalar(0.0)), Keyframe::new(s(1.0), Value::Scalar(10.0))];
-        let m = EaseCurve::measure(&keys, 0, false).unwrap();
-        assert!((m.out_speed - 1.0).abs() < 1e-9 && (m.in_influence - 100.0 / 3.0).abs() < 1e-9, "{m:?}");
-        // Easing the second segment keeps the auto-Bezier middle key's incoming side.
-        let mut keys = vec![
-            Keyframe::new(s(0.0), Value::Scalar(0.0)),
-            Keyframe::new(s(1.0), Value::Scalar(10.0)).eased(),
-            Keyframe::new(s(2.0), Value::Scalar(30.0)).eased(),
-        ];
-        keys[1].auto_bezier = true;
-        let before = evaluate(&keys, s(0.5), false);
-        assert!(CURVE.apply(&mut keys, 1, false));
-        assert!(!keys[1].auto_bezier);
-        assert_eq!(evaluate(&keys, s(0.5), false), before);
-        let held = vec![Keyframe::new(s(0.0), Value::Scalar(0.0)).hold(), Keyframe::new(s(1.0), Value::Scalar(10.0))];
-        assert!(EaseCurve::measure(&held, 0, false).is_none());
-        let flat = vec![Keyframe::new(s(0.0), Value::Scalar(5.0)), Keyframe::new(s(1.0), Value::Scalar(5.0))];
-        assert!(EaseCurve::measure(&flat, 0, false).is_none());
-    }
-}
diff --git a/crates/keyframe/src/lib.rs b/crates/keyframe/src/lib.rs
index 584b4070..13814c53 100644
--- a/crates/keyframe/src/lib.rs
+++ b/crates/keyframe/src/lib.rs
@@ -10,11 +10,9 @@
 
 #![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]
 
-pub mod ease_curve;
 pub mod text_doc;
 pub mod value;
 
-pub use ease_curve::EaseCurve;
 use effectcraft_time::{TICKS_PER_SECOND, Tick};
 use serde::{Deserialize, Serialize};
 pub use text_doc::{BaselineOption, CharStyle, Composer, Direction, FigureStyle, FigureWidth, Kerning, OpenType, ParaStyle, StyleRun};
diff --git a/crates/script/src/lib.rs b/crates/script/src/lib.rs
index df2d2dcd..d1c9568c 100644
--- a/crates/script/src/lib.rs
+++ b/crates/script/src/lib.rs
@@ -14,7 +14,8 @@
 //! ```
 //!
 //! * **Object model** (`prelude.js`): `app` (project, open/newProject, undo groups,
-//!   `executeCommand`/`findMenuCommandId`, `scheduleTask`), `Project`, `ItemCollection`,
+//!   `executeCommand`/`findMenuCommandId`, `scheduleTask`, `settings` kept in the settings
+//!   folder), `Project`, `ItemCollection`,
 //!   `CompItem`/`FootageItem`/`FolderItem`, `LayerCollection`, `AVLayer`/`TextLayer`/
 //!   `ShapeLayer`/`CameraLayer`/`LightLayer`, `PropertyGroup`/`Property` (values, keyframes,
 //!   eases, expressions), `MaskPropertyGroup`, `TextDocument`, `Shape`, `KeyframeEase`,
@@ -82,6 +83,8 @@ pub fn run_code(s: &mut Session, code: &str, name: &str) -> Outcome {
 #[cfg(test)]
 mod tests;
 #[cfg(test)]
+mod tests_ease_presets;
+#[cfg(test)]
 mod tests_panels;
 #[cfg(test)]
 mod tests_ui;
diff --git a/crates/script/src/model.rs b/crates/script/src/model.rs
index 4a92f396..e0f17fef 100644
--- a/crates/script/src/model.rs
+++ b/crates/script/src/model.rs
@@ -92,6 +92,20 @@ fn label_index(l: Label) -> usize {
     Label::ALL.iter().position(|x| *x == l).unwrap_or(0)
 }
 
+/// A comp's selected properties as `[layer, uid]`: the selected ones, then those with selected
+/// keyframes (selecting a keyframe selects its property in After Effects, so scripts find
+/// selected keys through `selectedProperties`).
+fn selected_props(s: &Session, c: &effectcraft_project::Comp) -> Vec<J> {
+    let mut v: Vec<(u64, u64)> = vec![];
+    let keyed = s.state.selected_keys.iter().map(|k| (k.layer, k.prop));
+    for (l, p) in s.state.selected_props.iter().copied().chain(keyed) {
+        if c.layer(l).is_some() && !v.contains(&(l.0, p)) {
+            v.push((l.0, p));
+        }
+    }
+    v.into_iter().map(|(l, p)| json!([l, p])).collect()
+}
+
 fn item(s: &Session, a: &J) -> R {
     let id = ItemId(u(a, "id").ok_or("missing id")?);
     let it = s.project.item(id).ok_or("the item no longer exists (it was deleted)")?;
@@ -123,7 +137,7 @@ fn item(s: &Session, a: &J) -> R {
                         "duration": c.duration.seconds(), "frameRate": fps, "frameDuration": c.frame_duration().seconds(),
                         "layers": c.layers.iter().map(|l| l.id.0).collect::<Vec<_>>(),
                         "selectedLayers": sel,
-                        "selectedProperties": s.state.selected_props.iter().filter(|(l, _)| c.layer(*l).is_some()).map(|(l, p)| json!([l.0, p])).collect::<Vec<_>>(),
+                        "selectedProperties": selected_props(s, c),
                         "time": s.time_of(cid).seconds(),
                         "workAreaStart": c.work_area.0.seconds(), "workAreaDuration": (c.work_area.1 - c.work_area.0).seconds(),
                         "bgColor": c.background, "displayStartTime": c.display_start.seconds(),
@@ -321,6 +335,7 @@ fn node_json(c: &Comp, l: &Layer, uid: u64) -> R {
             o["type"] = json!(p.value.kind_name());
             o["dims"] = json!(p.value.dims());
             o["spatial"] = json!(p.spatial);
+            o["interpolates"] = json!(p.value.interpolates());
             o["numKeys"] = json!(p.keys.len());
             o["expression"] = json!(p.expr.as_ref().map(|e| e.text.clone()).unwrap_or_default());
             o["expressionEnabled"] = json!(p.has_expression());
@@ -471,29 +486,36 @@ fn keys(s: &Session, a: &J) -> R {
     let p = l.props.find(uid).ok_or("the property no longer exists (it was deleted)")?;
     let sel: Vec<Tick> = s.state.selected_keys.iter().filter(|k| k.layer == l.id && k.prop == uid).map(|k| k.time).collect();
     let _ = cid;
-    let ease = |e: &[effectcraft_keyframe::Ease], n: usize| -> J {
-        let n = n.max(1);
-        // Influence is stored as a fraction; scripts see percent.
-        let mut v: Vec<J> = e.iter().map(|x| json!({"speed": x.speed, "influence": x.influence * 100.0})).collect();
-        let d = e.first().cloned().unwrap_or_default();
-        while v.len() < n {
-            v.push(json!({"speed": d.speed, "influence": d.influence * 100.0}));
-        }
+    let dims = if p.spatial { 1 } else { p.value.dims().max(1) };
+    // Each side's ease as it plays (After Effects reports linear and auto-Bezier sides this way
+    // too), else as stored; influence is stored as a fraction, scripts see percent.
+    let ease = |i: usize, out: bool| -> J {
+        let Some(k) = p.keys.get(i) else { return json!([]) };
+        let stored = if out { &k.out_ease } else { &k.in_ease };
+        let v: Vec<J> = (0..dims)
+            .map(|d| {
+                let e =
+                    effectcraft_keyframe::side_ease(&p.keys, i, d, p.spatial, out).or_else(|| stored.get(d).or(stored.first()).copied()).unwrap_or_default();
+                json!({"speed": e.speed, "influence": e.influence * 100.0})
+            })
+            .collect();
         J::Array(v)
     };
-    let dims = if p.spatial { 1 } else { p.value.dims().max(1) };
     let out: Vec<J> = p
         .keys
         .iter()
-        .map(|k| {
+        .enumerate()
+        .map(|(i, k)| {
+            // Spatial tangents as the motion path plays (auto-Bezier and continuous keys too).
+            let (spatial_in, spatial_out) = if p.spatial { effectcraft_keyframe::spatial_tangents(&p.keys, i) } else { (k.spatial_in, k.spatial_out) };
             json!({
                 "time": l.comp_time(k.time).seconds(),
                 "layerTime": k.time.seconds(),
                 "value": js_value(c, &k.value),
                 "inInterp": interp(k.in_interp), "outInterp": interp(k.out_interp),
-                "inEase": ease(&k.in_ease, dims), "outEase": ease(&k.out_ease, dims),
+                "inEase": ease(i, false), "outEase": ease(i, true),
                 "continuous": k.continuous, "autoBezier": k.auto_bezier, "roving": k.roving,
-                "spatialIn": k.spatial_in, "spatialOut": k.spatial_out,
+                "spatialIn": spatial_in, "spatialOut": spatial_out,
                 "spatialContinuous": k.spatial_continuous, "spatialAutoBezier": k.spatial_auto,
                 "selected": sel.contains(&k.time),
             })
diff --git a/crates/script/src/prelude.js b/crates/script/src/prelude.js
index 358017e7..f52765e7 100644
--- a/crates/script/src/prelude.js
+++ b/crates/script/src/prelude.js
@@ -824,31 +824,30 @@ Property.prototype.property = function () { return null; };
   };
   P.keyTime = function (i) { return this.__key(i).time; };
   P.keyValue = function (i) { return this.__fromEngine(this.__key(i).value, this.__info()); };
-  // Select key `i` (only) so the selection-based keyframe commands act on it.
-  P.__select = function (i) {
-    var k = this.__key(i);
-    __call("keys.select", { comp: this.__layer.__comp, keys: [{ layer: this.__layer.__id, prop: this.__uid, time: k.layerTime }] });
-    return k;
-  };
-  P.removeKey = function (i) {
-    this.__select(i);
-    __call("keys.delete", { comp: this.__layer.__comp });
+  // Run a keyframe command that acts on the selected keys on key `i` only; the user's key
+  // selection stays as it was, as with After Effects' per-key methods.
+  P.__keyCmd = function (i, id, params) {
+    this.__key(i);
+    params = params || {};
+    params.comp = this.__layer.__comp;
+    params.__keys = [{ layer: this.__layer.__id, prop: this.__uid, index: __num(i) - 1 }];
+    return __call(id, params);
   };
+  P.removeKey = function (i) { this.__keyCmd(i, "keys.delete"); };
   P.keyInInterpolationType = function (i) { return KeyframeInterpolationType[this.__key(i).inInterp]; };
   P.keyOutInterpolationType = function (i) { return KeyframeInterpolationType[this.__key(i).outInterp]; };
-  P.isInterpolationTypeValid = function (t) { return t === 6612 || t === 6613 || t === 6614; };
+  // Values that don't interpolate (checkboxes, popups, text) only hold.
+  P.isInterpolationTypeValid = function (t) { return t === 6614 || ((t === 6612 || t === 6613) && this.__info().interpolates !== false); };
   P.setInterpolationTypeAtKey = function (i, inType, outType) {
     if (outType === undefined) outType = inType;
     if (!__interpKey[inType] || !__interpKey[outType]) throw __err("Bad KeyframeInterpolationType");
-    this.__select(i);
-    __call("keys.interpolation", { comp: this.__layer.__comp, "in": __interpKey[inType], out: __interpKey[outType] });
+    this.__keyCmd(i, "keys.interpolation", { "in": __interpKey[inType], out: __interpKey[outType] });
   };
   P.keyInTemporalEase = function (i) { return this.__key(i).inEase.map(function (e) { return new KeyframeEase(e.speed, e.influence); }); };
   P.keyOutTemporalEase = function (i) { return this.__key(i).outEase.map(function (e) { return new KeyframeEase(e.speed, e.influence); }); };
   P.setTemporalEaseAtKey = function (i, inEase, outEase) {
     if (outEase === undefined) outEase = inEase;
     if (!(inEase instanceof Array) || !(outEase instanceof Array)) throw __err("setTemporalEaseAtKey: eases must be arrays of KeyframeEase");
-    this.__select(i);
     function sp(a) { return a.map(function (e) { return __num(e.speed, "speed"); }); }
     function inf(a) {
       return a.map(function (e) {
@@ -857,14 +856,14 @@ Property.prototype.property = function () { return null; };
         return x;
       });
     }
-    __call("keys.velocity", { comp: this.__layer.__comp, inSpeed: sp(inEase), inInfluence: inf(inEase), outSpeed: sp(outEase), outInfluence: inf(outEase) });
+    this.__keyCmd(i, "keys.velocity", { inSpeed: sp(inEase), inInfluence: inf(inEase), outSpeed: sp(outEase), outInfluence: inf(outEase) });
   };
   P.keyTemporalContinuous = function (i) { return !!this.__key(i).continuous; };
-  P.setTemporalContinuousAtKey = function (i, b) { this.__select(i); __call("keys.interpolation", { comp: this.__layer.__comp, continuous: !!b }); };
+  P.setTemporalContinuousAtKey = function (i, b) { this.__keyCmd(i, "keys.interpolation", { continuous: !!b }); };
   P.keyTemporalAutoBezier = function (i) { return !!this.__key(i).autoBezier; };
-  P.setTemporalAutoBezierAtKey = function (i, b) { this.__select(i); __call("keys.interpolation", { comp: this.__layer.__comp, autoBezier: !!b }); };
+  P.setTemporalAutoBezierAtKey = function (i, b) { this.__keyCmd(i, "keys.interpolation", { autoBezier: !!b }); };
   P.keyRoving = function (i) { return !!this.__key(i).roving; };
-  P.setRovingAtKey = function (i, b) { this.__select(i); __call("keys.interpolation", { comp: this.__layer.__comp, roving: !!b }); };
+  P.setRovingAtKey = function (i, b) { this.__keyCmd(i, "keys.interpolation", { roving: !!b }); };
   P.keyInSpatialTangent = function (i) { return this.__key(i).spatialIn.slice(0, this.__info().dims); };
   P.keyOutSpatialTangent = function (i) { return this.__key(i).spatialOut.slice(0, this.__info().dims); };
   P.keySpatialContinuous = function (i) { return !!this.__key(i).spatialContinuous; };
@@ -873,8 +872,8 @@ Property.prototype.property = function () { return null; };
     var k = this.__key(i);
     __call("keys.setSpatialTangents", this.__ref({ time: k.layerTime, "in": inT, out: outT === undefined ? inT : outT }));
   };
-  P.setSpatialContinuousAtKey = function (i, b) { this.__select(i); __call("keys.interpolation", { comp: this.__layer.__comp, spatial: b ? "continuousBezier" : "bezier" }); };
-  P.setSpatialAutoBezierAtKey = function (i, b) { this.__select(i); __call("keys.interpolation", { comp: this.__layer.__comp, spatial: b ? "autoBezier" : "bezier" }); };
+  P.setSpatialContinuousAtKey = function (i, b) { this.__keyCmd(i, "keys.interpolation", { spatial: b ? "continuousBezier" : "bezier" }); };
+  P.setSpatialAutoBezierAtKey = function (i, b) { this.__keyCmd(i, "keys.interpolation", { spatial: b ? "autoBezier" : "bezier" }); };
   P.keySelected = function (i) { return !!this.__key(i).selected; };
   P.setSelectedAtKey = function (i, b) {
     var k = this.__key(i);
@@ -1743,11 +1742,11 @@ var app = {
   exitCode: 0,
   saveProjectOnCrash: true,
   onError: null,
+  // Kept in the settings folder, so they last between runs (`script.settings.*`).
   settings: {
-    __s: {},
-    haveSetting: function (sec, key) { return (sec + "/" + key) in this.__s; },
-    getSetting: function (sec, key) { return this.__s[sec + "/" + key] || ""; },
-    saveSetting: function (sec, key, v) { this.__s[sec + "/" + key] = String(v); },
+    haveSetting: function (sec, key) { return __call("script.settings.get", { section: String(sec), key: String(key) }).have; },
+    getSetting: function (sec, key) { return __call("script.settings.get", { section: String(sec), key: String(key) }).value; },
+    saveSetting: function (sec, key, v) { __call("script.settings.save", { section: String(sec), key: String(key), value: String(v) }); },
   },
   preferences: {
     havePref: function () { return false; },
diff --git a/crates/script/src/runtime.rs b/crates/script/src/runtime.rs
index 9b48e770..62479c14 100644
--- a/crates/script/src/runtime.rs
+++ b/crates/script/src/runtime.rs
@@ -121,11 +121,17 @@ pub(crate) fn js_str(s: &str) -> JsValue {
 /// target comp made active for its duration.
 fn native_exec(_: &JsValue, args: &[JsValue], ctx: &mut Context) -> JsResult<JsValue> {
     let id = arg_string(args, 0, ctx)?;
-    let params = arg_json(args, 1, ctx)?;
+    let mut params = arg_json(args, 1, ctx)?;
     if id == "script.run" || id == "file.runScript" {
         return Err(throw("scripts can't run scripts"));
     }
-    let r = with_active(|a| Ok(exec(&mut a.session, &id, params)));
+    let keys = params.as_object_mut().and_then(|o| o.remove("__keys"));
+    let r = with_active(|a| {
+        Ok(match &keys {
+            Some(k) => exec_on_keys(&mut a.session, &id, params, k),
+            None => exec(&mut a.session, &id, params),
+        })
+    });
     match r {
         Ok(Ok(v)) => Ok(js_str(&v.to_string())),
         Ok(Err(e)) | Err(e) => Err(throw(e)),
@@ -164,6 +170,35 @@ pub(crate) fn exec(s: &mut Session, id: &str, params: J) -> Result<J, String> {
     r.map_err(|e| e.to_string())
 }
 
+/// Run a keyframe command that acts on the selected keys (`keys.velocity`, `keys.interpolation`,
+/// `keys.delete`) on the keys `targets` names instead (`[{layer, prop, index}]`, 0-based, in the
+/// command's comp): After Effects' per-key methods (`setTemporalEaseAtKey`, `removeKey`…) leave
+/// the user's key selection as it was. Selected keys that no longer exist drop out of it.
+fn exec_on_keys(s: &mut Session, id: &str, params: J, targets: &J) -> Result<J, String> {
+    use effectcraft_engine::KeyRef;
+    use effectcraft_engine::project::{ItemId, LayerId};
+    let cid = params.get("comp").and_then(J::as_u64).map(ItemId).or(s.state.active_comp).ok_or("no composition is open")?;
+    let comp = s.project.comp(cid).ok_or("the composition no longer exists")?;
+    let mut keys = vec![];
+    for t in targets.as_array().into_iter().flatten() {
+        let (Some(layer), Some(prop), Some(index)) = (t["layer"].as_u64(), t["prop"].as_u64(), t["index"].as_u64()) else {
+            return Err(format!("bad keyframe reference {t}"));
+        };
+        let l = comp.layer(LayerId(layer)).ok_or("the layer no longer exists")?;
+        if l.switches.locked {
+            return Err(format!("Can not change keyframes of \"{}\": the layer is locked", l.name));
+        }
+        let key = l.props.find(prop).and_then(|pr| pr.keys.get(usize::try_from(index).ok()?)).ok_or("the keyframe no longer exists")?;
+        keys.push(KeyRef { layer: LayerId(layer), prop, time: key.time });
+    }
+    let saved = std::mem::replace(&mut s.state.selected_keys, keys);
+    let r = exec(s, id, params);
+    let comp = s.active_comp();
+    let exists = |k: &KeyRef| comp.and_then(|c| c.layer(k.layer)).and_then(|l| l.props.find(k.prop)).is_some_and(|pr| pr.keys.iter().any(|x| x.time == k.time));
+    s.state.selected_keys = saved.into_iter().filter(exists).collect();
+    r
+}
+
 /// `__query(kind, json)` → JSON.
 fn native_query(_: &JsValue, args: &[JsValue], ctx: &mut Context) -> JsResult<JsValue> {
     let kind = arg_string(args, 0, ctx)?;
diff --git a/crates/script/src/tests_ease_presets.rs b/crates/script/src/tests_ease_presets.rs
new file mode 100644
index 00000000..c803c27a
--- /dev/null
+++ b/crates/script/src/tests_ease_presets.rs
@@ -0,0 +1,321 @@
+//! The scripting API the bundled Ease Presets ScriptUI panel uses (After Effects parity:
+//! `app.settings` that last between runs, per-key methods that keep the key selection, eases and
+//! spatial tangents reported as they play, `selectedProperties` with keyed properties,
+//! `isInterpolationTypeValid`), and the panel itself (`extensions/scriptui-panels/Ease
+//! Presets.jsx`) easing selected keyframes, keeping user presets and taking over the presets the
+//! core panel of v0.6.0 saved.
+
+use std::sync::Arc;
+
+use effectcraft_engine::Session;
+use effectcraft_engine::commands::scripts::SCRIPT_SETTINGS_FILE;
+use effectcraft_engine::config::{ConfigStore, MemoryConfig};
+use effectcraft_engine::project::{LayerId, Property};
+use effectcraft_keyframe::{Ease, Interp, ease_progress};
+use effectcraft_time::Tick;
+use serde_json::{Value, json};
+
+use crate::run_code;
+
+const PANEL: &str = "Ease Presets.jsx";
+
+fn session(store: &Arc<MemoryConfig>) -> Session {
+    let mut s = Session { expr: Some(Arc::new(effectcraft_expr::Expressions)), ..Default::default() };
+    crate::install(&mut s);
+    s.config = Some(store.clone());
+    s.load_settings();
+    s
+}
+
+/// A comp with one solid; returns its id.
+fn setup(s: &mut Session) -> u64 {
+    s.execute("comp.new", json!({"name": "Ease", "width": 640, "height": 360, "frameRate": 30, "duration": 10})).unwrap();
+    s.execute("layer.newSolid", json!({"name": "Box", "color": "#ff0000", "width": 100, "height": 100})).unwrap()["layer"].as_u64().unwrap()
+}
+
+fn animate(s: &mut Session, l: u64, path: &str, keys: &[(f64, Value)]) {
+    for (t, v) in keys {
+        s.execute("prop.addKey", json!({"layer": l, "path": path, "time": t, "value": v})).unwrap();
+    }
+}
+
+fn prop(s: &Session, l: u64, path: &str) -> Property {
+    s.active_comp().unwrap().layer(LayerId(l)).unwrap().props.prop(path).unwrap().clone()
+}
+
+fn close(a: f64, b: f64, tol: f64) -> bool {
+    (a - b).abs() < tol
+}
+
+fn ok(s: &mut Session, code: &str) -> Value {
+    let out = run_code(s, code, "test.jsx");
+    assert!(out.error.is_none(), "{:?}", out.error);
+    out.result
+}
+
+fn at(s: f64) -> Tick {
+    Tick::from_seconds_f64(s)
+}
+
+#[test]
+fn app_settings_last_between_runs() {
+    let store = Arc::new(MemoryConfig::default());
+    let mut s = session(&store);
+    ok(&mut s, r#"app.settings.saveSetting("My Tool", "size", 12); app.settings.saveSetting("My Tool", "name", "Box");"#);
+    // A new run (the next launch) reads them back.
+    let mut s = session(&store);
+    let r = ok(
+        &mut s,
+        r#"[app.settings.haveSetting("My Tool", "size"), app.settings.getSetting("My Tool", "size"), app.settings.getSetting("My Tool", "name"), app.settings.haveSetting("My Tool", "nope")]"#,
+    );
+    assert_eq!(r, json!([true, "12", "Box", false]));
+    assert_eq!(s.execute("script.settings.get", json!({"section": "My Tool", "key": "name"})).unwrap(), json!({"have": true, "value": "Box"}));
+    // A corrupt settings file loads as none, never an error.
+    store.write(SCRIPT_SETTINGS_FILE, "{oops").unwrap();
+    let mut s = session(&store);
+    assert_eq!(ok(&mut s, r#"app.settings.haveSetting("My Tool", "size")"#), json!(false));
+    assert!(s.execute("script.settings.save", json!({"section": "x"})).is_err());
+}
+
+#[test]
+fn per_key_methods_keep_the_key_selection_and_report_eases_as_they_play() {
+    let store = Arc::new(MemoryConfig::default());
+    let mut s = session(&store);
+    let l = setup(&mut s);
+    animate(&mut s, l, "transform/opacity", &[(0.0, json!(0)), (1.0, json!(100)), (2.0, json!(0))]);
+    let key = |t: f64| json!({"layer": l, "path": "transform/opacity", "time": t});
+    s.execute("edit.deselectAll", json!({})).unwrap();
+    s.execute("keys.select", json!({"keys": [key(0.0), key(2.0)]})).unwrap();
+    let before = s.state.selected_keys.clone();
+    let r = ok(
+        &mut s,
+        r#"var comp = app.project.activeItem, p = comp.layer(1).transform.opacity;
+        // A linear side reports the speed it plays at (33.3 % influence).
+        var lin = p.keyInTemporalEase(3)[0];
+        p.setTemporalEaseAtKey(2, [new KeyframeEase(0, 50)], [new KeyframeEase(0, 75)]);
+        p.setInterpolationTypeAtKey(3, KeyframeInterpolationType.HOLD, KeyframeInterpolationType.HOLD);
+        // Keyed properties are selected properties, as in After Effects.
+        var sel = comp.selectedProperties;
+        [lin.speed, lin.influence, p.selectedKeys, sel.length, sel.length ? sel[0].name : ""]"#,
+    );
+    assert!(close(r[0].as_f64().unwrap(), -100.0, 1e-9) && close(r[1].as_f64().unwrap(), 100.0 / 3.0, 1e-9), "{r}");
+    assert_eq!(r[2], json!([1, 3]), "the selection is the user's");
+    assert_eq!((r[3].clone(), r[4].clone()), (json!(1), json!("Opacity")));
+    assert_eq!(s.state.selected_keys, before);
+    let op = prop(&s, l, "transform/opacity");
+    assert_eq!((op.keys[1].in_ease[0], op.keys[1].out_ease[0]), (Ease { speed: 0.0, influence: 0.5 }, Ease { speed: 0.0, influence: 0.75 }));
+    assert_eq!(op.keys[2].in_interp, Interp::Hold);
+    // removeKey drops the removed key from the selection, keeps the rest.
+    ok(&mut s, "app.project.activeItem.layer(1).transform.opacity.removeKey(3)");
+    assert_eq!(s.state.selected_keys, before[..1]);
+    // Values that don't interpolate only hold.
+    let r = ok(
+        &mut s,
+        r#"var comp = app.project.activeItem, o = comp.layer(1).transform.opacity, t = comp.layers.addText("Hi").text.sourceText;
+        [t.isInterpolationTypeValid(KeyframeInterpolationType.BEZIER), t.isInterpolationTypeValid(KeyframeInterpolationType.HOLD), o.isInterpolationTypeValid(KeyframeInterpolationType.BEZIER)]"#,
+    );
+    assert_eq!(r, json!([false, true, true]));
+}
+
+#[test]
+fn spatial_tangents_are_reported_as_the_path_plays() {
+    let store = Arc::new(MemoryConfig::default());
+    let mut s = session(&store);
+    let l = setup(&mut s);
+    animate(&mut s, l, "transform/position", &[(0.0, json!([0, 0, 0])), (1.0, json!([100, 0, 0])), (2.0, json!([100, 100, 0]))]);
+    let pos = prop(&s, l, "transform/position");
+    let (inn, out) = effectcraft_keyframe::spatial_tangents(&pos.keys, 1);
+    let r = ok(&mut s, "var p = app.project.activeItem.layer(1).transform.position; [p.keyInSpatialTangent(2), p.keyOutSpatialTangent(2)]");
+    for (got, want) in [(&r[0], inn), (&r[1], out)] {
+        for d in 0..2 {
+            assert!(close(got[d].as_f64().unwrap(), want[d], 1e-9), "{r} vs {inn:?} {out:?}");
+        }
+    }
+    assert!(out[0].abs() + out[1].abs() > 1.0, "the middle key's path curves: {out:?}");
+    assert_ne!(pos.keys[1].spatial_out, out, "auto-Bezier: the stored tangent isn't the one that plays");
+}
+
+/// The panel's window and a control's description by name.
+fn open_panel(s: &mut Session) -> u64 {
+    let r = s.execute("window.scriptPanel", json!({"name": PANEL})).unwrap();
+    r["window"].as_u64().unwrap()
+}
+
+fn control(s: &mut Session, win: u64, name: &str) -> Value {
+    fn find(w: &Value, name: &str) -> Option<Value> {
+        if w["name"] == name {
+            return Some(w.clone());
+        }
+        w["children"].as_array()?.iter().find_map(|c| find(c, name))
+    }
+    let w = s.execute("scriptui.get", json!({"window": win})).unwrap();
+    find(&w["root"], name).unwrap_or_else(|| panic!("no control {name}"))
+}
+
+fn set(s: &mut Session, win: u64, widget: &str, value: Value) {
+    s.execute("scriptui.set", json!({"window": win, "widget": widget, "value": value})).unwrap();
+}
+
+fn click(s: &mut Session, win: u64, widget: &str) {
+    s.execute("scriptui.click", json!({"window": win, "widget": widget})).unwrap();
+}
+
+fn status(s: &mut Session, win: u64) -> String {
+    control(s, win, "status")["text"].as_str().unwrap().to_string()
+}
+
+#[test]
+fn the_ease_presets_panel_eases_every_selected_pair_in_one_undo_step() {
+    let store = Arc::new(MemoryConfig::default());
+    let mut s = session(&store);
+    let l = setup(&mut s);
+    animate(&mut s, l, "transform/opacity", &[(0.0, json!(0)), (1.0, json!(100)), (3.0, json!(20))]);
+    animate(&mut s, l, "transform/rotation", &[(0.0, json!(0)), (2.0, json!(90))]);
+    s.execute("prop.select", json!({"layer": l, "path": "transform/opacity"})).unwrap();
+    s.execute("prop.select", json!({"layer": l, "path": "transform/rotation", "add": true})).unwrap();
+    let selected = s.state.selected_keys.clone();
+    let win = open_panel(&mut s);
+    // It is a bundled extension listed with the ScriptUI panels.
+    let list = s.execute("file.scripts.list", json!({})).unwrap();
+    assert!(list.as_array().unwrap().iter().any(|e| e["name"] == PANEL && e["panel"] == true && e["source"] == "extension"));
+    let steps = s.history.undo.len();
+    set(&mut s, win, "presets", json!("Ease In-Out"));
+    assert_eq!(status(&mut s, win), "Eased 3 keyframe pair(s) with \u{201c}Ease In-Out\u{201d}");
+    assert_eq!(s.history.undo.len(), steps + 1, "one undo step");
+    assert_eq!(s.history.undo.last().map(|(label, _)| label.as_str()), Some("Apply Ease Preset"));
+    assert_eq!(s.state.selected_keys, selected, "the keys stay selected for the next preset");
+    let eased = Ease { speed: 0.0, influence: 0.5 };
+    let op = prop(&s, l, "transform/opacity");
+    assert_eq!((op.keys[0].out_interp, op.keys[0].out_ease[0]), (Interp::Bezier, eased));
+    assert_eq!((op.keys[1].in_ease[0], op.keys[1].out_ease[0]), (eased, eased));
+    assert_eq!((op.keys[2].in_interp, op.keys[2].in_ease[0]), (Interp::Bezier, eased));
+    // The first key's in side and the last key's out side are not part of a pair.
+    assert_eq!((op.keys[0].in_interp, op.keys[2].out_interp), (Interp::Linear, Interp::Linear));
+    // A symmetric curve passes the middle value at mid-time, slow near the keys.
+    assert!(close(op.value_at(at(2.0)).as_f64(), 60.0, 1e-6));
+    let quarter = op.value_at(at(1.5)).as_f64();
+    assert!(close(quarter, 100.0 - 80.0 * ease_progress(0.0, 0.5, 0.0, 0.5, 0.25), 1e-6), "{quarter}");
+    assert_eq!(prop(&s, l, "transform/rotation").keys[1].in_interp, Interp::Bezier);
+    s.execute("edit.undo", json!({})).unwrap();
+    let op = prop(&s, l, "transform/opacity");
+    assert!(op.keys.iter().all(|k| k.in_interp == Interp::Linear && k.out_interp == Interp::Linear));
+    // Nothing selected: nothing changes, and the panel says why.
+    s.execute("edit.deselectAll", json!({})).unwrap();
+    let steps = s.history.undo.len();
+    set(&mut s, win, "presets", json!("Linear"));
+    assert_eq!(status(&mut s, win), "Select two or more neighbouring keyframes of a property");
+    assert_eq!(s.history.undo.len(), steps);
+}
+
+#[test]
+fn a_typed_curve_scales_to_each_dimension_and_follows_motion_paths() {
+    let store = Arc::new(MemoryConfig::default());
+    let mut s = session(&store);
+    let l = setup(&mut s);
+    animate(&mut s, l, "transform/scale", &[(0.0, json!([100, 100])), (1.0, json!([200, 50]))]);
+    animate(&mut s, l, "transform/position", &[(0.0, json!([0, 0, 0])), (2.0, json!([300, 400, 0]))]);
+    s.execute("prop.select", json!({"layer": l, "path": "transform/scale"})).unwrap();
+    let win = open_panel(&mut s);
+    let typed = |s: &mut Session, c: [f64; 4]| {
+        for (name, v) in ["outInfluence", "outSpeed", "inInfluence", "inSpeed"].iter().zip(c) {
+            set(s, win, name, json!(v.to_string()));
+        }
+        click(s, win, "apply");
+    };
+    typed(&mut s, [60.0, 0.0, 20.0, 2.0]);
+    let sc = prop(&s, l, "transform/scale");
+    // X rises 100/s and Y falls 50/s: the in speed (2× average) is per dimension.
+    assert_eq!(sc.keys[1].in_ease[..2], [Ease { speed: 200.0, influence: 0.2 }, Ease { speed: -100.0, influence: 0.2 }]);
+    let f = ease_progress(0.0, 0.6, 2.0, 0.2, 0.5);
+    let v = sc.value_at(at(0.5)).as_vec2();
+    assert!(close(v[0], 100.0 + 100.0 * f, 1e-6) && close(v[1], 100.0 - 50.0 * f, 1e-6), "{v:?}");
+    // On Position the speed is along the 500 px path.
+    s.execute("prop.select", json!({"layer": l, "path": "transform/position"})).unwrap();
+    typed(&mut s, [25.0, 0.4, 75.0, 0.0]);
+    let pos = prop(&s, l, "transform/position");
+    assert!(pos.keys[0].out_ease.iter().all(|e| close(e.speed, 0.4 * 250.0, 1e-6) && close(e.influence, 0.25, 1e-9)), "{:?}", pos.keys[0].out_ease);
+    let f = ease_progress(0.4, 0.25, 0.0, 0.75, 0.5);
+    let p = pos.value_at(at(1.0)).as_vec2();
+    assert!(close(p[0], 300.0 * f, 0.05) && close(p[1], 400.0 * f, 0.05), "{p:?} {f}");
+    // From Keys reads the applied curve back into the fields.
+    for name in ["outInfluence", "outSpeed", "inInfluence", "inSpeed"] {
+        set(&mut s, win, name, json!("1"));
+    }
+    click(&mut s, win, "fromKeys");
+    let fields: Vec<String> =
+        ["outInfluence", "outSpeed", "inInfluence", "inSpeed"].iter().map(|n| control(&mut s, win, n)["text"].as_str().unwrap().to_string()).collect();
+    assert_eq!(fields, ["25", "0.4", "75", "0"]);
+}
+
+#[test]
+fn user_presets_save_rename_delete_and_persist() {
+    let store = Arc::new(MemoryConfig::default());
+    let mut s = session(&store);
+    let l = setup(&mut s);
+    animate(&mut s, l, "transform/opacity", &[(0.0, json!(0)), (1.0, json!(100))]);
+    s.execute("prop.select", json!({"layer": l, "path": "transform/opacity"})).unwrap();
+    let win = open_panel(&mut s);
+    set(&mut s, win, "presets", json!("Decelerate"));
+    // Save keeps the curve in the fields under the typed name.
+    set(&mut s, win, "name", json!("  Settle "));
+    click(&mut s, win, "save");
+    assert_eq!(status(&mut s, win), "Saved the ease preset \u{201c}Settle\u{201d}");
+    // Built-in names are refused.
+    set(&mut s, win, "name", json!("linear"));
+    click(&mut s, win, "save");
+    assert!(status(&mut s, win).contains("is a built-in preset"));
+    let items = |s: &mut Session| control(s, win, "presets")["items"].clone();
+    assert_eq!(items(&mut s).as_array().unwrap().last().unwrap(), "Settle");
+    // Rename and Delete act on the selected user preset; built-in presets can't change.
+    set(&mut s, win, "presets", json!("Linear"));
+    set(&mut s, win, "name", json!("Straight"));
+    click(&mut s, win, "rename");
+    assert_eq!(status(&mut s, win), "Select one of your own presets first");
+    set(&mut s, win, "presets", json!("Settle"));
+    set(&mut s, win, "name", json!("Soft Landing"));
+    click(&mut s, win, "rename");
+    let names = items(&mut s);
+    assert!(names.as_array().unwrap().contains(&json!("Soft Landing")) && !names.as_array().unwrap().contains(&json!("Settle")), "{names}");
+    // Kept with app.settings: a new run of the panel (the next launch) lists them.
+    let stored: Value = serde_json::from_str(&store.read(SCRIPT_SETTINGS_FILE).unwrap()).unwrap();
+    let presets: Value = serde_json::from_str(stored["Ease Presets"]["userPresets"].as_str().unwrap()).unwrap();
+    assert_eq!(presets["presets"][0]["name"], "Soft Landing");
+    assert!(close(presets["presets"][0]["curve"]["outSpeed"].as_f64().unwrap(), 1.5, 1e-9), "{presets}");
+    let mut s2 = session(&store);
+    setup(&mut s2);
+    let win2 = open_panel(&mut s2);
+    assert_eq!(control(&mut s2, win2, "presets")["items"].as_array().unwrap().len(), 13);
+    set(&mut s2, win2, "presets", json!("Soft Landing"));
+    click(&mut s2, win2, "delete");
+    assert_eq!(control(&mut s2, win2, "presets")["items"].as_array().unwrap().len(), 12, "the built-in presets");
+}
+
+/// User presets the core Ease Presets panel of v0.6.0 saved (`ease_presets.json`) move to the
+/// panel's settings when settings load, once; unusable entries are skipped by the panel.
+#[test]
+fn presets_saved_by_the_old_core_panel_carry_over() {
+    let store = Arc::new(MemoryConfig::default());
+    let c = json!({"outInfluence": 30, "outSpeed": 0, "inInfluence": 30, "inSpeed": 0});
+    let old = json!({"version": 1, "presets": [
+        {"name": "Snap", "curve": c},
+        {"name": "Linear", "curve": c},
+        {"name": "", "curve": c},
+        {"name": "No curve"},
+        {"name": "snap", "curve": c},
+        {"name": "Bad", "curve": {"outInfluence": "x", "outSpeed": 0, "inInfluence": 30, "inSpeed": 0}}
+    ]});
+    store.write("ease_presets.json", &old.to_string()).unwrap();
+    let mut s = session(&store);
+    setup(&mut s);
+    let win = open_panel(&mut s);
+    let items = control(&mut s, win, "presets")["items"].clone();
+    assert_eq!(items.as_array().unwrap().len(), 13, "{items}");
+    assert_eq!(items[12], "Snap");
+    // Deleting it there is final: the old file doesn't come back.
+    set(&mut s, win, "presets", json!("Snap"));
+    click(&mut s, win, "delete");
+    let mut s = session(&store);
+    setup(&mut s);
+    let win = open_panel(&mut s);
+    assert_eq!(control(&mut s, win, "presets")["items"].as_array().unwrap().len(), 12);
+}
diff --git a/crates/ui-egui/src/dock.rs b/crates/ui-egui/src/dock.rs
index e62b6d46..058f601b 100644
--- a/crates/ui-egui/src/dock.rs
+++ b/crates/ui-egui/src/dock.rs
@@ -50,12 +50,10 @@ pub enum PanelKind {
     CreateNullsFromPaths,
     /// Window ▸ VR Comp Editor (our own panel).
     VrCompEditor,
-    /// Window ▸ Ease Presets (our own panel).
-    EasePresets,
 }
 
 impl PanelKind {
-    pub const ALL: [PanelKind; 35] = [
+    pub const ALL: [PanelKind; 34] = [
         PanelKind::Project,
         PanelKind::EffectControls,
         PanelKind::Composition,
@@ -90,7 +88,6 @@ impl PanelKind {
         PanelKind::ContentAwareFill,
         PanelKind::CreateNullsFromPaths,
         PanelKind::VrCompEditor,
-        PanelKind::EasePresets,
     ];
     pub fn title(self) -> &'static str {
         match self {
@@ -130,7 +127,6 @@ impl PanelKind {
             PanelKind::ContentAwareFill => "Content-Aware Fill",
             PanelKind::CreateNullsFromPaths => "Create Nulls From Paths",
             PanelKind::VrCompEditor => "VR Comp Editor",
-            PanelKind::EasePresets => "Ease Presets",
         }
     }
     pub fn id(self) -> String {
@@ -371,7 +367,6 @@ pub fn workspace(name: &str) -> DockNode {
                             ContentAwareFill,
                             CreateNullsFromPaths,
                             VrCompEditor,
-                            EasePresets,
                         ],
                     ),
                 ),
diff --git a/crates/ui-egui/src/i18n.rs b/crates/ui-egui/src/i18n.rs
index 7c86e572..ee08566f 100644
--- a/crates/ui-egui/src/i18n.rs
+++ b/crates/ui-egui/src/i18n.rs
@@ -754,7 +754,6 @@ const SIMPLIFIED_CHINESE: &[(&str, &str, &str)] = &[
     ("window.panel", "Render Queue", "渲染队列"),
     ("window.panel", "Timeline", "时间轴"),
     ("window.panel", "Create Nulls From Paths", "从路径创建空对象"),
-    ("window.panel", "Ease Presets", "缓动预设"),
     ("window.panel", "VR Comp Editor", "VR 合成编辑器"),
     ("", "Help", "帮助"),
     ("help.docs", "EffectCraft Help...", "EffectCraft 帮助..."),
@@ -1378,7 +1377,6 @@ const TRADITIONAL_CHINESE: &[(&str, &str, &str)] = &[
     ("window.panel", "Render Queue", "渲染佇列"),
     ("window.panel", "Timeline", "時間軸"),
     ("window.panel", "Create Nulls From Paths", "從路徑建立空物件"),
-    ("window.panel", "Ease Presets", "緩動預設集"),
     ("window.panel", "VR Comp Editor", "VR 合成編輯器"),
     ("", "Help", "說明"),
     ("help.docs", "EffectCraft Help...", "EffectCraft 說明..."),
@@ -1999,7 +1997,6 @@ const JAPANESE: &[(&str, &str, &str)] = &[
     ("window.panel", "Render Queue", "レンダーキュー"),
     ("window.panel", "Timeline", "タイムライン"),
     ("window.panel", "Create Nulls From Paths", "パスからヌルを作成"),
-    ("window.panel", "Ease Presets", "イーズプリセット"),
     ("window.panel", "VR Comp Editor", "VRコンポジションエディター"),
     ("", "Help", "ヘルプ"),
     ("help.docs", "EffectCraft Help...", "EffectCraftヘルプ..."),
diff --git a/crates/ui-egui/src/panels/ease_presets.rs b/crates/ui-egui/src/panels/ease_presets.rs
deleted file mode 100644
index cb069238..00000000
--- a/crates/ui-egui/src/panels/ease_presets.rs
+++ /dev/null
@@ -1,243 +0,0 @@
-//! Ease Presets panel (Window ▸ Ease Presets): easing curves kept by name and applied to pairs of
-//! keyframes (our own design and presets). The value graph at the top edits a working curve by
-//! dragging its two handles, and Apply eases the selected keyframes with it; From Keys reads the
-//! curve between the first selected pair. Clicking a preset's thumbnail loads it and applies it.
-//! Save Current keeps the working curve under the name in the field; Rename and Delete act on the
-//! selected user preset. Every action is a `keys.easePreset.*` command.
-//!
-//! Automation ids: `easePresets.graph`, `easePresets.handle.out` / `.in`, `easePresets.apply`,
-//! `easePresets.fromKeys`, `easePresets.name`, `easePresets.save`, `easePresets.rename`,
-//! `easePresets.delete`, `easePresets.preset.<n>` (1-based, labelled with the preset's name).
-
-use effectcraft_engine::ease_presets;
-use effectcraft_engine::keyframe::EaseCurve;
-use egui::epaint::CubicBezierShape;
-use egui::{Align2, Color32, CursorIcon, Pos2, Rect, Sense, Stroke, StrokeKind, pos2, vec2};
-use serde::{Deserialize, Serialize};
-use serde_json::json;
-
-use super::panel_kit as kit;
-use crate::theme::Tokens;
-use crate::{EffectcraftApp, widgets};
-
-/// Panel state (serde in the UI state).
-#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
-#[serde(default)]
-pub struct EasePanelState {
-    /// The curve the graph shows and Apply uses.
-    pub curve: EaseCurve,
-    /// The preset clicked last (Rename and Delete act on it).
-    pub selected: Option<String>,
-    /// Name for Save Current and Rename.
-    pub name: String,
-}
-
-impl Default for EasePanelState {
-    fn default() -> Self {
-        EasePanelState { curve: EaseCurve::LINEAR, selected: None, name: String::new() }
-    }
-}
-
-/// Value range of the graph: room for handles above and below the keys.
-const V_MIN: f64 = -0.35;
-const V_MAX: f64 = 1.35;
-const TILE: egui::Vec2 = vec2(84.0, 64.0);
-const GAP: f32 = 6.0;
-const ROW: f32 = 30.0;
-/// Height of the controls under the graph (numbers, three button rows, status, "Presets").
-const CONTROLS: f32 = 154.0;
-/// Panels at least this wide put the presets beside the graph and controls.
-const SIDE_BY_SIDE: f32 = 560.0;
-
-/// Screen point of normalised time `x` and value `v` in `r`, values `lo..hi` bottom to top.
-fn to_screen(r: Rect, lo: f64, hi: f64, x: f64, v: f64) -> Pos2 {
-    pos2(r.min.x + r.width() * x as f32, r.max.y - r.height() * ((v - lo) / (hi - lo)) as f32)
-}
-
-/// The curve from (0, 0) to (1, 1) through its handles.
-fn curve_shape(c: &EaseCurve, at: impl Fn(f64, f64) -> Pos2, stroke: Stroke) -> CubicBezierShape {
-    let [x1, y1, x2, y2] = c.handles();
-    CubicBezierShape::from_points_stroke([at(0.0, 0.0), at(x1, y1), at(x2, y2), at(1.0, 1.0)], false, Color32::TRANSPARENT, stroke)
-}
-
-pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, rect: Rect) {
-    let t = app.tokens;
-    let p = ui.painter().with_clip_rect(rect);
-    let mut st = app.ui.ease_presets.clone();
-    let pairs = ease_presets::selected_pairs(&app.session).len();
-    let x0 = rect.min.x + 10.0;
-    // Wide panels: graph and controls on the left, presets on the right; else presets below,
-    // with room for at least one row of them.
-    let side = rect.width() >= SIDE_BY_SIDE;
-    let w = if side { 300.0 } else { (rect.width() - 20.0).max(210.0) };
-    let room = rect.height() - 16.0 - CONTROLS - if side { 0.0 } else { TILE.y + GAP };
-    let g = Rect::from_min_size(pos2(x0, rect.min.y + 10.0), vec2(w, (w * 0.6).min(room).clamp(90.0, 220.0)));
-    graph(app, ui, g, &mut st.curve);
-    let c = st.curve;
-    let mut y = g.max.y + 4.0;
-    let numbers = format!("Out {:.1} % · {:.2}      In {:.1} % · {:.2}", c.out_influence, c.out_speed, c.in_influence, c.in_speed);
-    p.text(pos2(x0, y + 8.0), Align2::LEFT_CENTER, numbers, Tokens::mono(11.0), t.text_faint);
-    y += 22.0;
-    let at = |x: f32, y: f32, width: f32| Rect::from_min_size(pos2(x, y), vec2(width, 24.0));
-    if kit::button(app, ui, at(x0, y, 90.0), "easePresets.apply", "Apply", pairs > 0) {
-        apply(app, json!({"curve": c}), pairs, "the curve");
-    }
-    if kit::button(app, ui, at(x0 + 96.0, y, 100.0), "easePresets.fromKeys", "From Keys", false)
-        && let Some(v) = kit::exec(app, "keys.easePreset.capture", json!({}))
-        && let Ok(curve) = serde_json::from_value(v)
-    {
-        st.curve = curve;
-        st.selected = None;
-    }
-    y += ROW;
-    let field = at(x0, y, (w - 116.0).max(80.0));
-    widgets::text_field(ui, field, &mut st.name, "Preset name", &t);
-    app.auto.add("easePresets.name", field, "Preset name");
-    let name = st.name.trim().to_string();
-    if kit::button(app, ui, at(field.max.x + 6.0, y, 110.0), "easePresets.save", "Save Current", false) {
-        if name.is_empty() {
-            app.ui.status = "Type a name for the preset first".into();
-        } else if let Some(v) = kit::exec(app, "keys.easePreset.save", json!({"name": name, "curve": c})) {
-            st.selected = v["name"].as_str().map(str::to_string);
-            app.ui.status = format!("Saved the ease preset “{}”", st.selected.as_deref().unwrap_or(&name));
-        }
-    }
-    y += ROW;
-    // Rename and Delete act on the selected user preset.
-    let user = st.selected.clone().filter(|n| app.session.ease_presets.iter().any(|q| &q.name == n));
-    let rename = kit::button(app, ui, at(x0, y, 90.0), "easePresets.rename", "Rename", false);
-    let delete = kit::button(app, ui, at(x0 + 96.0, y, 90.0), "easePresets.delete", "Delete", false);
-    match (&user, rename, delete) {
-        (None, true, _) | (None, _, true) => app.ui.status = "Select one of your own presets first".into(),
-        (Some(old), true, _) if name.is_empty() => app.ui.status = format!("Type a new name for “{old}” first"),
-        (Some(old), true, _) => {
-            if let Some(v) = kit::exec(app, "keys.easePreset.rename", json!({"name": old, "newName": name})) {
-                st.selected = v["name"].as_str().map(str::to_string);
-            }
-        }
-        (Some(old), _, true) => {
-            let deleted = kit::exec(app, "keys.easePreset.delete", json!({"name": old})).is_some();
-            if deleted {
-                st.selected = None;
-            }
-        }
-        _ => {}
-    }
-    y += ROW;
-    let msg = if pairs > 0 {
-        format!("{pairs} keyframe pair{} selected", if pairs == 1 { "" } else { "s" })
-    } else {
-        "Select two or more neighbouring keyframes".into()
-    };
-    p.text(pos2(x0, y + 4.0), Align2::LEFT_CENTER, msg, Tokens::ui(11.0), t.text_faint);
-    y += 16.0;
-    let head = if side { pos2(x0 + w + 16.0, rect.min.y + 6.0) } else { pos2(x0, y) };
-    kit::label(ui, head, "Presets", &t);
-    let list = Rect::from_min_max(head + vec2(0.0, 22.0), pos2(rect.max.x - 10.0, rect.max.y - 6.0));
-    if let Some((name, curve)) = grid(app, ui, list, st.selected.as_deref()) {
-        st.curve = curve;
-        if pairs > 0 {
-            apply(app, json!({"preset": name}), pairs, &format!("“{name}”"));
-        }
-        st.selected = Some(name);
-    }
-    if st != app.ui.ease_presets {
-        app.ui.ease_presets = st;
-    }
-}
-
-fn apply(app: &mut EffectcraftApp, params: serde_json::Value, pairs: usize, what: &str) {
-    if pairs == 0 {
-        app.ui.status = "Select two or more neighbouring keyframes of a property".into();
-    } else if let Some(r) = kit::exec(app, "keys.easePreset.apply", params) {
-        app.ui.status = format!("Eased {} keyframe pair(s) with {what}", r["pairs"]);
-    }
-}
-
-/// The working curve's value graph: keys at (0, 0) and (1, 1), the linear ease for reference, and
-/// the two handles, dragged to edit the curve.
-fn graph(app: &mut EffectcraftApp, ui: &mut egui::Ui, g: Rect, curve: &mut EaseCurve) {
-    let t = app.tokens;
-    let p = ui.painter().with_clip_rect(g);
-    p.rect_filled(g, 3.0, t.field_bg);
-    p.rect_stroke(g, 3.0, Stroke::new(1.0, t.field_border), StrokeKind::Inside);
-    app.auto.add("easePresets.graph", g, "Ease curve");
-    let plot = g.shrink2(vec2(16.0, 6.0));
-    let at = |x: f64, v: f64| to_screen(plot, V_MIN, V_MAX, x, v);
-    for v in [0.0, 1.0] {
-        p.line_segment([at(0.0, v), at(1.0, v)], Stroke::new(1.0, t.separator));
-    }
-    p.add(egui::Shape::dashed_line(&[at(0.0, 0.0), at(1.0, 1.0)], Stroke::new(1.0, t.separator), 4.0, 4.0));
-    p.add(curve_shape(curve, at, Stroke::new(2.0, t.accent)));
-    let [x1, y1, x2, y2] = curve.handles();
-    let mut next = None;
-    for (out, key, h) in [(true, at(0.0, 0.0), at(x1, y1)), (false, at(1.0, 1.0), at(x2, y2))] {
-        p.line_segment([key, h], Stroke::new(1.0, t.text_dim));
-        p.rect_filled(Rect::from_center_size(key, vec2(7.0, 7.0)), 1.0, t.keyframe);
-        let r = Rect::from_center_size(h, vec2(14.0, 14.0));
-        let resp = ui.interact(r, egui::Id::new(("easePresets.handle", out)), Sense::drag());
-        app.auto.add(if out { "easePresets.handle.out" } else { "easePresets.handle.in" }, r, if out { "Out handle" } else { "In handle" });
-        let hot = resp.hovered() || resp.dragged();
-        if hot {
-            ui.ctx().set_cursor_icon(if resp.dragged() { CursorIcon::Grabbing } else { CursorIcon::Grab });
-        }
-        p.circle_filled(h, if hot { 5.5 } else { 4.5 }, if hot { t.keyframe_selected } else { t.text });
-        if resp.dragged() {
-            let to = h + resp.drag_delta();
-            let x = f64::from((to.x - plot.min.x) / plot.width()).clamp(0.0, 1.0);
-            let v = (V_MIN + f64::from((plot.max.y - to.y) / plot.height()) * (V_MAX - V_MIN)).clamp(V_MIN, V_MAX);
-            next = EaseCurve::from_handles(if out { [x, v, x2, y2] } else { [x1, y1, x, v] });
-        }
-    }
-    if let Some(c) = next {
-        *curve = c;
-    }
-}
-
-/// Preset thumbnails in a wrapping grid that scrolls with the wheel; returns the clicked one.
-fn grid(app: &mut EffectcraftApp, ui: &mut egui::Ui, list: Rect, selected: Option<&str>) -> Option<(String, EaseCurve)> {
-    let t = app.tokens;
-    let p = ui.painter().with_clip_rect(list);
-    let scroll = widgets::PanelScroll::begin(ui, egui::Id::new("ease-presets-scroll"), list);
-    let cols = (((list.width() + GAP) / (TILE.x + GAP)).floor() as usize).max(1);
-    let (mut clicked, mut count) = (None, 0);
-    for (n, (name, curve, built_in)) in ease_presets::presets(&app.session).enumerate() {
-        count = n + 1;
-        let r = Rect::from_min_size(list.min + vec2((n % cols) as f32 * (TILE.x + GAP), (n / cols) as f32 * (TILE.y + GAP) - scroll.offset), TILE);
-        if !r.intersects(list) {
-            continue;
-        }
-        let resp = ui.interact(r.intersect(list), egui::Id::new(("easePresets.preset", n)), Sense::click());
-        app.auto.add(&format!("easePresets.preset.{count}"), r, name);
-        let on = selected == Some(name);
-        p.rect_filled(
-            r,
-            4.0,
-            if on {
-                t.row_selected
-            } else if resp.hovered() {
-                t.hover
-            } else {
-                t.field_bg
-            },
-        );
-        let thumb = Rect::from_min_size(r.min, vec2(TILE.x, TILE.y - 16.0)).shrink2(vec2(12.0, 7.0));
-        let [_, y1, _, y2] = curve.handles();
-        let (lo, hi) = (y1.min(y2).min(0.0), y1.max(y2).max(1.0));
-        p.add(curve_shape(&curve, |x, v| to_screen(thumb, lo, hi, x, v), Stroke::new(1.5, if on { t.text } else { t.text_dim })));
-        widgets::text_fit(
-            &p,
-            pos2(r.center().x, r.max.y - 9.0),
-            Align2::CENTER_CENTER,
-            name,
-            Tokens::ui(11.0),
-            TILE.x - 6.0,
-            if built_in { t.text_dim } else { t.text },
-        );
-        if resp.on_hover_text(format!("{name}: click to apply it to the selected keyframes")).clicked() {
-            clicked = Some((name.to_string(), curve));
-        }
-    }
-    scroll.end(ui, &mut app.auto, "easePresets.scroll", count.div_ceil(cols) as f32 * (TILE.y + GAP), &t);
-    clicked
-}
diff --git a/crates/ui-egui/src/panels/mod.rs b/crates/ui-egui/src/panels/mod.rs
index f95bd176..361a123a 100644
--- a/crates/ui-egui/src/panels/mod.rs
+++ b/crates/ui-egui/src/panels/mod.rs
@@ -7,7 +7,6 @@ pub mod content_fill_panel;
 pub mod delete_items;
 pub mod dialogs;
 pub mod dialogs_3d;
-pub mod ease_presets;
 pub mod effect_controls;
 pub mod effects_presets;
 pub mod essential;
@@ -128,7 +127,6 @@ pub fn show(app: &mut EffectcraftApp, ui: &mut egui::Ui, p: PanelKind, rect: Rec
         PanelKind::ContentAwareFill => content_fill_panel::show(app, ui, rect),
         PanelKind::CreateNullsFromPaths => path_vr_panels::create_nulls(app, ui, rect),
         PanelKind::VrCompEditor => path_vr_panels::vr_editor(app, ui, rect),
-        PanelKind::EasePresets => ease_presets::show(app, ui, rect),
     }
 }
 
diff --git a/crates/ui-egui/src/state.rs b/crates/ui-egui/src/state.rs
index 3b9901f3..d7a7edcd 100644
--- a/crates/ui-egui/src/state.rs
+++ b/crates/ui-egui/src/state.rs
@@ -667,9 +667,6 @@ pub struct UiState {
     /// Lumetri Scopes panel options.
     #[serde(default)]
     pub scopes: crate::panels::scopes_panel::ScopesState,
-    /// Ease Presets panel: working curve, selected preset, name field.
-    #[serde(default)]
-    pub ease_presets: crate::panels::ease_presets::EasePanelState,
 }
 
 impl Default for UiState {
@@ -724,7 +721,6 @@ impl Default for UiState {
             mini_flowchart: None,
             flowchart: Default::default(),
             scopes: Default::default(),
-            ease_presets: Default::default(),
         }
     }
 }
diff --git a/crates/ui-egui/tests/ui_keyframes.rs b/crates/ui-egui/tests/ui_keyframes.rs
index 82805f60..50ccf1ef 100644
--- a/crates/ui-egui/tests/ui_keyframes.rs
+++ b/crates/ui-egui/tests/ui_keyframes.rs
@@ -1,7 +1,6 @@
 //! Headless checks for Timeline keyframes as a person uses them: dragging keys over many frames
 //! in one gesture (the drag used to end after the first frame), Shift-snapping, Ctrl+C /
-//! Ctrl+V, which the windowing layer delivers as clipboard events rather than key presses, and
-//! easing selected keys from the Ease Presets panel.
+//! Ctrl+V, which the windowing layer delivers as clipboard events rather than key presses.
 
 use effectcraft_engine::Session;
 use effectcraft_engine::project::LayerId;
@@ -255,45 +254,6 @@ fn k_follows_the_revealed_properties_and_auto_select_picks_the_speed_graph_for_p
     assert!(h.state().auto.find(&format!("timeline.graph.key.{pos}.1.0")).is_some(), "value graph: X and Y");
 }
 
-fn center(h: &Harness<'_, EffectcraftApp>, id: &str) -> Pos2 {
-    let e = h.state().auto.find(id).unwrap_or_else(|| panic!("no {id}"));
-    pos2(e.rect[0] + e.rect[2] / 2.0, e.rect[1] + e.rect[3] / 2.0)
-}
-
-#[test]
-fn clicking_an_ease_preset_eases_the_selected_keys_and_handles_edit_the_curve() {
-    use effectcraft_engine::keyframe::{Ease, Interp};
-    use effectcraft_ui_egui::dock::PanelKind;
-    let (mut h, id, _) = harness();
-    h.state_mut().session.execute("prop.select", json!({"layer": id.0, "path": "transform/opacity"})).unwrap();
-    h.state_mut().show_panel(PanelKind::EasePresets);
-    h.state_mut().ui.maximized = Some(PanelKind::EasePresets);
-    h.run_steps(4);
-    let opacity =
-        |h: &Harness<'_, EffectcraftApp>| h.state().session.active_comp().unwrap().layer(id).unwrap().props.prop("transform/opacity").unwrap().clone();
-    let tile = h.state().auto.query("easePresets.preset.").into_iter().find(|e| e.label == "Ease In-Out").expect("the Ease In-Out thumbnail").id.clone();
-    let steps = h.state().session.history.undo.len();
-    let at = center(&h, &tile);
-    click_with(&mut h, at, Default::default());
-    let op = opacity(&h);
-    let eased = Ease { speed: 0.0, influence: 0.5 };
-    assert_eq!((op.keys[0].out_interp, op.keys[0].out_ease.clone()), (Interp::Bezier, vec![eased]));
-    assert_eq!((op.keys[1].in_interp, op.keys[1].in_ease.clone()), (Interp::Bezier, vec![eased]));
-    assert_eq!(h.state().session.history.undo.len(), steps + 1);
-    assert_eq!(h.state().ui.ease_presets.selected.as_deref(), Some("Ease In-Out"));
-    // Dragging the out handle to the right lengthens its influence; Apply uses the edited curve.
-    let graph = h.state().auto.find("easePresets.graph").unwrap().rect;
-    let from = center(&h, "easePresets.handle.out");
-    drag(&mut h, from, from + egui::vec2(graph[2] * 0.2, 0.0), Default::default());
-    let out = h.state().ui.ease_presets.curve.out_influence;
-    assert!(out > 60.0 && out < 75.0, "{out}");
-    let apply = center(&h, "easePresets.apply");
-    click_with(&mut h, apply, Default::default());
-    let applied = opacity(&h).keys[0].out_ease[0].influence;
-    assert!((applied * 100.0 - out).abs() < 1e-9, "{applied} vs {out}");
-    assert_eq!(h.state().session.history.undo.len(), steps + 2);
-}
-
 /// #284: in the Graph Editor, dragging the handle of one selected key moves the same handle of
 /// every selected key with it (After Effects), in one undo step.
 #[test]
diff --git a/crates/ui-egui/tests/ui_scriptui.rs b/crates/ui-egui/tests/ui_scriptui.rs
index c48ed36c..5a01d18f 100644
--- a/crates/ui-egui/tests/ui_scriptui.rs
+++ b/crates/ui-egui/tests/ui_scriptui.rs
@@ -112,6 +112,42 @@ fn panels_open_at_quit_dock_again_at_launch() {
     assert_eq!(store.read(effectcraft_engine::commands::scripts::OPEN_PANELS_FILE).as_deref(), Some(r#"{"open":[]}"#));
 }
 
+/// The bundled Ease Presets ScriptUI panel (Window ▸ Ease Presets.jsx) docks, and clicking a
+/// preset in its list eases the selected keyframes in one undo step.
+#[test]
+fn ease_presets_panel_eases_the_selected_keys_from_its_list() {
+    use effectcraft_engine::keyframe::{Ease, Interp};
+    use egui_kittest::kittest::Queryable;
+    let mut h = harness();
+    let s = &mut h.state_mut().session;
+    let l = s.execute("layer.newSolid", json!({"name": "Box", "color": "#e04020", "width": 80, "height": 80})).unwrap()["layer"].as_u64().unwrap();
+    for (t, v) in [(0.0, 0.0), (1.0, 100.0)] {
+        s.execute("prop.addKey", json!({"layer": l, "path": "transform/opacity", "time": t, "value": v})).unwrap();
+    }
+    s.execute("prop.select", json!({"layer": l, "path": "transform/opacity"})).unwrap();
+    let cx = effectcraft_engine::menus::DynCtx::default();
+    let (panels, _) = effectcraft_engine::menus::dynamic(s, "scriptPanels", &cx);
+    assert!(panels.iter().any(|e| e.label == "Ease Presets.jsx"), "listed in the Window menu");
+    s.execute("window.scriptPanel", json!({"name": "Ease Presets.jsx"})).unwrap();
+    h.run_steps(3);
+    let panel = h.state().session.script_ui.windows.iter().find(|w| w.script == "Ease Presets.jsx").unwrap().id;
+    assert!(h.state().ui.dock.contains(PanelKind::ScriptPanel(panel)), "the panel docks");
+    h.state_mut().ui.maximized = Some(PanelKind::ScriptPanel(panel));
+    h.run_steps(3);
+    let steps = h.state().session.history.undo.len();
+    let item = h.query_by_label("Ease In-Out").expect("the Ease In-Out preset").rect().center();
+    h.input_mut().events.push(Event::PointerMoved(item));
+    for pressed in [true, false] {
+        h.input_mut().events.push(Event::PointerButton { pos: item, button: egui::PointerButton::Primary, pressed, modifiers: Default::default() });
+    }
+    h.run_steps(3);
+    let op = h.state().session.active_comp().unwrap().layer(effectcraft_engine::project::LayerId(l)).unwrap().props.prop("transform/opacity").unwrap().clone();
+    let eased = Ease { speed: 0.0, influence: 0.5 };
+    assert_eq!((op.keys[0].out_interp, op.keys[0].out_ease[0]), (Interp::Bezier, eased));
+    assert_eq!((op.keys[1].in_interp, op.keys[1].in_ease[0]), (Interp::Bezier, eased));
+    assert_eq!(h.state().session.history.undo.len(), steps + 1);
+}
+
 #[test]
 fn history_panel_jumps_between_branches() {
     let mut h = harness();
diff --git a/docs/agents.md b/docs/agents.md
index fd31d50a..207406f5 100644
--- a/docs/agents.md
+++ b/docs/agents.md
@@ -460,7 +460,10 @@ Scripts that build ScriptUI windows publish them to the session; agents drive th
 A dialog's `show()` waits for the user: the `script.run` / `file.runScript` reply carries
 `"waiting": true`, and the script continues (its final output arrives in the reply of the click
 that closes the dialog). File ▸ Scripts: `file.scripts.list`, `file.runScript {"name": …}`,
-`file.installScript` / `file.installScriptUIPanel {"path": …}`, `window.scriptPanel {"name": …}`.
+`file.installScript` / `file.installScriptUIPanel {"path": …}`, `window.scriptPanel {"name": …}`,
+`window.restoreScriptPanels` (the panels open when the app last quit). Scripts' `app.settings`:
+`script.settings.get {"section": …, "key": …}` and `script.settings.save {…, "value": …}`.
+Extension points and the bundled extensions: [plugins.md](plugins.md).
 
 ### Timeline: layer order, properties and shortcuts
 
diff --git a/docs/gaps.md b/docs/gaps.md
index 4673245d..51928fc0 100644
--- a/docs/gaps.md
+++ b/docs/gaps.md
@@ -200,9 +200,12 @@ The most important missing piece: it turns every other estimate here into a meas
   panels in the user's ScriptUI Panels folder are listed in the Window menu, dock like any panel
   and open again at the next launch. Missing: the Startup and Shutdown script folders, keyboard
   shortcuts for scripts, ExtendScript's `#include` / `#target` directives and `.jsxbin`.
-- Done so far: ease presets (Window ▸ Ease Presets, `keys.easePreset.*`, #254) cover what
-  ease-curve plug-ins are used for: easing curves kept by name, drawn and edited in a value graph,
-  and applied to pairs of keyframes ([parity.md](parity.md#update-ease-presets-254)).
+- Done so far: ease presets (#254) cover what ease-curve plug-ins are used for: easing curves kept
+  by name and applied to pairs of keyframes. Modelled on a third-party panel, they are not core: a
+  ScriptUI panel bundled as an optional extension (`extensions/scriptui-panels/Ease Presets.jsx`,
+  Window ▸ Ease Presets.jsx) on the public scripting API, which needed `app.settings` that last,
+  per-key methods that keep the key selection, and eases reported as they play
+  ([plugins.md](plugins.md#bundled-extensions), [parity.md](parity.md)).
 
 ### G9. Reach
 
diff --git a/docs/parity.md b/docs/parity.md
index 0c47dc35..af8eaca4 100644
--- a/docs/parity.md
+++ b/docs/parity.md
@@ -400,27 +400,40 @@ Browser in the web app (landed in M13.10: browser storage and File System Access
   wrong signatures and versions, fuel exhaustion, traps and bit-identical output; script
   `Socket` validates ports, and ScriptUI resource strings accept trailing array commas.
 
-## Update: ease presets (#254)
+## Update: plug-ins and extensions as in After Effects; ease presets become a ScriptUI panel
 
-**Window ▸ Ease Presets** is our own panel for what ease-curve plug-ins are used for in After
-Effects (G8): keep easing curves by name and apply them to pairs of keyframes. A curve is the out
-handle of the first key and the in handle of the second, in the Keyframe Velocity dialog's terms:
-influence in percent, and speed relative to the segment's average speed, so one curve fits any
-duration and change of value. Applying it eases every pair of neighbouring selected keyframes of
-each property in one undo step, per dimension, and along the motion path for spatial properties
-(as Easy Ease does); an Auto Bezier key keeps its other side. Twelve built-in curves (Linear,
-Smooth, Ease In-Out Soft / plain / Strong, Accelerate and Decelerate with Strong variants, Expo
-In-Out / Accelerate / Decelerate) are our own numbers; user presets are kept in the settings store
-(`ease_presets.json`; a corrupt file or entry is skipped, never fatal). The panel draws each preset
-as a thumbnail (a click applies it) and the working curve in a value graph whose two handles drag;
-Apply, From Keys (the curve between the first selected pair), Save Current, Rename and Delete.
-Commands: `keys.easePreset.apply {preset | curve}` (`curve` as `{outInfluence, outSpeed,
-inInfluence, inSpeed}` or cubic-bezier handles `[x1, y1, x2, y2]`), `keys.easePreset.capture`,
-`keys.easePreset.save {name, curve?}`, `keys.easePreset.list`, `keys.easePreset.rename {name,
-newName}`, `keys.easePreset.delete {name}`; automation ids `easePresets.*`.
+EffectCraft's core keeps After Effects parity; what After Effects users get from third parties is
+an extension, on the same extension points After Effects has ([plugins.md](plugins.md) compares
+them: scripts, ScriptUI panels, effect plug-ins, with a guide to writing a panel).
 
-Not yet: curves with more than one bend (bounce and elastic shapes, which need keyframes in
-between), preset import / export files, and a live preview on the keys while dragging the handles.
+- **ScriptUI panels** in `Scripts/ScriptUI Panels/` of the settings folder are listed at the
+  bottom of the Window menu and dock like any panel (as before); the panels open when the app quits
+  now open again at the next launch (`window.restoreScriptPanels`), as After Effects reopens its
+  workspace's panels.
+- **Scripting API** (parity fixes the Ease Presets panel needed): `app.settings` lasts between
+  runs (`script_settings.json`, `script.settings.get` / `save`); per-key methods
+  (`setTemporalEaseAtKey`, `setInterpolationTypeAtKey`, `removeKey`, the continuous / auto-Bezier /
+  roving setters) no longer change the user's key selection; `keyInTemporalEase` /
+  `keyOutTemporalEase` report linear and auto-Bezier sides as they play, and
+  `keyIn/OutSpatialTangent` the tangents the motion path plays; `selectedProperties` includes the
+  properties of selected keyframes; `isInterpolationTypeValid` is false for Linear and Bezier on
+  values that only hold.
+- **Ease presets** (#254), modelled on a third-party panel, moved out of the core: they are the
+  bundled ScriptUI panel `extensions/scriptui-panels/Ease Presets.jsx` (Window ▸ Ease
+  Presets.jsx), written only against the public scripting API. A curve is the out side of the
+  first key and the in side of the second, in the Keyframe Velocity dialog's terms (influence in
+  percent, speed relative to the segment's average speed); clicking a preset eases every pair of
+  neighbouring selected keyframes in one undo step, per dimension and along the motion path for
+  spatial properties, leaving the keys' other sides as they play. The twelve built-in curves are
+  unchanged; user presets (Save, Rename, Delete) are kept with `app.settings`, and those saved by
+  the core panel of v0.6.0 (`ease_presets.json`) move there the first time settings load. The
+  panel shows the working curve as a drawing and its four numbers as fields (the value graph's
+  handles don't drag: ScriptUI panels get no mouse-drag events here). The `keys.easePreset.*`
+  commands and `EaseCurve` are gone. Not yet: curves with more than one bend (bounce and elastic
+  shapes), preset import / export files.
+- **Snapping options** (#265): the Tools bar's menu has After Effects' two options, Snap Edges
+  Extended and Snap to Features in Collapsed Compositions and Text Layers (the layers inside
+  collapsed precomp layers snap); the per-feature toggles are gone and every feature snaps.
 
 ## Update: M5.9–M5.14 keyframes, M3.15 clipboard, M12.8 responsiveness
 
diff --git a/docs/plugins.md b/docs/plugins.md
index 2e542302..d24c078b 100644
--- a/docs/plugins.md
+++ b/docs/plugins.md
@@ -19,7 +19,7 @@ Guide):
 | `Scripts/ScriptUI Panels`: listed at the bottom of the Window menu, dockable like the app's own panels, `this` is the panel | `Scripts/ScriptUI Panels/` in the settings folder (File ▸ Scripts ▸ Install ScriptUI Panel… copies one there), listed at the bottom of the Window menu, docked like any panel, `this` is the panel; the panels open when the app quits open again at the next launch | Same. Where a panel was docked isn't kept: workspace layouts aren't saved between launches |
 | Keyboard shortcuts for scripts (the Keyboard Shortcuts editor lists the scripts of the Scripts folder) | Shortcuts bind to commands and menu entries; the File ▸ Scripts and Window menu entries of scripts aren't offered | Gap |
 | Running a script from the command line (`afterfx -r script.jsx`) | `effectcraft-cli script`, the control channel's and MCP's `script.run` | Same purpose, other entry points |
-| `app.settings` (kept in the preferences between sessions) | Kept for the run only | Gap |
+| `app.settings` (kept in the preferences between sessions) | Kept in `script_settings.json` in the settings folder (`script.settings.get` / `script.settings.save`) | Same |
 | Allow Scripts to Write Files and Access Network | Settings ▸ Scripting & Expressions | Same |
 
 The settings folder is `~/Library/Application Support/EffectCraft` on macOS, `%APPDATA%\EffectCraft`
@@ -84,10 +84,44 @@ Supported controls: `panel`, `group`, `button`, `iconbutton`, `statictext`, `edi
 `tabbedpanel` / `tab` and `image`, with ScriptUI's automatic layout (`orientation`,
 `alignChildren`, `alignment`, `margins`, `spacing`, `preferredSize`), resource strings, event
 handlers (`onClick`, `onChange`, `onChanging`, `onClose`, `addEventListener`) and `onDraw` with
-ScriptUIGraphics. Agents use a panel like a user: `scriptui.list`, `scriptui.get` (its controls),
-`scriptui.click`, `scriptui.set` and `scriptui.close`; every control has the automation id
+ScriptUIGraphics. Mouse events (`mousedown`, `mousemove`…) aren't sent to scripts yet. Agents use
+a panel like a user: `scriptui.list`, `scriptui.get` (its controls), `scriptui.click`,
+`scriptui.set` and `scriptui.close`; every control has the automation id
 `scriptui.<window>.<control id or name>`. The bundled sample `Layer Tools.jsx`
-(`crates/engine/scripts/ScriptUI Panels/`) is a longer example.
+(`crates/engine/scripts/ScriptUI Panels/`) and the Ease Presets extension below are longer
+examples.
+
+## Bundled extensions
+
+Optional tools that ship with EffectCraft but are not part of its core: they are scripts on the
+public scripting API, like the third-party scripts After Effects users install, and are listed
+with the bundled samples (`file.scripts.list` reports them as `extension`). A script of the same
+name in your Scripts folders takes their place.
+
+### Ease Presets (`extensions/scriptui-panels/Ease Presets.jsx`)
+
+Window ▸ Ease Presets.jsx: easing curves kept by name and applied to pairs of neighbouring
+selected keyframes (#254; it was a core panel in v0.6.0). A curve is the out side of a segment's
+first key and the in side of its second, in the Keyframe Velocity dialog's terms: influence in
+percent, and speed relative to the segment's average speed (1 = as fast as a straight line, 0 = at
+rest), so one curve fits any duration and change of value.
+
+* Click a preset to apply it to every pair of neighbouring selected keyframes of each selected
+  property, in one undo step (per dimension, and along the motion path for spatial properties;
+  the keys' other sides keep playing as they did). The keys stay selected, so you can try another.
+* The drawing shows the working curve; type its numbers (Out % and Speed, In % and Speed) and
+  click Apply, or click From Keys to read the curve between the first selected pair.
+* Save keeps the working curve under the typed name (replacing a preset of that name); Rename
+  and Delete act on the selected preset of your own. The twelve built-in presets can't change.
+* User presets are kept with `app.settings` (section `Ease Presets`, key `userPresets`, in
+  `script_settings.json` in the settings folder). Presets saved by the v0.6.0 core panel
+  (`ease_presets.json`) move there the first time a later version loads its settings; the old
+  file is left as it was.
+
+It uses only After Effects' documented scripting API (`comp.selectedProperties`,
+`Property.selectedKeys`, `keyInTemporalEase` / `keyOutTemporalEase`, `setTemporalEaseAtKey` with
+`KeyframeEase`, `setInterpolationTypeAtKey`, `app.settings`, ScriptUI), so it is also a worked
+example of a keyframe tool.
 
 ## Effect plug-ins
 
diff --git a/extensions/scriptui-panels/Ease Presets.jsx b/extensions/scriptui-panels/Ease Presets.jsx
new file mode 100644
index 00000000..a08fdbcc
--- /dev/null
+++ b/extensions/scriptui-panels/Ease Presets.jsx	
@@ -0,0 +1,454 @@
+// Ease Presets: easing curves kept by name and applied to pairs of neighbouring selected keyframes.
+//
+// A ScriptUI panel that ships with EffectCraft as an optional extension (Window ▸ Ease
+// Presets.jsx). It uses only After Effects' documented scripting API: comp.selectedProperties,
+// Property.selectedKeys, keyInTemporalEase / keyOutTemporalEase, setTemporalEaseAtKey with
+// KeyframeEase, setInterpolationTypeAtKey, app.settings and ScriptUI. Original work by the
+// EffectCraft contributors, MIT OR Apache-2.0.
+//
+// A curve is the out side of a segment's first key and the in side of its second, in the
+// Keyframe Velocity dialog's terms: influence in percent of the segment, and speed relative to the
+// segment's average speed (1 = as fast as a straight line, 0 = at rest). Applied to a segment, the
+// speeds are scaled to it: per dimension, along the motion path for spatial properties, or as
+// overall progress for shapes.
+//
+// User presets are kept with app.settings (section "Ease Presets", key "userPresets") as JSON:
+// {"version": 1, "presets": [{"name": …, "curve": {"outInfluence", "outSpeed", "inInfluence",
+// "inSpeed"}}]}.
+
+(function easePresets(thisObj) {
+  var SECTION = "Ease Presets";
+  var KEY = "userPresets";
+  var MAX_NAME = 64;
+  var MIN_INFLUENCE = 0.1;
+  var MAX_SPEED = 100;
+  var BEZIER = KeyframeInterpolationType.BEZIER;
+  var HOLD = KeyframeInterpolationType.HOLD;
+
+  function curve(outInfluence, outSpeed, inInfluence, inSpeed) {
+    return { outInfluence: outInfluence, outSpeed: outSpeed, inInfluence: inInfluence, inSpeed: inSpeed };
+  }
+
+  // Our own presets. "Accelerate" starts slowly, "Decelerate" settles slowly.
+  var BUILT_IN = [
+    { name: "Linear", curve: curve(100 / 3, 1, 100 / 3, 1) },
+    { name: "Smooth", curve: curve(40, 0.25, 40, 0.25) },
+    { name: "Ease In-Out Soft", curve: curve(25, 0, 25, 0) },
+    { name: "Ease In-Out", curve: curve(50, 0, 50, 0) },
+    { name: "Ease In-Out Strong", curve: curve(75, 0, 75, 0) },
+    { name: "Accelerate", curve: curve(50, 0, 20, 1.5) },
+    { name: "Accelerate Strong", curve: curve(80, 0, 15, 2.5) },
+    { name: "Decelerate", curve: curve(20, 1.5, 50, 0) },
+    { name: "Decelerate Strong", curve: curve(15, 2.5, 80, 0) },
+    { name: "Expo In-Out", curve: curve(88, 0, 88, 0) },
+    { name: "Expo Accelerate", curve: curve(75, 0, 12, 7) },
+    { name: "Expo Decelerate", curve: curve(12, 7, 75, 0) }
+  ];
+
+  // ------------------------------------------------------------------ presets
+
+  function finite(v) {
+    return typeof v === "number" && isFinite(v);
+  }
+
+  // The curve with influences in 0.1–100 % and speeds within ±100; null when a number is missing.
+  function sanitized(c) {
+    if (!c || !finite(c.outInfluence) || !finite(c.outSpeed) || !finite(c.inInfluence) || !finite(c.inSpeed)) return null;
+    var inf = function (v) { return Math.min(100, Math.max(MIN_INFLUENCE, v)); };
+    var speed = function (v) { return Math.min(MAX_SPEED, Math.max(-MAX_SPEED, v)); };
+    return curve(inf(c.outInfluence), speed(c.outSpeed), inf(c.inInfluence), speed(c.inSpeed));
+  }
+
+  function cleanName(name) {
+    var n = String(name === undefined || name === null ? "" : name).replace(/^\s+|\s+$/g, "");
+    return n.length > 0 && n.length <= MAX_NAME ? n : null;
+  }
+
+  function same(a, b) {
+    return a.toLowerCase() === b.toLowerCase();
+  }
+
+  function find(list, name) {
+    for (var i = 0; i < list.length; i++) if (same(list[i].name, name)) return i;
+    return -1;
+  }
+
+  // User presets; entries that don't parse, have no usable name or repeat a name are skipped.
+  function loadUser() {
+    var out = [];
+    if (!app.settings.haveSetting(SECTION, KEY)) return out;
+    var doc;
+    try {
+      doc = JSON.parse(app.settings.getSetting(SECTION, KEY));
+    } catch (e) {
+      return out;
+    }
+    var list = doc && doc.presets instanceof Array ? doc.presets : [];
+    for (var i = 0; i < list.length; i++) {
+      var name = cleanName(list[i] && list[i].name);
+      var c = sanitized(list[i] && list[i].curve);
+      if (name && c && find(BUILT_IN, name) < 0 && find(out, name) < 0) out.push({ name: name, curve: c });
+    }
+    return out;
+  }
+
+  function saveUser(list) {
+    app.settings.saveSetting(SECTION, KEY, JSON.stringify({ version: 1, presets: list }));
+  }
+
+  // ------------------------------------------------------------------ keyframes
+
+  // Pairs of neighbouring selected keyframes of the active comp: {prop, key} (the earlier key's
+  // index), by property.
+  function selectedPairs() {
+    var comp = app.project.activeItem;
+    var out = [];
+    if (!(comp instanceof CompItem)) return out;
+    var props = comp.selectedProperties;
+    for (var i = 0; i < props.length; i++) {
+      var p = props[i];
+      if (p.propertyType !== PropertyType.PROPERTY || p.numKeys < 2 || !p.isInterpolationTypeValid(BEZIER)) continue;
+      var keys = p.selectedKeys;
+      for (var k = 0; k + 1 < keys.length; k++) if (keys[k + 1] === keys[k] + 1) out.push({ prop: p, key: keys[k] });
+    }
+    return out;
+  }
+
+  // Length of the motion path from `a` to `b` with the tangents of their keys.
+  function pathLength(a, outTangent, inTangent, b) {
+    var p = [], n = Math.max(a.length, b.length), len = 0, prev = null;
+    for (var d = 0; d < n; d++) p.push([a[d] || 0, (a[d] || 0) + (outTangent[d] || 0), (b[d] || 0) + (inTangent[d] || 0), b[d] || 0]);
+    for (var s = 0; s <= 128; s++) {
+      var t = s / 128, u = 1 - t, pt = [];
+      for (var e = 0; e < n; e++) pt.push(u * u * u * p[e][0] + 3 * u * u * t * p[e][1] + 3 * u * t * t * p[e][2] + t * t * t * p[e][3]);
+      if (prev) {
+        var sq = 0;
+        for (var f = 0; f < n; f++) sq += (pt[f] - prev[f]) * (pt[f] - prev[f]);
+        len += Math.sqrt(sq);
+      }
+      prev = pt;
+    }
+    return len;
+  }
+
+  // The layer a property belongs to.
+  function layerOf(p) {
+    return p.propertyGroup(p.propertyDepth);
+  }
+
+  // Average speed of segment `a` → `a + 1` for each entry of its eases, in the units the eases use
+  // (keyframe times move with the layer, so the duration is in the layer's time). Null when the
+  // segment has no duration.
+  function slopes(p, a) {
+    var stretch = layerOf(p).stretch || 100;
+    var dur = (p.keyTime(a + 1) - p.keyTime(a)) * 100 / stretch;
+    if (!(dur > 0) || !isFinite(dur)) return null;
+    var n = Math.max(1, p.keyOutTemporalEase(a).length);
+    var v0 = p.keyValue(a), v1 = p.keyValue(a + 1), out = [];
+    var vt = p.propertyValueType;
+    if (vt === PropertyValueType.TwoD_SPATIAL || vt === PropertyValueType.ThreeD_SPATIAL) {
+      var speed = pathLength(v0, p.keyOutSpatialTangent(a), p.keyInSpatialTangent(a + 1), v1) / dur;
+      for (var i = 0; i < n; i++) out.push(speed);
+    } else if (typeof v0 === "number" && typeof v1 === "number") {
+      out.push((v1 - v0) / dur);
+    } else if (v0 instanceof Array && v1 instanceof Array && v0.length === v1.length) {
+      for (var d = 0; d < n; d++) out.push(((v1[d] || 0) - (v0[d] || 0)) / dur);
+    } else {
+      // Shapes and other values ease their overall progress.
+      for (var j = 0; j < n; j++) out.push(1 / dur);
+    }
+    return out;
+  }
+
+  // Ease one side of key `k` with `eases`, leaving its other side as it plays (auto-Bezier and
+  // linear sides keep their shape; a continuous key stops being continuous, its sides now differ).
+  function easeSide(p, k, out, eases) {
+    var inType = p.keyInInterpolationType(k), outType = p.keyOutInterpolationType(k);
+    var inEase = p.keyInTemporalEase(k), outEase = p.keyOutTemporalEase(k);
+    if (p.keyTemporalContinuous(k)) p.setTemporalContinuousAtKey(k, false);
+    if (out) {
+      p.setTemporalEaseAtKey(k, inEase, eases);
+      p.setInterpolationTypeAtKey(k, inType, BEZIER);
+    } else {
+      p.setTemporalEaseAtKey(k, eases, outEase);
+      p.setInterpolationTypeAtKey(k, BEZIER, outType);
+    }
+  }
+
+  // Ease every pair of neighbouring selected keyframes with `c` (one undo step). Returns the
+  // number of pairs eased.
+  function applyCurve(c) {
+    var pairs = selectedPairs(), n = 0;
+    if (!pairs.length) return 0;
+    app.beginUndoGroup("Apply Ease Preset");
+    try {
+      for (var i = 0; i < pairs.length; i++) {
+        var p = pairs[i].prop, a = pairs[i].key, s = slopes(p, a);
+        if (!s) continue;
+        var outE = [], inE = [];
+        for (var d = 0; d < s.length; d++) {
+          outE.push(new KeyframeEase(c.outSpeed * s[d], c.outInfluence));
+          inE.push(new KeyframeEase(c.inSpeed * s[d], c.inInfluence));
+        }
+        easeSide(p, a, true, outE);
+        easeSide(p, a + 1, false, inE);
+        n++;
+      }
+    } finally {
+      app.endUndoGroup();
+    }
+    return n;
+  }
+
+  // The curve between the first selected pair of keyframes (measured on the dimension that
+  // changes most); null for holds and segments whose value doesn't change.
+  function captureCurve() {
+    var pairs = selectedPairs();
+    if (!pairs.length) return null;
+    var p = pairs[0].prop, a = pairs[0].key;
+    if (p.keyOutInterpolationType(a) === HOLD) return null;
+    var s = slopes(p, a);
+    if (!s) return null;
+    var d = 0;
+    for (var i = 1; i < s.length; i++) if (Math.abs(s[i]) > Math.abs(s[d])) d = i;
+    if (Math.abs(s[d]) < 1e-12) return null;
+    var o = p.keyOutTemporalEase(a), n = p.keyInTemporalEase(a + 1);
+    var oe = o[d] || o[0], ne = n[d] || n[0];
+    if (!oe || !ne) return null;
+    return sanitized(curve(oe.influence, oe.speed / s[d], ne.influence, ne.speed / s[d]));
+  }
+
+  // ------------------------------------------------------------------ panel
+
+  var ui = thisObj instanceof Panel ? thisObj : new Window("palette", "Ease Presets", undefined, { resizeable: true });
+  ui.orientation = "column";
+  ui.alignChildren = ["fill", "top"];
+  ui.spacing = 6;
+
+  var user = loadUser();
+  var working = BUILT_IN[0].curve;
+  var refreshing = false;
+
+  var list = ui.add("listbox", undefined, [], { name: "presets" });
+  list.preferredSize = [220, 150];
+  list.helpTip = "Click a preset to apply it to the selected keyframes";
+
+  // The working curve in the normalised value graph: keys at (0, 0) and (1, 1).
+  var graph = ui.add("group");
+  graph.preferredSize = [220, 110];
+  graph.onDraw = function () {
+    var g = this.graphics, w = this.size.width, h = this.size.height;
+    var lo = -0.35, hi = 1.35, m = 10;
+    var at = function (x, v) { return [m + (w - 2 * m) * x, h - m - (h - 2 * m) * (v - lo) / (hi - lo)]; };
+    var frame = g.newPen(g.PenType.SOLID_COLOR, [0.5, 0.5, 0.5, 0.6], 1);
+    g.newPath();
+    g.rectPath(0, 0, w, h);
+    g.strokePath(frame);
+    g.newPath();
+    var a = at(0, 0), b = at(1, 0), c0 = at(0, 1), d = at(1, 1);
+    g.moveTo(a[0], a[1]);
+    g.lineTo(b[0], b[1]);
+    g.moveTo(c0[0], c0[1]);
+    g.lineTo(d[0], d[1]);
+    g.strokePath(frame);
+    // Handles: (out influence, out speed × out influence) and (1 − in influence, 1 − in speed × in influence).
+    var oi = working.outInfluence / 100, ii = working.inInfluence / 100;
+    var h1 = [oi, working.outSpeed * oi], h2 = [1 - ii, 1 - working.inSpeed * ii];
+    var handles = g.newPen(g.PenType.SOLID_COLOR, [0.8, 0.8, 0.8, 1], 1);
+    var p1 = at(h1[0], h1[1]), p2 = at(h2[0], h2[1]), k0 = at(0, 0), k1 = at(1, 1);
+    g.newPath();
+    g.moveTo(k0[0], k0[1]);
+    g.lineTo(p1[0], p1[1]);
+    g.moveTo(k1[0], k1[1]);
+    g.lineTo(p2[0], p2[1]);
+    g.strokePath(handles);
+    var accent = g.newPen(g.PenType.SOLID_COLOR, [0.29, 0.56, 1, 1], 2);
+    g.newPath();
+    for (var s = 0; s <= 48; s++) {
+      var t = s / 48, u = 1 - t;
+      var x = 3 * u * u * t * h1[0] + 3 * u * t * t * h2[0] + t * t * t;
+      var v = 3 * u * u * t * h1[1] + 3 * u * t * t * h2[1] + t * t * t;
+      var q = at(x, v);
+      if (s === 0) g.moveTo(q[0], q[1]);
+      else g.lineTo(q[0], q[1]);
+    }
+    g.strokePath(accent);
+  };
+
+  function field(row, label, name) {
+    row.add("statictext", undefined, label);
+    var f = row.add("edittext", undefined, "", { name: name });
+    f.characters = 5;
+    return f;
+  }
+  var outRow = ui.add("group");
+  var outInfluence = field(outRow, "Out %", "outInfluence");
+  var outSpeed = field(outRow, "Speed", "outSpeed");
+  var inRow = ui.add("group");
+  var inInfluence = field(inRow, "In %", "inInfluence");
+  var inSpeed = field(inRow, "Speed", "inSpeed");
+
+  var actions = ui.add("group");
+  var applyButton = actions.add("button", undefined, "Apply", { name: "apply" });
+  var fromKeys = actions.add("button", undefined, "From Keys", { name: "fromKeys" });
+  var nameRow = ui.add("group");
+  nameRow.alignChildren = ["fill", "center"];
+  var nameField = nameRow.add("edittext", undefined, "", { name: "name" });
+  nameField.characters = 14;
+  nameField.helpTip = "Preset name";
+  var saveButton = nameRow.add("button", undefined, "Save", { name: "save" });
+  var edits = ui.add("group");
+  var renameButton = edits.add("button", undefined, "Rename", { name: "rename" });
+  var deleteButton = edits.add("button", undefined, "Delete", { name: "delete" });
+  var status = ui.add("statictext", undefined, "", { name: "status" });
+  status.alignment = ["fill", "top"];
+
+  function round(v, places) {
+    var f = Math.pow(10, places);
+    return String(Math.round(v * f) / f);
+  }
+
+  function showCurve(c) {
+    working = c;
+    outInfluence.text = round(c.outInfluence, 1);
+    outSpeed.text = round(c.outSpeed, 2);
+    inInfluence.text = round(c.inInfluence, 1);
+    inSpeed.text = round(c.inSpeed, 2);
+  }
+
+  // The curve typed into the fields (null when one isn't a number).
+  function typedCurve() {
+    return sanitized(curve(parseFloat(outInfluence.text), parseFloat(outSpeed.text), parseFloat(inInfluence.text), parseFloat(inSpeed.text)));
+  }
+
+  function presets() {
+    return BUILT_IN.concat(user);
+  }
+
+  // The user preset selected in the list (null for built-in ones and no selection).
+  function selectedUser() {
+    var item = list.selection;
+    if (!item) return null;
+    var i = find(user, item.text);
+    return i < 0 ? null : user[i];
+  }
+
+  function refresh(select) {
+    refreshing = true;
+    list.removeAll();
+    var all = presets();
+    for (var i = 0; i < all.length; i++) list.add("item", all[i].name);
+    if (select) {
+      var j = find(all, select);
+      if (j >= 0) list.selection = j;
+    }
+    refreshing = false;
+  }
+
+  function apply(c, what) {
+    var n = applyCurve(c);
+    status.text = n > 0 ? "Eased " + n + " keyframe pair(s) with " + what : "Select two or more neighbouring keyframes of a property";
+    return n;
+  }
+
+  list.onChange = function () {
+    if (refreshing || !list.selection) return;
+    var all = presets(), i = find(all, list.selection.text);
+    if (i < 0) return;
+    showCurve(all[i].curve);
+    nameField.text = find(user, all[i].name) >= 0 ? all[i].name : "";
+    apply(all[i].curve, "“" + all[i].name + "”");
+  };
+
+  var onTyped = function () {
+    var c = typedCurve();
+    if (c) working = c;
+  };
+  outInfluence.onChange = outSpeed.onChange = inInfluence.onChange = inSpeed.onChange = onTyped;
+
+  applyButton.onClick = function () {
+    var c = typedCurve();
+    if (!c) {
+      status.text = "Type numbers for the influences and speeds";
+      return;
+    }
+    showCurve(c);
+    apply(c, "the curve");
+  };
+
+  fromKeys.onClick = function () {
+    var c = captureCurve();
+    if (!c) {
+      status.text = "Select two neighbouring keyframes whose value changes";
+      return;
+    }
+    showCurve(c);
+    status.text = "Read the curve of the selected keyframes";
+  };
+
+  saveButton.onClick = function () {
+    var name = cleanName(nameField.text), c = typedCurve();
+    if (!name) {
+      status.text = "Type a name for the preset first";
+      return;
+    }
+    if (find(BUILT_IN, name) >= 0) {
+      status.text = "“" + name + "” is a built-in preset; choose another name";
+      return;
+    }
+    if (!c) {
+      status.text = "Type numbers for the influences and speeds";
+      return;
+    }
+    // Saving under an existing name replaces that preset.
+    var i = find(user, name);
+    if (i >= 0) user[i] = { name: name, curve: c };
+    else user.push({ name: name, curve: c });
+    saveUser(user);
+    refresh(name);
+    status.text = "Saved the ease preset “" + name + "”";
+  };
+
+  renameButton.onClick = function () {
+    var p = selectedUser(), name = cleanName(nameField.text);
+    if (!p) {
+      status.text = "Select one of your own presets first";
+      return;
+    }
+    if (!name) {
+      status.text = "Type a new name for “" + p.name + "” first";
+      return;
+    }
+    var other = find(user, name);
+    if (find(BUILT_IN, name) >= 0 || (other >= 0 && user[other] !== p)) {
+      status.text = "An ease preset named “" + name + "” exists";
+      return;
+    }
+    p.name = name;
+    saveUser(user);
+    refresh(name);
+    status.text = "Renamed to “" + name + "”";
+  };
+
+  deleteButton.onClick = function () {
+    var p = selectedUser();
+    if (!p) {
+      status.text = "Select one of your own presets first";
+      return;
+    }
+    user.splice(find(user, p.name), 1);
+    saveUser(user);
+    refresh(null);
+    nameField.text = "";
+    status.text = "Deleted “" + p.name + "”";
+  };
+
+  refresh(null);
+  showCurve(working);
+  status.text = "Select keyframes, then click a preset";
+  if (ui instanceof Window) {
+    ui.show();
+  } else {
+    ui.layout.layout(true);
+  }
+})(this);
diff --git a/extensions/scriptui-panels/Ease Presets.jsx.attribution b/extensions/scriptui-panels/Ease Presets.jsx.attribution
new file mode 100644
index 00000000..18a95b7a
--- /dev/null
+++ b/extensions/scriptui-panels/Ease Presets.jsx.attribution	
@@ -0,0 +1,7 @@
+asset:        Ease Presets.jsx
+title:        EffectCraft bundled ScriptUI panel (Ease Presets) and its built-in ease presets
+author:       EffectCraft contributors
+source:       original work
+license:      MIT OR Apache-2.0
+added:        2026-10-09 by EffectCraft contributors
+notes:        Written from scratch for EffectCraft against After Effects' documented scripting behaviour (Scripting Guide); not derived from any Adobe sample or third-party panel. The twelve built-in curves are our own values, moved unchanged from the core Ease Presets panel (#254).