README: gesture and voice fields

A voice requirement records in the browser and ships PCM to the relay
as one binary frame (voice.js, same mount/stop contract as gesture);
its value becomes {key, digest, duration_ms}. Requirement.value
presets a field and, on a dynamic page, takes the URL segment - so
value: "{key}" tells the voice field where to record. A url resource
source takes the segment too. Resource items with an https `audio`
field render an <audio> player. The gesture widget reports picks to
the relay for ranking.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

Cargo.lock

@@ -2948,7 +2948,7 @@ dependencies = [
 
 [[package]]
 name = "portal"
-version = "0.3.8"
+version = "0.3.10"
 dependencies = [
  "anyhow",
  "arc-swap",

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "portal"
-version = "0.3.8"
+version = "0.3.10"
 edition = "2021"
 
 [lib]

README.md

@@ -39,6 +39,16 @@ stream.
   `requires_chain` gates a page on verifiable answer provenance next
   to `qualifies`' Kanidm-group identity gate (see
   `docs/design/filesystem-routes.md`).
+- **Gesture and voice fields** (`gesture.js`, `voice.js`): a stroke
+  becomes a redoal gesture key through a relay (ADR-0013/0015 in the
+  redoal repo) - the input shows the key's own decode under the
+  stroke, who is at a similar shape now, and *places* with recordings
+  the visitor can pick to make that key theirs; a voice field records
+  in the browser and leaves the audio at a key. Actions may be
+  templated from the answer (`/shape/{curve.key}`) onto dynamic
+  pages, whose URL segment also fills `value: "{key}"` presets and
+  `url` resource sources; resource items with an https `audio` field
+  render a player.
 - **Announced pages** (`src/announce.rs`): a question with an
   `event: {starts, duration, place}` window is announced in the
   header (not the footer nav) while the window is open, becomes a

gesture.js

@@ -49,6 +49,9 @@ class GestureWidget {
         this.hidden = hidden || null;
         this.relayUrl = relayUrl || '';
         this.ghost = null;
+        this.ownKey = null;
+        this.selected = null; // {key, path, distance} - a place the visitor picked
+        this.seenKeys = new Set();
         this.points = [];
         this.drawing = false;
         this.stopped = false;
@@ -62,7 +65,12 @@ class GestureWidget {
         container.appendChild(this.canvas);
         this.echoes = document.createElement('div');
         this.echoes.className = 'gesture-echoes';
+        this.echoes.setAttribute('role', 'listbox');
+        this.echoes.setAttribute('aria-label', 'places near your shape');
         container.appendChild(this.echoes);
+        this.empty = document.createElement('p');
+        this.empty.className = 'gesture-empty';
+        container.appendChild(this.empty);
         if (this.relayUrl) {
             this.status = document.createElement('span');
             this.status.className = 'gesture-status offline';
@@ -116,6 +124,11 @@ class GestureWidget {
         // (and any ghost from the previous round).
         this.drawing = true;
         this.ghost = null;
+        this.ownKey = null;
+        this.selected = null;
+        this.seenKeys.clear();
+        this.echoes.replaceChildren();
+        this.empty.textContent = '';
         this.points = [this.pos(e)];
         this.render();
     }
@@ -214,14 +227,20 @@ class GestureWidget {
             return;
         }
         if (msg.type === 'ack') {
-            if (this.points.length >= 2) {
-                this.setValue({ points: this.normalized(), key: msg.key });
-            }
+            this.ownKey = msg.key;
             // Version nibble is the key's first hex digit.
             const version = parseInt((msg.key || '0')[0], 16);
-            this.ghost = version >= 2 && Array.isArray(msg.path) ? msg.path : null;
-            this.render();
-        } else if (msg.type === 'echo') {
+            this.ownGhost = version >= 2 && Array.isArray(msg.path) ? msg.path : null;
+            this.applySelection();
+            // Places arrive right after the ack; say so if none do.
+            clearTimeout(this.emptyTimer);
+            this.emptyTimer = setTimeout(() => {
+                if (!this.echoes.children.length) this.empty.textContent = msg.empty || 'Nothing kept at this shape yet.';
+            }, 1500);
+        } else if (msg.type === 'echo' || msg.type === 'place') {
+            if (!msg.key || this.seenKeys.has(msg.key)) return;
+            this.seenKeys.add(msg.key);
+            this.empty.textContent = '';
             this.addEchoThumbnail(msg);
         }
         // 'error' frames are intentionally silent: the widget is a
@@ -229,9 +248,54 @@ class GestureWidget {
         // alarm anyone mid-form.
     }
 
+    // The key the input carries: the visitor's own, or the place they
+    // picked (selection re-derives the key - the ghost under the
+    // stroke becomes that place's decode, and the answer records both).
+    applySelection() {
+        if (this.points.length < 2) return;
+        const points = this.normalized();
+        if (this.selected) {
+            this.ghost = this.selected.path;
+            this.setValue({ points, key: this.selected.key, own_key: this.ownKey, selected_from: this.ownKey, selected_distance: this.selected.distance });
+        } else {
+            this.ghost = this.ownGhost || null;
+            this.setValue({ points, key: this.ownKey });
+        }
+        for (const el of this.echoes.children) {
+            el.classList.toggle('selected', !!this.selected && el.dataset.key === this.selected.key);
+            el.setAttribute('aria-selected', String(!!this.selected && el.dataset.key === this.selected.key));
+        }
+        this.render();
+    }
+
+    select(thumb) {
+        const key = thumb.dataset.key;
+        if (this.selected && this.selected.key === key) {
+            this.selected = null;
+        } else {
+            this.selected = { key, path: JSON.parse(thumb.dataset.path), distance: Number(thumb.dataset.distance) };
+            // The relay counts picks per place for ranking.
+            if (this.ws && this.ws.readyState === WebSocket.OPEN && this.ownKey) {
+                this.ws.send(JSON.stringify({ type: 'select', key, from: this.ownKey, distance: this.selected.distance }));
+            }
+        }
+        this.applySelection();
+    }
+
     addEchoThumbnail(msg) {
         const thumb = document.createElement('canvas');
-        thumb.className = 'gesture-echo';
+        thumb.className = 'gesture-echo' + (msg.type === 'place' ? ' place' : '');
+        thumb.dataset.key = msg.key;
+        thumb.dataset.path = JSON.stringify(msg.path || []);
+        thumb.dataset.distance = String(msg.distance || 0);
+        thumb.setAttribute('role', 'option');
+        thumb.setAttribute('tabindex', '0');
+        thumb.setAttribute('aria-selected', 'false');
+        thumb.title = msg.type === 'place'
+            ? `A place with ${msg.recordings || 0} recording${msg.recordings === 1 ? '' : 's'} - tap to make it your address`
+            : 'Someone at this shape right now';
+        thumb.addEventListener('click', () => this.select(thumb));
+        thumb.addEventListener('keydown', (e) => { if (e.key === 'Enter' || e.key === ' ') { e.preventDefault(); this.select(thumb); } });
         // Closer strokes render stronger; 500 is comfortably past the
         // relay's default threshold, so everything stays visible.
         const strength = Math.max(0.35, Math.min(1, 1 - msg.distance / 500));
@@ -296,6 +360,7 @@ class GestureWidget {
 
     stop() {
         this.stopped = true;
+        clearTimeout(this.emptyTimer);
         if (this.reconnectTimer) clearTimeout(this.reconnectTimer);
         if (this.ws) {
             // The close event still fires, but scheduleReconnect

src/app.rs

@@ -498,6 +498,28 @@ mod prosekit {
 // prosekit's hidden-input bridge for the value, yes.js's typed-handle
 // lifecycle for cleanup - it may own a live WebSocket to a
 // redoal-relay, which SPA navigation must close (`stop()`).
+#[cfg(feature = "hydrate")]
+#[cfg(feature = "hydrate")]
+mod voice {
+    use wasm_bindgen::prelude::*;
+
+    #[wasm_bindgen(module = "/voice.js")]
+    extern "C" {
+        pub type VoiceWidget;
+
+        #[wasm_bindgen(js_name = mountVoice)]
+        pub fn mount_voice(
+            container: &web_sys::HtmlDivElement,
+            hidden: &web_sys::HtmlInputElement,
+            relay_url: &str,
+            key: &str,
+        ) -> VoiceWidget;
+
+        #[wasm_bindgen(method)]
+        pub fn stop(this: &VoiceWidget);
+    }
+}
+
 #[cfg(feature = "hydrate")]
 mod gesture {
     use wasm_bindgen::prelude::*;
@@ -766,12 +788,16 @@ fn AlternativeCard(
                     .or_insert_with(|| RwSignal::new(Vec::new()));
                 select_multi.insert(req.name.clone(), req.multiple);
             } else {
-                if req.kind == "gesture" {
+                // Widget-owned fields hold JSON objects, not strings.
+                if req.kind == "gesture" || req.kind == "voice" {
                     gesture_fields.insert(req.name.clone());
                 }
+                // A voice field's preset is the key it records at,
+                // not a value to submit.
+                let preset = if req.kind == "voice" { String::new() } else { req.value.clone().unwrap_or_default() };
                 field_map
                     .entry(req.name.clone())
-                    .or_insert_with(|| RwSignal::new(String::new()));
+                    .or_insert_with(|| RwSignal::new(preset));
             }
         }
     }
@@ -1138,6 +1164,54 @@ fn AlternativeCard(
                                                     .into_any();
                                                 }
 
+                                                if req.kind == "voice" {
+                                                    let container_ref: NodeRef<leptos::html::Div> = NodeRef::new();
+                                                    let hidden_ref: NodeRef<leptos::html::Input> = NodeRef::new();
+
+                                                    #[cfg(feature = "hydrate")]
+                                                    {
+                                                        let relay = req.relay.clone().unwrap_or_default();
+                                                        let key = req.value.clone().unwrap_or_default();
+                                                        let widget: StoredValue<Option<voice::VoiceWidget>, LocalStorage> =
+                                                            StoredValue::new_local(None);
+                                                        Effect::new(move |_| {
+                                                            let (Some(container), Some(hidden)) =
+                                                                (container_ref.get(), hidden_ref.get())
+                                                            else {
+                                                                return;
+                                                            };
+                                                            if widget.with_value(|w| w.is_some()) {
+                                                                return;
+                                                            }
+                                                            widget.set_value(Some(voice::mount_voice(
+                                                                &container, &hidden, &relay, &key,
+                                                            )));
+                                                        });
+                                                        on_cleanup(move || {
+                                                            widget.update_value(|opt| {
+                                                                if let Some(w) = opt.take() {
+                                                                    w.stop();
+                                                                }
+                                                            });
+                                                        });
+                                                    }
+
+                                                    return view! {
+                                                        <div class="field">
+                                                            {label_text}
+                                                            <input
+                                                                id=field_id
+                                                                type="hidden"
+                                                                node_ref=hidden_ref
+                                                                prop:value=move || sig.get()
+                                                                on:input=move |ev| sig.set(event_target_value(&ev))
+                                                            />
+                                                            <div class="voice-wrap" node_ref=container_ref></div>
+                                                        </div>
+                                                    }
+                                                    .into_any();
+                                                }
+
                                                 if req.kind == "prosekit" {
                                                     let container_ref: NodeRef<leptos::html::Div> = NodeRef::new();
                                                     let hidden_ref: NodeRef<leptos::html::Input> = NodeRef::new();
@@ -1454,8 +1528,11 @@ fn ItemCard(item: serde_json::Value) -> impl IntoView {
     let name = text_field(&obj, &["name", "title"]);
     let description = text_field(&obj, &["description"]);
     let url = text_field(&obj, &["url", "html_url"]);
+    // A playable recording (an https URL to audio) renders as a
+    // player, not a link - the relay's /blob/<digest>.wav.
+    let audio = text_field(&obj, &["audio"]).filter(|a| a.starts_with("https://"));
 
-    let known = ["name", "title", "description", "url", "html_url"];
+    let known = ["name", "title", "description", "url", "html_url", "audio"];
     let extra: Vec<(String, String)> = obj
         .iter()
         .filter(|(k, v)| !known.contains(&k.as_str()) && !v.is_null())
@@ -1495,6 +1572,7 @@ fn ItemCard(item: serde_json::Value) -> impl IntoView {
                     }
                 })}
             {description.map(|d| view! { <p class="item-card-description">{d}</p> })}
+            {audio.map(|src| view! { <audio class="item-card-audio" controls preload="none" src=src></audio> })}
             {(!extra.is_empty())
                 .then(|| {
                     view! {
@@ -1999,11 +2077,18 @@ pub async fn submit_answer(
     if alt.disabled {
         return Err(ServerFnError::new("this alternative isn't open yet"));
     }
-    let next = alt.action.clone();
     let record_as = alt.record_as.clone();
 
     let responses: serde_json::Value = serde_json::from_str(&responses_json)
         .map_err(|e| ServerFnError::new(format!("invalid responses: {e}")))?;
+    // `/shape/{curve.key}`: the next page may be chosen by the answer.
+    let next = match alt.action.as_deref() {
+        Some(action) => Some(
+            crate::content::template_action(action, &responses)
+                .ok_or_else(|| ServerFnError::new("this answer is missing what the next page needs"))?,
+        ),
+        None => None,
+    };
 
     let parent_hashes: Vec<String> = parent_hash.into_iter().collect();
     let timestamp_ms = chrono::Utc::now().timestamp_millis();

src/content.rs

@@ -136,6 +136,43 @@ impl Question {
     }
 }
 
+/// An alternative's `action` may carry `{field}` / `{field.sub}`
+/// placeholders filled from the submitted responses - `/shape/{curve.key}`
+/// lands on the dynamic page `/shape/[key]` for the key the visitor's
+/// stroke was given. Returns `None` when a placeholder has no value
+/// (or a non-scalar one) in `responses`.
+pub fn template_action(action: &str, responses: &serde_json::Value) -> Option<String> {
+    let mut out = String::new();
+    let mut rest = action;
+    while let Some(start) = rest.find('{') {
+        out.push_str(&rest[..start]);
+        let end = rest[start..].find('}')? + start;
+        let path = &rest[start + 1..end];
+        let mut value = responses;
+        for seg in path.split('.') {
+            value = value.get(seg)?;
+        }
+        let scalar = match value {
+            serde_json::Value::String(s) => s.clone(),
+            serde_json::Value::Number(n) => n.to_string(),
+            serde_json::Value::Bool(b) => b.to_string(),
+            _ => return None,
+        };
+        if scalar.is_empty() {
+            return None;
+        }
+        // A URL segment: keep it to what a segment can carry.
+        let safe: String = scalar
+            .chars()
+            .map(|c| if c.is_ascii_alphanumeric() || "-_.".contains(c) { c } else { '-' })
+            .collect();
+        out.push_str(&safe);
+        rest = &rest[end + 1..];
+    }
+    out.push_str(rest);
+    Some(out)
+}
+
 /// Descriptions are inline markdown: `[text](https://…)` links,
 /// `*emphasis*`, `**strong**`, `` `code` ``. Block structure is
 /// flattened (a description is one paragraph) and raw HTML in the
@@ -402,7 +439,13 @@ pub struct Requirement {
     /// the selected file's current content.
     #[serde(default)]
     pub bind: Option<Bind>,
-    /// `type: gesture` only - ws(s):// URL of a redoal-relay instance
+    /// A preset value the field starts with. On a dynamic page the
+    /// URL segment substitutes into `{name}` placeholders here, like
+    /// resource keys - `value: "{key}"` on a hidden field carries the
+    /// page's key into the answer.
+    #[serde(default)]
+    pub value: Option<String>,
+    /// `type: gesture` / `type: voice` - ws(s):// URL of a redoal-relay instance
     /// the drawing widget connects to for live echoes of similar
     /// strokes. Absent means the widget works offline: the drawn path
     /// still submits, it just never gets a network-computed key or
@@ -780,15 +823,26 @@ pub fn resolve_question(
                     }
                 }
             };
+            // A url source's address takes the segment too:
+            // `https://relay.redoal.com/place/{key}`.
+            let substitute_url = |src: &mut ResourceSource| {
+                if let ResourceSource::Url { url } = src {
+                    for (name, value) in &captures {
+                        *url = url.replace(&format!("{{{name}}}"), value);
+                    }
+                }
+            };
             for alt in &mut resolved.alternatives {
                 for feature in &mut alt.features {
                     if let Some(res) = &mut feature.resource {
                         substitute(&mut res.key);
+                        substitute_url(&mut res.source);
                     }
                     for req in &mut feature.requirements {
                         if let Some(res) = &mut req.resource {
                             substitute(&mut res.key);
                         }
+                        substitute(&mut req.value);
                     }
                 }
             }
@@ -1053,6 +1107,26 @@ pub fn validate_questions(
             // A dangling action is a literal dead end: the submit
             // button navigates to "Nothing here".
             if let Some(action) = &alternative.action {
+                if action.contains('{') {
+                    // Placeholders are filled at submit time; the
+                    // shape must land on a dynamic page once filled.
+                    let probe = template_action(action, &serde_json::json!({}));
+                    let filled = {
+                        let mut a = action.clone();
+                        while let (Some(i), Some(j)) = (a.find('{'), a.find('}')) {
+                            a.replace_range(i..=j, "x");
+                        }
+                        a
+                    };
+                    let _ = probe;
+                    match resolve_question(questions, &filled) {
+                        Some(target) if target.is_dynamic() => continue,
+                        _ => anyhow::bail!(
+                            "question {:?} alternative {:?}: templated action {:?} must land on a dynamic page ([name].yaml)",
+                            question.id, alternative.name, action
+                        ),
+                    }
+                }
                 match questions.get(action) {
                     None => anyhow::bail!(
                         "question {:?} alternative {:?}: action {:?} does not match any declared question id",
@@ -1094,9 +1168,9 @@ pub fn validate_questions(
                         );
                     }
                     if let Some(relay) = &requirement.relay {
-                        if requirement.kind != "gesture" {
+                        if requirement.kind != "gesture" && requirement.kind != "voice" {
                             anyhow::bail!(
-                                "question {:?} alternative {:?} feature {:?}: requirement {:?} declares relay but is type {:?} - relay only makes sense on type: gesture",
+                                "question {:?} alternative {:?} feature {:?}: requirement {:?} declares relay but is type {:?} - relay only makes sense on type: gesture or voice",
                                 question.id, alternative.name, feature.name, requirement.name, requirement.kind
                             );
                         }
@@ -1950,4 +2024,40 @@ alternatives:
         assert_eq!(render_inline_markdown("[ok](/shape)"), "<a href=\"/shape\">ok</a>");
         assert_eq!(render_inline_markdown("[mail](mailto:bl@uhhm.no)"), "<a href=\"mailto:bl@uhhm.no\">mail</a>");
     }
+
+    #[test]
+    fn action_templates_from_responses() {
+        let r = serde_json::json!({"curve": {"key": "20aa98", "points": [[0,0]]}, "n": 3});
+        assert_eq!(template_action("/shape/{curve.key}", &r).as_deref(), Some("/shape/20aa98"));
+        assert_eq!(template_action("/x/{n}/y", &r).as_deref(), Some("/x/3/y"));
+        assert_eq!(template_action("/shape", &r).as_deref(), Some("/shape"));
+        assert!(template_action("/shape/{curve.missing}", &r).is_none());
+        assert!(template_action("/shape/{curve.points}", &r).is_none());
+        let odd = serde_json::json!({"k": "a/b c"});
+        assert_eq!(template_action("/p/{k}", &odd).as_deref(), Some("/p/a-b-c"));
+    }
+
+    #[test]
+    fn dynamic_page_fills_requirement_values() {
+        let q: Question = serde_yaml::from_str(
+            "id: /shape/[key]\nname: P\nalternatives:\n  - name: A\n    features:\n      - name: F\n        requirements:\n          - name: key\n            type: hidden\n            value: \"{key}\"\n",
+        )
+        .unwrap();
+        let mut qs = std::collections::HashMap::new();
+        qs.insert(q.id.clone(), q);
+        let page = resolve_question(&qs, "/shape/20aa98").unwrap();
+        assert_eq!(page.alternatives[0].features[0].requirements[0].value.as_deref(), Some("20aa98"));
+
+        let q: Question = serde_yaml::from_str(
+            "id: /shape/[key]\nname: P\nalternatives:\n  - name: A\n    features:\n      - name: F\n        resource:\n          source: { kind: url, url: \"https://relay.example/place/{key}\" }\n          public: true\n",
+        )
+        .unwrap();
+        let mut qs = std::collections::HashMap::new();
+        qs.insert(q.id.clone(), q);
+        let page = resolve_question(&qs, "/shape/20aa98").unwrap();
+        match &page.alternatives[0].features[0].resource.as_ref().unwrap().source {
+            ResourceSource::Url { url } => assert_eq!(url, "https://relay.example/place/20aa98"),
+            _ => panic!(),
+        }
+    }
 }

style/main.css

@@ -448,6 +448,57 @@ main.not-found {
   margin-bottom: 0.15em;
 }
 
+/* voice field (voice.js): a record button, a status line, a preview */
+.voice-wrap {
+  display: flex;
+  flex-wrap: wrap;
+  align-items: center;
+  gap: 0.6rem 1rem;
+}
+
+.voice-button {
+  font: inherit;
+  padding: 0.55rem 1.1rem;
+  border: 0.06rem solid var(--accent);
+  border-radius: 2rem;
+  background: transparent;
+  color: var(--ink);
+  cursor: pointer;
+}
+
+.voice-button:hover:not(:disabled) {
+  background: var(--accent);
+  color: var(--paper);
+}
+
+.voice-button.recording {
+  background: var(--accent);
+  color: var(--paper);
+  animation: voice-pulse 1.2s ease-in-out infinite;
+}
+
+.voice-button:disabled {
+  opacity: 0.5;
+  cursor: default;
+}
+
+@keyframes voice-pulse {
+  50% { opacity: 0.6; }
+}
+
+.voice-status {
+  font-size: 0.85rem;
+  color: var(--ink-dim);
+}
+
+.voice-preview,
+.item-card-audio {
+  display: block;
+  width: 100%;
+  max-width: 28rem;
+  margin-top: 0.4rem;
+}
+
 /* links inside markdown descriptions */
 .alt-description a,
 .feature p a {
@@ -597,6 +648,34 @@ textarea:focus {
   opacity: var(--echo-strength, 1);
 }
 
+/* places are pickable: the pick re-derives the input's key */
+.gesture-echo {
+  cursor: pointer;
+  transition: opacity 0.5s ease, border-color 120ms, transform 120ms;
+}
+
+.gesture-echo:hover,
+.gesture-echo:focus-visible {
+  border-color: var(--accent);
+  outline: none;
+}
+
+.gesture-echo.selected {
+  border-color: var(--accent);
+  box-shadow: 0 0 0 0.12rem var(--accent);
+  transform: translateY(-0.1rem);
+}
+
+.gesture-empty {
+  margin: 0.5rem 0 0;
+  font-size: 0.85rem;
+  color: var(--ink-dim);
+}
+
+.gesture-empty:empty {
+  display: none;
+}
+
 .gesture-status {
   position: absolute;
   top: 0.55rem;

voice.js

@@ -0,0 +1,162 @@
+// A `type: voice` requirement: leave a recording at a gesture key.
+// Same contract as gesture.js - portal mounts it with the field's
+// hidden input and the relay URL, and calls stop() on navigation.
+//
+// The browser records with MediaRecorder (whatever container it
+// likes), decodes that to PCM with WebAudio, resamples to mono 48 kHz,
+// and ships one binary frame `[0x01][20-byte key][i16le PCM]` to the
+// relay, which encodes with the one recording codec, signs as itself,
+// keeps it and announces it (ADR-0015). The field's value becomes
+// {key, digest, duration_ms} once the relay confirms.
+//
+// Palette: colors come from the page's custom properties, no copy here.
+
+const MAX_SECONDS = 60;
+const SAMPLE_RATE = 48000;
+
+class VoiceWidget {
+    constructor(container, hidden, relayUrl, key) {
+        this.container = container;
+        this.hidden = hidden || null;
+        this.relayUrl = relayUrl || '';
+        this.key = (key || '').trim();
+        this.stopped = false;
+        this.recorder = null;
+        this.stream = null;
+        this.chunks = [];
+        this.ws = null;
+
+        this.button = document.createElement('button');
+        this.button.type = 'button';
+        this.button.className = 'voice-button';
+        this.button.textContent = 'Record';
+        this.status = document.createElement('span');
+        this.status.className = 'voice-status';
+        this.preview = document.createElement('audio');
+        this.preview.className = 'voice-preview';
+        this.preview.controls = true;
+        this.preview.hidden = true;
+        container.append(this.button, this.status, this.preview);
+
+        this._onClick = () => this.toggle();
+        this.button.addEventListener('click', this._onClick);
+        if (!this.key || this.key.length !== 40) {
+            this.button.disabled = true;
+            this.say('This page has no address to leave a voice at.');
+        } else if (!navigator.mediaDevices || !window.MediaRecorder) {
+            this.button.disabled = true;
+            this.say('Recording needs a browser with a microphone API.');
+        }
+    }
+
+    say(text) {
+        this.status.textContent = text;
+    }
+
+    async toggle() {
+        if (this.recorder && this.recorder.state === 'recording') {
+            this.recorder.stop();
+            return;
+        }
+        try {
+            this.stream = await navigator.mediaDevices.getUserMedia({ audio: true });
+        } catch {
+            this.say('Microphone access was declined.');
+            return;
+        }
+        this.chunks = [];
+        this.recorder = new MediaRecorder(this.stream);
+        this.recorder.addEventListener('dataavailable', (e) => { if (e.data.size) this.chunks.push(e.data); });
+        this.recorder.addEventListener('stop', () => this.finish());
+        this.recorder.start();
+        this.button.textContent = 'Stop';
+        this.button.classList.add('recording');
+        this.say(`Recording — up to ${MAX_SECONDS} seconds.`);
+        this.capTimer = setTimeout(() => { if (this.recorder && this.recorder.state === 'recording') this.recorder.stop(); }, MAX_SECONDS * 1000);
+    }
+
+    async finish() {
+        clearTimeout(this.capTimer);
+        this.button.textContent = 'Record again';
+        this.button.classList.remove('recording');
+        if (this.stream) { this.stream.getTracks().forEach((t) => t.stop()); this.stream = null; }
+        const blob = new Blob(this.chunks, { type: this.recorder.mimeType || 'audio/webm' });
+        if (!blob.size) { this.say('Nothing was recorded.'); return; }
+        this.preview.src = URL.createObjectURL(blob);
+        this.preview.hidden = false;
+        this.say('Sending…');
+        let pcm;
+        try {
+            pcm = await this.toPcm16(await blob.arrayBuffer());
+        } catch (e) {
+            this.say('Could not decode the recording.');
+            return;
+        }
+        this.upload(pcm);
+    }
+
+    // Decode → mono 48 kHz Float32 → Int16 little-endian bytes.
+    async toPcm16(buffer) {
+        const ctx = new (window.AudioContext || window.webkitAudioContext)();
+        const decoded = await ctx.decodeAudioData(buffer);
+        await ctx.close();
+        const frames = Math.ceil(decoded.duration * SAMPLE_RATE);
+        const offline = new OfflineAudioContext(1, frames, SAMPLE_RATE);
+        const src = offline.createBufferSource();
+        src.buffer = decoded;
+        src.connect(offline.destination);
+        src.start();
+        const rendered = await offline.startRendering();
+        const f32 = rendered.getChannelData(0);
+        const out = new Uint8Array(f32.length * 2);
+        const view = new DataView(out.buffer);
+        for (let i = 0; i < f32.length; i++) {
+            const s = Math.max(-1, Math.min(1, f32[i]));
+            view.setInt16(i * 2, s < 0 ? s * 32768 : s * 32767, true);
+        }
+        return out;
+    }
+
+    upload(pcm) {
+        if (!this.relayUrl) { this.say('No relay to send to.'); return; }
+        const frame = new Uint8Array(1 + 20 + pcm.length);
+        frame[0] = 1;
+        for (let i = 0; i < 20; i++) frame[1 + i] = parseInt(this.key.substr(i * 2, 2), 16);
+        frame.set(pcm, 21);
+        const ws = new WebSocket(this.relayUrl);
+        ws.binaryType = 'arraybuffer';
+        this.ws = ws;
+        ws.addEventListener('open', () => ws.send(frame));
+        ws.addEventListener('message', (e) => {
+            let msg; try { msg = JSON.parse(e.data); } catch { return; }
+            if (msg.type === 'published') {
+                this.setValue({ key: this.key, digest: msg.digest, duration_ms: msg.duration_ms });
+                this.say(`Kept at this address — ${Math.round(msg.duration_ms / 1000)} s.`);
+                ws.close();
+            } else if (msg.type === 'error') {
+                this.say(msg.message || 'The relay declined the recording.');
+                ws.close();
+            }
+        });
+        ws.addEventListener('error', () => this.say('The relay could not be reached.'));
+    }
+
+    setValue(value) {
+        if (!this.hidden) return;
+        this.hidden.value = JSON.stringify(value);
+        this.hidden.dispatchEvent(new Event('input', { bubbles: true }));
+    }
+
+    stop() {
+        this.stopped = true;
+        clearTimeout(this.capTimer);
+        if (this.recorder && this.recorder.state === 'recording') this.recorder.stop();
+        if (this.stream) this.stream.getTracks().forEach((t) => t.stop());
+        if (this.ws) this.ws.close();
+        this.button.removeEventListener('click', this._onClick);
+    }
+}
+
+export function mountVoice(container, hidden, relayUrl, key) {
+    return new VoiceWidget(container, hidden, relayUrl, key);
+}