Merge main into feat/voice-outlines

Adopts main's loadBundledJson(url, {signal}) and builds the Census and
Who's On First pack URLs when they are read, not at import.

src/layers/aircraft/index.js

@@ -9,6 +9,7 @@ export * from '../../data/cockpitContactDot.js';
 export * from '../../data/contactMatch.js';
 export * from '../../data/iconOrientation.js';
 export * from '../../data/layerState.js';
+export * from '../../data/layerStateCoordinator.js';
 export * from '../../data/modelVisualAnchor.js';
 export * from '../../data/motionModel.js';
 export * from '../../data/renderAltitude.js';

src/layers/bikeshare/model.js

@@ -1,36 +1,12 @@
+import {
+  extractStationsArray,
+  normalizeGbfsBool,
+  parseStationInformation,
+  parseStationStatus,
+  toNonNegativeInteger,
+} from '../../sources/gbfsStations.js';
+
 export function createModel({ state: layerState, services, parts, source }) {
-  /**
-   * Coerce a GBFS boolean field to a native boolean.
-   * GBFS feeds are inconsistent — some use booleans, others use 0/1 or strings.
-   * @param {*} value - Raw field value from GBFS JSON.
-   * @param {boolean} [fallback=true] - Default when value is null/undefined/unrecognized.
-   * @returns {boolean}
-   */
-
-  function normalizeGbfsBool(value, fallback = true) {
-    if (value == null) return fallback;
-    if (typeof value === 'boolean') return value;
-    const num = Number(value);
-    if (Number.isFinite(num)) return num !== 0;
-    const text = String(value).trim().toLowerCase();
-    if (text === 'true' || text === 'yes') return true;
-    if (text === 'false' || text === 'no') return false;
-    return fallback;
-  }
-
-  /**
-   * Parse a value as a non-negative integer, returning fallback on failure.
-   * @param {*} value - Raw numeric value.
-   * @param {number|null} [fallback=null] - Returned when value is not a valid non-negative number.
-   * @returns {number|null}
-   */
-
-  function toNonNegativeInteger(value, fallback = null) {
-    const n = Number(value);
-    if (!Number.isFinite(n) || n < 0) return fallback;
-    return Math.round(n);
-  }
-
   /**
    * Build a globally unique render key for a station.
    * @param {string} cityId - City identifier.
@@ -63,93 +39,6 @@ export function createModel({ state: layerState, services, parts, source }) {
     return 6371 * 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));
   }
 
-  /**
-   * Extract the stations array from a GBFS JSON payload.
-   * Handles multiple response shapes: { data: { stations: [...] } },
-   * { data: [...] }, and nested objects with a stations sub-key.
-   * @param {Object} payload - Parsed GBFS JSON response.
-   * @returns {Object[]} Array of raw station objects (may be empty).
-   */
-
-  function extractStationsArray(payload) {
-    const data = payload?.data;
-    if (Array.isArray(data?.stations)) return data.stations;
-    if (Array.isArray(data)) return data;
-    // Some feeds nest stations under an additional key (e.g. locale wrappers)
-    if (data && typeof data === 'object') {
-      for (const value of Object.values(data)) {
-        if (Array.isArray(value?.stations)) return value.stations;
-      }
-    }
-    return [];
-  }
-
-  /**
-   * Parse a GBFS station_information payload into a Map of station metadata.
-   * Handles field-name variations across different GBFS providers
-   * (station_id vs id, lat vs latitude, etc.). Stations with missing or
-   * invalid coordinates are silently skipped.
-   * @param {Object} payload - Parsed station_information.json response.
-   * @returns {Map<string, Object>} Map of stationId to station info objects.
-   */
-
-  function parseStationInformation(payload) {
-    const stations = extractStationsArray(payload);
-    const stationMap = new Map();
-
-    for (const raw of stations) {
-      // Accept both GBFS 2.x (station_id) and alternate (id) field names
-      const stationId = String(raw?.station_id ?? raw?.id ?? '').trim();
-      const lat = Number(raw?.lat ?? raw?.latitude);
-      const lon = Number(raw?.lon ?? raw?.longitude);
-      if (!stationId || !Number.isFinite(lat) || !Number.isFinite(lon))
-        continue;
-
-      stationMap.set(stationId, {
-        stationId,
-        name: String(raw?.name || raw?.short_name || '').trim(),
-        lat,
-        lon,
-        capacity: toNonNegativeInteger(raw?.capacity),
-        isInstalled: normalizeGbfsBool(raw?.is_installed, true),
-        isRenting: normalizeGbfsBool(raw?.is_renting, true),
-        isReturning: normalizeGbfsBool(raw?.is_returning, true),
-      });
-    }
-
-    return stationMap;
-  }
-
-  /**
-   * Parse a GBFS station_status payload into a Map of real-time availability.
-   * @param {Object} payload - Parsed station_status.json response.
-   * @returns {Map<string, Object>} Map of stationId to status objects containing
-   *   bikesAvailable, docksAvailable, and operational flags.
-   */
-
-  function parseStationStatus(payload) {
-    const stations = extractStationsArray(payload);
-    const statusMap = new Map();
-
-    for (const raw of stations) {
-      const stationId = String(raw?.station_id ?? raw?.id ?? '').trim();
-      if (!stationId) continue;
-
-      const bikes = toNonNegativeInteger(raw?.num_bikes_available);
-      const docks = toNonNegativeInteger(raw?.num_docks_available);
-      statusMap.set(stationId, {
-        stationId,
-        bikesAvailable: bikes,
-        docksAvailable: docks,
-        isInstalled: normalizeGbfsBool(raw?.is_installed, true),
-        isRenting: normalizeGbfsBool(raw?.is_renting, true),
-        isReturning: normalizeGbfsBool(raw?.is_returning, true),
-        lastReported: toNonNegativeInteger(raw?.last_reported),
-      });
-    }
-
-    return statusMap;
-  }
   return {
     normalizeGbfsBool,
     toNonNegativeInteger,

src/layers/cctv/source.js

@@ -51,5 +51,18 @@ export function createCctvSource({
     },
     getFrameUrl: frameUrlFor,
     getMediaUrl: mediaUrlFor,
+    /** Read one current frame through the registered frame endpoint. */
+    async getFrame(camera, { signal } = {}) {
+      signal?.throwIfAborted();
+      const response = await fetchImpl(frameUrlFor(camera), {
+        cache: 'no-store',
+        signal,
+      });
+      if (!response.ok) throw new Error('Camera frame HTTP ' + response.status);
+      const bytes = new Uint8Array(await response.arrayBuffer());
+      signal?.throwIfAborted();
+      const type = response.headers.get('content-type') || '';
+      return { contentType: type.split(';')[0].trim().toLowerCase(), bytes };
+    },
   };
 }

src/layers/cctv/source.test.mjs

@@ -148,3 +148,28 @@ test('camera construction is inert and destruction cancels a pending catalog and
   assert.equal(a.getStats().count, 0);
   assert.equal(b.getStats().count, 0);
 });
+
+test('frames are read through the registered frame endpoint', async () => {
+  const png = Uint8Array.from([0x89, 0x50, 0x4e, 0x47]);
+  const requested = [];
+  const source = createCctvSource({
+    fetchImpl: async (url, init) => {
+      requested.push({ url, cache: init.cache });
+      return new Response(png, {
+        headers: { 'Content-Type': 'Image/PNG; charset=binary' },
+      });
+    },
+  });
+  const frame = await source.getFrame(camera);
+  assert.equal(frame.contentType, 'image/png');
+  assert.deepEqual([...frame.bytes], [...png]);
+  assert.equal(
+    requested[0].url.split('?')[0],
+    '/api/cctv/frame/pack%2Fcamera%20%3Fx',
+  );
+  assert.equal(requested[0].cache, 'no-store');
+  const failing = createCctvSource({
+    fetchImpl: async () => new Response(null, { status: 502 }),
+  });
+  await assert.rejects(failing.getFrame(camera), /Camera frame HTTP 502/);
+});

src/layers/installations/namesLoading.test.mjs

@@ -4,22 +4,47 @@ import { readFileSync } from 'node:fs';
 import { createInstallationSource } from './source.js';
 import { createIngestion } from './ingestion.js';
 import { decodeOpenFreeMapMilitaryTile } from '../../sources/openFreeMap.js';
-import { createMilitaryNamesLoader, loadMilitaryNames } from '../../data/militaryNames.js';
+import {
+  createMilitaryNamesLoader,
+  loadMilitaryNames,
+} from '../../data/militaryNames.js';
 import { loadBundledJson } from '../../data/bundledJson.js';
 
 const box = { south: 30.3, west: -97.8, north: 30.33, east: -97.74 };
 const wide = { south: 20, west: -130, north: 60, east: -60 };
-const tile = decodeOpenFreeMapMilitaryTile(readFileSync(new URL('../../data/fixtures/ofm-camp-mabry-12-935-1685.pbf', import.meta.url)), 12, 935, 1685);
-const flush = async () => { for (let i = 0; i < 30; i++) await Promise.resolve(); };
-function deferred() { let resolve; const promise = new Promise((r) => { resolve = r; }); return { promise, resolve }; }
-function sourceWith(job) { return createInstallationSource({
-  loadNames: () => job.promise,
-  fetchImpl: async () => Response.json({ unavailable: true }),
-  mapTiles: { fetchBounds: async () => ({ tiles: [tile] }), clear() {} },
-}); }
+const tile = decodeOpenFreeMapMilitaryTile(
+  readFileSync(
+    new URL(
+      '../../data/fixtures/ofm-camp-mabry-12-935-1685.pbf',
+      import.meta.url,
+    ),
+  ),
+  12,
+  935,
+  1685,
+);
+const flush = async () => {
+  for (let i = 0; i < 30; i++) await Promise.resolve();
+};
+function deferred() {
+  let resolve;
+  const promise = new Promise((r) => {
+    resolve = r;
+  });
+  return { promise, resolve };
+}
+function sourceWith(job) {
+  return createInstallationSource({
+    loadNames: () => job.promise,
+    fetchImpl: async () => Response.json({ unavailable: true }),
+    mapTiles: { fetchBounds: async () => ({ tiles: [tile] }), clear() {} },
+  });
+}
 
 test('close polygons publish immediately while a wide consumer can cancel its independent names wait', async () => {
-  const job = deferred(), source = sourceWith(job), abort = new AbortController();
+  const job = deferred(),
+    source = sourceWith(job),
+    abort = new AbortController();
   const waiting = source.getMappedSites(wide, { signal: abort.signal });
   const rejection = assert.rejects(waiting, { name: 'AbortError' });
   const payload = await source.getMappedSites(box);
@@ -32,48 +57,81 @@ test('close polygons publish immediately while a wide consumer can cancel its in
   assert.ok(enriched.records.some((r) => r.name === 'Camp Mabry'));
 });
 
-for (const stale of [false, true]) test(`late names ${stale ? 'cannot publish to a superseded view' : 'enrich the current published polygons'}`, async () => {
-  const job = deferred(), source = sourceWith(job), publications = [];
-  let currentBox = box;
-  const state = { enabled: true, viewer: {}, records: [], googleSearchRequested: false };
-  const ingestion = createIngestion({ state, source,
-    services: { render: { governorRequestRender() {} }, ground: { resolveGroundFloorCellsBounded: async () => {} } },
-    parts: {
-      viewport: { loadArea: () => ({ box: currentBox, coverage: {} }), clearUnavailableRetry() {}, scheduleUnavailableRetry() {} },
-      model: { installationWithinViewport: () => true },
-      rendering: { renderRecords: () => publications.push(state.records), warmInstallationFloors() {} },
-    },
+for (const stale of [false, true])
+  test(`late names ${stale ? 'cannot publish to a superseded view' : 'enrich the current published polygons'}`, async () => {
+    const job = deferred(),
+      source = sourceWith(job),
+      publications = [];
+    let currentBox = box;
+    const state = {
+      enabled: true,
+      viewer: {},
+      records: [],
+      googleSearchRequested: false,
+    };
+    const ingestion = createIngestion({
+      state,
+      source,
+      services: {
+        render: { governorRequestRender() {} },
+        ground: { resolveGroundFloorCellsBounded: async () => {} },
+      },
+      parts: {
+        viewport: {
+          loadArea: () => ({ box: currentBox, coverage: {} }),
+          clearUnavailableRetry() {},
+          scheduleUnavailableRetry() {},
+        },
+        model: { installationWithinViewport: () => true },
+        rendering: {
+          renderRecords: () => publications.push(state.records),
+          warmInstallationFloors() {},
+        },
+      },
+    });
+    await ingestion.loadInstallations();
+    assert.equal(state.loading, false);
+    assert.ok(publications[0].length);
+    if (stale) {
+      currentBox = wide;
+      state.enabled = false;
+      state.abort.abort();
+    }
+    job.resolve(await loadMilitaryNames());
+    await flush();
+    assert.equal(publications.length, stale ? 1 : 2);
+    if (!stale) assert.ok(state.records.some((r) => r.name === 'Camp Mabry'));
+    state.abort.abort();
   });
-  await ingestion.loadInstallations();
-  assert.equal(state.loading, false);
-  assert.ok(publications[0].length);
-  if (stale) { currentBox = wide; state.enabled = false; state.abort.abort(); }
-  job.resolve(await loadMilitaryNames());
-  await flush();
-  assert.equal(publications.length, stale ? 1 : 2);
-  if (!stale) assert.ok(state.records.some((r) => r.name === 'Camp Mabry'));
-  state.abort.abort();
-});
 
-for (const stage of ['response', 'body']) test(`shared names ${stage} deadline aborts and releases the retryable loader`, async (t) => {
-  t.mock.timers.enable({ apis: ['setTimeout', 'Date'] });
-  let calls = 0, signal;
-  t.mock.method(globalThis, 'fetch', async (_url, options) => {
-    calls++; signal = options.signal;
-    if (calls > 1) return Response.json({ records: [], classes: [] });
-    if (stage === 'response') return new Promise(() => {});
-    return { ok: true, json: () => new Promise(() => {}) };
+for (const stage of ['response', 'body'])
+  test(`shared names ${stage} deadline aborts and releases the retryable loader`, async (t) => {
+    t.mock.timers.enable({ apis: ['setTimeout', 'Date'] });
+    let calls = 0,
+      signal;
+    t.mock.method(globalThis, 'fetch', async (_url, options) => {
+      calls++;
+      signal = options.signal;
+      if (calls > 1) return Response.json({ records: [], classes: [] });
+      if (stage === 'response') return new Promise(() => {});
+      return { ok: true, json: () => new Promise(() => {}) };
+    });
+    const load = createMilitaryNamesLoader({
+      timeoutMs: 50,
+      cooldownMs: 100,
+      loadPack: (signal) =>
+        loadBundledJson(new URL('https://example.test/names.json'), { signal }),
+    });
+    const first = load();
+    assert.equal(load(), first, 'shared acquisition');
+    const rejected = assert.rejects(first, { name: 'TimeoutError' });
+    await flush();
+    t.mock.timers.tick(51);
+    await rejected;
+    assert.equal(signal.aborted, true);
+    await assert.rejects(load(), { name: 'TimeoutError' });
+    assert.equal(calls, 1);
+    t.mock.timers.tick(101);
+    assert.deepEqual((await load()).records, []);
+    assert.equal(calls, 2);
   });
-  const load = createMilitaryNamesLoader({ timeoutMs: 50, cooldownMs: 100,
-    loadPack: (signal) => loadBundledJson(new URL('https://example.test/names.json'), null, { signal }) });
-  const first = load();
-  assert.equal(load(), first, 'shared acquisition');
-  const rejected = assert.rejects(first, { name: 'TimeoutError' });
-  await flush(); t.mock.timers.tick(51); await rejected;
-  assert.equal(signal.aborted, true);
-  await assert.rejects(load(), { name: 'TimeoutError' });
-  assert.equal(calls, 1);
-  t.mock.timers.tick(101);
-  assert.deepEqual((await load()).records, []);
-  assert.equal(calls, 2);
-});

src/layers/installations/source.js

@@ -101,7 +101,7 @@ export function createInstallationSource({
 } = {}) {
   let overpassUnavailable = false;
   const installationIds = new Map();
-  async function getNamedSites(box, signal) {
+  async function getNamedSites(box, signal, thinned = true) {
     const names = await waitForSignal(loadNames(), signal).catch((cause) => {
       signal?.throwIfAborted();
       throw Object.assign(
@@ -112,7 +112,13 @@ export function createInstallationSource({
       );
     });
     signal?.throwIfAborted();
-    const { records, count } = militaryNamesInView(names, box);
+    // The map keeps one site per display cell; queries can ask for all.
+    const { records, count } = militaryNamesInView(
+      names,
+      box,
+      thinned ? undefined : Infinity,
+      thinned,
+    );
     return {
       records,
       namedInView: count,
@@ -124,9 +130,9 @@ export function createInstallationSource({
       source: 'OpenStreetMap',
     };
   }
-  async function getTileSites(box, signal) {
+  async function getTileSites(box, signal, thinned) {
     const zoom = installationTileZoom(box);
-    if (zoom === null) return getNamedSites(box, signal);
+    if (zoom === null) return getNamedSites(box, signal, thinned);
     let names = null;
     const namesJob = waitForSignal(loadNames(), signal)
       .then((loaded) => {
@@ -181,7 +187,7 @@ export function createInstallationSource({
       mapTiles.clear();
       installationIds.clear();
     },
-    async getMappedSites(box, { exact = false, signal } = {}) {
+    async getMappedSites(box, { exact = false, thinned = true, signal } = {}) {
       const { south, west, north, east } = box || {};
       if (
         ![south, west, north, east].every(Number.isFinite) ||
@@ -197,8 +203,8 @@ export function createInstallationSource({
         throw new TypeError('A bounded installation viewport is required');
       signal?.throwIfAborted();
       if (east < west || north - south > 10 || east - west > 10)
-        return getNamedSites(box, signal);
-      if (overpassUnavailable) return getTileSites(box, signal);
+        return getNamedSites(box, signal, thinned);
+      if (overpassUnavailable) return getTileSites(box, signal, thinned);
       const query = new URLSearchParams(
         Object.entries({ south, west, north, east }).map(([key, value]) => [
           key,
@@ -213,7 +219,7 @@ export function createInstallationSource({
       signal?.throwIfAborted();
       if (isUnavailableCapability(body)) {
         overpassUnavailable = true;
-        return getTileSites(box, signal);
+        return getTileSites(box, signal, thinned);
       }
       if (!response.ok)
         throw Object.assign(

src/layers/launches/source.js

@@ -2,16 +2,24 @@
 export function createLaunchSource({
   fetchImpl = (...args) => globalThis.fetch(...args),
 } = {}) {
+  /** The launch payload, and whether the proxy served it from a stale cache. */
+  async function getLaunchSnapshot({ signal } = {}) {
+    signal?.throwIfAborted();
+    const response = await fetchImpl('/api/launches', { signal });
+    if (!response.ok) throw new Error(`HTTP ${response.status}`);
+    const payload = await response.json();
+    signal?.throwIfAborted();
+    if (!Array.isArray(payload) && !Array.isArray(payload?.results))
+      throw new Error('Malformed launch snapshot');
+    return {
+      payload,
+      stale: response.headers?.get?.('x-gev-cache') === 'STALE-ERROR',
+    };
+  }
   return {
-    async getLaunches({ signal } = {}) {
-      signal?.throwIfAborted();
-      const response = await fetchImpl('/api/launches', { signal });
-      if (!response.ok) throw new Error(`HTTP ${response.status}`);
-      const payload = await response.json();
-      signal?.throwIfAborted();
-      if (!Array.isArray(payload) && !Array.isArray(payload?.results))
-        throw new Error('Malformed launch snapshot');
-      return payload;
+    getLaunchSnapshot,
+    async getLaunches(options) {
+      return (await getLaunchSnapshot(options)).payload;
     },
     async getActiveTle({ signal } = {}) {
       signal?.throwIfAborted();

src/layers/satellites/orbits.js

@@ -8,6 +8,7 @@ import {
   twoline2satrec,
 } from 'satellite.js';
 import { findNextSatellitePass } from '../../data/satellitePass.js';
+import { parseTleText } from '../../sources/tle.js';
 import { ORBIT_PATH_STEPS, ISS_NORAD } from './policy.js';
 
 export function createOrbits({ state: layerState, services, parts, source }) {
@@ -40,24 +41,7 @@ export function createOrbits({ state: layerState, services, parts, source }) {
   /**
    * Parse TLE text into array of { name, line1, line2 } objects.
    */
-
-  function parseTLE(text) {
-    const lines = text
-      .trim()
-      .split('\n')
-      .map((l) => l.trim())
-      .filter((l) => l.length > 0);
-    const result = [];
-    for (let i = 0; i < lines.length - 2; i += 3) {
-      const name = lines[i];
-      const line1 = lines[i + 1];
-      const line2 = lines[i + 2];
-      if (line1.startsWith('1 ') && line2.startsWith('2 ')) {
-        result.push({ name, line1, line2 });
-      }
-    }
-    return result;
-  }
+  const parseTLE = parseTleText;
 
   /**
    * Propagate satellite position at a given JS Date.

src/layers/satellites/source.js

@@ -19,7 +19,10 @@ export function createSatelliteSource({
       const response = await fetchImpl(`/api/celestrak/${group}`, { signal });
       const text = response.ok ? await response.text() : '';
       signal?.throwIfAborted();
-      return { ok: response.ok, status: response.status, text };
+      // The proxy serves its last copy, marked STALE-ERROR, when CelesTrak
+      // is down.
+      const stale = response.headers?.get?.('x-tle-cache') === 'STALE-ERROR';
+      return { ok: response.ok, status: response.status, text, stale };
     },
   };
 }

src/layers/submarineCables/bundledSource.js

@@ -1,14 +1,19 @@
 // This dataset is CC BY-NC-SA 3.0, not the project's MIT license.
 // Commercial users must remove it or obtain a TeleGeography license.
 // See DATA_SOURCES.md and the bundled dataset's source.json.
-const cableUrl = new URL(
-  '../../data/local_data/telegeography_submarine_cables/cable-geo.json',
-  import.meta.url,
-).href;
-const landingPointUrl = new URL(
-  '../../data/local_data/telegeography_submarine_cables/landing-point-geo.json',
-  import.meta.url,
-).href;
+// Resolved when read, so importing this module never needs a module URL.
+function cableUrl() {
+  return new URL(
+    '../../data/local_data/telegeography_submarine_cables/cable-geo.json',
+    import.meta.url,
+  ).href;
+}
+function landingPointUrl() {
+  return new URL(
+    '../../data/local_data/telegeography_submarine_cables/landing-point-geo.json',
+    import.meta.url,
+  ).href;
+}
 
 /** Supply GeoJSON collections without coupling the renderer to asset URLs. */
 export function createBundledCableSource({
@@ -33,8 +38,8 @@ export function createBundledCableSource({
     label: 'TeleGeography',
     async fetch(signal) {
       const [cables, landingPoints] = await Promise.all([
-        read(cableUrl, signal),
-        read(landingPointUrl, signal),
+        read(cableUrl(), signal),
+        read(landingPointUrl(), signal),
       ]);
       return { cables, landingPoints };
     },

src/layers/traffic/flowSource.js

@@ -25,21 +25,31 @@ export function createFlowTileSource({
     maxTiles: 16,
   });
   let partial = false;
+  /**
+   * Flow segments for bounds, with whether any covering tile failed to load
+   * for this request.
+   */
+  async function fetchFlowDetail(bounds, { signal, zoom = 12 } = {}) {
+    const result = await tiles.fetchBounds(bounds, {
+      zoom,
+      signal,
+      tiles: bounds.coverage?.coarse,
+    });
+    partial = result.partial;
+    const segments = bounds.coverage
+      ? result.tiles.flat()
+      : result.tiles.flat().flatMap((segment) =>
+          clipTileLine(segment.coords, bounds).map((coords) => ({
+            ...segment,
+            coords,
+          })),
+        );
+    return { segments, partial: result.partial === true };
+  }
   return {
-    async fetchFlowForBounds(bounds, { signal, zoom = 12 } = {}) {
-      const result = await tiles.fetchBounds(bounds, {
-        zoom,
-        signal,
-        tiles: bounds.coverage?.coarse,
-      });
-      partial = result.partial;
-      if (bounds.coverage) return result.tiles.flat();
-      return result.tiles.flat().flatMap((segment) =>
-        clipTileLine(segment.coords, bounds).map((coords) => ({
-          ...segment,
-          coords,
-        })),
-      );
+    fetchFlowDetail,
+    async fetchFlowForBounds(bounds, options) {
+      return (await fetchFlowDetail(bounds, options)).segments;
     },
     getFlowSessionStats: () => ({ ...tiles.getStats(), partial }),
     resetFlowTileCache: () => tiles.clear(),

src/layers/transit/source.js

@@ -5,6 +5,21 @@ export function createTransitSource({
   fetchImpl = (...args) => fetch(...args),
 } = {}) {
   return {
+    /** Read the public catalog of enabled feeds. */
+    async getFeeds({ signal } = {}) {
+      signal?.throwIfAborted();
+      const response = await fetchImpl('/api/transit/feeds', {
+        signal,
+        headers: { Accept: 'application/json' },
+      });
+      if (!response.ok)
+        throw new Error('Transit feeds HTTP ' + response.status);
+      const body = await response.json();
+      signal?.throwIfAborted();
+      if (!Array.isArray(body?.feeds))
+        throw new Error('Malformed transit feed catalog');
+      return body.feeds;
+    },
     getHistory(feedId, vehicleId, { signal } = {}) {
       signal?.throwIfAborted();
       return fetchTransitHistory(feedId, vehicleId, signal, fetchImpl);

src/layers/transit/source.test.mjs

@@ -0,0 +1,46 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { createTransitSource } from './source.js';
+
+const json = (body, status = 200) =>
+  new Response(JSON.stringify(body), {
+    status,
+    headers: { 'Content-Type': 'application/json' },
+  });
+
+test('the feed catalog is read from the public catalog route', async () => {
+  const requested = [];
+  const feeds = [
+    {
+      id: 'mbta',
+      name: 'MBTA',
+      center: { lat: 42.36, lon: -71.06 },
+      loadRadiusKm: 60,
+    },
+  ];
+  const source = createTransitSource({
+    fetchImpl: async (url) => {
+      requested.push(url);
+      return json({ feeds });
+    },
+  });
+  assert.deepEqual(await source.getFeeds(), feeds);
+  assert.deepEqual(requested, ['/api/transit/feeds']);
+});
+
+test('feed catalog failures are reported', async () => {
+  const failing = createTransitSource({ fetchImpl: async () => json({}, 503) });
+  await assert.rejects(failing.getFeeds(), /Transit feeds HTTP 503/);
+  const malformed = createTransitSource({
+    fetchImpl: async () => json({ feeds: {} }),
+  });
+  await assert.rejects(malformed.getFeeds(), /Malformed transit feed catalog/);
+  const aborted = new AbortController();
+  aborted.abort();
+  await assert.rejects(
+    createTransitSource({
+      fetchImpl: async () => json({ feeds: [] }),
+    }).getFeeds({ signal: aborted.signal }),
+    (error) => error.name === 'AbortError',
+  );
+});

src/layers/vessels/cameraArea.js

@@ -0,0 +1,33 @@
+import * as Cesium from 'cesium';
+import { viewAreaRadiusKm } from './viewArea.js';
+
+/**
+ * The area a viewer is looking at, as `{ lat, lon, radiusKm }`: centered on
+ * the point in the middle of the screen (or below the camera when the middle
+ * shows sky), sized by the camera's height. Null for a view that wants every
+ * vessel.
+ */
+export function vesselViewArea(viewer) {
+  const camera = viewer?.camera;
+  const scene = viewer?.scene;
+  const height = camera?.positionCartographic?.height;
+  const radiusKm = viewAreaRadiusKm(height);
+  if (radiusKm == null) return null;
+  let center = camera.positionCartographic;
+  const canvas = scene?.canvas;
+  if (canvas?.clientWidth && canvas?.clientHeight) {
+    try {
+      const hit = camera.pickEllipsoid(
+        new Cesium.Cartesian2(canvas.clientWidth / 2, canvas.clientHeight / 2),
+        scene.globe?.ellipsoid,
+      );
+      if (hit) center = Cesium.Cartographic.fromCartesian(hit);
+    } catch {
+      /* the camera position stands in */
+    }
+  }
+  const lat = Cesium.Math.toDegrees(center.latitude);
+  const lon = Cesium.Math.toDegrees(center.longitude);
+  if (!Number.isFinite(lat) || !Number.isFinite(lon)) return null;
+  return { lat, lon, radiusKm };
+}

src/layers/vessels/index.js

@@ -1,6 +1,7 @@
 import { createVesselState } from './state.js';
 import { createLifecycle } from './lifecycle.js';
 import { createIngestion } from './ingestion.js';
+import { vesselViewArea } from './cameraArea.js';
 import { createVesselSnapshotRenderer } from './snapshotRenderer.js';
 import { createRendering } from './rendering.js';
 import { createSelection } from './selection.js';
@@ -36,6 +37,7 @@ export function createVesselLayer({ source, services, options = {} } = {}) {
     feed: vesselState.state.feed,
     readSource: () => vesselState._source,
     readViewer: () => vesselState.state.viewer,
+    readArea: vesselViewArea,
     getRowLimit: parts.rendering.renderRowLimit,
     readCount: () => vesselState.state.records.all.length,
     applyRows: parts.snapshots.reconcileVessels,

src/layers/vessels/ingestion.js

@@ -1,10 +1,12 @@
 import { AIS_FIRST_CONNECT_LABEL } from './recordPolicy.js';
+import { viewAreaMovedEnough } from './viewArea.js';
 
 /** Own source requests and classified feed state through explicit operations. */
 export function createIngestion({
   feed,
   readSource,
   readViewer,
+  readArea = () => null,
   getRowLimit,
   readCount,
   applyRows,
@@ -34,8 +36,11 @@ export function createIngestion({
               AbortSignal.timeout(10000),
             ])
           : requestController.signal;
+      // Ask for the vessels in view; a wide view asks for every vessel.
+      const area = readArea(viewer);
+      feed.lastArea = area;
       const snapshot = await readSource().getSnapshot(
-        { maxRows: getRowLimit() },
+        { maxRows: getRowLimit(), ...(area ? { area } : {}) },
         { signal },
       );
       if (!ownsAisRequest(requestController, requestSessionId)) return;
@@ -169,6 +174,15 @@ export function createIngestion({
           : new Date(record.observedAtMs).toISOString(),
     };
   }
+  /** Ask again when the view moved away from the last area asked for. */
+  function refreshIfMoved(viewer) {
+    if (!feed.enabled || feed.loading) return Promise.resolve();
+    const active = viewer || readViewer();
+    if (!viewAreaMovedEnough(feed.lastArea ?? null, readArea(active)))
+      return Promise.resolve();
+    return loadLivePositions(active);
+  }
+
   const methods = {
     update(viewer) {
       if (!feed.enabled) return Promise.resolve();
@@ -178,6 +192,7 @@ export function createIngestion({
 
   return {
     loadLivePositions,
+    refreshIfMoved,
     ownsAisRequest,
     applyAisFeedSnapshot,
     vesselDisplayRow,
@@ -209,5 +224,9 @@ export function createVesselFeed() {
     firstConnectDeadline: null,
     firstConnectTimer: null,
     abort: null,
+    /** The area last asked for, null for every vessel. */
+    lastArea: null,
+    /** Stops listening for camera moves. */
+    removeViewListener: null,
   };
 }

src/layers/vessels/ingestion.test.mjs

@@ -104,3 +104,46 @@ test('vessel ingestion converts source units once and retains warm records on a
   assert.equal(probe.feed.loading, false);
   assert.equal(probe.feed.abort, null);
 });
+
+test('vessels are asked for by the area in view, and again only when the view moves away', async () => {
+  const asked = [];
+  let area = { lat: 37.8, lon: -122.4, radiusKm: 40 };
+  const feed = createVesselFeed();
+  feed.enabled = true;
+  feed.sessionId = 1;
+  const ingestion = createIngestion({
+    feed,
+    readSource: () => ({
+      getSnapshot: async (query) => {
+        asked.push(query);
+        return { records: [], source: 'Feed' };
+      },
+    }),
+    readViewer: () => ({}),
+    readArea: () => area,
+    getRowLimit: () => 500,
+    readCount: () => 0,
+    now: () => 0,
+    setSourceLabel: () => {},
+    applyRows: () => {},
+    classifySnapshot: () => ({
+      acceptedRows: [],
+      acceptedRowCount: 0,
+      rawRowCount: 0,
+    }),
+    isDefinitiveTransportFailure: () => false,
+    isGraceEligibleTransport: () => false,
+    markUnavailable: () => {},
+    settleFirstConnect: () => {},
+  });
+  await ingestion.methods.update();
+  assert.deepEqual(asked, [{ maxRows: 500, area }]);
+  await ingestion.refreshIfMoved();
+  assert.equal(asked.length, 1);
+  area = { ...area, lat: 38.2 };
+  await ingestion.refreshIfMoved();
+  assert.deepEqual(asked.at(-1), { maxRows: 500, area });
+  area = null;
+  await ingestion.refreshIfMoved();
+  assert.deepEqual(asked.at(-1), { maxRows: 500 });
+});

src/layers/vessels/lifecycle.js

@@ -196,10 +196,18 @@ export function createLifecycle({
         state.records.byMmsi.has(pickedId),
       );
       restoreSpriteOrderOnEnable('ais', activeViewer);
+      // Vessels are asked for by view, so ask again when the view moves away.
+      removeViewListener();
+      const moveEnd = activeViewer?.camera?.moveEnd;
+      if (typeof moveEnd?.addEventListener === 'function')
+        state.feed.removeViewListener = moveEnd.addEventListener(() => {
+          components.ingestion.refreshIfMoved(activeViewer);
+        });
       return components.ingestion.loadLivePositions(activeViewer);
     },
 
     disable() {
+      removeViewListener();
       state.feed.enabled = false;
       invalidateAisSession();
       releaseContinuousRender('ais-vessels');
@@ -218,6 +226,7 @@ export function createLifecycle({
     },
 
     destroy(viewer) {
+      removeViewListener();
       const activeViewer = viewer || state.viewer;
       invalidateAisSession();
       releaseContinuousRender('ais-vessels'); // direct-destroy path (perf wave 2 fix)
@@ -241,6 +250,12 @@ export function createLifecycle({
     },
   };
 
+  function removeViewListener() {
+    const remove = state.feed.removeViewListener;
+    state.feed.removeViewListener = null;
+    if (typeof remove === 'function') remove();
+  }
+
   return {
     clearFirstConnectTimer,
     invalidateAisSession,

src/layers/vessels/viewArea.js

@@ -0,0 +1,31 @@
+/** Smallest area asked for around the view, in kilometres. */
+export const VIEW_AREA_MIN_RADIUS_KM = 10;
+/** Largest area asked for; a wider view asks for every vessel instead. */
+export const VIEW_AREA_MAX_RADIUS_KM = 450;
+
+/**
+ * The radius worth asking for from a camera this high, in kilometres: about
+ * the height, so the area covers what a camera looking down shows. Null when
+ * the view is wide enough that every vessel is wanted.
+ */
+export function viewAreaRadiusKm(heightM) {
+  if (!Number.isFinite(heightM)) return null;
+  const radiusKm = heightM / 1000;
+  if (radiusKm > VIEW_AREA_MAX_RADIUS_KM) return null;
+  return Math.max(VIEW_AREA_MIN_RADIUS_KM, radiusKm);
+}
+
+/**
+ * Whether a view moved far enough from the last area asked for to ask
+ * again: its radius changed by a quarter, or its center moved a quarter of
+ * the radius. Switching between an area and every vessel always counts.
+ */
+export function viewAreaMovedEnough(previous, next) {
+  if (!previous || !next) return previous !== next;
+  if (Math.abs(next.radiusKm - previous.radiusKm) >= previous.radiusKm * 0.25)
+    return true;
+  const lat = ((previous.lat + next.lat) / 2) * (Math.PI / 180);
+  const dLat = (next.lat - previous.lat) * 111.32;
+  const dLon = (next.lon - previous.lon) * 111.32 * Math.cos(lat);
+  return Math.hypot(dLat, dLon) >= previous.radiusKm * 0.25;
+}

src/layers/vessels/viewArea.test.mjs

@@ -0,0 +1,30 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import {
+  VIEW_AREA_MAX_RADIUS_KM,
+  VIEW_AREA_MIN_RADIUS_KM,
+  viewAreaMovedEnough,
+  viewAreaRadiusKm,
+} from './viewArea.js';
+
+test('the area asked for follows the camera height, and a wide view asks for every vessel', () => {
+  assert.equal(viewAreaRadiusKm(2_000), VIEW_AREA_MIN_RADIUS_KM);
+  assert.equal(viewAreaRadiusKm(80_000), 80);
+  assert.equal(
+    viewAreaRadiusKm(VIEW_AREA_MAX_RADIUS_KM * 1000),
+    VIEW_AREA_MAX_RADIUS_KM,
+  );
+  assert.equal(viewAreaRadiusKm(VIEW_AREA_MAX_RADIUS_KM * 1000 + 1), null);
+  assert.equal(viewAreaRadiusKm(Number.NaN), null);
+});
+
+test('a view asks again only after moving or zooming a quarter of its radius', () => {
+  const here = { lat: 37.8, lon: -122.4, radiusKm: 40 };
+  assert.equal(viewAreaMovedEnough(null, here), true);
+  assert.equal(viewAreaMovedEnough(here, null), true);
+  assert.equal(viewAreaMovedEnough(null, null), false);
+  assert.equal(viewAreaMovedEnough(here, { ...here, lat: 37.85 }), false);
+  assert.equal(viewAreaMovedEnough(here, { ...here, lat: 37.9 }), true);
+  assert.equal(viewAreaMovedEnough(here, { ...here, radiusKm: 45 }), false);
+  assert.equal(viewAreaMovedEnough(here, { ...here, radiusKm: 55 }), true);
+});

src/layers/weather/source.js

@@ -132,5 +132,19 @@ export function createWeatherSource({
         signal?.removeEventListener('abort', abort);
       }
     },
+    /** Read one image frame through the bounded image route. */
+    async getImage({ product, time, size, bbox = null, signal } = {}) {
+      signal?.throwIfAborted();
+      const response = await fetchImpl(
+        weatherImageUrl(product, time, size, bbox),
+        { signal, redirect: 'error' },
+      );
+      if (!response.ok)
+        throw new Error(`Weather image HTTP ${response.status}`);
+      const bytes = new Uint8Array(await response.arrayBuffer());
+      signal?.throwIfAborted();
+      const type = response.headers.get('content-type') || '';
+      return { contentType: type.split(';')[0].trim().toLowerCase(), bytes };
+    },
   };
 }

src/layers/weather/source.test.mjs

@@ -162,3 +162,40 @@ test('detail-window image URLs carry the bbox and omit the default detail size',
     /size/,
   );
 });
+
+test('image frames are read through the bounded image route', async () => {
+  const png = Uint8Array.from([0x89, 0x50, 0x4e, 0x47]);
+  const requested = [];
+  const source = createWeatherSource({
+    fetchImpl: async (url, init) => {
+      requested.push({ url, redirect: init.redirect });
+      return new Response(png, { headers: { 'Content-Type': 'image/PNG' } });
+    },
+  });
+  const frame = await source.getImage({
+    product: 'radar',
+    time,
+    size: { width: 1024, height: 512 },
+    bbox: { west: -100, south: 30, east: -96, north: 32 },
+  });
+  assert.equal(frame.contentType, 'image/png');
+  assert.deepEqual([...frame.bytes], [...png]);
+  assert.deepEqual(requested, [
+    {
+      url: weatherImageUrl(
+        'radar',
+        time,
+        { width: 1024, height: 512 },
+        { west: -100, south: 30, east: -96, north: 32 },
+      ),
+      redirect: 'error',
+    },
+  ]);
+  const failing = createWeatherSource({
+    fetchImpl: async () => new Response(null, { status: 409 }),
+  });
+  await assert.rejects(
+    failing.getImage({ product: 'radar', time }),
+    /Weather image HTTP 409/,
+  );
+});