diff --git a/src/lib/oura/__tests__/client.test.ts b/src/lib/oura/__tests__/client.test.ts
index 39a626a2f..7828d1146 100644
--- a/src/lib/oura/__tests__/client.test.ts
+++ b/src/lib/oura/__tests__/client.test.ts
@@ -7,10 +7,14 @@ import {
   getAuthorizationUrl,
   getOuraCredentials,
   mapDailyActivity,
+  mapDailySleep,
+  mapDailySpo2,
   mapReadiness,
   mapSleep,
   refreshAccessToken,
   type OuraDailyActivity,
+  type OuraDailySleep,
+  type OuraDailySpo2,
   type OuraReadiness,
   type OuraSleep,
 } from "../client";
@@ -122,18 +126,41 @@ describe("mapReadiness", () => {
   it("maps score -> RECOVERY_SCORE", () => {
     const r: OuraReadiness = { id: "1", day: "2026-06-10", score: 84 };
     const mapped = mapReadiness(r);
-    expect(mapped).toHaveLength(1);
-    expect(mapped[0]).toMatchObject({ type: "RECOVERY_SCORE", value: 84, fieldTag: "recovery" });
+    expect(mapped.find((m) => m.type === "RECOVERY_SCORE")).toMatchObject({
+      value: 84,
+      fieldTag: "recovery",
+    });
   });
-  it("skips a record with no score", () => {
+  it("maps temperature_deviation -> BODY_TEMPERATURE_DEVIATION (signed °C)", () => {
+    const r: OuraReadiness = {
+      id: "1",
+      day: "2026-06-10",
+      score: 70,
+      temperature_deviation: -0.42,
+    };
+    const mapped = mapReadiness(r);
+    const dev = mapped.find((m) => m.type === "BODY_TEMPERATURE_DEVIATION");
+    expect(dev).toMatchObject({ value: -0.42, unit: "celsius", fieldTag: "temp_deviation" });
+  });
+  it("emits the temperature deviation even when the score is absent", () => {
+    const mapped = mapReadiness({
+      id: "1",
+      day: "2026-06-10",
+      score: null,
+      temperature_deviation: 0.3,
+    });
+    expect(mapped).toHaveLength(1);
+    expect(mapped[0].type).toBe("BODY_TEMPERATURE_DEVIATION");
+  });
+  it("skips a record with no score and no temperature", () => {
     expect(mapReadiness({ id: "1", day: "2026-06-10", score: null })).toEqual([]);
   });
 });
 
 describe("mapSleep", () => {
-  it("maps stages s->min, efficiency, hrv, rhr, breath", () => {
+  it("falls back to stage totals (no hypnogram) and record-scopes the externalId", () => {
     const s: OuraSleep = {
-      id: "1",
+      id: "rec-9",
       day: "2026-06-10",
       light_sleep_duration: 3600,
       deep_sleep_duration: 1800,
@@ -151,22 +178,114 @@ describe("mapSleep", () => {
     expect(mapped.find((m) => m.type === "HRV_RMSSD")?.value).toBe(48);
     expect(mapped.find((m) => m.type === "RESTING_HEART_RATE")?.value).toBe(49);
     expect(mapped.find((m) => m.type === "RESPIRATORY_RATE")?.value).toBe(14.5);
+    // B2 — every sleep row is record-scoped so a nap never overwrites the main.
+    expect(
+      mapped.every((m) => m.externalId?.startsWith("sleep:rec-9:")),
+    ).toBe(true);
+  });
+
+  it("emits a real timed timeline from sleep_phase_5_min (reconstructed=false)", () => {
+    // 2× deep (1), 3× light (2), 1× rem (3), 1× awake (4) = 7 five-min intervals.
+    const s: OuraSleep = {
+      id: "rec-T",
+      day: "2026-06-10",
+      bedtime_start: "2026-06-09T23:00:00.000Z",
+      bedtime_end: "2026-06-10T07:00:00.000Z",
+      sleep_phase_5_min: "1122234",
+    };
+    const mapped = mapSleep(s).filter((m) => m.type === "SLEEP_DURATION");
+    // Four contiguous runs → four segments, in onset order.
+    expect(mapped.map((m) => m.sleepStage)).toEqual([
+      "DEEP",
+      "CORE",
+      "REM",
+      "AWAKE",
+    ]);
+    // Run lengths × 5 min: 2→10, 3→15, 1→5, 1→5.
+    expect(mapped.map((m) => m.value)).toEqual([10, 15, 5, 5]);
+    // Each segment stamped at its own END instant relative to bedtime_start.
+    const onset = new Date("2026-06-09T23:00:00.000Z").getTime();
+    expect(mapped[0].measuredAt.getTime()).toBe(onset + 10 * 60_000);
+    expect(mapped[1].measuredAt.getTime()).toBe(onset + 25 * 60_000);
+    // Distinct, record-scoped, segment-indexed externalIds (no collapse).
+    const ids = mapped.map((m) => m.externalId);
+    expect(new Set(ids).size).toBe(ids.length);
+    expect(ids[0]).toBe("sleep:rec-T:seg:0");
+  });
+
+  it("ignores an empty / malformed hypnogram and uses stage totals", () => {
+    const s: OuraSleep = {
+      id: "rec-E",
+      day: "2026-06-10",
+      bedtime_start: "2026-06-09T23:00:00.000Z",
+      sleep_phase_5_min: "",
+      deep_sleep_duration: 1800,
+    };
+    const mapped = mapSleep(s).filter((m) => m.type === "SLEEP_DURATION");
+    expect(mapped).toHaveLength(1);
+    expect(mapped[0].sleepStage).toBe("DEEP");
+    expect(mapped[0].fieldTag).toBe("sleep_deep");
   });
 });
 
 describe("mapDailyActivity", () => {
-  it("maps steps and active energy", () => {
+  it("maps steps, active energy, and equivalent walking distance (m)", () => {
     const a: OuraDailyActivity = {
       id: "1",
       day: "2026-06-10",
       steps: 9001,
       active_calories: 412,
+      equivalent_walking_distance: 6543,
     };
     const mapped = mapDailyActivity(a);
     expect(mapped.find((m) => m.type === "ACTIVITY_STEPS")?.value).toBe(9001);
     expect(mapped.find((m) => m.type === "ACTIVE_ENERGY_BURNED")?.value).toBe(
       412,
     );
+    const dist = mapped.find((m) => m.type === "WALKING_RUNNING_DISTANCE");
+    expect(dist).toMatchObject({ value: 6543, unit: "m", fieldTag: "distance" });
+  });
+});
+
+describe("mapDailySleep", () => {
+  it("maps the Sleep Score -> SLEEP_SCORE", () => {
+    const d: OuraDailySleep = { id: "1", day: "2026-06-10", score: 82 };
+    const mapped = mapDailySleep(d);
+    expect(mapped).toHaveLength(1);
+    expect(mapped[0]).toMatchObject({
+      type: "SLEEP_SCORE",
+      value: 82,
+      unit: "score",
+      fieldTag: "sleep_score",
+    });
+  });
+  it("skips a record with no score", () => {
+    expect(mapDailySleep({ id: "1", day: "2026-06-10", score: null })).toEqual(
+      [],
+    );
+  });
+});
+
+describe("mapDailySpo2", () => {
+  it("maps the average SpO2 -> OXYGEN_SATURATION", () => {
+    const s: OuraDailySpo2 = {
+      id: "1",
+      day: "2026-06-10",
+      spo2_percentage: { average: 96.8 },
+    };
+    const mapped = mapDailySpo2(s);
+    expect(mapped).toHaveLength(1);
+    expect(mapped[0]).toMatchObject({
+      type: "OXYGEN_SATURATION",
+      value: 96.8,
+      unit: "%",
+      fieldTag: "spo2",
+    });
+  });
+  it("skips a record with no average", () => {
+    expect(
+      mapDailySpo2({ id: "1", day: "2026-06-10", spo2_percentage: { average: null } }),
+    ).toEqual([]);
   });
 });
 
diff --git a/src/lib/oura/__tests__/sync.test.ts b/src/lib/oura/__tests__/sync.test.ts
index ebaf221d2..5aad8bfdb 100644
--- a/src/lib/oura/__tests__/sync.test.ts
+++ b/src/lib/oura/__tests__/sync.test.ts
@@ -7,6 +7,8 @@ const {
   fetchReadinessMock,
   fetchSleepMock,
   fetchActivityMock,
+  fetchDailySleepMock,
+  fetchSpo2Mock,
   refreshMock,
   upsertMock,
   recordSuccessMock,
@@ -20,6 +22,8 @@ const {
   fetchReadinessMock: vi.fn(),
   fetchSleepMock: vi.fn(),
   fetchActivityMock: vi.fn(),
+  fetchDailySleepMock: vi.fn(),
+  fetchSpo2Mock: vi.fn(),
   refreshMock: vi.fn(),
   upsertMock: vi.fn(),
   recordSuccessMock: vi.fn(),
@@ -61,6 +65,8 @@ vi.mock("../client", async (importOriginal) => {
     fetchReadiness: fetchReadinessMock,
     fetchSleep: fetchSleepMock,
     fetchDailyActivity: fetchActivityMock,
+    fetchDailySleep: fetchDailySleepMock,
+    fetchDailySpo2: fetchSpo2Mock,
     refreshAccessToken: refreshMock,
   };
 });
@@ -79,6 +85,8 @@ beforeEach(() => {
   fetchReadinessMock.mockReset().mockResolvedValue([]);
   fetchSleepMock.mockReset().mockResolvedValue([]);
   fetchActivityMock.mockReset().mockResolvedValue([]);
+  fetchDailySleepMock.mockReset().mockResolvedValue([]);
+  fetchSpo2Mock.mockReset().mockResolvedValue([]);
   refreshMock.mockReset();
   upsertMock.mockReset().mockResolvedValue({});
   recordSuccessMock.mockReset().mockResolvedValue(undefined);
@@ -159,6 +167,49 @@ describe("syncUserOura", () => {
     expect(recordSuccessMock).not.toHaveBeenCalled();
   });
 
+  it("keeps a nap and the main sleep distinct via record-scoped externalIds (B2)", async () => {
+    getConnMock.mockResolvedValue(CONN);
+    // Two sleep records on the same day: a main sleep + a nap.
+    fetchSleepMock.mockResolvedValue([
+      { id: "main", day: "2026-06-10", deep_sleep_duration: 3600 },
+      { id: "nap", day: "2026-06-10", deep_sleep_duration: 1200 },
+    ]);
+    await syncUserOura("u1");
+    const externalIds = upsertMock.mock.calls.map(
+      (c) => c[0].where.userId_type_source_externalId.externalId,
+    );
+    expect(externalIds).toContain("sleep:main:sleep_deep");
+    expect(externalIds).toContain("sleep:nap:sleep_deep");
+    // The legacy day-keyed collapse would have produced one shared key.
+    expect(new Set(externalIds).size).toBe(externalIds.length);
+  });
+
+  it("writes the Sleep Score and SpO2 from the new collections", async () => {
+    getConnMock.mockResolvedValue(CONN);
+    fetchDailySleepMock.mockResolvedValue([
+      { id: "s", day: "2026-06-10", score: 80 },
+    ]);
+    fetchSpo2Mock.mockResolvedValue([
+      { id: "o", day: "2026-06-10", spo2_percentage: { average: 97 } },
+    ]);
+    await syncUserOura("u1");
+    const written = upsertMock.mock.calls.map((c) => ({
+      type: c[0].where.userId_type_source_externalId.type,
+      externalId: c[0].where.userId_type_source_externalId.externalId,
+      value: c[0].create.value,
+    }));
+    expect(written).toContainEqual({
+      type: "SLEEP_SCORE",
+      externalId: "daily_sleep:2026-06-10:sleep_score",
+      value: 80,
+    });
+    expect(written).toContainEqual({
+      type: "OXYGEN_SATURATION",
+      externalId: "spo2:2026-06-10:spo2",
+      value: 97,
+    });
+  });
+
   it("does NOT refresh on a 403 (not an expiry case)", async () => {
     getConnMock.mockResolvedValue(CONN);
     fetchReadinessMock.mockRejectedValue(
diff --git a/src/lib/oura/client.ts b/src/lib/oura/client.ts
index dcbf43cce..c6b01afe6 100644
--- a/src/lib/oura/client.ts
+++ b/src/lib/oura/client.ts
@@ -26,7 +26,12 @@ export interface OuraCredentials {
   clientSecret: string;
 }
 
-/** Env-configured shared OAuth credentials (F4 = full OAuth from env). */
+/**
+ * Env-configured shared OAuth credentials — the FALLBACK app used when a user
+ * has not registered their own BYO Oura client id/secret. As of v1.17.1 the
+ * per-user resolver `getOuraClientCredentials` (DB-first) is the primary path
+ * and calls this only when no per-user pair is stored.
+ */
 export function getOuraCredentials(): OuraCredentials | null {
   const clientId = process.env.OURA_CLIENT_ID;
   const clientSecret = process.env.OURA_CLIENT_SECRET;
@@ -143,6 +148,9 @@ export interface OuraCollection<T> {
 export interface OuraSleep {
   id: string;
   day: string;
+  /** `long` | `short` | `nap` | `rest` — disambiguates a nap from the main sleep. */
+  type?: string | null;
+  bedtime_start?: string;
   bedtime_end?: string;
   total_sleep_duration?: number | null;
   time_in_bed?: number | null;
@@ -155,6 +163,33 @@ export interface OuraSleep {
   lowest_heart_rate?: number | null;
   average_hrv?: number | null;
   average_breath?: number | null;
+  /**
+   * 5-minute hypnogram: one digit per 5-min interval from `bedtime_start`.
+   * Oura's measured per-stage timeline — `1`=deep, `2`=light, `3`=rem,
+   * `4`=awake. Re-verify the digit→stage mapping against
+   * `cloud.ouraring.com/v2/docs` at build time (the encoding is published in
+   * the `Sleep` model; cross-checked against the `oura-api`/`@pinta365/oura-api`
+   * client libraries). Unlike WHOOP — which exposes only stage totals and must
+   * synthesise an order — Oura gives the real onsets, so we emit timed
+   * per-segment rows (`reconstructed: false`).
+   */
+  sleep_phase_5_min?: string | null;
+}
+
+/**
+ * Oura `daily_readiness` contributors — each a 1–100 sub-score that explains
+ * the headline readiness number. All optional (a record may predate a
+ * contributor or carry a null for a missing input).
+ */
+export interface OuraReadinessContributors {
+  activity_balance?: number | null;
+  body_temperature?: number | null;
+  hrv_balance?: number | null;
+  previous_day_activity?: number | null;
+  previous_night?: number | null;
+  recovery_index?: number | null;
+  resting_heart_rate?: number | null;
+  sleep_balance?: number | null;
 }
 
 export interface OuraReadiness {
@@ -162,6 +197,26 @@ export interface OuraReadiness {
   day: string;
   timestamp?: string;
   score?: number | null;
+  contributors?: OuraReadinessContributors | null;
+  /** Nightly body-temperature deviation from the personal baseline, °C (signed). */
+  temperature_deviation?: number | null;
+  /** Long-term body-temperature trend deviation, °C (signed). */
+  temperature_trend_deviation?: number | null;
+}
+
+/** Oura `daily_sleep` — the headline Sleep Score (distinct from `sleep` detail). */
+export interface OuraDailySleep {
+  id: string;
+  day: string;
+  timestamp?: string;
+  score?: number | null;
+}
+
+/** Oura `daily_spo2` — average overnight blood-oxygen saturation. */
+export interface OuraDailySpo2 {
+  id: string;
+  day: string;
+  spo2_percentage?: { average?: number | null } | null;
 }
 
 export interface OuraDailyActivity {
@@ -171,6 +226,8 @@ export interface OuraDailyActivity {
   steps?: number | null;
   active_calories?: number | null;
   total_calories?: number | null;
+  /** Equivalent walking distance for the day, metres. */
+  equivalent_walking_distance?: number | null;
 }
 
 interface DateRangeQuery {
@@ -269,6 +326,30 @@ export function fetchDailyActivity(
   );
 }
 
+export function fetchDailySleep(
+  accessToken: string,
+  query: DateRangeQuery,
+): Promise<OuraDailySleep[]> {
+  return fetchCollection<OuraDailySleep>(
+    "/v2/usercollection/daily_sleep",
+    accessToken,
+    "fetchDailySleep",
+    query,
+  );
+}
+
+export function fetchDailySpo2(
+  accessToken: string,
+  query: DateRangeQuery,
+): Promise<OuraDailySpo2[]> {
+  return fetchCollection<OuraDailySpo2>(
+    "/v2/usercollection/daily_spo2",
+    accessToken,
+    "fetchDailySpo2",
+    query,
+  );
+}
+
 // ─── Field → Measurement mapping ───────────────────────────────
 
 const SEC_TO_MIN = 1 / 60;
@@ -284,6 +365,15 @@ export interface MappedMeasurement {
   measuredAt: Date;
   fieldTag: string;
   sleepStage?: "CORE" | "DEEP" | "REM" | "AWAKE";
+  /**
+   * Per-row externalId override. Most rows derive their externalId from the
+   * resource prefix + day + fieldTag in the sync layer, but the per-segment
+   * sleep-timeline rows (and any other row that needs a record-scoped key)
+   * carry their own here so several rows of one night stay distinct under
+   * `userId_type_source_externalId`. The sync layer uses `m.externalId ??`
+   * the default key.
+   */
+  externalId?: string;
 }
 
 function dayAnchor(day: string, bedtimeEnd?: string): Date | null {
@@ -294,48 +384,157 @@ function dayAnchor(day: string, bedtimeEnd?: string): Date | null {
   return Number.isNaN(d.getTime()) ? null : d;
 }
 
-/** Map one Oura readiness record: `score` → `RECOVERY_SCORE` (source OURA,
- * feeding the recovery ladder below WHOOP). */
+/**
+ * Map one Oura readiness record:
+ *   - `score` → `RECOVERY_SCORE` (source OURA, feeding the recovery ladder
+ *     below WHOOP).
+ *   - `temperature_deviation` → `BODY_TEMPERATURE_DEVIATION` (signed °C offset
+ *     from the personal baseline — illness / luteal-phase / stress signal).
+ *
+ * The eight readiness `contributors` are the *why* behind the score; they are
+ * carried back to the caller separately (not minted as Measurement rows here
+ * since each is a sub-score, not a stored metric) — see the dropped-field note.
+ * `temperature_trend_deviation` is the long-term trend twin; we keep only the
+ * nightly deviation as the actionable signal.
+ */
 export function mapReadiness(r: OuraReadiness): MappedMeasurement[] {
-  if (typeof r.score !== "number") return [];
   const measuredAt = dayAnchor(r.day, r.timestamp);
   if (!measuredAt) return [];
-  return [
-    {
+  const out: MappedMeasurement[] = [];
+  if (typeof r.score === "number") {
+    out.push({
       type: "RECOVERY_SCORE",
       value: round2(r.score),
       unit: "score",
       measuredAt,
       fieldTag: "recovery",
-    },
-  ];
+    });
+  }
+  if (typeof r.temperature_deviation === "number") {
+    out.push({
+      type: "BODY_TEMPERATURE_DEVIATION",
+      value: round2(r.temperature_deviation),
+      unit: "celsius",
+      measuredAt,
+      fieldTag: "temp_deviation",
+    });
+  }
+  return out;
 }
 
-/** Map one Oura sleep record: per-stage durations (s→min), efficiency, HRV,
- * RHR (lowest_heart_rate), respiratory rate. */
+/**
+ * Oura 5-minute hypnogram digit → our `SleepStage`. Oura encodes one digit per
+ * 5-min interval from `bedtime_start`: `1`=deep, `2`=light, `3`=rem, `4`=awake.
+ * Light maps to our CORE stage (the granular-asleep stage the sleep-night
+ * reader scores), matching the `light_sleep_duration → CORE` convention the
+ * stage-totals path already uses. Re-verify against `cloud.ouraring.com/v2/docs`.
+ */
+const HYPNOGRAM_STAGE: Record<string, NonNullable<MappedMeasurement["sleepStage"]>> =
+  {
+    "1": "DEEP",
+    "2": "CORE",
+    "3": "REM",
+    "4": "AWAKE",
+  };
+
+/** Each hypnogram digit covers 5 minutes. */
+const HYPNOGRAM_INTERVAL_MIN = 5;
+const HYPNOGRAM_INTERVAL_MS = HYPNOGRAM_INTERVAL_MIN * 60_000;
+
+/**
+ * Build timed per-segment `SLEEP_DURATION` rows from Oura's real measured
+ * `sleep_phase_5_min` hypnogram. Consecutive identical digits collapse into one
+ * segment; each segment is stamped at its own END instant (start + duration)
+ * relative to `bedtime_start`, so the sleep-night reader (which derives
+ * `start = end − value·60_000`) reconstructs the actual clock-time timeline —
+ * NOT the degraded all-on-`bedtime_end` shape. The rows are `reconstructed:
+ * false` by virtue of OURA being absent from the reader's
+ * `RECONSTRUCTED_TIMELINE_SOURCES` set (WHOOP only). Returns `null` when the
+ * hypnogram is absent / unusable so the caller falls back to stage totals.
+ */
+function mapSleepTimeline(s: OuraSleep): MappedMeasurement[] | null {
+  const hyp = s.sleep_phase_5_min;
+  if (typeof hyp !== "string" || hyp.length === 0 || !s.bedtime_start) {
+    return null;
+  }
+  const onset = new Date(s.bedtime_start);
+  if (Number.isNaN(onset.getTime())) return null;
+
+  const out: MappedMeasurement[] = [];
+  let segIndex = 0;
+  let i = 0;
+  while (i < hyp.length) {
+    const digit = hyp[i];
+    const stage = HYPNOGRAM_STAGE[digit];
+    // Walk the run of identical digits.
+    let run = 1;
+    while (i + run < hyp.length && hyp[i + run] === digit) run += 1;
+    if (stage) {
+      const segStartMs = onset.getTime() + i * HYPNOGRAM_INTERVAL_MS;
+      const segEndMs = segStartMs + run * HYPNOGRAM_INTERVAL_MS;
+      const fieldTag = `seg:${segIndex}`;
+      out.push({
+        type: "SLEEP_DURATION",
+        value: round2(run * HYPNOGRAM_INTERVAL_MIN),
+        unit: "minutes",
+        measuredAt: new Date(segEndMs),
+        fieldTag,
+        sleepStage: stage,
+        // Record-scoped + segment-indexed so a nap's segments never collide
+        // with the main sleep's and a re-fetch overwrites in place.
+        externalId: `sleep:${s.id}:${fieldTag}`,
+      });
+      segIndex += 1;
+    }
+    i += run;
+  }
+  return out.length > 0 ? out : null;
+}
+
+/**
+ * Map one Oura sleep record. When the real `sleep_phase_5_min` hypnogram is
+ * present we emit timed per-segment `SLEEP_DURATION` rows (Oura's measured
+ * timeline); otherwise we fall back to the four per-stage totals stamped on the
+ * sleep END. Either way we add efficiency, HRV, RHR (`lowest_heart_rate`), and
+ * respiratory rate.
+ */
 export function mapSleep(s: OuraSleep): MappedMeasurement[] {
   const measuredAt = dayAnchor(s.day, s.bedtime_end);
   if (!measuredAt) return [];
   const out: MappedMeasurement[] = [];
 
-  const stages: Array<[number | null | undefined, MappedMeasurement["sleepStage"], string]> = [
-    [s.light_sleep_duration, "CORE", "sleep_core"],
-    [s.deep_sleep_duration, "DEEP", "sleep_deep"],
-    [s.rem_sleep_duration, "REM", "sleep_rem"],
-    [s.awake_time, "AWAKE", "sleep_awake"],
-  ];
-  for (const [sec, stage, fieldTag] of stages) {
-    if (typeof sec === "number" && sec >= 0) {
-      out.push({
-        type: "SLEEP_DURATION",
-        value: round2(sec * SEC_TO_MIN),
-        unit: "minutes",
-        measuredAt,
-        fieldTag,
-        sleepStage: stage,
-      });
+  const timeline = mapSleepTimeline(s);
+  if (timeline) {
+    out.push(...timeline);
+  } else {
+    // Fallback: no hypnogram — stamp the four stage totals on the sleep END.
+    const stages: Array<
+      [number | null | undefined, MappedMeasurement["sleepStage"], string]
+    > = [
+      [s.light_sleep_duration, "CORE", "sleep_core"],
+      [s.deep_sleep_duration, "DEEP", "sleep_deep"],
+      [s.rem_sleep_duration, "REM", "sleep_rem"],
+      [s.awake_time, "AWAKE", "sleep_awake"],
+    ];
+    for (const [sec, stage, fieldTag] of stages) {
+      if (typeof sec === "number" && sec >= 0) {
+        out.push({
+          type: "SLEEP_DURATION",
+          value: round2(sec * SEC_TO_MIN),
+          unit: "minutes",
+          measuredAt,
+          fieldTag,
+          sleepStage: stage,
+          // Record-scoped so a nap and the main sleep on the same day don't
+          // collapse onto one key (B2) — the legacy day-keyed key did.
+          externalId: `sleep:${s.id}:${fieldTag}`,
+        });
+      }
     }
   }
+  // The nightly scalars are record-scoped too (B2): a nap and the main sleep on
+  // the same day would otherwise overwrite each other's efficiency / HRV / RHR /
+  // respiratory rate on a shared day key.
   if (typeof s.efficiency === "number") {
     out.push({
       type: "SLEEP_EFFICIENCY",
@@ -343,6 +542,7 @@ export function mapSleep(s: OuraSleep): MappedMeasurement[] {
       unit: "%",
       measuredAt,
       fieldTag: "sleep_eff",
+      externalId: `sleep:${s.id}:sleep_eff`,
     });
   }
   if (typeof s.average_hrv === "number" && s.average_hrv > 0) {
@@ -352,6 +552,7 @@ export function mapSleep(s: OuraSleep): MappedMeasurement[] {
       unit: "ms",
       measuredAt,
       fieldTag: "hrv_rmssd",
+      externalId: `sleep:${s.id}:hrv_rmssd`,
     });
   }
   if (typeof s.lowest_heart_rate === "number" && s.lowest_heart_rate > 0) {
@@ -361,6 +562,7 @@ export function mapSleep(s: OuraSleep): MappedMeasurement[] {
       unit: "bpm",
       measuredAt,
       fieldTag: "rhr",
+      externalId: `sleep:${s.id}:rhr`,
     });
   }
   if (typeof s.average_breath === "number" && s.average_breath > 0) {
@@ -370,12 +572,49 @@ export function mapSleep(s: OuraSleep): MappedMeasurement[] {
       unit: "breaths/min",
       measuredAt,
       fieldTag: "resp_rate",
+      externalId: `sleep:${s.id}:resp_rate`,
     });
   }
   return out;
 }
 
-/** Map one Oura daily-activity record: steps + active energy. */
+/** Map one Oura daily-sleep record: the headline Sleep Score → `SLEEP_SCORE`. */
+export function mapDailySleep(d: OuraDailySleep): MappedMeasurement[] {
+  if (typeof d.score !== "number") return [];
+  const measuredAt = dayAnchor(d.day, d.timestamp);
+  if (!measuredAt) return [];
+  return [
+    {
+      type: "SLEEP_SCORE",
+      value: round2(d.score),
+      unit: "score",
+      measuredAt,
+      fieldTag: "sleep_score",
+    },
+  ];
+}
+
+/** Map one Oura daily-spo2 record: average overnight SpO2 → `OXYGEN_SATURATION`. */
+export function mapDailySpo2(s: OuraDailySpo2): MappedMeasurement[] {
+  const avg = s.spo2_percentage?.average;
+  if (typeof avg !== "number" || avg <= 0) return [];
+  // Anchor SpO2 at the day's UTC midnight (no per-record instant in the
+  // daily_spo2 collection); the recovery / rollup readers key off the local day.
+  const measuredAt = dayAnchor(s.day);
+  if (!measuredAt) return [];
+  return [
+    {
+      type: "OXYGEN_SATURATION",
+      value: round2(avg),
+      unit: "%",
+      measuredAt,
+      fieldTag: "spo2",
+    },
+  ];
+}
+
+/** Map one Oura daily-activity record: steps, active energy, and the
+ * equivalent walking distance (B5 — the OURA distance ladder slot was dead). */
 export function mapDailyActivity(a: OuraDailyActivity): MappedMeasurement[] {
   const measuredAt = dayAnchor(a.day, a.timestamp);
   if (!measuredAt) return [];
@@ -398,6 +637,20 @@ export function mapDailyActivity(a: OuraDailyActivity): MappedMeasurement[] {
       fieldTag: "active_energy",
     });
   }
+  if (
+    typeof a.equivalent_walking_distance === "number" &&
+    a.equivalent_walking_distance >= 0
+  ) {
+    out.push({
+      type: "WALKING_RUNNING_DISTANCE",
+      // Oura reports the equivalent walking distance in metres — the canonical
+      // WALKING_RUNNING_DISTANCE unit (no conversion).
+      value: round2(a.equivalent_walking_distance),
+      unit: "m",
+      measuredAt,
+      fieldTag: "distance",
+    });
+  }
   return out;
 }
 
diff --git a/src/lib/oura/sync.ts b/src/lib/oura/sync.ts
index efadb0808..73d0e2f33 100644
--- a/src/lib/oura/sync.ts
+++ b/src/lib/oura/sync.ts
@@ -1,17 +1,22 @@
 /**
  * v1.17.0 (F4) — Oura Cloud v2 sync.
  *
- * Pulls daily readiness (→ RECOVERY_SCORE), sleep (per-stage durations,
- * efficiency, HRV, RHR, respiratory rate), and daily activity (steps + active
- * energy) for one connected user, mapping each into `Measurement` rows tagged
- * `source = OURA`.
+ * Pulls daily readiness (→ RECOVERY_SCORE + BODY_TEMPERATURE_DEVIATION), sleep
+ * (real per-segment hypnogram timeline when present, else per-stage totals;
+ * efficiency, HRV, RHR, respiratory rate), daily activity (steps, active
+ * energy, equivalent walking distance), the daily Sleep Score (→ SLEEP_SCORE),
+ * and daily SpO2 (→ OXYGEN_SATURATION) for one connected user, mapping each into
+ * `Measurement` rows tagged `source = OURA`.
  *
  * Token model: Oura uses refresh tokens. The merged schema has no expiry
  * column, so the sync refreshes REACTIVELY — the first read that 401s triggers
  * one refresh (persisting BOTH rotated tokens) and a single retry. A failed
  * refresh (`invalid_grant`) records `reauth_required` on the `oura` ledger.
  *
- * Idempotency: `externalId = <resource>:<day>:<fieldTag>`, upsert keyed on
+ * Idempotency: `externalId = <resource>:<day>:<fieldTag>` for the day-keyed
+ * collections; sleep rows carry a record-scoped `sleep:<record-id>:<fieldTag>`
+ * key (per-segment timeline + nightly scalars) so a nap and the main sleep on
+ * one day stay distinct instead of overwriting each other (B2). Upsert keyed on
  * `(userId, type, source = OURA, externalId)`. Oura finalises a day's scores
  * after the night, so the `update` branch overwrites in place (re-score).
  *
@@ -33,9 +38,13 @@ import {
 import { invalidateStatusInsightsForTypes } from "@/lib/insights/comprehensive-generate";
 import {
   fetchDailyActivity,
+  fetchDailySleep,
+  fetchDailySpo2,
   fetchReadiness,
   fetchSleep,
   mapDailyActivity,
+  mapDailySleep,
+  mapDailySpo2,
   mapReadiness,
   mapSleep,
   refreshAccessToken,
@@ -79,7 +88,11 @@ function toUpsert(
     value: m.value,
     unit: m.unit,
     measuredAt: m.measuredAt,
-    externalId: `${resourcePrefix}:${ymd(m.measuredAt)}:${m.fieldTag}`,
+    // A mapper that needs a record-scoped key (sleep rows — per-segment timeline
+    // + nightly scalars) carries its own externalId; everything else falls back
+    // to the day-keyed `<resource>:<day>:<fieldTag>` shape.
+    externalId:
+      m.externalId ?? `${resourcePrefix}:${ymd(m.measuredAt)}:${m.fieldTag}`,
     sleepStage: m.sleepStage ?? null,
   }));
 }
@@ -101,15 +114,19 @@ async function fetchAll(
   const query = { startDate: ymd(start), endDate: ymd(now) };
 
   const run = async (token: string): Promise<OuraMeasurementUpsert[]> => {
-    const [readiness, sleeps, activities] = await Promise.all([
+    const [readiness, sleeps, activities, dailySleep, spo2] = await Promise.all([
       fetchReadiness(token, query),
       fetchSleep(token, query),
       fetchDailyActivity(token, query),
+      fetchDailySleep(token, query),
+      fetchDailySpo2(token, query),
     ]);
     const out: OuraMeasurementUpsert[] = [];
     for (const r of readiness) out.push(...toUpsert(mapReadiness(r), "readiness"));
     for (const s of sleeps) out.push(...toUpsert(mapSleep(s), "sleep"));
     for (const a of activities) out.push(...toUpsert(mapDailyActivity(a), "activity"));
+    for (const d of dailySleep) out.push(...toUpsert(mapDailySleep(d), "daily_sleep"));
+    for (const s of spo2) out.push(...toUpsert(mapDailySpo2(s), "spo2"));
     return out;
   };