diff --git a/src/analytics/slo/bi-slo.ts b/src/analytics/slo/bi-slo.ts
new file mode 100644
index 0000000..b4bad4b
--- /dev/null
+++ b/src/analytics/slo/bi-slo.ts
@@ -0,0 +1,501 @@
+/**
+ * src/analytics/slo/bi-slo.ts
+ * ============================
+ * BI-P103 — BI SLO. DoD: "measured baselines exist".
+ *
+ * An SLO you cannot measure from real telemetry is a wish, so every objective
+ * here declares WHERE its number comes from, and the evaluator refuses to
+ * produce a number it does not have. Three ways that refusal shows up, each of
+ * which is a lie the usual implementation tells:
+ *
+ *   insufficient_data     nothing (or too little) was observed in the window.
+ *                         An availability objective evaluated over zero events
+ *                         is NOT 100% attainment — it is silence. This is the
+ *                         single most common false green in SLO reporting, and
+ *                         it is the same shape BI-P025 found in a quality
+ *                         check over an empty table.
+ *   not_measurable_here   the objective is real but these events cannot
+ *                         measure it. Dashboard data FRESHNESS is a property
+ *                         of the dataset (BI-P026 / BI-P105 watermarks), not
+ *                         of a usage event, and REPORT DELIVERY is N0TIFY's
+ *                         fact — aud0's seven types carry no delivery event.
+ *                         Saying so beats fabricating a proxy.
+ *   low_confidence        a p95 or p99 computed from a handful of samples. The
+ *                         number is reported WITH its sample size and marked,
+ *                         because a p99 over 12 requests is the 12th-slowest
+ *                         request wearing a percentile's clothes.
+ *
+ * The measurement path is aud0's seven BI usage event types (BI-P076, merged
+ * in aud0#34), produced by src/analytics/slo/usage-events.ts. There is
+ * deliberately no second telemetry path: two measurement systems disagree, and
+ * the disagreement is discovered during an incident.
+ */
+import type { Aud0BiEvent } from './usage-events';
+
+export const BI_WORKLOAD_CLASSES = ['interactive_dashboard', 'exploration', 'report'] as const;
+export type BiWorkloadClass = (typeof BI_WORKLOAD_CLASSES)[number];
+
+export const SLO_OBJECTIVE_KINDS = [
+  'availability',
+  'latency_p95_first',
+  'latency_p95_cached',
+  'latency_p95',
+  'latency_p99',
+  'error_rate',
+  'freshness',
+  'max_result_rows',
+  'timeout',
+  'completion_sla',
+  'delivery_sla',
+] as const;
+export type SloObjectiveKind = (typeof SLO_OBJECTIVE_KINDS)[number];
+
+/** Where the number comes from. `none` is an admission, not a placeholder. */
+export const MEASUREMENT_SOURCES = [
+  'aud0_bi_usage_events',
+  'analytics_freshness_watermark',
+  'n0tify_delivery_receipt',
+  'engine_configuration',
+] as const;
+export type MeasurementSource = (typeof MEASUREMENT_SOURCES)[number];
+
+export interface SloObjective {
+  objective_id: string;
+  workload: BiWorkloadClass;
+  kind: SloObjectiveKind;
+  /** Target value; unit is fixed by kind (ms, ratio, rows, seconds). */
+  target: number;
+  unit: 'ms' | 'ratio' | 'rows' | 'seconds';
+  /** Higher-is-better (availability) vs lower-is-better (latency). */
+  direction: 'at_least' | 'at_most';
+  measured_from: MeasurementSource;
+  /** Fewer samples than this and the verdict carries low_confidence. */
+  min_samples: number;
+  rationale: string;
+}
+
+/**
+ * The catalogue, field-for-field with what BI-P103 lists per workload class.
+ * Targets are STARTING POINTS chosen to be honest about what has been
+ * measured: they are the thresholds the evaluator compares against, and
+ * evidence/bi-p103 records the first baselines rather than pretending the
+ * targets were derived from a year of production traffic.
+ */
+export const BI_SLO_CATALOGUE: readonly SloObjective[] = [
+  // ── interactive dashboard ────────────────────────────────────────────────
+  {
+    objective_id: 'dash.availability',
+    workload: 'interactive_dashboard',
+    kind: 'availability',
+    target: 0.995,
+    unit: 'ratio',
+    direction: 'at_least',
+    measured_from: 'aud0_bi_usage_events',
+    min_samples: 100,
+    rationale: 'completed / (completed + failed) for dashboard-surface queries.',
+  },
+  {
+    objective_id: 'dash.p95_first_query',
+    workload: 'interactive_dashboard',
+    kind: 'latency_p95_first',
+    target: 3000,
+    unit: 'ms',
+    direction: 'at_most',
+    measured_from: 'aud0_bi_usage_events',
+    min_samples: 50,
+    rationale: 'cache_hit=false: what a user waits for when they open the dashboard cold.',
+  },
+  {
+    objective_id: 'dash.p95_cached',
+    workload: 'interactive_dashboard',
+    kind: 'latency_p95_cached',
+    target: 400,
+    unit: 'ms',
+    direction: 'at_most',
+    measured_from: 'aud0_bi_usage_events',
+    min_samples: 50,
+    rationale:
+      'cache_hit=true: BI-P020 cache hits, measured separately so a high hit rate cannot hide a slow cold path.',
+  },
+  {
+    objective_id: 'dash.error_rate',
+    workload: 'interactive_dashboard',
+    kind: 'error_rate',
+    target: 0.005,
+    unit: 'ratio',
+    direction: 'at_most',
+    measured_from: 'aud0_bi_usage_events',
+    min_samples: 100,
+    rationale: 'failed / terminal. Cancellations count as failures here: the user did not get an answer.',
+  },
+  {
+    objective_id: 'dash.freshness',
+    workload: 'interactive_dashboard',
+    kind: 'freshness',
+    target: 900,
+    unit: 'seconds',
+    direction: 'at_most',
+    measured_from: 'analytics_freshness_watermark',
+    min_samples: 1,
+    rationale:
+      'Data age is a property of the DATASET (BI-P026 freshness, BI-P105 watermark), not of a usage ' +
+      'event. Usage events cannot measure it and this evaluator does not pretend to.',
+  },
+  // ── exploration ──────────────────────────────────────────────────────────
+  {
+    objective_id: 'explore.p95',
+    workload: 'exploration',
+    kind: 'latency_p95',
+    target: 10_000,
+    unit: 'ms',
+    direction: 'at_most',
+    measured_from: 'aud0_bi_usage_events',
+    min_samples: 50,
+    rationale: 'explore-surface queries; an analyst tolerates more than a dashboard viewer.',
+  },
+  {
+    objective_id: 'explore.p99',
+    workload: 'exploration',
+    kind: 'latency_p99',
+    target: 60_000,
+    unit: 'ms',
+    direction: 'at_most',
+    measured_from: 'aud0_bi_usage_events',
+    min_samples: 200,
+    rationale: 'p99 needs a genuinely large sample; below min_samples it is reported as low confidence.',
+  },
+  {
+    objective_id: 'explore.max_result',
+    workload: 'exploration',
+    kind: 'max_result_rows',
+    target: 1_000_000,
+    unit: 'rows',
+    direction: 'at_most',
+    measured_from: 'aud0_bi_usage_events',
+    min_samples: 1,
+    rationale: 'BI-P012 truncates at the engine ceiling; this watches what actually came back.',
+  },
+  {
+    objective_id: 'explore.timeout',
+    workload: 'exploration',
+    kind: 'timeout',
+    target: 300,
+    unit: 'seconds',
+    direction: 'at_most',
+    measured_from: 'engine_configuration',
+    min_samples: 1,
+    rationale: 'The configured ceiling (BI-P012 settings profile), not an observation.',
+  },
+  // ── reports ──────────────────────────────────────────────────────────────
+  {
+    objective_id: 'report.completion_sla',
+    workload: 'report',
+    kind: 'completion_sla',
+    target: 900_000,
+    unit: 'ms',
+    direction: 'at_most',
+    measured_from: 'aud0_bi_usage_events',
+    min_samples: 20,
+    rationale: 'aud0.report_generated duration_ms: submitted to produced.',
+  },
+  {
+    objective_id: 'report.delivery_sla',
+    workload: 'report',
+    kind: 'delivery_sla',
+    target: 300_000,
+    unit: 'ms',
+    direction: 'at_most',
+    measured_from: 'n0tify_delivery_receipt',
+    min_samples: 20,
+    rationale:
+      "Produced is not delivered. aud0 has no delivery event; the receipt is N0TIFY's, so this " +
+      'objective is declared and reported unmeasured rather than proxied by completion.',
+  },
+];
+
+export const SLO_STATUSES = ['met', 'breached', 'insufficient_data', 'not_measurable_here'] as const;
+export type SloStatus = (typeof SLO_STATUSES)[number];
+
+export interface SloResult {
+  objective_id: string;
+  workload: BiWorkloadClass;
+  kind: SloObjectiveKind;
+  status: SloStatus;
+  target: number;
+  unit: SloObjective['unit'];
+  /** The measured value, or undefined when nothing could be measured. */
+  observed?: number;
+  sample_size: number;
+  /** True when a percentile was computed from fewer samples than min_samples. */
+  low_confidence?: boolean;
+  detail: string;
+}
+
+export interface SloReport {
+  window_from: string;
+  window_to: string;
+  results: SloResult[];
+  /** Queries that started and never reached a terminal event in the window. */
+  unresolved_queries: number;
+  /** True only when EVERY objective produced a real number. */
+  fully_measured: boolean;
+}
+
+interface QueryFact {
+  query_id: string;
+  surface?: string;
+  started_at: number;
+  outcome?: 'completed' | 'failed';
+  duration_ms?: number;
+  row_count?: number;
+  cache_hit?: boolean;
+}
+
+function num(v: unknown): number | undefined {
+  return typeof v === 'number' && Number.isFinite(v) ? v : undefined;
+}
+
+function str(v: unknown): string | undefined {
+  return typeof v === 'string' ? v : undefined;
+}
+
+/**
+ * Nearest-rank percentile. No interpolation: with small samples an
+ * interpolated p99 invents a value that no request ever experienced.
+ */
+export function percentile(sorted: number[], q: number): number | undefined {
+  if (sorted.length === 0) return undefined;
+  const rank = Math.ceil(q * sorted.length);
+  return sorted[Math.min(sorted.length - 1, Math.max(0, rank - 1))];
+}
+
+/** Fold the seven event types into per-query facts. */
+function foldQueries(events: Aud0BiEvent[]): Map<string, QueryFact> {
+  const facts = new Map<string, QueryFact>();
+  for (const e of events) {
+    const qid = str(e.payload.query_id);
+    if (!qid) continue;
+    const at = Date.parse(e.occurred_at);
+    const existing = facts.get(qid) ?? { query_id: qid, started_at: Number.isNaN(at) ? 0 : at };
+    if (e.payload.surface !== undefined) existing.surface = str(e.payload.surface);
+    if (e.event_type === 'aud0.analytics_query_started' && !Number.isNaN(at)) existing.started_at = at;
+    if (e.event_type === 'aud0.analytics_query_completed') {
+      existing.outcome = 'completed';
+      existing.duration_ms = num(e.payload.duration_ms);
+      existing.row_count = num(e.payload.row_count);
+      existing.cache_hit = e.payload.cache_hit === true;
+    }
+    if (e.event_type === 'aud0.analytics_query_failed') {
+      existing.outcome = 'failed';
+      existing.duration_ms = num(e.payload.duration_ms);
+    }
+    facts.set(qid, existing);
+  }
+  return facts;
+}
+
+function result(
+  o: SloObjective,
+  status: SloStatus,
+  sample_size: number,
+  detail: string,
+  observed?: number,
+  low_confidence?: boolean,
+): SloResult {
+  const r: SloResult = {
+    objective_id: o.objective_id,
+    workload: o.workload,
+    kind: o.kind,
+    status,
+    target: o.target,
+    unit: o.unit,
+    sample_size,
+    detail,
+  };
+  if (observed !== undefined) r.observed = observed;
+  if (low_confidence) r.low_confidence = true;
+  return r;
+}
+
+function compare(o: SloObjective, observed: number): SloStatus {
+  return o.direction === 'at_least'
+    ? observed >= o.target
+      ? 'met'
+      : 'breached'
+    : observed <= o.target
+      ? 'met'
+      : 'breached';
+}
+
+/**
+ * Evaluate the catalogue over a window of AUD0 BI usage events.
+ *
+ * Events are DATA: they arrive from aud0's read model, they were written by
+ * other services, and nothing in them is treated as an instruction or as a
+ * schema. Unknown event types and unknown payload keys are ignored, never
+ * spread.
+ */
+export function evaluateBiSlos(args: {
+  events: Aud0BiEvent[];
+  from: Date;
+  to: Date;
+  objectives?: readonly SloObjective[];
+}): SloReport {
+  const objectives = args.objectives ?? BI_SLO_CATALOGUE;
+  const fromMs = args.from.getTime();
+  const toMs = args.to.getTime();
+  const inWindow = args.events.filter((e) => {
+    const t = Date.parse(e.occurred_at);
+    return !Number.isNaN(t) && t >= fromMs && t <= toMs;
+  });
+
+  const queries = [...foldQueries(inWindow).values()];
+  const dashboardQueries = queries.filter((q) => q.surface === 'dashboard');
+  const exploreQueries = queries.filter((q) => q.surface === 'explore');
+  const terminal = (qs: QueryFact[]) => qs.filter((q) => q.outcome !== undefined);
+  const durations = (qs: QueryFact[]) =>
+    qs
+      .map((q) => q.duration_ms)
+      .filter((d): d is number => d !== undefined)
+      .sort((a, b) => a - b);
+
+  const reportDurations = inWindow
+    .filter((e) => e.event_type === 'aud0.report_generated')
+    .map((e) => num(e.payload.duration_ms))
+    .filter((d): d is number => d !== undefined)
+    .sort((a, b) => a - b);
+
+  const results = objectives.map((o) => {
+    if (o.measured_from !== 'aud0_bi_usage_events') {
+      return result(
+        o,
+        'not_measurable_here',
+        0,
+        `measured from ${o.measured_from}; BI usage events cannot answer it — ${o.rationale}`,
+      );
+    }
+
+    switch (o.kind) {
+      case 'availability':
+      case 'error_rate': {
+        const t = terminal(dashboardQueries);
+        if (t.length === 0) {
+          return result(o, 'insufficient_data', 0, 'no terminal dashboard query events in the window');
+        }
+        const failed = t.filter((q) => q.outcome === 'failed').length;
+        const observed = o.kind === 'availability' ? (t.length - failed) / t.length : failed / t.length;
+        const status = compare(o, observed);
+        return result(
+          o,
+          t.length < o.min_samples ? 'insufficient_data' : status,
+          t.length,
+          t.length < o.min_samples
+            ? `${t.length} terminal queries is below the ${o.min_samples} this objective requires; ` +
+                `the ratio ${observed.toFixed(4)} is reported but not judged`
+            : `${failed} failed of ${t.length} terminal queries`,
+          observed,
+          t.length < o.min_samples,
+        );
+      }
+      case 'latency_p95_first':
+      case 'latency_p95_cached': {
+        const wanted = o.kind === 'latency_p95_cached';
+        const sample = durations(dashboardQueries.filter((q) => (q.cache_hit === true) === wanted));
+        const p95 = percentile(sample, 0.95);
+        if (p95 === undefined) {
+          return result(
+            o,
+            'insufficient_data',
+            0,
+            `no ${wanted ? 'cached' : 'uncached'} dashboard durations`,
+          );
+        }
+        const low = sample.length < o.min_samples;
+        return result(
+          o,
+          low ? 'insufficient_data' : compare(o, p95),
+          sample.length,
+          low
+            ? `p95 over ${sample.length} samples (needs ${o.min_samples}) — reported, not judged`
+            : `p95 over ${sample.length} samples`,
+          p95,
+          low,
+        );
+      }
+      case 'latency_p95':
+      case 'latency_p99': {
+        const sample = durations(exploreQueries);
+        const q = o.kind === 'latency_p99' ? 0.99 : 0.95;
+        const value = percentile(sample, q);
+        if (value === undefined) return result(o, 'insufficient_data', 0, 'no exploration durations');
+        const low = sample.length < o.min_samples;
+        return result(
+          o,
+          low ? 'insufficient_data' : compare(o, value),
+          sample.length,
+          low
+            ? `p${q * 100} over ${sample.length} samples (needs ${o.min_samples}); with this few samples ` +
+                `it is the ${Math.ceil((1 - q) * sample.length) || 1}-slowest request, not a percentile`
+            : `p${q * 100} over ${sample.length} samples`,
+          value,
+          low,
+        );
+      }
+      case 'max_result_rows': {
+        const rows = exploreQueries
+          .map((q) => q.row_count)
+          .filter((r): r is number => r !== undefined)
+          .sort((a, b) => b - a);
+        if (rows.length === 0) return result(o, 'insufficient_data', 0, 'no exploration row counts');
+        return result(o, compare(o, rows[0]), rows.length, `largest result seen in the window`, rows[0]);
+      }
+      case 'completion_sla': {
+        const p95 = percentile(reportDurations, 0.95);
+        if (p95 === undefined) return result(o, 'insufficient_data', 0, 'no report_generated events');
+        const low = reportDurations.length < o.min_samples;
+        return result(
+          o,
+          low ? 'insufficient_data' : compare(o, p95),
+          reportDurations.length,
+          low ? `p95 over ${reportDurations.length} reports (needs ${o.min_samples})` : 'p95 report duration',
+          p95,
+          low,
+        );
+      }
+      default:
+        return result(o, 'not_measurable_here', 0, `no evaluator for kind "${o.kind}"`);
+    }
+  });
+
+  const unresolved = queries.filter((q) => q.outcome === undefined).length;
+  return {
+    window_from: args.from.toISOString(),
+    window_to: args.to.toISOString(),
+    results,
+    unresolved_queries: unresolved,
+    fully_measured: results.every((r) => r.status === 'met' || r.status === 'breached'),
+  };
+}
+
+/**
+ * One line an operator can read: how many objectives are actually being
+ * measured. "9 of 11 met" is meaningless if the other two were never
+ * measured, so the summary counts them separately and never rolls them in.
+ */
+export function summariseSloReport(report: SloReport): {
+  met: number;
+  breached: number;
+  insufficient_data: number;
+  not_measurable_here: number;
+  measured_fraction: number;
+} {
+  const count = (s: SloStatus) => report.results.filter((r) => r.status === s).length;
+  const measured = count('met') + count('breached');
+  return {
+    met: count('met'),
+    breached: count('breached'),
+    insufficient_data: count('insufficient_data'),
+    not_measurable_here: count('not_measurable_here'),
+    measured_fraction: report.results.length === 0 ? 0 : measured / report.results.length,
+  };
+}
diff --git a/src/analytics/slo/usage-events.ts b/src/analytics/slo/usage-events.ts
new file mode 100644
index 0000000..dec22ba
--- /dev/null
+++ b/src/analytics/slo/usage-events.ts
@@ -0,0 +1,209 @@
+/**
+ * src/analytics/slo/usage-events.ts
+ * ==================================
+ * BI-P103's measurement path: 0pt emits the AUD0 BI usage events (aud0#34,
+ * BI-P076) that the SLO evaluator then reads.
+ *
+ * aud0 says it plainly in docs/BI_ANALYTICS_USAGE.md: "Zero real producers
+ * emit these seven types today." An SLO computed from a second, private
+ * telemetry path would be a number nobody else can audit, so 0pt becomes a
+ * producer instead of inventing one.
+ *
+ * THE PAYLOAD IS AN ALLOWLIST, BUILT FIELD BY NAMED FIELD. AUD0's ingest
+ * refuses result-bearing payloads with a 400 and its schemas are `.strict()`,
+ * so a leak here is a 400 rather than a breach — but a producer that has to be
+ * refused is a producer that is broken. `biUsageEventsForExecution` therefore
+ * never spreads an execution record; it names each field, and
+ * tests/analytics/bi-slo.test.ts feeds it a record carrying SQL text, an error
+ * message, a tenant id and a result sample, then asserts none of it appears in
+ * the output.
+ *
+ * WHAT IS DELIBERATELY NOT SENT: `compiled_query_hash` goes out as
+ * `query_hash` (aud0 requires a 64-hex digest and nothing else), the statement
+ * never leaves 0pt at all, `error_code` travels but `error_message` does not,
+ * and `row_count` travels but no row does.
+ */
+
+/** The seven event types, named exactly as aud0 registers them. */
+export const AUD0_BI_EVENT_TYPES = [
+  'aud0.analytics_query_started',
+  'aud0.analytics_query_completed',
+  'aud0.analytics_query_failed',
+  'aud0.dashboard_viewed',
+  'aud0.report_generated',
+  'aud0.dataset_exported',
+  'aud0.metric_queried',
+] as const;
+export type Aud0BiEventType = (typeof AUD0_BI_EVENT_TYPES)[number];
+
+/** aud0's closed surface list (BI_SURFACES). */
+export const BI_SURFACES = ['dashboard', 'report', 'explore', 'api', 'scheduled', 'notebook'] as const;
+export type BiSurface = (typeof BI_SURFACES)[number];
+
+export interface Aud0BiEvent {
+  event_type: Aud0BiEventType;
+  /** Bounded, allowlisted metadata. Never a result, a statement or a message. */
+  payload: Record<string, string | number | boolean | string[]>;
+  /** Occurrence time, used by the SLO window. */
+  occurred_at: string;
+}
+
+/**
+ * The 0pt-side view of one execution. Intentionally a SUPERSET of what may be
+ * emitted — it carries the fields 0pt genuinely has, including the ones that
+ * must never leave — so that the mapping below is a real filter rather than a
+ * rename.
+ */
+export interface ExecutionTelemetry {
+  query_id: string;
+  /** 64-hex; anything else is dropped rather than reshaped. */
+  compiled_query_hash?: string;
+  /** NEVER emitted. Present here because 0pt has it. */
+  compiled_sql?: string;
+  /** NEVER emitted. */
+  error_message?: string;
+  error_code?: string;
+  /** NEVER emitted — a consumer must not be able to name a tenant, BI-P016. */
+  tenant_id?: string;
+  dataset_id?: string;
+  engine?: string;
+  surface?: BiSurface;
+  state: 'succeeded' | 'failed' | 'cancelled' | 'running';
+  started_at: string;
+  finished_at?: string;
+  duration_ms?: number;
+  row_count?: number;
+  bytes_scanned?: number;
+  cache_hit?: boolean;
+  filter_keys?: string[];
+  /** NEVER emitted: filter VALUES are facts about a subject. */
+  filter_values?: Record<string, string[]>;
+  /** NEVER emitted. */
+  result_sample?: unknown;
+  metric_name?: string;
+  dimension_keys?: string[];
+  granularity?: string;
+  dashboard_id?: string;
+  widget_count?: number;
+}
+
+const SHA256 = /^[0-9a-f]{64}$/;
+const MAX_KEY_NAMES = 50;
+const MAX_SHORT_TEXT = 120;
+
+function shortText(v: string | undefined): string | undefined {
+  if (!v) return undefined;
+  return v.slice(0, MAX_SHORT_TEXT);
+}
+
+function keyNames(v: string[] | undefined): string[] | undefined {
+  if (!v || v.length === 0) return undefined;
+  return v.slice(0, MAX_KEY_NAMES).map((k) => k.slice(0, MAX_SHORT_TEXT));
+}
+
+function put(
+  payload: Record<string, string | number | boolean | string[]>,
+  key: string,
+  value: string | number | boolean | string[] | undefined,
+): void {
+  if (value === undefined) return;
+  payload[key] = value;
+}
+
+/**
+ * Map one execution to its AUD0 usage events.
+ *
+ * A running execution emits only `started`: a query that has not finished is
+ * neither a success nor a failure, and the SLO evaluator counts it as
+ * unresolved rather than quietly as one or the other.
+ */
+export function biUsageEventsForExecution(t: ExecutionTelemetry): Aud0BiEvent[] {
+  const base: Record<string, string | number | boolean | string[]> = {};
+  put(base, 'query_id', t.query_id);
+  if (t.compiled_query_hash && SHA256.test(t.compiled_query_hash)) {
+    put(base, 'query_hash', t.compiled_query_hash);
+  }
+  put(base, 'dataset_id', t.dataset_id);
+  put(base, 'engine', shortText(t.engine));
+  put(base, 'surface', t.surface);
+  put(base, 'filter_keys', keyNames(t.filter_keys));
+
+  const events: Aud0BiEvent[] = [
+    { event_type: 'aud0.analytics_query_started', payload: { ...base }, occurred_at: t.started_at },
+  ];
+
+  if (t.state === 'succeeded') {
+    const payload = { ...base };
+    put(payload, 'duration_ms', t.duration_ms);
+    put(payload, 'row_count', t.row_count);
+    put(payload, 'bytes_scanned', t.bytes_scanned);
+    put(payload, 'cache_hit', t.cache_hit);
+    events.push({
+      event_type: 'aud0.analytics_query_completed',
+      payload,
+      occurred_at: t.finished_at ?? t.started_at,
+    });
+  } else if (t.state === 'failed' || t.state === 'cancelled') {
+    const payload = { ...base };
+    put(payload, 'duration_ms', t.duration_ms);
+    // A CODE. `error_message` is never mapped, at any length.
+    put(
+      payload,
+      'error_code',
+      shortText(t.error_code ?? (t.state === 'cancelled' ? 'CANCELLED' : undefined)),
+    );
+    events.push({
+      event_type: 'aud0.analytics_query_failed',
+      payload,
+      occurred_at: t.finished_at ?? t.started_at,
+    });
+  }
+
+  if (t.metric_name) {
+    const payload: Record<string, string | number | boolean | string[]> = {};
+    put(payload, 'metric_name', shortText(t.metric_name));
+    put(payload, 'dataset_id', t.dataset_id);
+    put(payload, 'surface', t.surface);
+    put(payload, 'engine', shortText(t.engine));
+    put(payload, 'dimension_keys', keyNames(t.dimension_keys));
+    put(payload, 'granularity', shortText(t.granularity));
+    put(payload, 'row_count', t.row_count);
+    put(payload, 'duration_ms', t.duration_ms);
+    events.push({
+      event_type: 'aud0.metric_queried',
+      payload,
+      occurred_at: t.finished_at ?? t.started_at,
+    });
+  }
+
+  if (t.dashboard_id) {
+    const payload: Record<string, string | number | boolean | string[]> = {};
+    put(payload, 'dashboard_id', t.dashboard_id);
+    put(payload, 'widget_count', t.widget_count);
+    put(payload, 'duration_ms', t.duration_ms);
+    put(payload, 'surface', t.surface ?? 'dashboard');
+    events.push({ event_type: 'aud0.dashboard_viewed', payload, occurred_at: t.started_at });
+  }
+
+  return events;
+}
+
+/** Every payload key this producer can ever emit. Pinned by test. */
+export const EMITTABLE_PAYLOAD_KEYS = [
+  'query_id',
+  'query_hash',
+  'dataset_id',
+  'engine',
+  'surface',
+  'filter_keys',
+  'duration_ms',
+  'row_count',
+  'bytes_scanned',
+  'cache_hit',
+  'error_code',
+  'metric_name',
+  'dimension_keys',
+  'granularity',
+  'dashboard_id',
+  'widget_count',
+] as const;
diff --git a/tests/analytics/bi-slo.test.ts b/tests/analytics/bi-slo.test.ts
new file mode 100644
index 0000000..1dc5df2
--- /dev/null
+++ b/tests/analytics/bi-slo.test.ts
@@ -0,0 +1,293 @@
+/**
+ * tests/analytics/bi-slo.test.ts
+ * ===============================
+ * BI-P103 — BI SLO, and the AUD0 usage events it is measured from.
+ *
+ * Two failure modes are attacked directly, because both look like a healthy
+ * dashboard:
+ *
+ *   1. AN SLO REPORT OVER SILENCE. Zero events must not read as 100%
+ *      availability. Every objective in an empty window must come back
+ *      `insufficient_data`, and `fully_measured` must be false.
+ *   2. A PRODUCER THAT LEAKS. The emitter is handed an execution record
+ *      carrying SQL text, a database error message quoting a personnummer,
+ *      filter VALUES, a tenant id and a result sample — everything AUD0's
+ *      BI-P076 ingest exists to refuse — and none of it may appear in any
+ *      emitted payload. The test greps the serialized events, and first
+ *      proves the grep finds those strings in the INPUT so a clean result
+ *      cannot be a broken detector.
+ */
+import { describe, expect, it } from 'vitest';
+import {
+  BI_SLO_CATALOGUE,
+  evaluateBiSlos,
+  percentile,
+  summariseSloReport,
+  type SloResult,
+} from '@/src/analytics/slo/bi-slo';
+import {
+  biUsageEventsForExecution,
+  EMITTABLE_PAYLOAD_KEYS,
+  type Aud0BiEvent,
+  type ExecutionTelemetry,
+} from '@/src/analytics/slo/usage-events';
+
+const FROM = new Date('2026-09-07T00:00:00.000Z');
+const TO = new Date('2026-09-07T23:59:59.000Z');
+
+function queryEvents(args: {
+  n: number;
+  surface: 'dashboard' | 'explore';
+  outcome: 'completed' | 'failed' | 'running';
+  durationMs: (i: number) => number;
+  cacheHit?: boolean;
+  idPrefix?: string;
+}): Aud0BiEvent[] {
+  const out: Aud0BiEvent[] = [];
+  for (let i = 0; i < args.n; i += 1) {
+    const t: ExecutionTelemetry = {
+      query_id: `${args.idPrefix ?? args.surface}_${i}`,
+      surface: args.surface,
+      state: args.outcome === 'completed' ? 'succeeded' : args.outcome === 'failed' ? 'failed' : 'running',
+      started_at: new Date(FROM.getTime() + i * 1000).toISOString(),
+      finished_at: new Date(FROM.getTime() + i * 1000 + args.durationMs(i)).toISOString(),
+      duration_ms: args.durationMs(i),
+      ...(args.cacheHit !== undefined ? { cache_hit: args.cacheHit } : {}),
+      ...(args.outcome === 'failed' ? { error_code: 'TIMEOUT' } : {}),
+    };
+    out.push(...biUsageEventsForExecution(t));
+  }
+  return out;
+}
+
+function byId(results: SloResult[], id: string): SloResult {
+  const r = results.find((x) => x.objective_id === id);
+  if (!r) throw new Error(`no result for ${id}`);
+  return r;
+}
+
+describe('BI-P103 — an SLO over silence is not a met SLO', () => {
+  it('an empty window makes every measurable objective insufficient_data, never 100%', () => {
+    const report = evaluateBiSlos({ events: [], from: FROM, to: TO });
+    expect(report.fully_measured).toBe(false);
+    for (const r of report.results) {
+      expect(['insufficient_data', 'not_measurable_here']).toContain(r.status);
+      expect(r.status).not.toBe('met');
+    }
+    const summary = summariseSloReport(report);
+    expect(summary.met).toBe(0);
+    expect(summary.measured_fraction).toBe(0);
+  });
+
+  it('a started query that never finished is unresolved, not a success', () => {
+    const events = queryEvents({ n: 200, surface: 'dashboard', outcome: 'running', durationMs: () => 100 });
+    const report = evaluateBiSlos({ events, from: FROM, to: TO });
+    expect(report.unresolved_queries).toBe(200);
+    expect(byId(report.results, 'dash.availability').status).toBe('insufficient_data');
+    expect(byId(report.results, 'dash.availability').observed).toBeUndefined();
+  });
+
+  it('a percentile below min_samples is reported WITH its sample size and not judged', () => {
+    const events = queryEvents({
+      n: 12,
+      surface: 'explore',
+      outcome: 'completed',
+      durationMs: (i) => 1000 + i * 10,
+    });
+    const p99 = byId(evaluateBiSlos({ events, from: FROM, to: TO }).results, 'explore.p99');
+    expect(p99.status).toBe('insufficient_data');
+    expect(p99.low_confidence).toBe(true);
+    expect(p99.sample_size).toBe(12);
+    expect(p99.observed).toBeDefined(); // reported…
+    expect(p99.detail).toMatch(/not a percentile/); // …with the caveat attached
+  });
+
+  it('freshness and delivery are declared not_measurable_here rather than proxied', () => {
+    const report = evaluateBiSlos({ events: [], from: FROM, to: TO });
+    const freshness = byId(report.results, 'dash.freshness');
+    const delivery = byId(report.results, 'report.delivery_sla');
+    expect(freshness.status).toBe('not_measurable_here');
+    expect(freshness.detail).toMatch(/analytics_freshness_watermark/);
+    expect(delivery.status).toBe('not_measurable_here');
+    expect(delivery.detail).toMatch(/n0tify_delivery_receipt/);
+  });
+});
+
+describe('BI-P103 — real measurement from real events', () => {
+  it('computes availability, error rate and both dashboard latencies', () => {
+    const events = [
+      ...queryEvents({
+        n: 180,
+        surface: 'dashboard',
+        outcome: 'completed',
+        cacheHit: false,
+        durationMs: (i) => 500 + i * 10,
+        idPrefix: 'cold',
+      }),
+      ...queryEvents({
+        n: 120,
+        surface: 'dashboard',
+        outcome: 'completed',
+        cacheHit: true,
+        durationMs: () => 120,
+        idPrefix: 'warm',
+      }),
+      ...queryEvents({
+        n: 3,
+        surface: 'dashboard',
+        outcome: 'failed',
+        durationMs: () => 900,
+        idPrefix: 'bad',
+      }),
+    ];
+    const { results } = evaluateBiSlos({ events, from: FROM, to: TO });
+
+    const availability = byId(results, 'dash.availability');
+    expect(availability.sample_size).toBe(303);
+    expect(availability.observed).toBeCloseTo(300 / 303, 6);
+    expect(availability.status).toBe('breached'); // 0.9901 < 0.995 target
+
+    const errorRate = byId(results, 'dash.error_rate');
+    expect(errorRate.observed).toBeCloseTo(3 / 303, 6);
+
+    const cold = byId(results, 'dash.p95_first_query');
+    expect(cold.sample_size).toBe(183); // 180 cold + 3 failures, which had no cache hit
+    expect(cold.status).toBe('met');
+
+    const cached = byId(results, 'dash.p95_cached');
+    expect(cached.sample_size).toBe(120);
+    expect(cached.observed).toBe(120);
+    expect(cached.status).toBe('met');
+  });
+
+  it('a breach is reported as a breach', () => {
+    const events = queryEvents({
+      n: 60,
+      surface: 'dashboard',
+      outcome: 'completed',
+      cacheHit: false,
+      durationMs: () => 9000,
+    });
+    expect(
+      byId(evaluateBiSlos({ events, from: FROM, to: TO }).results, 'dash.p95_first_query'),
+    ).toMatchObject({ status: 'breached', observed: 9000 });
+  });
+
+  it('events outside the window do not count', () => {
+    const events = queryEvents({ n: 200, surface: 'dashboard', outcome: 'completed', durationMs: () => 100 });
+    const report = evaluateBiSlos({
+      events,
+      from: new Date('2026-09-08T00:00:00.000Z'),
+      to: new Date('2026-09-08T23:59:59.000Z'),
+    });
+    expect(byId(report.results, 'dash.availability').status).toBe('insufficient_data');
+  });
+
+  it('percentile is nearest-rank — it never invents a value nobody experienced', () => {
+    const sample = [10, 20, 30, 40];
+    expect(percentile(sample, 0.95)).toBe(40);
+    expect(percentile(sample, 0.5)).toBe(20);
+    expect(percentile([], 0.95)).toBeUndefined();
+  });
+
+  it('the catalogue covers all three workload classes and every field BI-P103 names', () => {
+    const kinds = new Set(BI_SLO_CATALOGUE.map((o) => `${o.workload}:${o.kind}`));
+    for (const expected of [
+      'interactive_dashboard:availability',
+      'interactive_dashboard:latency_p95_first',
+      'interactive_dashboard:latency_p95_cached',
+      'interactive_dashboard:error_rate',
+      'interactive_dashboard:freshness',
+      'exploration:latency_p95',
+      'exploration:latency_p99',
+      'exploration:max_result_rows',
+      'exploration:timeout',
+      'report:completion_sla',
+      'report:delivery_sla',
+    ]) {
+      expect(kinds.has(expected), expected).toBe(true);
+    }
+  });
+});
+
+describe('BI-P103 — the producer cannot leak a result into AUD0', () => {
+  const hostile: ExecutionTelemetry = {
+    query_id: 'q_1',
+    compiled_query_hash: 'f'.repeat(64),
+    compiled_sql: "SELECT * FROM customers WHERE personnummer = '19800101-1234'",
+    error_message: 'duplicate key value violates unique constraint (personnummer)=(19800101-1234)',
+    error_code: 'CONFLICT',
+    tenant_id: 't_alpha',
+    dataset_id: 'ds_sales',
+    engine: 'clickhouse',
+    surface: 'dashboard',
+    state: 'failed',
+    started_at: '2026-09-07T10:00:00.000Z',
+    finished_at: '2026-09-07T10:00:02.000Z',
+    duration_ms: 2000,
+    filter_keys: ['region'],
+    filter_values: { region: ['Gotland'] },
+    result_sample: [{ customer: 'Anna Andersson', revenue: 42 }],
+    metric_name: 'revenue',
+    dashboard_id: 'dash_sales',
+    widget_count: 4,
+  };
+
+  it('emits none of the forbidden material', () => {
+    const events = biUsageEventsForExecution(hostile);
+    const serialized = JSON.stringify(events);
+
+    // The detector must be able to find these strings — they are in the input.
+    const input = JSON.stringify(hostile);
+    for (const secret of ['19800101-1234', 'Anna Andersson', 'Gotland', 't_alpha', 'SELECT *']) {
+      expect(input, `detector check for ${secret}`).toContain(secret);
+    }
+    for (const secret of [
+      '19800101-1234',
+      'Anna Andersson',
+      'Gotland',
+      't_alpha',
+      'SELECT *',
+      'duplicate key',
+    ]) {
+      expect(serialized, secret).not.toContain(secret);
+    }
+  });
+
+  it('every emitted key is on the allowlist AUD0 accepts', () => {
+    const events = biUsageEventsForExecution(hostile);
+    for (const e of events) {
+      for (const key of Object.keys(e.payload)) {
+        expect(EMITTABLE_PAYLOAD_KEYS, `${e.event_type}.${key}`).toContain(key);
+      }
+    }
+  });
+
+  it('a query_hash that is not a sha256 digest is dropped, not reshaped', () => {
+    const events = biUsageEventsForExecution({ ...hostile, compiled_query_hash: 'SELECT 1' });
+    for (const e of events) expect(e.payload.query_hash).toBeUndefined();
+  });
+
+  it('a running query emits only "started" — it is neither a success nor a failure', () => {
+    const events = biUsageEventsForExecution({
+      ...hostile,
+      state: 'running',
+      metric_name: undefined,
+      dashboard_id: undefined,
+    });
+    expect(events.map((e) => e.event_type)).toEqual(['aud0.analytics_query_started']);
+  });
+
+  it('a cancelled query is reported as failed with a CODE', () => {
+    const events = biUsageEventsForExecution({
+      ...hostile,
+      state: 'cancelled',
+      error_code: undefined,
+      metric_name: undefined,
+      dashboard_id: undefined,
+    });
+    const failed = events.find((e) => e.event_type === 'aud0.analytics_query_failed');
+    expect(failed?.payload.error_code).toBe('CANCELLED');
+    expect(failed?.payload.error_message).toBeUndefined();
+  });
+});