diff --git a/apps/commons-api/migrations/versioned/031_fast_artifact_provenance.sql b/apps/commons-api/migrations/versioned/031_fast_artifact_provenance.sql
new file mode 100644
index 00000000..ac0228ee
--- /dev/null
+++ b/apps/commons-api/migrations/versioned/031_fast_artifact_provenance.sql
@@ -0,0 +1,6 @@
+-- Artifact provenance resolves derivations through the source artifact id
+-- stored in metadata. Keep that lookup indexed and exclude deleted revisions
+-- so opening the provenance tab remains fast as a Library grows.
+CREATE INDEX IF NOT EXISTS idx_library_item_revision_source
+  ON library_item ((metadata->>'sourceFileId'))
+  WHERE deleted_at IS NULL;
diff --git a/apps/commons-api/models/schema.ts b/apps/commons-api/models/schema.ts
index 9c01f103..76e29dd1 100644
--- a/apps/commons-api/models/schema.ts
+++ b/apps/commons-api/models/schema.ts
@@ -753,6 +753,9 @@ export const libraryItem = pgTable(
       table.ownerUserId,
       table.sha256,
     ),
+    revisionSourceIdx: index('idx_library_item_revision_source')
+      .on(sql`(${table.metadata}->>'sourceFileId')`)
+      .where(sql`${table.deletedAt} is null`),
   }),
 );
 
@@ -2397,7 +2400,7 @@ export const provenanceEvent = pgTable(
   'provenance_event',
   {
     eventId: uuid('event_id')
-      .default(sql`uuid_generate_v4()`)
+      .default(sql`gen_random_uuid()`)
       .primaryKey(),
     traceId: uuid('trace_id')
       .notNull()
diff --git a/apps/commons-api/src/files/library.controller.ts b/apps/commons-api/src/files/library.controller.ts
index 8b027f5f..24b02e22 100644
--- a/apps/commons-api/src/files/library.controller.ts
+++ b/apps/commons-api/src/files/library.controller.ts
@@ -81,8 +81,18 @@ export class LibraryController {
 
   @Get(':itemId/provenance')
   @RateLimit({ limit: 120, windowMs: 60_000, keyStrategy: 'user' })
-  provenance(@Req() req: Request, @Param('itemId') itemId: string) {
-    return this.library.provenance(itemId, principalFrom(req));
+  provenance(
+    @Req() req: Request,
+    @Param('itemId') itemId: string,
+    @Query('eventLimit') eventLimit?: string,
+  ) {
+    const parsedEventLimit =
+      eventLimit === undefined ? undefined : Number(eventLimit);
+    return this.library.provenance(
+      itemId,
+      principalFrom(req),
+      Number.isFinite(parsedEventLimit) ? parsedEventLimit : undefined,
+    );
   }
 
   @Patch(':itemId')
diff --git a/apps/commons-api/src/files/library.service.spec.ts b/apps/commons-api/src/files/library.service.spec.ts
index b3d69030..0d036bf8 100644
--- a/apps/commons-api/src/files/library.service.spec.ts
+++ b/apps/commons-api/src/files/library.service.spec.ts
@@ -236,3 +236,140 @@ describe('LibraryService agent discovery', () => {
     expect(context).toEqual({ ownerId: 'user-1', workspaceId: undefined });
   });
 });
+
+describe('LibraryService artifact provenance', () => {
+  const item = {
+    itemId: '11111111-1111-4111-8111-111111111111',
+    ownerUserId: 'user-1',
+    workspaceId: null,
+    sourceAgentId: 'agent-1',
+    sourceSessionId: null,
+    kind: 'document',
+    name: 'Fast provenance.docx',
+    description: null,
+    mimeType:
+      'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
+    sizeBytes: 1024,
+    sha256: 'a'.repeat(64),
+    source: 'agent_generated',
+    status: 'ready',
+    visibility: 'private',
+    textPreview: 'Fast provenance',
+    extractedTextChars: 15,
+    extractionError: null,
+    metadata: {},
+    isFavorite: false,
+    deletedAt: null,
+    createdAt: new Date('2026-08-31T00:00:00.000Z'),
+    updatedAt: new Date('2026-08-31T00:00:00.000Z'),
+  };
+
+  function harness() {
+    const eventRows = Array.from({ length: 40 }, (_, index) => {
+      const sequence = 50 - index;
+      return {
+        eventId: `event-${sequence}`,
+        traceId: '22222222-2222-4222-8222-222222222222',
+        sessionId: null,
+        sequence,
+        category: 'tool',
+        eventType: 'tool.completed',
+        name: `Event ${sequence}`,
+        phase: null,
+        status: 'completed',
+        spanId: null,
+        parentSpanId: null,
+        summary: null,
+        payload: null,
+        result: null,
+        contentHash: null,
+        inputTokens: null,
+        outputTokens: null,
+        cachedTokens: null,
+        costUsd: null,
+        durationMs: 1,
+        eaaAction: null,
+        metadata: {},
+        startedAt: new Date(
+          `2026-08-31T00:00:${String(sequence).padStart(2, '0')}.000Z`,
+        ),
+        endedAt: null,
+        createdAt: new Date('2026-08-31T00:01:00.000Z'),
+      };
+    });
+    const values = jest.fn().mockResolvedValue(undefined);
+    const db = {
+      query: {
+        libraryItem: {
+          findFirst: jest.fn().mockResolvedValue(item),
+          findMany: jest.fn().mockResolvedValue([]),
+        },
+        libraryLink: {
+          findMany: jest.fn().mockResolvedValue([
+            {
+              scopeType: 'provenance_trace',
+              scopeId: '22222222-2222-4222-8222-222222222222',
+            },
+          ]),
+        },
+        provenanceRun: {
+          findMany: jest.fn().mockResolvedValue([
+            {
+              traceId: '22222222-2222-4222-8222-222222222222',
+              status: 'completed',
+              captureMode: 'metadata',
+              eventCount: 75,
+              droppedEventCount: 0,
+              startedAt: new Date('2026-08-31T00:00:00.000Z'),
+              anchorStatus: 'not_requested',
+            },
+          ]),
+        },
+        provenanceEvent: { findMany: jest.fn().mockResolvedValue(eventRows) },
+        libraryAuditEvent: { findMany: jest.fn().mockResolvedValue([]) },
+        libraryGrant: { findMany: jest.fn().mockResolvedValue([]) },
+        libraryShareLink: { findMany: jest.fn().mockResolvedValue([]) },
+      },
+      insert: jest.fn().mockReturnValue({ values }),
+    } as any;
+    return {
+      db,
+      service: new LibraryService(db, {} as any, {} as any, {} as any),
+    };
+  }
+
+  it('returns only the newest 40 events in chronological display order', async () => {
+    const { db, service } = harness();
+
+    const record = (await service.provenance('item-1', {
+      principalId: 'user-1',
+      principalType: 'user',
+    })) as any;
+
+    expect(db.query.provenanceEvent.findMany).toHaveBeenCalledWith(
+      expect.objectContaining({ limit: 40 }),
+    );
+    expect(record.actions).toHaveLength(40);
+    expect(record.actions[0].sequence).toBe(11);
+    expect(record.actions.at(-1).sequence).toBe(50);
+    expect(record.disclosure).toMatchObject({
+      eventsIncluded: true,
+      eventsReturned: 40,
+      eventsTruncated: true,
+    });
+  });
+
+  it('can return compact provenance without querying event rows', async () => {
+    const { db, service } = harness();
+
+    const record = (await service.provenance(
+      'item-1',
+      { principalId: 'user-1', principalType: 'user' },
+      0,
+    )) as any;
+
+    expect(db.query.provenanceEvent.findMany).not.toHaveBeenCalled();
+    expect(record.actions).toEqual([]);
+    expect(record.disclosure.eventsIncluded).toBe(false);
+  });
+});
diff --git a/apps/commons-api/src/files/library.service.ts b/apps/commons-api/src/files/library.service.ts
index 7b5f5c34..4e3bfcd0 100644
--- a/apps/commons-api/src/files/library.service.ts
+++ b/apps/commons-api/src/files/library.service.ts
@@ -235,17 +235,24 @@ export class LibraryService {
     };
   }
 
-  async provenance(itemId: string, principal: LibraryPrincipal) {
+  async provenance(
+    itemId: string,
+    principal: LibraryPrincipal,
+    requestedEventLimit = 40,
+  ) {
     const item = await this.getAccessible(itemId, principal);
-    const result = await this.buildArtifactProvenance(item, true);
-    await this.audit(itemId, principal, 'provenance_viewed');
+    const eventLimit = clamp(Math.floor(requestedEventLimit), 0, 100);
+    const [result] = await Promise.all([
+      this.buildArtifactProvenance(item, eventLimit),
+      this.audit(itemId, principal, 'provenance_viewed'),
+    ]);
     return result;
   }
 
   /** A safe EAA-oriented projection for compact UI, export, and sharing. */
   private async buildArtifactProvenance(
     item: typeof schema.libraryItem.$inferSelect,
-    includeEvents: boolean,
+    eventLimit?: number,
   ) {
     const links = await this.db.query.libraryLink.findMany({
       where: (table) => eq(table.itemId, item.itemId),
@@ -265,38 +272,48 @@ export class LibraryService {
           })
         : [];
     const traceIds = runs.map((run) => run.traceId);
-    const [events, audits, grants, shares] = await Promise.all([
-      includeEvents && traceIds.length
-        ? this.db.query.provenanceEvent.findMany({
-            where: (table) => inArray(table.traceId, traceIds),
-            orderBy: (table) => [asc(table.startedAt), asc(table.sequence)],
-          })
-        : Promise.resolve([]),
-      this.db.query.libraryAuditEvent.findMany({
-        where: (table) => eq(table.itemId, item.itemId),
-        orderBy: (table) => asc(table.createdAt),
-      }),
-      this.db.query.libraryGrant.findMany({
-        where: (table) => eq(table.itemId, item.itemId),
-      }),
-      this.db.query.libraryShareLink.findMany({
-        where: (table) => eq(table.itemId, item.itemId),
-      }),
-    ]);
     const sourceFileId = stringValue(
       item.metadata?.sourceFileId ?? item.metadata?.revisionOf,
     );
-    const source = sourceFileId
-      ? await this.db.query.libraryItem.findFirst({
-          where: (table) => eq(table.itemId, sourceFileId),
-        })
-      : undefined;
-    const revisions = await this.db.query.libraryItem.findMany({
-      where: (table) =>
-        sql`${table.metadata}->>'sourceFileId' = ${item.itemId}`,
-      orderBy: (table) => asc(table.createdAt),
-      limit: 25,
-    });
+    const [events, audits, grants, shares, source, revisions] =
+      await Promise.all([
+        eventLimit !== 0 && traceIds.length
+          ? this.db.query.provenanceEvent.findMany({
+              where: (table) => inArray(table.traceId, traceIds),
+              orderBy: (table) =>
+                eventLimit === undefined
+                  ? [asc(table.startedAt), asc(table.sequence)]
+                  : [desc(table.startedAt), desc(table.sequence)],
+              ...(eventLimit === undefined ? {} : { limit: eventLimit }),
+            })
+          : Promise.resolve([]),
+        this.db.query.libraryAuditEvent.findMany({
+          where: (table) => eq(table.itemId, item.itemId),
+          orderBy: (table) => asc(table.createdAt),
+        }),
+        this.db.query.libraryGrant.findMany({
+          where: (table) => eq(table.itemId, item.itemId),
+        }),
+        this.db.query.libraryShareLink.findMany({
+          where: (table) => eq(table.itemId, item.itemId),
+        }),
+        sourceFileId
+          ? this.db.query.libraryItem.findFirst({
+              where: (table) => eq(table.itemId, sourceFileId),
+            })
+          : Promise.resolve(undefined),
+        this.db.query.libraryItem.findMany({
+          where: (table) =>
+            and(
+              isNull(table.deletedAt),
+              sql`${table.metadata}->>'sourceFileId' = ${item.itemId}`,
+            ),
+          orderBy: (table) => asc(table.createdAt),
+          limit: 25,
+        }),
+      ]);
+    const orderedEvents =
+      eventLimit === undefined ? events : [...events].reverse();
     const metadataProvenance = recordValue(item.metadata?.provenance);
     const contentHash = `sha256:${item.sha256}`;
 
@@ -346,26 +363,27 @@ export class LibraryService {
         anchorProvider: run.anchorProvider,
         anchorRef: run.anchorRef,
       })),
-      actions: includeEvents
-        ? events.map((event) => ({
-            id:
-              stringValue((event.eaaAction as any)?.id) ??
-              `urn:agentcommons:event:${event.traceId}:${event.sequence}`,
-            traceId: event.traceId,
-            sequence: event.sequence,
-            category: event.category,
-            eventType: event.eventType,
-            name: event.name,
-            summary: event.summary,
-            status: event.status,
-            performedBy: stringValue((event.eaaAction as any)?.performedBy),
-            contentHash: event.contentHash,
-            startedAt: event.startedAt,
-            endedAt: event.endedAt,
-            durationMs: event.durationMs,
-            lineage: recordValue(event.metadata)?.lineage,
-          }))
-        : [],
+      actions:
+        eventLimit !== 0
+          ? orderedEvents.map((event) => ({
+              id:
+                stringValue((event.eaaAction as any)?.id) ??
+                `urn:agentcommons:event:${event.traceId}:${event.sequence}`,
+              traceId: event.traceId,
+              sequence: event.sequence,
+              category: event.category,
+              eventType: event.eventType,
+              name: event.name,
+              summary: event.summary,
+              status: event.status,
+              performedBy: stringValue((event.eaaAction as any)?.performedBy),
+              contentHash: event.contentHash,
+              startedAt: event.startedAt,
+              endedAt: event.endedAt,
+              durationMs: event.durationMs,
+              lineage: recordValue(event.metadata)?.lineage,
+            }))
+          : [],
       derivation: {
         source: source
           ? {
@@ -437,7 +455,12 @@ export class LibraryService {
         traceId: stringValue(event.metadata?.traceId),
       })),
       disclosure: {
-        eventsIncluded: includeEvents,
+        eventsIncluded: eventLimit !== 0,
+        eventsReturned: orderedEvents.length,
+        eventsTruncated:
+          eventLimit !== undefined &&
+          runs.reduce((total, run) => total + Number(run.eventCount ?? 0), 0) >
+            orderedEvents.length,
         privateReasoningIncluded: false,
         credentialsIncluded: false,
       },
@@ -795,9 +818,10 @@ export class LibraryService {
         ? this.files.createShareDownloadUrl(item.itemId)
         : Promise.resolve(undefined),
       disclosure.provenance
-        ? this.buildArtifactProvenance(item, disclosure.events).then(
-            redactSharedProvenance,
-          )
+        ? this.buildArtifactProvenance(
+            item,
+            disclosure.events ? undefined : 0,
+          ).then(redactSharedProvenance)
         : Promise.resolve(undefined),
     ]);
     const download = settledValue(downloadResult);
diff --git a/apps/commons-app/components/artifacts/artifact-surface.tsx b/apps/commons-app/components/artifacts/artifact-surface.tsx
index 566bee5b..9c0f3540 100644
--- a/apps/commons-app/components/artifacts/artifact-surface.tsx
+++ b/apps/commons-app/components/artifacts/artifact-surface.tsx
@@ -55,6 +55,7 @@ export function ArtifactSurface({
   );
   const [provenanceLoading, setProvenanceLoading] = useState(false);
   const [provenanceError, setProvenanceError] = useState("");
+  const provenanceAbortRef = useRef<AbortController | null>(null);
 
   const load = useCallback(async () => {
     setLoading(true);
@@ -81,10 +82,18 @@ export function ArtifactSurface({
   }, [artifact.fileId]);
 
   useEffect(() => {
+    provenanceAbortRef.current?.abort("artifact-changed");
+    provenanceAbortRef.current = null;
     setPreview(null);
     setProvenance(null);
+    setProvenanceLoading(false);
+    setProvenanceError("");
     setView("preview");
-    load();
+    void load();
+    return () => {
+      provenanceAbortRef.current?.abort("artifact-changed");
+      provenanceAbortRef.current = null;
+    };
   }, [load]);
 
   useEffect(() => {
@@ -113,39 +122,55 @@ export function ArtifactSurface({
     }
   }
 
-  useEffect(() => {
-    if (view !== "provenance" || provenance || provenanceLoading) return;
-    let cancelled = false;
+  const loadProvenance = useCallback(async () => {
+    if (provenance || provenanceAbortRef.current) return;
+    const controller = new AbortController();
+    provenanceAbortRef.current = controller;
+    const timeoutId = window.setTimeout(
+      () => controller.abort("timeout"),
+      8_000,
+    );
     setProvenanceLoading(true);
     setProvenanceError("");
-    fetch(`/api/library/${encodeURIComponent(artifact.fileId)}/provenance`, {
-      cache: "no-store",
-    })
-      .then(async (response) => {
-        const data = await response.json().catch(() => null);
-        if (!response.ok) {
-          throw new Error(
-            data?.message || data?.error || "Could not load provenance",
-          );
-        }
-        if (!cancelled) setProvenance(data?.data ?? data);
-      })
-      .catch((cause) => {
-        if (!cancelled) {
-          setProvenanceError(
-            cause instanceof Error
-              ? cause.message
-              : "Could not load provenance",
-          );
-        }
-      })
-      .finally(() => {
-        if (!cancelled) setProvenanceLoading(false);
-      });
-    return () => {
-      cancelled = true;
-    };
-  }, [artifact.fileId, provenance, provenanceLoading, view]);
+    try {
+      const response = await fetch(
+        `/api/library/${encodeURIComponent(artifact.fileId)}/provenance?eventLimit=40`,
+        { cache: "no-store", signal: controller.signal },
+      );
+      const data = await response.json().catch(() => null);
+      if (!response.ok) {
+        throw new Error(
+          data?.message || data?.error || "Could not load provenance",
+        );
+      }
+      setProvenance(data?.data ?? data);
+    } catch (cause) {
+      if (controller.signal.reason === "artifact-changed") return;
+      setProvenanceError(
+        controller.signal.reason === "timeout"
+          ? "Provenance took too long to load. Please try again."
+          : cause instanceof Error
+            ? cause.message
+            : "Could not load provenance",
+      );
+    } finally {
+      window.clearTimeout(timeoutId);
+      if (provenanceAbortRef.current === controller) {
+        provenanceAbortRef.current = null;
+        setProvenanceLoading(false);
+      }
+    }
+  }, [artifact.fileId, provenance]);
+
+  useEffect(() => {
+    if (view === "provenance") void loadProvenance();
+  }, [loadProvenance, view]);
+
+  useEffect(() => {
+    if (!preview || provenance || provenanceError) return;
+    const timeoutId = window.setTimeout(() => void loadProvenance(), 150);
+    return () => window.clearTimeout(timeoutId);
+  }, [loadProvenance, preview, provenance, provenanceError]);
 
   const resolved = useMemo<ArtifactRef>(
     () => ({
@@ -203,7 +228,10 @@ export function ArtifactSurface({
         <div className="ml-auto flex items-center gap-0.5">
           <ToolbarButton
             label="View provenance"
-            onClick={() => setView("provenance")}
+            onClick={() => {
+              setView("provenance");
+              void loadProvenance();
+            }}
           >
             <span className="text-[10px] font-semibold">Pr</span>
           </ToolbarButton>
@@ -282,7 +310,10 @@ export function ArtifactSurface({
           ) : null}
           <SurfaceTab
             active={view === "provenance"}
-            onClick={() => setView("provenance")}
+            onClick={() => {
+              setView("provenance");
+              void loadProvenance();
+            }}
             icon={BadgeCheck}
           >
             Provenance
@@ -320,7 +351,11 @@ export function ArtifactSurface({
         provenanceLoading ? (
           <CenteredMessage message="Loading provenance…" loading />
         ) : provenanceError ? (
-          <CenteredMessage message={provenanceError} />
+          <CenteredMessage
+            message={provenanceError}
+            actionLabel="Try again"
+            onAction={() => void loadProvenance()}
+          />
         ) : provenance ? (
           <ArtifactProvenance record={provenance} itemId={artifact.fileId} />
         ) : null
@@ -686,9 +721,13 @@ function SurfaceTab({
 function CenteredMessage({
   message,
   loading = false,
+  actionLabel,
+  onAction,
 }: {
   message: string;
   loading?: boolean;
+  actionLabel?: string;
+  onAction?: () => void;
 }) {
   return (
     <div className="flex min-h-0 flex-1 items-center justify-center p-8 text-center text-xs text-stone-500">
@@ -696,7 +735,16 @@ function CenteredMessage({
         {loading ? (
           <Loader2 className="mx-auto mb-2 h-4 w-4 animate-spin" />
         ) : null}
-        {message}
+        <p>{message}</p>
+        {actionLabel && onAction ? (
+          <button
+            type="button"
+            onClick={onAction}
+            className="mt-3 inline-flex items-center rounded-lg border border-stone-200 bg-white px-3 py-1.5 text-[11px] font-medium text-stone-700 shadow-sm hover:bg-stone-50"
+          >
+            {actionLabel}
+          </button>
+        ) : null}
       </div>
     </div>
   );
diff --git a/apps/commons-app/components/provenance/artifact-provenance.tsx b/apps/commons-app/components/provenance/artifact-provenance.tsx
index e407ec5f..cf1f274a 100644
--- a/apps/commons-app/components/provenance/artifact-provenance.tsx
+++ b/apps/commons-app/components/provenance/artifact-provenance.tsx
@@ -104,6 +104,8 @@ export type ArtifactProvenanceRecord = {
   }>;
   disclosure: {
     eventsIncluded: boolean;
+    eventsReturned?: number;
+    eventsTruncated?: boolean;
     privateReasoningIncluded: false;
     credentialsIncluded: false;
   };
@@ -296,7 +298,18 @@ export function ArtifactProvenance({
         ) : null}
 
         <section className="mt-4 rounded-xl border border-stone-200 bg-white p-4">
-          <SectionTitle icon={Clock3}>Trail</SectionTitle>
+          <div className="flex items-center justify-between gap-3">
+            <SectionTitle icon={Clock3}>Trail</SectionTitle>
+            {record.disclosure.eventsTruncated ? (
+              <span className="text-[10px] text-stone-400">
+                Latest{" "}
+                {record.disclosure.eventsReturned ?? record.actions.length}
+                {record.capture.eventCount
+                  ? ` of ${record.capture.eventCount}`
+                  : ""}
+              </span>
+            ) : null}
+          </div>
           <div className="mt-3 divide-y divide-stone-100">
             {actionRows.length ? (
               actionRows.slice(-40).map((action) => (