diff --git a/packages/cultmesh-ts/test/realtime-quic-provider.test.ts b/packages/cultmesh-ts/test/realtime-quic-provider.test.ts
new file mode 100644
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+++ b/packages/cultmesh-ts/test/realtime-quic-provider.test.ts
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+// `CultMeshQuicRealtimeProvider`, Cut 5's StreamPixels role, exercised
+// end-to-end against the real native bridge and the real consumer connector
+// from Cut 4 (no mocks): reliable ordering in both directions
+// (`CultMeshQuicRealtimeTransportTests.cs:71-110`), latest-only coalescing
+// per `(channel, body)` key, a non-blocking broadcast, the uppercase pin, and
+// eviction on peer shutdown.
+//
+// Skips instead of failing when no native bridge is available; see
+// `realtime-quic-native.test.ts` for why.
+
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import { join } from "node:path";
+import test from "node:test";
+
+import {
+  CultMeshQuicRealtimeConnector,
+  CultMeshQuicRealtimeProvider,
+  type CultMeshRealtimeCandidate,
+  type CultMeshRealtimeTarget,
+  type CultMeshRealtimeTransport,
+} from "../src/realtime-quic";
+import type { CultMeshRealtimeFrame } from "../src/realtime-wire";
+import { nativeBridgeAvailable } from "./support/native-bridge";
+
+// __dirname at runtime is dist-test/test; fixtures are binary and are never
+// compiled/copied there, so they are read from their source location, two
+// levels up.
+const FIXTURE_P12 = join(__dirname, "..", "..", "test", "fixtures", "quic-test.p12");
+
+function testFrame(overrides: Partial<CultMeshRealtimeFrame> = {}): CultMeshRealtimeFrame {
+  return {
+    channelId: "aetheria.entities",
+    schemaId: "eve.entity_soa.v1",
+    bodyId: "body:aetheria:entities",
+    producerEpoch: 7n,
+    sequence: 1n,
+    delivery: "latest-only",
+    payload: new Uint8Array([3, 4, 5]),
+    ...overrides,
+  };
+}
+
+async function startProvider(): Promise<CultMeshQuicRealtimeProvider> {
+  return await CultMeshQuicRealtimeProvider.listen({
+    host: "127.0.0.1",
+    port: 0,
+    serverCertificate: { pkcs12: readFileSync(FIXTURE_P12), password: "" },
+  });
+}
+
+async function dialProvider(provider: CultMeshQuicRealtimeProvider): Promise<CultMeshRealtimeTransport> {
+  const target: CultMeshRealtimeTarget = { verseId: "aetheria", authorityRuntimeId: "service:aetheria.daemon" };
+  const candidate: CultMeshRealtimeCandidate = {
+    endpoint: provider.advertisedEndpoint,
+    authorityRuntimeId: target.authorityRuntimeId,
+    priority: 0,
+    generation: "gen-1",
+  };
+  const connector = new CultMeshQuicRealtimeConnector();
+  return await connector.connect(candidate, target);
+}
+
+async function waitUntil(predicate: () => boolean, timeoutMs = 5_000): Promise<void> {
+  const deadline = Date.now() + timeoutMs;
+  while (!predicate()) {
+    if (Date.now() >= deadline) throw new Error("timed out waiting for a provider condition");
+    await new Promise((resolve) => setTimeout(resolve, 10));
+  }
+}
+
+test("the advertised endpoint carries an uppercase cert-sha256 pin the Unity connector requires", async (t) => {
+  if (!nativeBridgeAvailable()) return void t.skip("no native bridge available");
+  const provider = await startProvider();
+  try {
+    assert.match(
+      provider.advertisedEndpoint,
+      /^cultmesh-state\+quic:\/\/127\.0\.0\.1:\d+\?cert-sha256=[0-9A-F]{64}$/,
+    );
+    // Not merely uppercase-tolerant: it must not contain a lowercase hex digit.
+    const pin = new URL(provider.advertisedEndpoint).searchParams.get("cert-sha256")!;
+    assert.equal(pin, pin.toUpperCase());
+    assert.notEqual(pin, pin.toLowerCase());
+  } finally {
+    provider.dispose();
+  }
+});
+
+test("reliable-ordered delivers frames in order, provider to consumer and consumer to provider", async (t) => {
+  if (!nativeBridgeAvailable()) return void t.skip("no native bridge available");
+  const provider = await startProvider();
+  try {
+    const consumer = await dialProvider(provider);
+    try {
+      await waitUntil(() => provider.connectionCount === 1);
+
+      await provider.broadcast(testFrame({ delivery: "reliable-ordered", sequence: 1n }));
+      await provider.broadcast(testFrame({ delivery: "reliable-ordered", sequence: 2n }));
+      const firstAtConsumer = await consumer.receiveFrame();
+      const secondAtConsumer = await consumer.receiveFrame();
+      assert.deepEqual([firstAtConsumer.sequence, secondAtConsumer.sequence], [1n, 2n]);
+
+      await consumer.sendFrame(testFrame({ delivery: "reliable-ordered", sequence: 3n }));
+      await consumer.sendFrame(testFrame({ delivery: "reliable-ordered", sequence: 4n }));
+      const firstAtProvider = await provider.receive();
+      const secondAtProvider = await provider.receive();
+      assert.deepEqual([firstAtProvider.sequence, secondAtProvider.sequence], [3n, 4n]);
+    } finally {
+      consumer.dispose();
+    }
+  } finally {
+    provider.dispose();
+  }
+});
+
+test("latest-only broadcast coalesces back-to-back sends for the same key to the newest frame, and never blocks on I/O", async (t) => {
+  if (!nativeBridgeAvailable()) return void t.skip("no native bridge available");
+  const provider = await startProvider();
+  try {
+    const consumer = await dialProvider(provider);
+    try {
+      await waitUntil(() => provider.connectionCount === 1);
+
+      // Three broadcasts for the same (channelId, bodyId) key, issued back to
+      // back with no await between them. `broadcast` for latest-only never
+      // awaits any I/O (mutating it to await the peer's send would make this
+      // loop, and the assertion below, run after real network round trips
+      // instead of within one JS turn): the synchronous middle publish is
+      // therefore always coalesced away, deterministically, not by luck of
+      // network timing. Mutating the coalescing key (e.g. dropping bodyId)
+      // would let sequence 200 leak through as a separate delivered frame
+      // instead of overwriting 100.
+      const before = Date.now();
+      const first = provider.broadcast(testFrame({ sequence: 1n }));
+      const second = provider.broadcast(testFrame({ sequence: 100n }));
+      const third = provider.broadcast(testFrame({ sequence: 200n }));
+      const afterCallsReturned = Date.now();
+      // All three promises exist before any of them could possibly have
+      // waited on the peer's round trip: the loop above ran in well under a
+      // network round trip's worth of time.
+      assert.ok(afterCallsReturned - before < 50, "broadcast must not block on any peer's I/O");
+      await Promise.all([first, second, third]);
+
+      // The consumer's own receive-side inbox (Cut 4) also coalesces
+      // latest-only frames it has not yet read, so whether 1 is delivered as
+      // its own frame or is itself coalesced away by 200 arriving first
+      // depends on read timing; that is Cut 4's contract, not this test's.
+      // What this test owns is the provider's outbox: 100 must never appear,
+      // and the last frame delivered must be 200.
+      const received: bigint[] = [];
+      let last: bigint | undefined;
+      while (last !== 200n) {
+        const frame = await consumer.receiveFrame();
+        received.push(frame.sequence);
+        last = frame.sequence;
+      }
+      assert.ok(!received.includes(100n), `100 must be coalesced away, got ${received}`);
+      assert.ok(received.length <= 2, `expected at most 2 delivered frames, got ${received}`);
+      assert.equal(last, 200n);
+    } finally {
+      consumer.dispose();
+    }
+  } finally {
+    provider.dispose();
+  }
+});
+
+test("a stalled peer's outbox holds at most one pending frame per key across many broadcasts", async (t) => {
+  if (!nativeBridgeAvailable()) return void t.skip("no native bridge available");
+  const provider = await startProvider();
+  try {
+    const consumer = await dialProvider(provider);
+    try {
+      await waitUntil(() => provider.connectionCount === 1);
+
+      // 200 broadcasts, none awaited individually, none read by the consumer
+      // until they are all issued: mirrors the interop lane's stalled-reader
+      // scenario at unit-test speed. `broadcast` completing this loop at all
+      // (bounded time) proves it never blocks on the unread peer.
+      const started = Date.now();
+      const sends: Promise<void>[] = [];
+      for (let sequence = 1; sequence <= 200; sequence += 1) {
+        sends.push(provider.broadcast(testFrame({ sequence: BigInt(sequence) })));
+      }
+      await Promise.all(sends);
+      assert.ok(Date.now() - started < 2_000, "200 broadcasts to one key must complete quickly, unread");
+
+      const receivedSequences: bigint[] = [];
+      let last: bigint | undefined;
+      while (last !== 200n) {
+        const frame = await consumer.receiveFrame();
+        receivedSequences.push(frame.sequence);
+        last = frame.sequence;
+      }
+      assert.equal(last, 200n);
+      // Coalescing means far fewer than 200 frames were actually put on the
+      // wire; the exact count depends on scheduling, but it must be small.
+      assert.ok(receivedSequences.length < 200, `expected coalescing, got ${receivedSequences.length} frames`);
+    } finally {
+      consumer.dispose();
+    }
+  } finally {
+    provider.dispose();
+  }
+});
+
+test("unreliable broadcast fails closed", async (t) => {
+  if (!nativeBridgeAvailable()) return void t.skip("no native bridge available");
+  const provider = await startProvider();
+  try {
+    const consumer = await dialProvider(provider);
+    try {
+      await waitUntil(() => provider.connectionCount === 1);
+      await assert.rejects(provider.broadcast(testFrame({ delivery: "unreliable" })), /datagrams/i);
+    } finally {
+      consumer.dispose();
+    }
+  } finally {
+    provider.dispose();
+  }
+});
+
+test("a peer is evicted from the provider on connection shutdown", async (t) => {
+  if (!nativeBridgeAvailable()) return void t.skip("no native bridge available");
+  const provider = await startProvider();
+  try {
+    const consumer = await dialProvider(provider);
+    await waitUntil(() => provider.connectionCount === 1);
+    consumer.dispose();
+    await waitUntil(() => provider.connectionCount === 0);
+  } finally {
+    provider.dispose();
+  }
+});
+
+test("connectionCount reflects accepted peers, and dispose releases the runtime for a fresh listen", async (t) => {
+  if (!nativeBridgeAvailable()) return void t.skip("no native bridge available");
+  const provider = await startProvider();
+  assert.equal(provider.connectionCount, 0);
+  const consumer = await dialProvider(provider);
+  try {
+    await waitUntil(() => provider.connectionCount === 1);
+  } finally {
+    consumer.dispose();
+    provider.dispose();
+  }
+  // A leaked runtime reference from any earlier path (accept, handshake
+  // timeout, dispose) would leave the shared runtime unable to open a fresh
+  // listener cleanly; opening and tearing down a second provider proves
+  // release ran on every path exercised above.
+  const again = await startProvider();
+  again.dispose();
+});