diff --git a/scripts/lib/channel-contract-test-plan.mjs b/scripts/lib/channel-contract-test-plan.mjs
index cab5ca29935..80a45a69178 100644
--- a/scripts/lib/channel-contract-test-plan.mjs
+++ b/scripts/lib/channel-contract-test-plan.mjs
@@ -14,17 +14,26 @@ function listContractTestFiles(rootDir = "src/channels/plugins/contracts") {
 
 const CONTRACT_FILE_WEIGHTS = new Map([
   ["channel-import-guardrails.test.ts", 18],
-  ["directory.registry-backed.contract.test.ts", 12],
   ["outbound-payload.contract.test.ts", 18],
-  ["plugin.registry-backed.contract.test.ts", 34],
   ["plugins-core.catalog.paths.contract.test.ts", 28],
   ["plugins-core.catalog.entries.contract.test.ts", 16],
   ["session-binding.registry-backed.contract.test.ts", 16],
-  ["surfaces-only.registry-backed.contract.test.ts", 36],
 ]);
 
 function resolveContractFileWeight(file) {
   const name = file.replaceAll("\\", "/").split("/").pop();
+  if (name.startsWith("plugin.registry-backed-shard-")) {
+    return 5;
+  }
+  if (name.startsWith("surfaces-only.registry-backed-shard-")) {
+    return 5;
+  }
+  if (name.startsWith("directory.registry-backed-shard-")) {
+    return 4;
+  }
+  if (name.startsWith("threading.registry-backed-shard-")) {
+    return 4;
+  }
   return CONTRACT_FILE_WEIGHTS.get(name) ?? 8;
 }
 
diff --git a/src/channels/plugins/contracts/directory.registry-backed-shard-a.contract.test.ts b/src/channels/plugins/contracts/directory.registry-backed-shard-a.contract.test.ts
new file mode 100644
index 00000000000..18bf28604d0
--- /dev/null
+++ b/src/channels/plugins/contracts/directory.registry-backed-shard-a.contract.test.ts
@@ -0,0 +1,3 @@
+import { installDirectoryContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installDirectoryContractRegistryShard({ shardIndex: 0, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/directory.registry-backed-shard-b.contract.test.ts b/src/channels/plugins/contracts/directory.registry-backed-shard-b.contract.test.ts
new file mode 100644
index 00000000000..575e76d433a
--- /dev/null
+++ b/src/channels/plugins/contracts/directory.registry-backed-shard-b.contract.test.ts
@@ -0,0 +1,3 @@
+import { installDirectoryContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installDirectoryContractRegistryShard({ shardIndex: 1, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/directory.registry-backed-shard-c.contract.test.ts b/src/channels/plugins/contracts/directory.registry-backed-shard-c.contract.test.ts
new file mode 100644
index 00000000000..3c715463846
--- /dev/null
+++ b/src/channels/plugins/contracts/directory.registry-backed-shard-c.contract.test.ts
@@ -0,0 +1,3 @@
+import { installDirectoryContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installDirectoryContractRegistryShard({ shardIndex: 2, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/directory.registry-backed-shard-d.contract.test.ts b/src/channels/plugins/contracts/directory.registry-backed-shard-d.contract.test.ts
new file mode 100644
index 00000000000..da83d6e2007
--- /dev/null
+++ b/src/channels/plugins/contracts/directory.registry-backed-shard-d.contract.test.ts
@@ -0,0 +1,3 @@
+import { installDirectoryContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installDirectoryContractRegistryShard({ shardIndex: 3, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/directory.registry-backed-shard-e.contract.test.ts b/src/channels/plugins/contracts/directory.registry-backed-shard-e.contract.test.ts
new file mode 100644
index 00000000000..89c475756b4
--- /dev/null
+++ b/src/channels/plugins/contracts/directory.registry-backed-shard-e.contract.test.ts
@@ -0,0 +1,3 @@
+import { installDirectoryContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installDirectoryContractRegistryShard({ shardIndex: 4, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/directory.registry-backed-shard-f.contract.test.ts b/src/channels/plugins/contracts/directory.registry-backed-shard-f.contract.test.ts
new file mode 100644
index 00000000000..7c1ae4a43bd
--- /dev/null
+++ b/src/channels/plugins/contracts/directory.registry-backed-shard-f.contract.test.ts
@@ -0,0 +1,3 @@
+import { installDirectoryContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installDirectoryContractRegistryShard({ shardIndex: 5, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/directory.registry-backed-shard-g.contract.test.ts b/src/channels/plugins/contracts/directory.registry-backed-shard-g.contract.test.ts
new file mode 100644
index 00000000000..eaeb2780d2e
--- /dev/null
+++ b/src/channels/plugins/contracts/directory.registry-backed-shard-g.contract.test.ts
@@ -0,0 +1,3 @@
+import { installDirectoryContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installDirectoryContractRegistryShard({ shardIndex: 6, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/directory.registry-backed-shard-h.contract.test.ts b/src/channels/plugins/contracts/directory.registry-backed-shard-h.contract.test.ts
new file mode 100644
index 00000000000..95685ceee1c
--- /dev/null
+++ b/src/channels/plugins/contracts/directory.registry-backed-shard-h.contract.test.ts
@@ -0,0 +1,3 @@
+import { installDirectoryContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installDirectoryContractRegistryShard({ shardIndex: 7, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/directory.registry-backed.contract.test.ts b/src/channels/plugins/contracts/directory.registry-backed.contract.test.ts
deleted file mode 100644
index b203dfb1da0..00000000000
--- a/src/channels/plugins/contracts/directory.registry-backed.contract.test.ts
+++ /dev/null
@@ -1,14 +0,0 @@
-import { describe } from "vitest";
-import { getDirectoryContractRegistry } from "../../../../test/helpers/channels/surface-contract-registry.js";
-import { installChannelDirectoryContractSuite } from "../../../../test/helpers/channels/threading-directory-contract-suites.js";
-
-for (const entry of getDirectoryContractRegistry()) {
-  describe(`${entry.id} directory contract`, () => {
-    installChannelDirectoryContractSuite({
-      plugin: entry.plugin,
-      coverage: entry.coverage,
-      cfg: entry.cfg,
-      accountId: entry.accountId,
-    });
-  });
-}
diff --git a/src/channels/plugins/contracts/plugin.registry-backed-shard-a.contract.test.ts b/src/channels/plugins/contracts/plugin.registry-backed-shard-a.contract.test.ts
new file mode 100644
index 00000000000..66798b55eed
--- /dev/null
+++ b/src/channels/plugins/contracts/plugin.registry-backed-shard-a.contract.test.ts
@@ -0,0 +1,3 @@
+import { installPluginContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installPluginContractRegistryShard({ shardIndex: 0, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/plugin.registry-backed-shard-b.contract.test.ts b/src/channels/plugins/contracts/plugin.registry-backed-shard-b.contract.test.ts
new file mode 100644
index 00000000000..5869af73677
--- /dev/null
+++ b/src/channels/plugins/contracts/plugin.registry-backed-shard-b.contract.test.ts
@@ -0,0 +1,3 @@
+import { installPluginContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installPluginContractRegistryShard({ shardIndex: 1, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/plugin.registry-backed-shard-c.contract.test.ts b/src/channels/plugins/contracts/plugin.registry-backed-shard-c.contract.test.ts
new file mode 100644
index 00000000000..7db56b0c7c9
--- /dev/null
+++ b/src/channels/plugins/contracts/plugin.registry-backed-shard-c.contract.test.ts
@@ -0,0 +1,3 @@
+import { installPluginContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installPluginContractRegistryShard({ shardIndex: 2, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/plugin.registry-backed-shard-d.contract.test.ts b/src/channels/plugins/contracts/plugin.registry-backed-shard-d.contract.test.ts
new file mode 100644
index 00000000000..ba2466a71ff
--- /dev/null
+++ b/src/channels/plugins/contracts/plugin.registry-backed-shard-d.contract.test.ts
@@ -0,0 +1,3 @@
+import { installPluginContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installPluginContractRegistryShard({ shardIndex: 3, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/plugin.registry-backed-shard-e.contract.test.ts b/src/channels/plugins/contracts/plugin.registry-backed-shard-e.contract.test.ts
new file mode 100644
index 00000000000..b1c8efbe8b9
--- /dev/null
+++ b/src/channels/plugins/contracts/plugin.registry-backed-shard-e.contract.test.ts
@@ -0,0 +1,3 @@
+import { installPluginContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installPluginContractRegistryShard({ shardIndex: 4, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/plugin.registry-backed-shard-f.contract.test.ts b/src/channels/plugins/contracts/plugin.registry-backed-shard-f.contract.test.ts
new file mode 100644
index 00000000000..80c26ed8ccf
--- /dev/null
+++ b/src/channels/plugins/contracts/plugin.registry-backed-shard-f.contract.test.ts
@@ -0,0 +1,3 @@
+import { installPluginContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installPluginContractRegistryShard({ shardIndex: 5, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/plugin.registry-backed-shard-g.contract.test.ts b/src/channels/plugins/contracts/plugin.registry-backed-shard-g.contract.test.ts
new file mode 100644
index 00000000000..cfd28555252
--- /dev/null
+++ b/src/channels/plugins/contracts/plugin.registry-backed-shard-g.contract.test.ts
@@ -0,0 +1,3 @@
+import { installPluginContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installPluginContractRegistryShard({ shardIndex: 6, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/plugin.registry-backed-shard-h.contract.test.ts b/src/channels/plugins/contracts/plugin.registry-backed-shard-h.contract.test.ts
new file mode 100644
index 00000000000..7ee92b376be
--- /dev/null
+++ b/src/channels/plugins/contracts/plugin.registry-backed-shard-h.contract.test.ts
@@ -0,0 +1,3 @@
+import { installPluginContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installPluginContractRegistryShard({ shardIndex: 7, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/plugin.registry-backed.contract.test.ts b/src/channels/plugins/contracts/plugin.registry-backed.contract.test.ts
deleted file mode 100644
index e6602bdabe6..00000000000
--- a/src/channels/plugins/contracts/plugin.registry-backed.contract.test.ts
+++ /dev/null
@@ -1,11 +0,0 @@
-import { describe } from "vitest";
-import { installChannelPluginContractSuite } from "../../../../test/helpers/channels/registry-contract-suites.js";
-import { getPluginContractRegistry } from "../../../../test/helpers/channels/registry-plugin.js";
-
-for (const entry of getPluginContractRegistry()) {
-  describe(`${entry.id} plugin contract`, () => {
-    installChannelPluginContractSuite({
-      plugin: entry.plugin,
-    });
-  });
-}
diff --git a/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-a.contract.test.ts b/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-a.contract.test.ts
new file mode 100644
index 00000000000..ca9e1f78d3e
--- /dev/null
+++ b/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-a.contract.test.ts
@@ -0,0 +1,3 @@
+import { installSurfaceContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installSurfaceContractRegistryShard({ shardIndex: 0, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-b.contract.test.ts b/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-b.contract.test.ts
new file mode 100644
index 00000000000..d9435795433
--- /dev/null
+++ b/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-b.contract.test.ts
@@ -0,0 +1,3 @@
+import { installSurfaceContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installSurfaceContractRegistryShard({ shardIndex: 1, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-c.contract.test.ts b/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-c.contract.test.ts
new file mode 100644
index 00000000000..bd85f3164b0
--- /dev/null
+++ b/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-c.contract.test.ts
@@ -0,0 +1,3 @@
+import { installSurfaceContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installSurfaceContractRegistryShard({ shardIndex: 2, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-d.contract.test.ts b/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-d.contract.test.ts
new file mode 100644
index 00000000000..c246c3d09d1
--- /dev/null
+++ b/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-d.contract.test.ts
@@ -0,0 +1,3 @@
+import { installSurfaceContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installSurfaceContractRegistryShard({ shardIndex: 3, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-e.contract.test.ts b/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-e.contract.test.ts
new file mode 100644
index 00000000000..66d94dd8c63
--- /dev/null
+++ b/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-e.contract.test.ts
@@ -0,0 +1,3 @@
+import { installSurfaceContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installSurfaceContractRegistryShard({ shardIndex: 4, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-f.contract.test.ts b/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-f.contract.test.ts
new file mode 100644
index 00000000000..b08d8584ad1
--- /dev/null
+++ b/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-f.contract.test.ts
@@ -0,0 +1,3 @@
+import { installSurfaceContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installSurfaceContractRegistryShard({ shardIndex: 5, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-g.contract.test.ts b/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-g.contract.test.ts
new file mode 100644
index 00000000000..1ed4911bac1
--- /dev/null
+++ b/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-g.contract.test.ts
@@ -0,0 +1,3 @@
+import { installSurfaceContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installSurfaceContractRegistryShard({ shardIndex: 6, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-h.contract.test.ts b/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-h.contract.test.ts
new file mode 100644
index 00000000000..6f7b38b42dd
--- /dev/null
+++ b/src/channels/plugins/contracts/surfaces-only.registry-backed-shard-h.contract.test.ts
@@ -0,0 +1,3 @@
+import { installSurfaceContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installSurfaceContractRegistryShard({ shardIndex: 7, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/surfaces-only.registry-backed.contract.test.ts b/src/channels/plugins/contracts/surfaces-only.registry-backed.contract.test.ts
deleted file mode 100644
index dc42df3d95b..00000000000
--- a/src/channels/plugins/contracts/surfaces-only.registry-backed.contract.test.ts
+++ /dev/null
@@ -1,14 +0,0 @@
-import { describe } from "vitest";
-import { getSurfaceContractRegistry } from "../../../../test/helpers/channels/surface-contract-registry.js";
-import { installChannelSurfaceContractSuite } from "../../../../test/helpers/channels/surface-contract-suite.js";
-
-for (const entry of getSurfaceContractRegistry()) {
-  for (const surface of entry.surfaces) {
-    describe(`${entry.id} ${surface} surface contract`, () => {
-      installChannelSurfaceContractSuite({
-        plugin: entry.plugin,
-        surface,
-      });
-    });
-  }
-}
diff --git a/src/channels/plugins/contracts/threading.registry-backed-shard-a.contract.test.ts b/src/channels/plugins/contracts/threading.registry-backed-shard-a.contract.test.ts
new file mode 100644
index 00000000000..f1de5ddc67d
--- /dev/null
+++ b/src/channels/plugins/contracts/threading.registry-backed-shard-a.contract.test.ts
@@ -0,0 +1,3 @@
+import { installThreadingContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installThreadingContractRegistryShard({ shardIndex: 0, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/threading.registry-backed-shard-b.contract.test.ts b/src/channels/plugins/contracts/threading.registry-backed-shard-b.contract.test.ts
new file mode 100644
index 00000000000..7648c866c8c
--- /dev/null
+++ b/src/channels/plugins/contracts/threading.registry-backed-shard-b.contract.test.ts
@@ -0,0 +1,3 @@
+import { installThreadingContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installThreadingContractRegistryShard({ shardIndex: 1, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/threading.registry-backed-shard-c.contract.test.ts b/src/channels/plugins/contracts/threading.registry-backed-shard-c.contract.test.ts
new file mode 100644
index 00000000000..8f63743ade0
--- /dev/null
+++ b/src/channels/plugins/contracts/threading.registry-backed-shard-c.contract.test.ts
@@ -0,0 +1,3 @@
+import { installThreadingContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installThreadingContractRegistryShard({ shardIndex: 2, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/threading.registry-backed-shard-d.contract.test.ts b/src/channels/plugins/contracts/threading.registry-backed-shard-d.contract.test.ts
new file mode 100644
index 00000000000..49307be4df2
--- /dev/null
+++ b/src/channels/plugins/contracts/threading.registry-backed-shard-d.contract.test.ts
@@ -0,0 +1,3 @@
+import { installThreadingContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installThreadingContractRegistryShard({ shardIndex: 3, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/threading.registry-backed-shard-e.contract.test.ts b/src/channels/plugins/contracts/threading.registry-backed-shard-e.contract.test.ts
new file mode 100644
index 00000000000..4fa944a7c9c
--- /dev/null
+++ b/src/channels/plugins/contracts/threading.registry-backed-shard-e.contract.test.ts
@@ -0,0 +1,3 @@
+import { installThreadingContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installThreadingContractRegistryShard({ shardIndex: 4, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/threading.registry-backed-shard-f.contract.test.ts b/src/channels/plugins/contracts/threading.registry-backed-shard-f.contract.test.ts
new file mode 100644
index 00000000000..f59b1a0a5fa
--- /dev/null
+++ b/src/channels/plugins/contracts/threading.registry-backed-shard-f.contract.test.ts
@@ -0,0 +1,3 @@
+import { installThreadingContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installThreadingContractRegistryShard({ shardIndex: 5, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/threading.registry-backed-shard-g.contract.test.ts b/src/channels/plugins/contracts/threading.registry-backed-shard-g.contract.test.ts
new file mode 100644
index 00000000000..8288ac3fe0b
--- /dev/null
+++ b/src/channels/plugins/contracts/threading.registry-backed-shard-g.contract.test.ts
@@ -0,0 +1,3 @@
+import { installThreadingContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installThreadingContractRegistryShard({ shardIndex: 6, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/threading.registry-backed-shard-h.contract.test.ts b/src/channels/plugins/contracts/threading.registry-backed-shard-h.contract.test.ts
new file mode 100644
index 00000000000..e3f14c87085
--- /dev/null
+++ b/src/channels/plugins/contracts/threading.registry-backed-shard-h.contract.test.ts
@@ -0,0 +1,3 @@
+import { installThreadingContractRegistryShard } from "../../../../test/helpers/channels/registry-backed-contract-shards.js";
+
+installThreadingContractRegistryShard({ shardIndex: 7, shardCount: 8 });
diff --git a/src/channels/plugins/contracts/threading.registry-backed.contract.test.ts b/src/channels/plugins/contracts/threading.registry-backed.contract.test.ts
deleted file mode 100644
index 8dbf89f3d75..00000000000
--- a/src/channels/plugins/contracts/threading.registry-backed.contract.test.ts
+++ /dev/null
@@ -1,11 +0,0 @@
-import { describe } from "vitest";
-import { getThreadingContractRegistry } from "../../../../test/helpers/channels/surface-contract-registry.js";
-import { installChannelThreadingContractSuite } from "../../../../test/helpers/channels/threading-directory-contract-suites.js";
-
-for (const entry of getThreadingContractRegistry()) {
-  describe(`${entry.id} threading contract`, () => {
-    installChannelThreadingContractSuite({
-      plugin: entry.plugin,
-    });
-  });
-}
diff --git a/test/helpers/channels/registry-backed-contract-shards.ts b/test/helpers/channels/registry-backed-contract-shards.ts
new file mode 100644
index 00000000000..29179047702
--- /dev/null
+++ b/test/helpers/channels/registry-backed-contract-shards.ts
@@ -0,0 +1,92 @@
+import { describe, it } from "vitest";
+import { installChannelPluginContractSuite } from "./registry-contract-suites.js";
+import { getPluginContractRegistryShard } from "./registry-plugin.js";
+import {
+  getDirectoryContractRegistryShard,
+  getSurfaceContractRegistryShard,
+  getThreadingContractRegistryShard,
+} from "./surface-contract-registry.js";
+import { installChannelSurfaceContractSuite } from "./surface-contract-suite.js";
+import {
+  installChannelDirectoryContractSuite,
+  installChannelThreadingContractSuite,
+} from "./threading-directory-contract-suites.js";
+
+type ContractShardParams = {
+  shardIndex: number;
+  shardCount: number;
+};
+
+function installEmptyShardSuite(label: string) {
+  describe(label, () => {
+    it("has no matching bundled channels", () => {
+      // Keeps intentionally empty id-based shards visible to Vitest.
+    });
+  });
+}
+
+export function installSurfaceContractRegistryShard(params: ContractShardParams) {
+  const entries = getSurfaceContractRegistryShard(params);
+  if (entries.length === 0) {
+    installEmptyShardSuite("surface contract registry shard");
+    return;
+  }
+  for (const entry of entries) {
+    for (const surface of entry.surfaces) {
+      describe(`${entry.id} ${surface} surface contract`, () => {
+        installChannelSurfaceContractSuite({
+          plugin: entry.plugin,
+          surface,
+        });
+      });
+    }
+  }
+}
+
+export function installDirectoryContractRegistryShard(params: ContractShardParams) {
+  const entries = getDirectoryContractRegistryShard(params);
+  if (entries.length === 0) {
+    installEmptyShardSuite("directory contract registry shard");
+    return;
+  }
+  for (const entry of entries) {
+    describe(`${entry.id} directory contract`, () => {
+      installChannelDirectoryContractSuite({
+        plugin: entry.plugin,
+        coverage: entry.coverage,
+        cfg: entry.cfg,
+        accountId: entry.accountId,
+      });
+    });
+  }
+}
+
+export function installThreadingContractRegistryShard(params: ContractShardParams) {
+  const entries = getThreadingContractRegistryShard(params);
+  if (entries.length === 0) {
+    installEmptyShardSuite("threading contract registry shard");
+    return;
+  }
+  for (const entry of entries) {
+    describe(`${entry.id} threading contract`, () => {
+      installChannelThreadingContractSuite({
+        plugin: entry.plugin,
+      });
+    });
+  }
+}
+
+export function installPluginContractRegistryShard(params: ContractShardParams) {
+  const entries = getPluginContractRegistryShard(params);
+  if (entries.length === 0) {
+    installEmptyShardSuite("plugin contract registry shard");
+    return;
+  }
+  for (const entry of entries) {
+    describe(`${entry.id} plugin contract`, () => {
+      installChannelPluginContractSuite({
+        plugin: entry.plugin,
+      });
+    });
+  }
+}
diff --git a/test/helpers/channels/registry-plugin.ts b/test/helpers/channels/registry-plugin.ts
index f4b02e78001..6c6edc7b4b5 100644
--- a/test/helpers/channels/registry-plugin.ts
+++ b/test/helpers/channels/registry-plugin.ts
@@ -1,4 +1,9 @@
-import { listBundledChannelPlugins } from "../../../src/channels/plugins/bundled.js";
+import {
+  getBundledChannelPlugin,
+  listBundledChannelPluginIds,
+  listBundledChannelPlugins,
+} from "../../../src/channels/plugins/bundled.js";
+import type { ChannelId } from "../../../src/channels/plugins/channel-id.types.js";
 import { normalizeChannelMeta } from "../../../src/channels/plugins/meta-normalization.js";
 import type { ChannelPlugin } from "../../../src/channels/plugins/types.js";
 
@@ -7,12 +12,35 @@ type PluginContractEntry = {
   plugin: Pick<ChannelPlugin, "id" | "meta" | "capabilities" | "config">;
 };
 
-export function getPluginContractRegistry(): PluginContractEntry[] {
-  return listBundledChannelPlugins().map((plugin) => ({
+function toPluginContractEntry(plugin: ChannelPlugin): PluginContractEntry {
+  return {
     id: plugin.id,
     plugin: {
       ...plugin,
       meta: normalizeChannelMeta({ id: plugin.id, meta: plugin.meta }),
     },
-  }));
+  };
+}
+
+function getBundledChannelPluginIdsForShard(params: {
+  shardIndex: number;
+  shardCount: number;
+}): readonly ChannelId[] {
+  return listBundledChannelPluginIds().filter(
+    (_id, index) => index % params.shardCount === params.shardIndex,
+  );
+}
+
+export function getPluginContractRegistry(): PluginContractEntry[] {
+  return listBundledChannelPlugins().map(toPluginContractEntry);
+}
+
+export function getPluginContractRegistryShard(params: {
+  shardIndex: number;
+  shardCount: number;
+}): PluginContractEntry[] {
+  return getBundledChannelPluginIdsForShard(params).flatMap((id) => {
+    const plugin = getBundledChannelPlugin(id);
+    return plugin ? [toPluginContractEntry(plugin)] : [];
+  });
 }
diff --git a/test/helpers/channels/surface-contract-registry.ts b/test/helpers/channels/surface-contract-registry.ts
index b1a00cdb404..a6f8c02e1d4 100644
--- a/test/helpers/channels/surface-contract-registry.ts
+++ b/test/helpers/channels/surface-contract-registry.ts
@@ -1,7 +1,10 @@
 import {
+  getBundledChannelPlugin,
+  listBundledChannelPluginIds,
   listBundledChannelPlugins,
   setBundledChannelRuntime,
 } from "../../../src/channels/plugins/bundled.js";
+import type { ChannelId } from "../../../src/channels/plugins/channel-id.types.js";
 import type { ChannelPlugin } from "../../../src/channels/plugins/types.js";
 import type { OpenClawConfig } from "../../../src/config/config.js";
 import {
@@ -53,18 +56,52 @@ setBundledChannelRuntime("line", {
 } as never);
 
 let surfaceContractRegistryCache: SurfaceContractEntry[] | undefined;
+const surfaceContractEntryCache = new Map<ChannelId, SurfaceContractEntry | null>();
 let threadingContractRegistryCache: ThreadingContractEntry[] | undefined;
 let directoryContractRegistryCache: DirectoryContractEntry[] | undefined;
 
-export function getSurfaceContractRegistry(): SurfaceContractEntry[] {
-  surfaceContractRegistryCache ??= listBundledChannelPlugins().map((plugin) => ({
+function toSurfaceContractEntry(plugin: ChannelPlugin): SurfaceContractEntry {
+  return {
     id: plugin.id,
     plugin,
     surfaces: channelPluginSurfaceKeys.filter((surface) => Boolean(plugin[surface])),
-  }));
+  };
+}
+
+function getBundledChannelPluginIdsForShard(params: {
+  shardIndex: number;
+  shardCount: number;
+}): readonly ChannelId[] {
+  return listBundledChannelPluginIds().filter(
+    (_id, index) => index % params.shardCount === params.shardIndex,
+  );
+}
+
+function getSurfaceContractEntry(id: ChannelId): SurfaceContractEntry | undefined {
+  if (surfaceContractEntryCache.has(id)) {
+    return surfaceContractEntryCache.get(id) ?? undefined;
+  }
+  const plugin = getBundledChannelPlugin(id);
+  const entry = plugin ? toSurfaceContractEntry(plugin) : null;
+  surfaceContractEntryCache.set(id, entry);
+  return entry ?? undefined;
+}
+
+export function getSurfaceContractRegistry(): SurfaceContractEntry[] {
+  surfaceContractRegistryCache ??= listBundledChannelPlugins().map(toSurfaceContractEntry);
   return surfaceContractRegistryCache;
 }
 
+export function getSurfaceContractRegistryShard(params: {
+  shardIndex: number;
+  shardCount: number;
+}): SurfaceContractEntry[] {
+  return getBundledChannelPluginIdsForShard(params).flatMap((id) => {
+    const entry = getSurfaceContractEntry(id);
+    return entry ? [entry] : [];
+  });
+}
+
 export function getThreadingContractRegistry(): ThreadingContractEntry[] {
   threadingContractRegistryCache ??= getSurfaceContractRegistry()
     .filter((entry) => entry.surfaces.includes("threading"))
@@ -75,6 +112,18 @@ export function getThreadingContractRegistry(): ThreadingContractEntry[] {
   return threadingContractRegistryCache;
 }
 
+export function getThreadingContractRegistryShard(params: {
+  shardIndex: number;
+  shardCount: number;
+}): ThreadingContractEntry[] {
+  return getSurfaceContractRegistryShard(params)
+    .filter((entry) => entry.surfaces.includes("threading"))
+    .map((entry) => ({
+      id: entry.id,
+      plugin: entry.plugin,
+    }));
+}
+
 const directoryPresenceOnlyIds = new Set(["whatsapp", "zalouser"]);
 
 export function getDirectoryContractRegistry(): DirectoryContractEntry[] {
@@ -87,3 +136,16 @@ export function getDirectoryContractRegistry(): DirectoryContractEntry[] {
     }));
   return directoryContractRegistryCache;
 }
+
+export function getDirectoryContractRegistryShard(params: {
+  shardIndex: number;
+  shardCount: number;
+}): DirectoryContractEntry[] {
+  return getSurfaceContractRegistryShard(params)
+    .filter((entry) => entry.surfaces.includes("directory"))
+    .map((entry) => ({
+      id: entry.id,
+      plugin: entry.plugin,
+      coverage: directoryPresenceOnlyIds.has(entry.id) ? "presence" : "lookups",
+    }));
+}