diff --git a/nodejs/package.json b/nodejs/package.json
index ef06e3631..30c917a4c 100644
--- a/nodejs/package.json
+++ b/nodejs/package.json
@@ -40,7 +40,7 @@
         "format:check": "prettier --check \"src/**/*.ts\" \"test/**/*.ts\" --ignore-path .prettierignore",
         "lint": "eslint \"src/**/*.ts\" \"test/**/*.ts\"",
         "lint:fix": "eslint --fix \"src/**/*.ts\" \"test/**/*.ts\"",
-        "typecheck": "tsc --noEmit",
+        "typecheck": "tsc --noEmit && tsc --noEmit -p tsconfig.test.json",
         "generate": "cd ../scripts/codegen && npm run generate",
         "update:protocol-version": "tsx scripts/update-protocol-version.ts",
         "prepublishOnly": "npm run build",
diff --git a/nodejs/src/index.ts b/nodejs/src/index.ts
index ee231d79f..a34d23712 100644
--- a/nodejs/src/index.ts
+++ b/nodejs/src/index.ts
@@ -17,6 +17,19 @@ export {
     createSessionFsAdapter,
     SYSTEM_PROMPT_SECTIONS,
 } from "./types.js";
+// Re-export the generated session-event types (every *Event interface and
+// its corresponding *Data payload type, plus supporting unions/aliases) so
+// consumers can import them directly from "@github/copilot-sdk" instead of
+// reaching into the package's internal dist layout. See issue #1156.
+//
+// Three names from this file are also explicitly exported elsewhere in this
+// module — `SessionEvent` (re-exported below from `./types.js`),
+// `PermissionRequest` (re-exported below from `./types.js`), and
+// `AssistantMessageEvent` (re-exported above from `./session.js`). Per the
+// ECMAScript module spec, the explicit named re-exports shadow the names
+// arriving via `export type *`, so the hand-authored public API surface for
+// those three identifiers is preserved unchanged.
+export type * from "./generated/session-events.js";
 export type {
     CommandContext,
     CommandDefinition,
diff --git a/nodejs/test/session-event-types.test.ts b/nodejs/test/session-event-types.test.ts
new file mode 100644
index 000000000..de21ba2ba
--- /dev/null
+++ b/nodejs/test/session-event-types.test.ts
@@ -0,0 +1,182 @@
+/**
+ * Regression test for #1156: dedicated session event data/payload types are
+ * importable from the package entry point (`@github/copilot-sdk` /
+ * `src/index.js`).
+ *
+ * Before this fix, only the aggregate `SessionEvent` discriminated union was
+ * re-exported. The constituent `*Event` wrapper interfaces and their `*Data`
+ * payload types lived in `generated/session-events.ts` and could only be
+ * reached via a deep import (`@github/copilot-sdk/dist/generated/...`).
+ *
+ * Most of this file exercises the *type* surface — if these type-only imports
+ * compile, the public API exposes the types. The runtime assertions below only
+ * validate representative object shapes for those annotations; they do not
+ * prove that type-only exports exist at runtime.
+ */
+
+import { describe, expect, it } from "vitest";
+import type {
+    // The aggregate union; must still resolve via the package root.
+    SessionEvent,
+
+    // *Data payload types from the v0.3.0 generated session-event schema.
+    AssistantMessageData,
+    AssistantMessageDeltaData,
+    AssistantReasoningData,
+    AssistantTurnStartData,
+    ErrorData,
+    IdleData,
+    ResumeData,
+    StartData,
+    ToolExecutionCompleteData,
+    ToolExecutionPartialData,
+    ToolExecutionProgressData,
+    ToolExecutionStartData,
+    UserMessageData,
+
+    // *Event wrapper interfaces.
+    AssistantMessageEvent,
+    ErrorEvent,
+    IdleEvent,
+    ResumeEvent,
+    StartEvent,
+    ToolExecutionCompleteEvent,
+    ToolExecutionStartEvent,
+    UserMessageEvent,
+
+    // A sample of supporting auxiliary aliases/unions referenced by the
+    // *Data shapes — these must also be reachable so that consumers can
+    // narrow or annotate intermediate values.
+    UserMessageAgentMode,
+    UserMessageAttachment,
+    WorkingDirectoryContextHostType,
+} from "../src/index.js";
+
+/**
+ * Type-only helper: forces the compiler to resolve the supplied type
+ * parameter. If the type is not exported from `../src/index.js`, the file
+ * fails to type-check and the test never runs. There is no runtime body —
+ * the helper exists purely to make "is this type importable?" assertions
+ * compile-time checked.
+ */
+function assertImportable<_T>(): void {
+    /* no-op; compile-time check only */
+}
+
+/**
+ * Compile-time mutual-assignability check: passes only when `A` and `B`
+ * are structurally equivalent. Used below to pin the package-root
+ * `AssistantMessageEvent` (which is explicitly re-exported from
+ * `./session.js` and therefore shadows the generated `AssistantMessageEvent`
+ * arriving via `export type *`) to the corresponding arm of the generated
+ * `SessionEvent` union. If a future schema regen ever caused these two
+ * shapes to drift, this assertion would fail to type-check and `npm run
+ * typecheck` would surface it before the public API silently changed.
+ */
+type _AssertEqual<A, B> =
+    (<T>() => T extends A ? 1 : 2) extends <T>() => T extends B ? 1 : 2 ? true : false;
+type _AssistantMessageEventStaysAlignedWithSessionEventUnion = _AssertEqual<
+    AssistantMessageEvent,
+    Extract<SessionEvent, { type: "assistant.message" }>
+>;
+const _assistantMessageEventAlignmentCheck: _AssistantMessageEventStaysAlignedWithSessionEventUnion = true;
+
+describe("Session event type exports (#1156)", () => {
+    it("exposes the headline ToolExecutionStartData type with a usable shape", () => {
+        // This is the specific type called out in issue #1156. The annotation
+        // is the compile-time API-surface check; these assertions only validate
+        // the representative runtime object shape a consumer would use.
+        const data: ToolExecutionStartData = {
+            toolCallId: "call-1",
+            toolName: "shell",
+            arguments: { command: "ls" },
+            mcpServerName: "filesystem",
+            mcpToolName: "list_dir",
+            turnId: "turn-1",
+        };
+
+        expect(data.toolName).toBe("shell");
+        expect(data.toolCallId).toBe("call-1");
+        expect(data.arguments?.command).toBe("ls");
+        expect(data.mcpServerName).toBe("filesystem");
+        expect(data.mcpToolName).toBe("list_dir");
+        expect(data.turnId).toBe("turn-1");
+    });
+
+    it("wraps ToolExecutionStartData inside the exported ToolExecutionStartEvent", () => {
+        const event: ToolExecutionStartEvent = {
+            id: "evt-1",
+            parentId: null,
+            timestamp: "2026-01-01T00:00:00.000Z",
+            type: "tool.execution_start",
+            data: {
+                toolCallId: "call-1",
+                toolName: "shell",
+            },
+        };
+
+        expect(event.type).toBe("tool.execution_start");
+        expect(event.data.toolName).toBe("shell");
+        expect(event.parentId).toBeNull();
+    });
+
+    it("narrows the aggregate SessionEvent union to a dedicated *Data type", () => {
+        const evt: SessionEvent = {
+            id: "evt-2",
+            parentId: null,
+            timestamp: "2026-01-01T00:00:01.000Z",
+            type: "tool.execution_start",
+            data: {
+                toolCallId: "call-2",
+                toolName: "shell",
+            },
+        };
+
+        if (evt.type !== "tool.execution_start") {
+            throw new Error("expected tool.execution_start narrowing");
+        }
+
+        // After narrowing, `evt.data` must satisfy `ToolExecutionStartData`.
+        // Annotating the local with the dedicated *Data type proves the
+        // re-export is wired up correctly.
+        const data: ToolExecutionStartData = evt.data;
+        expect(data.toolCallId).toBe("call-2");
+        expect(data.toolName).toBe("shell");
+    });
+
+    it("re-exports the full set of *Data and *Event types named in v0.3.0", () => {
+        // Compile-time checks: if any of these fail to resolve, the file
+        // will not type-check and the test will not be executed.
+        assertImportable<AssistantMessageData>();
+        assertImportable<AssistantMessageDeltaData>();
+        assertImportable<AssistantReasoningData>();
+        assertImportable<AssistantTurnStartData>();
+        assertImportable<ErrorData>();
+        assertImportable<IdleData>();
+        assertImportable<ResumeData>();
+        assertImportable<StartData>();
+        assertImportable<ToolExecutionCompleteData>();
+        assertImportable<ToolExecutionPartialData>();
+        assertImportable<ToolExecutionProgressData>();
+        assertImportable<ToolExecutionStartData>();
+        assertImportable<UserMessageData>();
+
+        assertImportable<AssistantMessageEvent>();
+        assertImportable<ErrorEvent>();
+        assertImportable<IdleEvent>();
+        assertImportable<ResumeEvent>();
+        assertImportable<StartEvent>();
+        assertImportable<ToolExecutionCompleteEvent>();
+        assertImportable<ToolExecutionStartEvent>();
+        assertImportable<UserMessageEvent>();
+
+        // Supporting auxiliary types referenced by the *Data shapes — these
+        // must round-trip through the package root too, otherwise consumers
+        // annotating intermediate values would still need a deep import.
+        assertImportable<UserMessageAgentMode>();
+        assertImportable<UserMessageAttachment>();
+        assertImportable<WorkingDirectoryContextHostType>();
+
+        expect(true).toBe(true);
+    });
+});
diff --git a/nodejs/tsconfig.test.json b/nodejs/tsconfig.test.json
new file mode 100644
index 000000000..295748750
--- /dev/null
+++ b/nodejs/tsconfig.test.json
@@ -0,0 +1,10 @@
+{
+    "extends": "./tsconfig.json",
+    "compilerOptions": {
+        "noEmit": true,
+        "emitDeclarationOnly": false,
+        "types": ["node"]
+    },
+    "include": ["src/**/*", "test/session-event-types.test.ts"],
+    "exclude": ["node_modules", "dist"]
+}