1 files changed, 48 insertions, 0 deletions
diff --git a/packages/exec-backend/src/extension.ts b/packages/exec-backend/src/extension.ts
new file mode 100644
index 0000000..c07b7a8
--- /dev/null
+++ b/packages/exec-backend/src/extension.ts
@@ -0,0 +1,48 @@
+import type { Extension, Manifest } from "@dispatch/kernel";
+import type { ExecBackend } from "./backend.js";
+import { localExecBackend } from "./local.js";
+import type { ExecBackendResolver } from "./service.js";
+import { execBackendHandle } from "./service.js";
+
+export const manifest: Manifest = {
+	id: "exec-backend",
+	name: "Exec Backend",
+	version: "0.0.0",
+	apiVersion: "^0.1.0",
+	trust: "bundled",
+	activation: "eager",
+	contributes: { services: ["exec-backend/resolver"] },
+};
+
+/**
+ * The resolver provided by this extension.
+ *
+ * - `computerId` undefined → `LocalExecBackend` (today's local behavior).
+ * - `computerId` set → throws. Remote execution is wired by `host-bin` + the
+ *   `ssh` package in a later wave (`SshExecBackend` implements the same
+ *   `ExecBackend` interface). For now only the local path exists — failing
+ *   loudly here is safer than silently running locally when remote was requested.
+ */
+function resolveBackend(computerId?: string): ExecBackend {
+	if (computerId === undefined) return localExecBackend;
+	throw new Error(
+		`Remote execution (computerId="${computerId}") is not yet configured. ` +
+			"The SSH backend will be wired by the ssh package.",
+	);
+}
+
+/**
+ * Factory: create the `exec-backend` core extension.
+ *
+ * `activate` provides the local-only `ExecBackendResolver` via the typed
+ * service handle. Remote resolution is added in a later wave.
+ */
+export function createExecBackendExtension(): Extension {
+	return {
+		manifest,
+		activate(host) {
+			const resolver: ExecBackendResolver = resolveBackend;
+			host.provideService(execBackendHandle, resolver);
+		},
+	};
+}