Support captured CRDT changes in compound transaction contracts

src/capability-language/generic-types.ts

@@ -319,12 +319,12 @@ export class GenericSourceTypes {
       return { kind: "record", fields: Object.fromEntries(fields) };
     }
     const name = context.identifier()!.getText();
-    if (name === "change" && context.typeArguments())
-      throw new GenericTypeError(
-        "unsupported-prepared-change",
-        name,
-        "Authored change<T> transport values require LF-19; native edit contracts are available separately",
-      );
+    if (name === "change" && context.typeArguments()) {
+      const args = this.arguments(context.typeArguments());
+      if (args.length !== 1 || args[0]!.kind !== "value")
+        throw new GenericTypeError("invalid-change-type", name, "change<T> requires one materialized value type");
+      return { kind: "change", value: args[0]!.type };
+    }
     if (context.ATOM_REF()) return { kind: "object-ref", expectation: this.atom(name) };
     if (context.INTERFACE_REF())
       return {

src/capability-model/validation.ts

@@ -1,3 +1,4 @@
+import { isStorableType } from "./generics.js";
 import { validateInitialization } from "./initialization.js";
 import { validateExecutionContracts } from "./execution.js";
 import { resolveForwardedBinding, type ConcreteBinding } from "./forwarding.js";
@@ -244,6 +245,15 @@ const validateValueType = (
       requireText(issues, type.descriptorId, `${path}.descriptorId`, "Message descriptor identity");
       return;
     case "change":
+      if (!isStorableType(type.value))
+        issue(
+          issues,
+          "invalid-value-type",
+          path,
+          "change<T> requires a storable materialized type, not references or nested changes",
+        );
+      validateValueType(issues, type.value, path + ".value", indexes);
+      return;
     case "optional":
     case "list":
       validateValueType(issues, type.value, `${path}.value`, indexes);

src/execution-world/plan.ts

@@ -144,8 +144,8 @@ export function compileExecutionPlan(input: WorkspaceRevision): ExecutionPlan {
   for (const pkg of workspace.packageImports)
     for (const entry of pkg.exports)
       if (entry.execution && entry.execution.kind !== "remote") {
-        checkValue(entry.inputType, `${pkg.revisionId}/${entry.id}/input`);
-        checkValue(entry.outputType, `${pkg.revisionId}/${entry.id}/output`);
+        checkValue(entry.inputType, `${pkg.revisionId}/${entry.id}/input`, true);
+        checkValue(entry.outputType, `${pkg.revisionId}/${entry.id}/output`, true);
       }
   for (const attachment of attachments)
     if (attachment.kind === "state" && attachment.storagePolicy.kind === "crdt-document")
@@ -208,8 +208,8 @@ export function compileExecutionPlan(input: WorkspaceRevision): ExecutionPlan {
     operationMap.set(key, planned);
     const portable = planned.execution.kind !== "remote";
     if (portable) {
-      checkValue(planned.input, `${key}/input`, binding.kind === "state" && binding.primitive === "edit");
-      checkValue(planned.output, `${key}/output`);
+      checkValue(planned.input, `${key}/input`, true);
+      checkValue(planned.output, `${key}/output`, true);
     }
     if (binding.kind === "state") planned.dependencies.push({ kind: "state", slot: binding.slotId });
     else if (binding.kind === "edge")