implements PLN-0006

discussion/index.ndjson

@@ -4,6 +4,6 @@
 {"type":"discussion","id":"DSC-0003","status":"done","ticket":"packer-docs-import","title":"Import docs/packer into discussion-framework artifacts","created_at":"2026-03-26","updated_at":"2026-03-26","tags":["packer","migration","discussion-framework","docs-import"],"agendas":[],"decisions":[],"plans":[],"lessons":[{"id":"LSN-0009","file":"discussion/lessons/DSC-0003-packer-docs-import/LSN-0009-mental-model-packer-legacy.md","status":"done","created_at":"2026-03-26","updated_at":"2026-03-26"},{"id":"LSN-0010","file":"discussion/lessons/DSC-0003-packer-docs-import/LSN-0010-asset-identity-and-runtime-contract-legacy.md","status":"done","created_at":"2026-03-26","updated_at":"2026-03-26"},{"id":"LSN-0011","file":"discussion/lessons/DSC-0003-packer-docs-import/LSN-0011-foundations-workspace-runtime-and-build-legacy.md","status":"done","created_at":"2026-03-26","updated_at":"2026-03-26"},{"id":"LSN-0012","file":"discussion/lessons/DSC-0003-packer-docs-import/LSN-0012-runtime-ownership-and-studio-boundary-legacy.md","status":"done","created_at":"2026-03-26","updated_at":"2026-03-26"},{"id":"LSN-0013","file":"discussion/lessons/DSC-0003-packer-docs-import/LSN-0013-metadata-convergence-and-runtime-sink-legacy.md","status":"done","created_at":"2026-03-26","updated_at":"2026-03-26"},{"id":"LSN-0014","file":"discussion/lessons/DSC-0003-packer-docs-import/LSN-0014-pack-wizard-summary-validation-and-pack-execution-legacy.md","status":"done","created_at":"2026-03-26","updated_at":"2026-03-26"},{"id":"LSN-0015","file":"discussion/lessons/DSC-0003-packer-docs-import/LSN-0015-tile-bank-packing-contract-legacy.md","status":"done","created_at":"2026-03-26","updated_at":"2026-03-26"},{"id":"LSN-0017","file":"discussion/lessons/DSC-0003-packer-docs-import/LSN-0017-packer-docs-import-pattern.md","status":"done","created_at":"2026-03-26","updated_at":"2026-03-26"}]}
 {"type":"discussion","id":"DSC-0004","status":"open","ticket":"tilemap-and-metatile-runtime-binary-layout","title":"Tilemap and Metatile Runtime Binary Layout","created_at":"2026-03-26","updated_at":"2026-03-26","tags":["packer","legacy-import","tilemap","metatile","runtime-layout"],"agendas":[{"id":"AGD-0004","file":"AGD-0004-tilemap-and-metatile-runtime-binary-layout.md","status":"open","created_at":"2026-03-26","updated_at":"2026-03-26"}],"decisions":[],"plans":[],"lessons":[]}
 {"type":"discussion","id":"DSC-0005","status":"open","ticket":"variable-tile-bank-palette-serialization","title":"Variable Tile Bank Palette Serialization","created_at":"2026-03-26","updated_at":"2026-03-26","tags":["packer","legacy-import","tile-bank","palette-serialization","versioning"],"agendas":[{"id":"AGD-0005","file":"AGD-0005-variable-tile-bank-palette-serialization.md","status":"open","created_at":"2026-03-26","updated_at":"2026-03-26"}],"decisions":[],"plans":[],"lessons":[]}
-{"type":"discussion","id":"DSC-0006","status":"open","ticket":"pbs-game-facing-asset-refs-and-call-result-discard","title":"PBS Game-Facing Asset References and Ignored Call Result Lowering","created_at":"2026-03-27","updated_at":"2026-03-27","tags":["compiler","pbs","ergonomics","lowering","runtime","asset-identity","expression-statements"],"agendas":[{"id":"AGD-0006","file":"AGD-0006-pbs-game-facing-asset-refs-and-call-result-discard.md","status":"accepted","created_at":"2026-03-27","updated_at":"2026-03-27"}],"decisions":[{"id":"DEC-0005","file":"DEC-0005-pbs-asset-address-surface-and-be-lowering.md","status":"accepted","created_at":"2026-03-27","updated_at":"2026-03-27","ref_agenda":"AGD-0006"},{"id":"DEC-0006","file":"DEC-0006-pbs-ignored-values-lowering-and-warning.md","status":"accepted","created_at":"2026-03-27","updated_at":"2026-03-27","ref_agenda":"AGD-0006"}],"plans":[{"id":"PLN-0005","file":"PLN-0005-pbs-asset-address-surface-spec-propagation.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27","ref_decisions":["DEC-0005"]},{"id":"PLN-0006","file":"PLN-0006-pbs-asset-address-surface-implementation.md","status":"review","created_at":"2026-03-27","updated_at":"2026-03-27","ref_decisions":["DEC-0005"]},{"id":"PLN-0007","file":"PLN-0007-pbs-ignored-values-warning-implementation.md","status":"review","created_at":"2026-03-27","updated_at":"2026-03-27","ref_decisions":["DEC-0006"]}],"lessons":[]}
+{"type":"discussion","id":"DSC-0006","status":"open","ticket":"pbs-game-facing-asset-refs-and-call-result-discard","title":"PBS Game-Facing Asset References and Ignored Call Result Lowering","created_at":"2026-03-27","updated_at":"2026-03-27","tags":["compiler","pbs","ergonomics","lowering","runtime","asset-identity","expression-statements"],"agendas":[{"id":"AGD-0006","file":"AGD-0006-pbs-game-facing-asset-refs-and-call-result-discard.md","status":"accepted","created_at":"2026-03-27","updated_at":"2026-03-27"}],"decisions":[{"id":"DEC-0005","file":"DEC-0005-pbs-asset-address-surface-and-be-lowering.md","status":"accepted","created_at":"2026-03-27","updated_at":"2026-03-27","ref_agenda":"AGD-0006"},{"id":"DEC-0006","file":"DEC-0006-pbs-ignored-values-lowering-and-warning.md","status":"accepted","created_at":"2026-03-27","updated_at":"2026-03-27","ref_agenda":"AGD-0006"}],"plans":[{"id":"PLN-0005","file":"PLN-0005-pbs-asset-address-surface-spec-propagation.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27","ref_decisions":["DEC-0005"]},{"id":"PLN-0006","file":"PLN-0006-pbs-asset-address-surface-implementation.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27","ref_decisions":["DEC-0005"]},{"id":"PLN-0007","file":"PLN-0007-pbs-ignored-values-warning-implementation.md","status":"review","created_at":"2026-03-27","updated_at":"2026-03-27","ref_decisions":["DEC-0006"]}],"lessons":[]}
 {"type":"discussion","id":"DSC-0007","status":"done","ticket":"pbs-learn-to-discussion-lessons-migration","title":"Migrate PBS Learn Documents into Discussion Lessons","created_at":"2026-03-27","updated_at":"2026-03-27","tags":["compiler","pbs","migration","discussion-framework","lessons","learn-prune"],"agendas":[],"decisions":[],"plans":[],"lessons":[{"id":"LSN-0018","file":"discussion/lessons/DSC-0007-pbs-learn-to-discussion-lessons-migration/LSN-0018-pbs-ast-and-parser-contract-legacy.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0019","file":"discussion/lessons/DSC-0007-pbs-learn-to-discussion-lessons-migration/LSN-0019-pbs-name-resolution-and-linking-legacy.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0020","file":"discussion/lessons/DSC-0007-pbs-learn-to-discussion-lessons-migration/LSN-0020-pbs-runtime-values-identity-memory-boundaries-legacy.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0021","file":"discussion/lessons/DSC-0007-pbs-learn-to-discussion-lessons-migration/LSN-0021-pbs-diagnostics-and-conformance-governance-legacy.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"},{"id":"LSN-0022","file":"discussion/lessons/DSC-0007-pbs-learn-to-discussion-lessons-migration/LSN-0022-pbs-globals-lifecycle-and-published-entrypoint-legacy.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"}]}
 {"type":"discussion","id":"DSC-0008","status":"done","ticket":"pbs-low-level-asset-manager-surface","title":"PBS Low-Level Asset Manager Surface for Runtime AssetManager","created_at":"2026-03-27","updated_at":"2026-03-27","tags":["compiler","pbs","runtime","asset-manager","host-abi","stdlib","asset"],"agendas":[],"decisions":[],"plans":[],"lessons":[{"id":"LSN-0023","file":"discussion/lessons/DSC-0008-pbs-low-level-asset-manager-surface/LSN-0023-lowassets-runtime-aligned-sdk-surface.md","status":"done","created_at":"2026-03-27","updated_at":"2026-03-27"}]}

discussion/workflow/plans/PLN-0006-pbs-asset-address-surface-implementation.md

@@ -2,9 +2,9 @@
 id: PLN-0006
 ticket: pbs-game-facing-asset-refs-and-call-result-discard
 title: Implement DEC-0005 Addressable Surface, FESurfaceContext, and Backend Asset Lowering
-status: review
+status: done
 created: 2026-03-27
-completed:
+completed: 2026-03-27
 tags: [compiler, pbs, implementation, addressable, lowering, be-fe-contract, asset-identity]
 ---
 

prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/pbs/PbsFrontendCompiler.java

@@ -1,6 +1,7 @@
 package p.studio.compiler.pbs;
 
 import p.studio.compiler.messages.HostAdmissionContext;
+import p.studio.compiler.messages.FESurfaceContext;
 import p.studio.compiler.models.IRBackendExecutableFunction;
 import p.studio.compiler.models.IRBackendFile;
 import p.studio.compiler.models.IRFunction;
@@ -61,6 +62,16 @@ public final class PbsFrontendCompiler {
             final DiagnosticSink diagnostics,
             final SourceKind sourceKind,
             final HostAdmissionContext hostAdmissionContext) {
+        return compileFile(fileId, source, diagnostics, sourceKind, hostAdmissionContext, FESurfaceContext.empty());
+    }
+
+    public IRBackendFile compileFile(
+            final FileId fileId,
+            final String source,
+            final DiagnosticSink diagnostics,
+            final SourceKind sourceKind,
+            final HostAdmissionContext hostAdmissionContext,
+            final FESurfaceContext feSurfaceContext) {
         final var nameTable = new NameTable();
         final var admissionBaseline = diagnostics.errorCount();
         final var tokens = PbsLexer.lex(source, fileId, diagnostics);
@@ -76,6 +87,7 @@ public final class PbsFrontendCompiler {
                 ModuleId.none(),
                 ReadOnlyList.empty(),
                 hostAdmissionContext,
+                feSurfaceContext,
                 nameTable);
         if (diagnostics.errorCount() > admissionBaseline) {
             return IRBackendFile.empty(fileId);
@@ -91,6 +103,7 @@ public final class PbsFrontendCompiler {
             final ModuleId moduleId,
             final ReadOnlyList<ModuleReference> modulePool,
             final HostAdmissionContext hostAdmissionContext,
+            final FESurfaceContext feSurfaceContext,
             final NameTable nameTable) {
         return compileParsedFile(
                 fileId,
@@ -100,6 +113,7 @@ public final class PbsFrontendCompiler {
                 moduleId,
                 modulePool,
                 hostAdmissionContext,
+                feSurfaceContext,
                 nameTable,
                 ReadOnlyList.empty(),
                 ReadOnlyList.empty(),
@@ -116,6 +130,7 @@ public final class PbsFrontendCompiler {
             final ModuleId moduleId,
             final ReadOnlyList<ModuleReference> modulePool,
             final HostAdmissionContext hostAdmissionContext,
+            final FESurfaceContext feSurfaceContext,
             final NameTable nameTable,
             final ReadOnlyList<PbsAst.TopDecl> supplementalTopDecls,
             final ReadOnlyList<ImportedCallableSurface> importedCallables,
@@ -134,6 +149,9 @@ public final class PbsFrontendCompiler {
         final var effectiveImportedGlobals = importedGlobals == null
                 ? ReadOnlyList.<ImportedGlobalSurface>empty()
                 : importedGlobals;
+        final var effectiveFESurfaceContext = feSurfaceContext == null
+                ? FESurfaceContext.empty()
+                : feSurfaceContext;
         final var effectiveImportedReservedMetadata = importedReservedMetadata == null
                 ? IRReservedMetadata.empty()
                 : importedReservedMetadata;
@@ -147,7 +165,7 @@ public final class PbsFrontendCompiler {
                 effectiveModuleId,
                 effectiveImportedGlobals,
                 diagnostics);
-        flowSemanticsValidator.validate(ast, effectiveSupplementalTopDecls, diagnostics);
+        flowSemanticsValidator.validate(ast, effectiveSupplementalTopDecls, effectiveFESurfaceContext, diagnostics);
         lifecycleSemanticsValidator.validate(ast, effectiveSupplementalTopDecls, diagnostics);
         if (diagnostics.errorCount() > semanticsErrorBaseline) {
             return IRBackendFile.empty(fileId);
@@ -179,6 +197,7 @@ public final class PbsFrontendCompiler {
                 effectiveModuleId,
                 mergeReservedMetadata(reservedMetadata, effectiveImportedReservedMetadata),
                 effectiveNameTable,
+                effectiveFESurfaceContext,
                 diagnostics,
                 effectiveImportedCallables);
         if (diagnostics.errorCount() > loweringErrorBaseline) {

prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/pbs/lowering/PbsExecutableBodyLowerer.java

@@ -378,7 +378,7 @@ final class PbsExecutableBodyLowerer {
                     handleExpr.span(),
                     context);
             case PbsAst.AsExpr asExpr -> lowerExpression(asExpr.expression(), context);
-            case PbsAst.MemberExpr memberExpr -> lowerExpression(memberExpr.receiver(), context);
+            case PbsAst.MemberExpr memberExpr -> lowerMemberExpression(memberExpr, context);
             case PbsAst.PropagateExpr propagateExpr -> lowerExpression(propagateExpr.expression(), context);
             case PbsAst.GroupExpr groupExpr -> lowerExpression(groupExpr.expression(), context);
             case PbsAst.NewExpr newExpr -> lowerExpressionList(newExpr.arguments(), context);
@@ -426,6 +426,25 @@ final class PbsExecutableBodyLowerer {
         }
     }
 
+    private void lowerMemberExpression(
+            final PbsAst.MemberExpr memberExpr,
+            final PbsExecutableLoweringContext context) {
+        final var assetReference = flattenAssetReference(memberExpr);
+        if (assetReference != null) {
+            final var assetId = context.resolveAssetId(assetReference);
+            if (assetId == null) {
+                reportUnsupportedLowering(
+                        "asset reference does not resolve in backend-owned surface: " + assetReference,
+                        memberExpr.span(),
+                        context);
+                return;
+            }
+            emitPushI32(assetId, memberExpr.span(), context);
+            return;
+        }
+        lowerExpression(memberExpr.receiver(), context);
+    }
+
     private void lowerIfExpression(
             final PbsAst.IfExpr ifExpr,
             final PbsExecutableLoweringContext context) {
@@ -456,6 +475,9 @@ final class PbsExecutableBodyLowerer {
     private void lowerIdentifierExpression(
             final PbsAst.IdentifierExpr identifierExpr,
             final PbsExecutableLoweringContext context) {
+        if ("assets".equals(identifierExpr.name())) {
+            return;
+        }
         final var slot = context.localSlotByNameId().get(context.nameTable().register(identifierExpr.name()));
         if (slot != null) {
             emitGetLocal(slot, identifierExpr.span(), context);
@@ -472,6 +494,20 @@ final class PbsExecutableBodyLowerer {
         }
     }
 
+    private String flattenAssetReference(final PbsAst.Expression expression) {
+        if (expression instanceof PbsAst.IdentifierExpr identifierExpr) {
+            return "assets".equals(identifierExpr.name()) ? "assets" : null;
+        }
+        if (!(expression instanceof PbsAst.MemberExpr memberExpr)) {
+            return null;
+        }
+        final var receiverPath = flattenAssetReference(memberExpr.receiver());
+        if (receiverPath == null || receiverPath.isBlank()) {
+            return null;
+        }
+        return receiverPath + "." + memberExpr.memberName();
+    }
+
     private void lowerConstExpression(
             final PbsAst.Expression expression,
             final PbsExecutableLoweringContext context) {

prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/pbs/lowering/PbsExecutableLoweringContext.java

@@ -1,6 +1,7 @@
 package p.studio.compiler.pbs.lowering;
 
 import p.studio.compiler.models.IRBackendExecutableFunction;
+import p.studio.compiler.messages.Addressable;
 import p.studio.compiler.source.diagnostics.DiagnosticSink;
 import p.studio.compiler.source.identifiers.NameId;
 import p.studio.compiler.source.tables.IntrinsicTable;
@@ -66,6 +67,10 @@ final class PbsExecutableLoweringContext {
         return metadataIndex.constDeclByNameId();
     }
 
+    Map<String, Addressable> addressableByAddress() {
+        return metadataIndex.addressableByAddress();
+    }
+
     Map<String, String> builtinCanonicalBySourceType() {
         return metadataIndex.builtinCanonicalBySourceType();
     }
@@ -140,6 +145,14 @@ final class PbsExecutableLoweringContext {
         return constDeclByNameId().get(nameTable.register(constName));
     }
 
+    Integer resolveAssetId(final String address) {
+        if (address == null || address.isBlank()) {
+            return null;
+        }
+        final var addressable = addressableByAddress().get(address);
+        return addressable == null ? null : addressable.assetId();
+    }
+
     int declareLocalSlot(final String localName) {
         final var nameId = nameTable.register(localName);
         final var existing = localSlotByNameId.get(nameId);

prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/pbs/lowering/PbsExecutableLoweringModels.java

@@ -2,6 +2,7 @@ package p.studio.compiler.pbs.lowering;
 
 import p.studio.compiler.models.IRBackendExecutableFunction;
 import p.studio.compiler.models.IRReservedMetadata;
+import p.studio.compiler.messages.Addressable;
 import p.studio.compiler.pbs.ast.PbsAst;
 import p.studio.compiler.source.identifiers.CallableId;
 import p.studio.compiler.source.identifiers.NameId;
@@ -46,6 +47,7 @@ public class PbsExecutableLoweringModels {
             Map<NameId, String> builtinConstOwnerByNameId,
             Map<NameId, Integer> globalSlotByNameId,
             Map<NameId, PbsAst.ConstDecl> constDeclByNameId,
+            Map<String, Addressable> addressableByAddress,
             Map<PbsIntrinsicOwnerMethodKey, List<IRReservedMetadata.IntrinsicSurface>> intrinsicByOwnerAndMethod,
             Map<PbsIntrinsicCanonicalKey, String> intrinsicReturnOwnerByCanonical) {
     }

prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/pbs/lowering/PbsExecutableLoweringService.java

@@ -2,6 +2,7 @@ package p.studio.compiler.pbs.lowering;
 
 import p.studio.compiler.models.IRBackendExecutableFunction;
 import p.studio.compiler.models.IRReservedMetadata;
+import p.studio.compiler.messages.FESurfaceContext;
 import p.studio.compiler.pbs.PbsFrontendCompiler;
 import p.studio.compiler.pbs.ast.PbsAst;
 import p.studio.compiler.source.diagnostics.DiagnosticSink;
@@ -29,6 +30,7 @@ public final class PbsExecutableLoweringService {
             final ModuleId moduleId,
             final IRReservedMetadata reservedMetadata,
             final NameTable nameTable,
+            final FESurfaceContext feSurfaceContext,
             final DiagnosticSink diagnostics,
             final ReadOnlyList<PbsFrontendCompiler.ImportedCallableSurface> importedCallables) {
         final var normalizedModuleId = moduleId == null ? ModuleId.none() : moduleId;
@@ -37,6 +39,7 @@ public final class PbsExecutableLoweringService {
                 supplementalTopDecls,
                 reservedMetadata,
                 nameTable,
+                feSurfaceContext,
                 diagnostics);
         final var callableRegistry = callableRegistryFactory.create(
                 ast,

prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/pbs/lowering/PbsExecutableMetadataIndexFactory.java

@@ -1,6 +1,8 @@
 package p.studio.compiler.pbs.lowering;
 
 import p.studio.compiler.models.IRReservedMetadata;
+import p.studio.compiler.messages.Addressable;
+import p.studio.compiler.messages.FESurfaceContext;
 import p.studio.compiler.pbs.ast.PbsAst;
 import p.studio.compiler.pbs.semantics.PbsSemanticsErrors;
 import p.studio.compiler.source.diagnostics.DiagnosticPhase;
@@ -23,12 +25,14 @@ final class PbsExecutableMetadataIndexFactory {
             final ReadOnlyList<PbsAst.TopDecl> supplementalTopDecls,
             final IRReservedMetadata reservedMetadata,
             final NameTable nameTable,
+            final FESurfaceContext feSurfaceContext,
             final DiagnosticSink diagnostics) {
         final var hostByMethodName = indexHostBindingsByMethodName(reservedMetadata, nameTable);
         final var builtinCanonicalBySourceType = indexBuiltinCanonicalBySourceType(reservedMetadata);
         final var builtinConstOwnerByNameId = indexBuiltinConstOwners(reservedMetadata, nameTable);
         final var globalSlotByNameId = indexGlobalSlots(ast, nameTable);
         final var constDeclByNameId = indexConstDecls(ast, nameTable);
+        final var addressableByAddress = indexAddressables(feSurfaceContext);
         final var builtinSignatureByOwnerAndMethod = indexBuiltinSignatures(
                 ast,
                 supplementalTopDecls,
@@ -48,6 +52,7 @@ final class PbsExecutableMetadataIndexFactory {
                 builtinConstOwnerByNameId,
                 globalSlotByNameId,
                 constDeclByNameId,
+                addressableByAddress,
                 intrinsicByOwnerAndMethod,
                 intrinsicReturnOwnerByCanonical);
     }
@@ -112,6 +117,18 @@ final class PbsExecutableMetadataIndexFactory {
         return constDeclByNameId;
     }
 
+    private Map<String, Addressable> indexAddressables(final FESurfaceContext feSurfaceContext) {
+        final var addressableByAddress = new HashMap<String, Addressable>();
+        final var effectiveSurfaceContext = feSurfaceContext == null ? FESurfaceContext.empty() : feSurfaceContext;
+        for (final var addressable : effectiveSurfaceContext.assets()) {
+            if (addressable == null || addressable.address().isBlank()) {
+                continue;
+            }
+            addressableByAddress.putIfAbsent(addressable.address(), addressable);
+        }
+        return addressableByAddress;
+    }
+
     private Map<PbsIntrinsicOwnerMethodKey, PbsAst.FunctionSignature> indexBuiltinSignatures(
             final PbsAst.File ast,
             final ReadOnlyList<PbsAst.TopDecl> supplementalTopDecls,

prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/pbs/semantics/PbsFlowBodyAnalyzer.java

@@ -1,5 +1,6 @@
 package p.studio.compiler.pbs.semantics;
 
+import p.studio.compiler.messages.FESurfaceContext;
 import p.studio.compiler.pbs.ast.PbsAst;
 import p.studio.compiler.pbs.semantics.PbsFlowSemanticSupport.Model;
 import p.studio.compiler.pbs.semantics.PbsFlowSemanticSupport.Scope;
@@ -27,8 +28,9 @@ final class PbsFlowBodyAnalyzer {
     public void validate(
             final PbsAst.File ast,
             final ReadOnlyList<PbsAst.TopDecl> supplementalTopDecls,
+            final FESurfaceContext feSurfaceContext,
             final DiagnosticSink diagnostics) {
-        final var model = Model.from(ast, supplementalTopDecls);
+        final var model = Model.from(ast, supplementalTopDecls, feSurfaceContext, diagnostics);
 
         for (final var topDecl : ast.topDecls()) {
             validateTopDecl(topDecl, model, diagnostics);

prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/pbs/semantics/PbsFlowCallableResolutionAnalyzer.java

@@ -70,6 +70,11 @@ final class PbsFlowCallableResolutionAnalyzer {
     ExprResult analyzeMemberExpression(
             final PbsAst.MemberExpr memberExpr,
             final PbsFlowExpressionContext context) {
+        final var assetReference = flattenAssetReference(memberExpr);
+        if (assetReference != null) {
+            return resolveAssetReference(assetReference, memberExpr, context);
+        }
+
         final var receiver = analyzeValueExpression(memberExpr.receiver(), context, null).type();
         final var model = context.model();
         final var diagnostics = context.diagnostics();
@@ -320,6 +325,47 @@ final class PbsFlowCallableResolutionAnalyzer {
                 && receiver.name().equals(currentReceiverType.name());
     }
 
+    private ExprResult resolveAssetReference(
+            final String assetReference,
+            final PbsAst.MemberExpr memberExpr,
+            final PbsFlowExpressionContext context) {
+        final var diagnostics = context.diagnostics();
+        final var model = context.model();
+        final var resolvedAssetId = model.resolveAssetId(assetReference);
+        if (resolvedAssetId != null) {
+            return ExprResult.type(TypeView.addressable(assetReference));
+        }
+        if (model.isAssetNamespace(assetReference)) {
+            if (context.use() == ExprUse.VALUE) {
+                Diagnostics.error(diagnostics,
+                        PbsSemanticsErrors.E_SEM_INVALID_MEMBER_ACCESS.name(),
+                        "Asset namespace '%s' is not a terminal Addressable value".formatted(assetReference),
+                        memberExpr.span());
+                return ExprResult.type(TypeView.unknown());
+            }
+            return ExprResult.type(TypeView.assetNamespace(assetReference));
+        }
+        Diagnostics.error(diagnostics,
+                PbsSemanticsErrors.E_SEM_INVALID_MEMBER_ACCESS.name(),
+                "Asset reference '%s' does not resolve in the backend-provided surface".formatted(assetReference),
+                memberExpr.span());
+        return ExprResult.type(TypeView.unknown());
+    }
+
+    private String flattenAssetReference(final PbsAst.Expression expression) {
+        if (expression instanceof PbsAst.IdentifierExpr identifierExpr) {
+            return "assets".equals(identifierExpr.name()) ? "assets" : null;
+        }
+        if (!(expression instanceof PbsAst.MemberExpr memberExpr)) {
+            return null;
+        }
+        final var receiverPath = flattenAssetReference(memberExpr.receiver());
+        if (receiverPath == null || receiverPath.isBlank()) {
+            return null;
+        }
+        return receiverPath + "." + memberExpr.memberName();
+    }
+
     private ExprResult analyzeValueExpression(
             final PbsAst.Expression expression,
             final PbsFlowExpressionContext context,

prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/pbs/semantics/PbsFlowSemanticSupport.java

@@ -1,8 +1,11 @@
 package p.studio.compiler.pbs.semantics;
 
 import lombok.experimental.UtilityClass;
+import p.studio.compiler.messages.FESurfaceContext;
 import p.studio.compiler.pbs.ast.PbsAst;
 import p.studio.compiler.source.Span;
+import p.studio.compiler.source.diagnostics.DiagnosticSink;
+import p.studio.compiler.source.diagnostics.Diagnostics;
 import p.studio.utilities.structures.ReadOnlyList;
 
 import java.util.*;
@@ -44,7 +47,9 @@ final class PbsFlowSemanticSupport {
         OPTIONAL,
         RESULT,
         TUPLE,
-        TYPE_REF
+        TYPE_REF,
+        ADDRESSABLE,
+        ASSET_NAMESPACE
     }
     
     record TupleField(
@@ -126,6 +131,14 @@ final class PbsFlowSemanticSupport {
         static TypeView typeRef(final String name) {
             return new TypeView(Kind.TYPE_REF, name, List.of(), null, null, List.of(), null);
         }
+
+        static TypeView addressable(final String address) {
+            return new TypeView(Kind.ADDRESSABLE, address, List.of(), null, null, List.of(), null);
+        }
+
+        static TypeView assetNamespace(final String path) {
+            return new TypeView(Kind.ASSET_NAMESPACE, path, List.of(), null, null, List.of(), null);
+        }
     }
     
     record CallableSymbol(
@@ -176,14 +189,18 @@ final class PbsFlowSemanticSupport {
         final Set<String> knownEnumNames = new HashSet<>();
         final Set<String> knownErrorNames = new HashSet<>();
         final Set<String> knownCallbackNames = new HashSet<>();
+        final Map<String, Integer> assetIdByAddress = new HashMap<>();
+        final Set<String> assetNamespacePrefixes = new HashSet<>();
     
         static Model from(final PbsAst.File ast) {
-            return from(ast, ReadOnlyList.empty());
+            return from(ast, ReadOnlyList.empty(), FESurfaceContext.empty(), DiagnosticSink.empty());
         }
 
         static Model from(
                 final PbsAst.File ast,
-                final ReadOnlyList<PbsAst.TopDecl> supplementalTopDecls) {
+                final ReadOnlyList<PbsAst.TopDecl> supplementalTopDecls,
+                final FESurfaceContext feSurfaceContext,
+                final DiagnosticSink diagnostics) {
             final var model = new Model();
             for (final var topDecl : ast.topDecls()) {
                 model.registerKnownTopDecl(topDecl);
@@ -197,6 +214,7 @@ final class PbsFlowSemanticSupport {
             for (final var topDecl : supplementalTopDecls) {
                 model.ingestTopDecl(topDecl);
             }
+            model.ingestAssetSurface(feSurfaceContext, diagnostics);
             return model;
         }
 
@@ -377,6 +395,72 @@ final class PbsFlowSemanticSupport {
             }
         }
 
+        private void ingestAssetSurface(
+                final FESurfaceContext feSurfaceContext,
+                final DiagnosticSink diagnostics) {
+            final var effectiveSurfaceContext = feSurfaceContext == null ? FESurfaceContext.empty() : feSurfaceContext;
+            for (final var addressable : effectiveSurfaceContext.assets()) {
+                if (addressable == null || addressable.address().isBlank()) {
+                    continue;
+                }
+                assetIdByAddress.put(addressable.address(), addressable.assetId());
+                registerAssetNamespaces(addressable.address());
+            }
+            for (final var address : assetIdByAddress.keySet()) {
+                for (final var prefix : namespacePrefixesOf(address)) {
+                    if (assetIdByAddress.containsKey(prefix)) {
+                        Diagnostics.error(
+                                diagnostics,
+                                PbsSemanticsErrors.E_SEM_INVALID_MEMBER_ACCESS.name(),
+                                "Asset surface collision: '%s' cannot be both terminal and namespace prefix".formatted(prefix),
+                                astSyntheticSpan());
+                    }
+                }
+            }
+        }
+
+        boolean hasAssetNamespaceRoot() {
+            return assetNamespacePrefixes.contains("assets") || assetIdByAddress.containsKey("assets");
+        }
+
+        boolean isAssetNamespace(final String path) {
+            return assetNamespacePrefixes.contains(path);
+        }
+
+        Integer resolveAssetId(final String address) {
+            return assetIdByAddress.get(address);
+        }
+
+        private void registerAssetNamespaces(final String address) {
+            for (final var prefix : namespacePrefixesOf(address)) {
+                assetNamespacePrefixes.add(prefix);
+            }
+        }
+
+        private List<String> namespacePrefixesOf(final String address) {
+            final var segments = address.split("\\.");
+            final var prefixes = new ArrayList<String>();
+            if (segments.length <= 1) {
+                return prefixes;
+            }
+            final var builder = new StringBuilder();
+            for (int i = 0; i < segments.length - 1; i++) {
+                if (segments[i] == null || segments[i].isBlank()) {
+                    break;
+                }
+                if (builder.length() > 0) {
+                    builder.append('.');
+                }
+                builder.append(segments[i]);
+                prefixes.add(builder.toString());
+            }
+            return prefixes;
+        }
+
+        private Span astSyntheticSpan() {
+            return Span.none();
+        }
+    
         private CallableSymbol callableFrom(
                 final String name,
                 final ReadOnlyList<PbsAst.Parameter> parameters,
@@ -429,6 +513,9 @@ final class PbsFlowSemanticSupport {
                     if ("str".equals(typeRef.name())) {
                         yield TypeView.str();
                     }
+                    if ("Addressable".equals(typeRef.name())) {
+                        yield TypeView.addressable(typeRef.name());
+                    }
                     if (structs.containsKey(typeRef.name()) || knownStructNames.contains(typeRef.name())) {
                         yield TypeView.struct(typeRef.name());
                     }

prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/pbs/semantics/PbsFlowSemanticsValidator.java

@@ -1,5 +1,6 @@
 package p.studio.compiler.pbs.semantics;
 
+import p.studio.compiler.messages.FESurfaceContext;
 import p.studio.compiler.pbs.ast.PbsAst;
 import p.studio.compiler.source.diagnostics.DiagnosticSink;
 import p.studio.utilities.structures.ReadOnlyList;
@@ -8,13 +9,14 @@ public final class PbsFlowSemanticsValidator {
     private final PbsFlowBodyAnalyzer flowBodyAnalyzer = new PbsFlowBodyAnalyzer();
 
     public void validate(final PbsAst.File ast, final DiagnosticSink diagnostics) {
-        flowBodyAnalyzer.validate(ast, ReadOnlyList.empty(), diagnostics);
+        flowBodyAnalyzer.validate(ast, ReadOnlyList.empty(), FESurfaceContext.empty(), diagnostics);
     }
 
     public void validate(
             final PbsAst.File ast,
             final ReadOnlyList<PbsAst.TopDecl> supplementalTopDecls,
+            final FESurfaceContext feSurfaceContext,
             final DiagnosticSink diagnostics) {
-        flowBodyAnalyzer.validate(ast, supplementalTopDecls, diagnostics);
+        flowBodyAnalyzer.validate(ast, supplementalTopDecls, feSurfaceContext, diagnostics);
     }
 }

prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/pbs/semantics/PbsFlowStructuralExpressionAnalyzer.java

@@ -70,6 +70,10 @@ final class PbsFlowStructuralExpressionAnalyzer {
             return ExprResult.type(receiverType);
         }
         if (expression instanceof PbsAst.IdentifierExpr identifierExpr) {
+            if ("assets".equals(identifierExpr.name()) && model.hasAssetNamespaceRoot()) {
+                return ExprResult.type(TypeView.assetNamespace("assets"));
+            }
+
             final var localType = context.scope().resolve(identifierExpr.name());
             if (localType != null) {
                 return ExprResult.type(localType);

prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/pbs/semantics/PbsFlowTypeOps.java

@@ -47,7 +47,8 @@ final class PbsFlowTypeOps {
         }
         return switch (actual.kind()) {
             case UNIT, INT, FLOAT, BOOL, STR -> true;
-            case STRUCT, SERVICE, CONTRACT, CALLBACK, ENUM, ERROR, TYPE_REF -> actual.name().equals(expected.name());
+            case STRUCT, SERVICE, CONTRACT, CALLBACK, ENUM, ERROR, TYPE_REF, ASSET_NAMESPACE -> actual.name().equals(expected.name());
+            case ADDRESSABLE -> true;
             case OPTIONAL -> compatible(actual.inner(), expected.inner());
             case RESULT -> compatible(actual.errorType(), expected.errorType()) && compatible(actual.inner(), expected.inner());
             case TUPLE -> tupleCompatible(actual, expected);
@@ -173,6 +174,9 @@ final class PbsFlowTypeOps {
         if ("str".equals(name)) {
             return TypeView.str();
         }
+        if ("Addressable".equals(name)) {
+            return TypeView.addressable(name);
+        }
         if (model.structs.containsKey(name)) {
             return TypeView.struct(name);
         }

prometeu-compiler/frontends/prometeu-frontend-pbs/src/main/java/p/studio/compiler/services/PBSFrontendPhaseService.java

@@ -2,6 +2,7 @@ package p.studio.compiler.services;
 
 import lombok.extern.slf4j.Slf4j;
 import p.studio.compiler.messages.BuildingIssueSink;
+import p.studio.compiler.messages.FESurfaceContext;
 import p.studio.compiler.messages.FrontendPhaseContext;
 import p.studio.compiler.models.IRBackend;
 import p.studio.compiler.models.IRBackendExecutableFunction;
@@ -59,6 +60,7 @@ public class PBSFrontendPhaseService implements FrontendPhaseService {
             final LogAggregator logs,
             final BuildingIssueSink issues) {
         final var nameTable = ctx.nameTable();
+        final var feSurfaceContext = ctx.feSurfaceContext();
         final var assembly = moduleAssemblyService.assemble(ctx, nameTable, diagnostics, issues);
         final var parsedSourceFiles = assembly.parsedSourceFiles();
         final var importedSemanticContexts = importedSemanticContextService.build(parsedSourceFiles, assembly.moduleTable());
@@ -85,6 +87,7 @@ public class PBSFrontendPhaseService implements FrontendPhaseService {
                     parsedSource.moduleId(),
                     canonicalModulePool,
                     ctx.hostAdmissionContext(),
+                    feSurfaceContext,
                     nameTable,
                     importedSemanticContext.supplementalTopDecls(),
                     importedSemanticContext.importedCallables(),

prometeu-compiler/frontends/prometeu-frontend-pbs/src/test/java/p/studio/compiler/pbs/PbsFrontendCompilerTest.java

@@ -1,6 +1,8 @@
 package p.studio.compiler.pbs;
 
 import org.junit.jupiter.api.Test;
+import p.studio.compiler.messages.Addressable;
+import p.studio.compiler.messages.FESurfaceContext;
 import p.studio.compiler.messages.HostAdmissionContext;
 import p.studio.compiler.models.IRHiddenGlobalKind;
 import p.studio.compiler.models.IRGlobalVisibility;
@@ -458,6 +460,58 @@ class PbsFrontendCompilerTest {
                         && h.abiVersion() == 1));
     }
 
+    @Test
+    void shouldLowerBackendOwnedAssetReferenceToAssetId() {
+        final var source = """
+                fn boot() -> Addressable {
+                  return assets.ui.panel;
+                }
+                """;
+
+        final var diagnostics = DiagnosticSink.empty();
+        final var compiler = new PbsFrontendCompiler();
+        final var fileBackend = compiler.compileFile(
+                new FileId(12),
+                source,
+                diagnostics,
+                SourceKind.PROJECT,
+                HostAdmissionContext.permissiveDefault(),
+                new FESurfaceContext(ReadOnlyList.from(new Addressable("assets.ui.panel", 37))));
+
+        assertTrue(diagnostics.isEmpty(), diagnostics.stream().map(d -> d.getCode() + ":" + d.getMessage()).toList().toString());
+        final var executableBoot = fileBackend.executableFunctions().stream()
+                .filter(fn -> fn.callableName().equals("boot"))
+                .findFirst()
+                .orElseThrow();
+        assertTrue(executableBoot.instructions().stream().anyMatch(i ->
+                i.kind() == p.studio.compiler.models.IRBackendExecutableFunction.InstructionKind.PUSH_I32
+                        && "37".equals(i.label())));
+    }
+
+    @Test
+    void shouldRejectUnresolvedBackendOwnedAssetReference() {
+        final var source = """
+                fn boot() -> Addressable {
+                  return assets.ui.missing;
+                }
+                """;
+
+        final var diagnostics = DiagnosticSink.empty();
+        final var compiler = new PbsFrontendCompiler();
+        final var fileBackend = compiler.compileFile(
+                new FileId(13),
+                source,
+                diagnostics,
+                SourceKind.PROJECT,
+                HostAdmissionContext.permissiveDefault(),
+                new FESurfaceContext(ReadOnlyList.from(new Addressable("assets.ui.panel", 37))));
+
+        assertTrue(diagnostics.stream().anyMatch(d ->
+                d.getCode().equals(PbsSemanticsErrors.E_SEM_INVALID_MEMBER_ACCESS.name())
+                        && d.getMessage().contains("assets.ui.missing")));
+        assertEquals(0, fileBackend.executableFunctions().size());
+    }
+
     @Test
     void shouldRejectHostBindingWithoutCapabilityAtHostAdmission() {
         final var source = """

prometeu-compiler/frontends/prometeu-frontend-pbs/src/test/java/p/studio/compiler/services/PBSFrontendPhaseServiceTest.java

@@ -2,7 +2,9 @@ package p.studio.compiler.services;
 
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.io.TempDir;
+import p.studio.compiler.messages.Addressable;
 import p.studio.compiler.messages.BuildingIssueSink;
+import p.studio.compiler.messages.FESurfaceContext;
 import p.studio.compiler.messages.FrontendPhaseContext;
 import p.studio.compiler.models.IRGlobalVisibility;
 import p.studio.compiler.models.BuildStack;
@@ -40,6 +42,61 @@ class PBSFrontendPhaseServiceTest {
     @TempDir
     Path tempDir;
 
+    @Test
+    void shouldPropagateBackendOwnedAssetSurfaceIntoPbsFrontendCompilation() throws IOException {
+        final var projectRoot = tempDir.resolve("project-assets");
+        final var sourceRoot = projectRoot.resolve("src");
+        final var modulePath = sourceRoot.resolve("main");
+        Files.createDirectories(modulePath);
+
+        final var sourceFile = modulePath.resolve("source.pbs");
+        final var modBarrel = modulePath.resolve("mod.barrel");
+        Files.writeString(sourceFile, """
+                [Frame]
+                fn frame() -> void {
+                  let asset: Addressable = assets.ui.panel;
+                  return;
+                }
+                """);
+        Files.writeString(modBarrel, "pub fn frame() -> void;");
+
+        final var projectTable = new ProjectTable();
+        final var fileTable = new FileTable(1);
+        final var projectId = projectTable.register(ProjectDescriptor.builder()
+                .rootPath(projectRoot)
+                .name("core")
+                .version("1.0.0")
+                .sourceRoots(ReadOnlyList.wrap(List.of(sourceRoot)))
+                .build());
+
+        registerFile(projectId, projectRoot, sourceFile, fileTable);
+        registerFile(projectId, projectRoot, modBarrel, fileTable);
+
+        final var ctx = new FrontendPhaseContext(
+                projectTable,
+                fileTable,
+                new BuildStack(ReadOnlyList.wrap(List.of(projectId))),
+                1,
+                p.studio.compiler.messages.HostAdmissionContext.permissiveDefault(),
+                new FESurfaceContext(ReadOnlyList.from(new Addressable("assets.ui.panel", 91))));
+        final var diagnostics = DiagnosticSink.empty();
+
+        final var irBackend = new PBSFrontendPhaseService().compile(
+                ctx,
+                diagnostics,
+                LogAggregator.empty(),
+                BuildingIssueSink.empty());
+
+        assertTrue(diagnostics.isEmpty(), diagnostics.stream().map(d -> d.getCode() + ":" + d.getMessage()).toList().toString());
+        final var frameFn = irBackend.getExecutableFunctions().stream()
+                .filter(function -> "frame".equals(function.callableName()))
+                .findFirst()
+                .orElseThrow();
+        assertTrue(frameFn.instructions().stream().anyMatch(instruction ->
+                instruction.kind() == p.studio.compiler.models.IRBackendExecutableFunction.InstructionKind.PUSH_I32
+                        && "91".equals(instruction.label())));
+    }
+
     @Test
     void shouldReportInvalidBarrelFilename() throws IOException {
         final var projectRoot = tempDir.resolve("project");

prometeu-compiler/prometeu-frontend-api/src/main/java/p/studio/compiler/messages/Addressable.java

@@ -0,0 +1,17 @@
+package p.studio.compiler.messages;
+
+public record Addressable(
+        String address,
+        int assetId) {
+
+    public Addressable {
+        address = normalize(address);
+    }
+
+    private static String normalize(final String address) {
+        if (address == null) {
+            return "";
+        }
+        return address.trim();
+    }
+}

prometeu-compiler/prometeu-frontend-api/src/main/java/p/studio/compiler/messages/FESurfaceContext.java

@@ -0,0 +1,32 @@
+package p.studio.compiler.messages;
+
+import p.studio.utilities.structures.ReadOnlyList;
+
+import java.util.ArrayList;
+import java.util.LinkedHashMap;
+
+public record FESurfaceContext(
+        ReadOnlyList<Addressable> assets) {
+
+    public FESurfaceContext {
+        assets = normalizeAssets(assets);
+    }
+
+    public static FESurfaceContext empty() {
+        return new FESurfaceContext(ReadOnlyList.empty());
+    }
+
+    private static ReadOnlyList<Addressable> normalizeAssets(final ReadOnlyList<Addressable> assets) {
+        if (assets == null || assets.isEmpty()) {
+            return ReadOnlyList.empty();
+        }
+        final var dedup = new LinkedHashMap<String, Addressable>();
+        for (final var asset : assets) {
+            if (asset == null || asset.address().isBlank()) {
+                continue;
+            }
+            dedup.put(asset.address(), asset);
+        }
+        return ReadOnlyList.wrap(new ArrayList<>(dedup.values()));
+    }
+}

prometeu-compiler/prometeu-frontend-api/src/main/java/p/studio/compiler/messages/FrontendPhaseContext.java

@@ -14,12 +14,13 @@ public class FrontendPhaseContext {
     private final NameTable nameTable;
     private final int stdlibVersion;
     private final HostAdmissionContext hostAdmissionContext;
+    private final FESurfaceContext feSurfaceContext;
 
     public FrontendPhaseContext(
             final ProjectTableReader projectTable,
             final FileTableReader fileTable,
             final BuildStack stack) {
-        this(projectTable, fileTable, stack, 1, HostAdmissionContext.permissiveDefault());
+        this(projectTable, fileTable, stack, 1, HostAdmissionContext.permissiveDefault(), FESurfaceContext.empty());
     }
 
     public FrontendPhaseContext(
@@ -27,7 +28,7 @@ public class FrontendPhaseContext {
             final FileTableReader fileTable,
             final BuildStack stack,
             final int stdlibVersion) {
-        this(projectTable, fileTable, stack, stdlibVersion, HostAdmissionContext.permissiveDefault());
+        this(projectTable, fileTable, stack, stdlibVersion, HostAdmissionContext.permissiveDefault(), FESurfaceContext.empty());
     }
 
     public FrontendPhaseContext(
@@ -36,6 +37,16 @@ public class FrontendPhaseContext {
             final BuildStack stack,
             final int stdlibVersion,
             final HostAdmissionContext hostAdmissionContext) {
+        this(projectTable, fileTable, stack, stdlibVersion, hostAdmissionContext, FESurfaceContext.empty());
+    }
+
+    public FrontendPhaseContext(
+            final ProjectTableReader projectTable,
+            final FileTableReader fileTable,
+            final BuildStack stack,
+            final int stdlibVersion,
+            final HostAdmissionContext hostAdmissionContext,
+            final FESurfaceContext feSurfaceContext) {
         this.projectTable = projectTable;
         this.fileTable = fileTable;
         this.stack = stack;
@@ -44,6 +55,9 @@ public class FrontendPhaseContext {
         this.hostAdmissionContext = hostAdmissionContext == null
                 ? HostAdmissionContext.permissiveDefault()
                 : hostAdmissionContext;
+        this.feSurfaceContext = feSurfaceContext == null
+                ? FESurfaceContext.empty()
+                : feSurfaceContext;
     }
 
     public SourceKind sourceKind(final ProjectId projectId) {
@@ -61,4 +75,8 @@ public class FrontendPhaseContext {
     public NameTable nameTable() {
         return nameTable;
     }
+
+    public FESurfaceContext feSurfaceContext() {
+        return feSurfaceContext;
+    }
 }