diff --git a/prometeu-compiler/frontends/prometeu-frontend-pbs/src/test/java/p/studio/compiler/pbs/PbsGateUSdkInterfaceConformanceTest.java b/prometeu-compiler/frontends/prometeu-frontend-pbs/src/test/java/p/studio/compiler/pbs/PbsGateUSdkInterfaceConformanceTest.java
index 3e29f97a..6e16aa13 100644
--- a/prometeu-compiler/frontends/prometeu-frontend-pbs/src/test/java/p/studio/compiler/pbs/PbsGateUSdkInterfaceConformanceTest.java
+++ b/prometeu-compiler/frontends/prometeu-frontend-pbs/src/test/java/p/studio/compiler/pbs/PbsGateUSdkInterfaceConformanceTest.java
@@ -85,13 +85,14 @@ class PbsGateUSdkInterfaceConformanceTest {
                 tempDir.resolve("gate-u-reserved-import-positive"),
                 """
                 import { Color } from @core:color;
+                import { Composer } from @sdk:composer;
                 import { Gfx } from @sdk:gfx;
                 import { Input, InputPad, InputButton } from @sdk:input;
                 import { Assets } from @sdk:asset;
                 import { Log } from @sdk:log;
 
                 declare contract Renderer {
-                  fn render(gfx: Gfx, color: Color, input: Input, pad: InputPad, button: InputButton, assets: Assets, log: Log) -> void;
+                  fn render(composer: Composer, gfx: Gfx, color: Color, input: Input, pad: InputPad, button: InputButton, assets: Assets, log: Log) -> void;
                 }
                 """,
                 "pub contract Renderer;",
@@ -115,6 +116,11 @@ class PbsGateUSdkInterfaceConformanceTest {
                         && h.abiModule().equals("gfx")
                         && h.abiMethod().equals("clear")
                         && h.abiVersion() == 1));
+        assertTrue(positive.irBackend().getReservedMetadata().hostMethodBindings().stream()
+                .anyMatch(h -> h.ownerName().equals("LowComposer")
+                        && h.abiModule().equals("composer")
+                        && h.abiMethod().equals("emit_sprite")
+                        && h.abiVersion() == 1));
         assertTrue(positive.irBackend().getReservedMetadata().hostMethodBindings().stream()
                 .anyMatch(h -> h.ownerName().equals("LowLog")
                         && h.abiModule().equals("log")
diff --git a/prometeu-compiler/frontends/prometeu-frontend-pbs/src/test/java/p/studio/compiler/services/PBSFrontendPhaseServiceTest.java b/prometeu-compiler/frontends/prometeu-frontend-pbs/src/test/java/p/studio/compiler/services/PBSFrontendPhaseServiceTest.java
index ec9fa894..cac3a2ea 100644
--- a/prometeu-compiler/frontends/prometeu-frontend-pbs/src/test/java/p/studio/compiler/services/PBSFrontendPhaseServiceTest.java
+++ b/prometeu-compiler/frontends/prometeu-frontend-pbs/src/test/java/p/studio/compiler/services/PBSFrontendPhaseServiceTest.java
@@ -1006,8 +1006,72 @@ class PBSFrontendPhaseServiceTest {
     }
 
     @Test
-    void shouldLowerSdkGfxSetSpriteFacadeUsingBankIdContract() throws IOException {
-        final var projectRoot = tempDir.resolve("project-bootstrap-sdk-gfx-set-sprite");
+    void shouldLowerSdkComposerEmitSpriteFacadeUsingCanonicalComposerContract() throws IOException {
+        final var projectRoot = tempDir.resolve("project-bootstrap-sdk-composer-emit-sprite");
+        final var sourceRoot = projectRoot.resolve("src");
+        final var modulePath = sourceRoot.resolve("app");
+        Files.createDirectories(modulePath);
+
+        final var sourceFile = modulePath.resolve("source.pbs");
+        final var modBarrel = modulePath.resolve("mod.barrel");
+        Files.writeString(sourceFile, """
+                import { Composer } from @sdk:composer;
+
+                fn render() -> int
+                {
+                    return Composer.emit_sprite(7, 3, 12, 18, 0, 2, false, true, 1);
+                }
+
+                [Frame]
+                fn frame() -> void
+                {
+                    render();
+                    return;
+                }
+                """);
+        Files.writeString(modBarrel, """
+                pub fn render() -> int;
+                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("app")
+                .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);
+        final var diagnostics = DiagnosticSink.empty();
+
+        final var irBackend = new PBSFrontendPhaseService().compile(
+                ctx,
+                diagnostics,
+                LogAggregator.empty(),
+                BuildingIssueSink.empty());
+
+        assertTrue(diagnostics.stream().noneMatch(d ->
+                d.getCode().equals(PbsSemanticsErrors.E_SEM_EXEC_LOWERING_UNRESOLVED_CALLEE.name())));
+        assertTrue(irBackend.getExecutableFunctions().stream().anyMatch(function -> "frame".equals(function.callableName())));
+        assertTrue(irBackend.getReservedMetadata().hostMethodBindings().stream()
+                .anyMatch(h -> h.ownerName().equals("LowComposer")
+                        && h.sourceMethodName().equals("emit_sprite")
+                        && h.abiModule().equals("composer")
+                        && h.abiMethod().equals("emit_sprite")));
+    }
+
+    @Test
+    void shouldRejectLegacyGfxSetSpriteAfterComposerMigration() throws IOException {
+        final var projectRoot = tempDir.resolve("project-bootstrap-sdk-gfx-set-sprite-removed");
         final var sourceRoot = projectRoot.resolve("src");
         final var modulePath = sourceRoot.resolve("app");
         Files.createDirectories(modulePath);
@@ -1059,10 +1123,10 @@ class PBSFrontendPhaseServiceTest {
                 LogAggregator.empty(),
                 BuildingIssueSink.empty());
 
-        assertTrue(diagnostics.stream().noneMatch(d ->
-                d.getCode().equals(PbsSemanticsErrors.E_SEM_EXEC_LOWERING_UNRESOLVED_CALLEE.name())));
-        assertTrue(irBackend.getExecutableFunctions().stream().anyMatch(function -> "frame".equals(function.callableName())));
-        assertTrue(irBackend.getReservedMetadata().hostMethodBindings().stream()
+        assertTrue(diagnostics.stream().anyMatch(d ->
+                d.getCode().equals(PbsSemanticsErrors.E_SEM_INVALID_MEMBER_ACCESS.name())
+                        || d.getCode().equals(PbsSemanticsErrors.E_SEM_EXEC_LOWERING_UNRESOLVED_CALLEE.name())));
+        assertFalse(irBackend.getReservedMetadata().hostMethodBindings().stream()
                 .anyMatch(h -> h.ownerName().equals("LowGfx") && h.sourceMethodName().equals("set_sprite")));
     }