copybara-service · Oct 13, 2026 · Oct 13, 2026
diff --git a/bundle/src/test/java/dev/cel/bundle/CelImplTest.java b/bundle/src/test/java/dev/cel/bundle/CelImplTest.java
@@ -2119,17 +2119,11 @@ public void eval_withJsonFieldName_runtimeOptionDisabled_throws() throws Excepti
     CelAbstractSyntaxTree ast = celCompiler.compile("file.int64CamelCaseJsonName").getAst();
 
     CelEvaluationException e =
-        assertThrows(
-            CelEvaluationException.class,
-            () ->
-                celRuntime
-                    .createProgram(ast)
-                    .eval(ImmutableMap.of("file", SingleFile.getDefaultInstance())));
+        assertThrows(CelEvaluationException.class, () -> celRuntime.createProgram(ast));
+
     assertThat(e)
         .hasMessageThat()
-        .contains(
-            "field 'int64CamelCaseJsonName' is not declared in message"
-                + " 'dev.cel.testing.testdata.SingleFile");
+        .contains("json_name extension requires CelOptions.enableJsonFieldNames(true)");
   }
 
   @Test

diff --git a/common/src/main/java/dev/cel/common/CelSource.java b/common/src/main/java/dev/cel/common/CelSource.java
@@ -367,19 +367,19 @@ public CelSource build() {
   public abstract static class Extension {
 
     /** Identifier for the extension. Example: constant_folding */
-    abstract String id();
+    public abstract String id();
 
     /**
      * Version info. May be skipped if it isn't meaningful for the extension. (for example
      * constant_folding might always be v0.0).
      */
-    abstract Version version();
+    public abstract Version version();
 
     /**
      * If set, the listed components must understand the extension for the expression to evaluate
      * correctly.
      */
-    abstract ImmutableList<Component> affectedComponents();
+    public abstract ImmutableList<Component> affectedComponents();
 
     /** Version of the extension */
     @AutoValue
@@ -390,18 +390,20 @@ public abstract static class Version {
        * Major version changes indicate different required support level from the required
        * components.
        */
-      abstract long major();
+      public abstract long major();
 
       /**
        * Minor version changes must not change the observed behavior from existing implementations,
        * but may be provided informational.
        */
-      abstract long minor();
+      public abstract long minor();
 
       /** Create a new instance of Version with the provided major and minor values. */
       public static Version of(long major, long minor) {
         return new AutoValue_CelSource_Extension_Version(major, minor);
       }
+
+      Version() {}
     }
 
     /** CEL component specifier. */
@@ -427,5 +429,7 @@ public static Extension create(String id, Version version, Iterable<Component> c
     public static Extension create(String id, Version version, Component... components) {
       return create(id, version, Arrays.asList(components));
     }
+
+    Extension() {}
   }
 }
diff --git a/conformance/src/test/java/dev/cel/conformance/BUILD.bazel b/conformance/src/test/java/dev/cel/conformance/BUILD.bazel
@@ -17,6 +17,8 @@ java_library(
     deps = [
         "//:java_truth",
         "//checker:checker_builder",
+        "//common:cel_ast",
+        "//common:cel_source",
         "//common:compiler_common",
         "//common:container",
         "//common:options",

diff --git a/conformance/src/test/java/dev/cel/conformance/ConformanceTest.java b/conformance/src/test/java/dev/cel/conformance/ConformanceTest.java
@@ -31,9 +31,13 @@
 import com.google.protobuf.TypeRegistry;
 import dev.cel.checker.CelChecker;
 import dev.cel.checker.CelCheckerBuilder;
+import dev.cel.common.CelAbstractSyntaxTree;
 import dev.cel.common.CelContainer;
 import dev.cel.common.CelIssue;
 import dev.cel.common.CelOptions;
+import dev.cel.common.CelSource.Extension;
+import dev.cel.common.CelSource.Extension.Component;
+import dev.cel.common.CelSource.Extension.Version;
 import dev.cel.common.CelValidationResult;
 import dev.cel.common.CelVarDecl;
 import dev.cel.common.ast.CelBlock;
@@ -227,7 +231,19 @@ public void evaluate() throws Throwable {
       response = getChecker(test).check(response.getAst());
     }
     assertThat(response.getErrors()).isEmpty();
-    Type resultType = CelProtoTypes.celTypeToType(response.getAst().getResultType());
+    CelAbstractSyntaxTree ast = response.getAst();
+    if (ast.getExpr().callOrDefault().function().equals(CelBlock.FUNCTION_NAME)) {
+      ast =
+          CelAbstractSyntaxTree.newCheckedAst(
+              ast.getExpr(),
+              ast.getSource().toBuilder()
+                  .addAllExtensions(
+                      Extension.create("cel_block", Version.of(1, 1), Component.COMPONENT_RUNTIME))
+                  .build(),
+              ast.getReferenceMap(),
+              ast.getTypeMap());
+    }
+    Type resultType = CelProtoTypes.celTypeToType(ast.getResultType());
 
     if (test.getCheckOnly()) {
       assertThat(test.hasTypedResult()).isTrue();
@@ -244,8 +260,8 @@ public void evaluate() throws Throwable {
     ExprValue result = null;
     CelEvaluationException error = null;
     try {
-      Program program = runtime.createProgram(response.getAst());
-      result = toExprValue(program.eval(getBindings(test)), response.getAst().getResultType());
+      Program program = runtime.createProgram(ast);
+      result = toExprValue(program.eval(getBindings(test)), ast.getResultType());
     } catch (CelEvaluationException e) {
       error = e;
     }

diff --git a/optimizer/src/test/java/dev/cel/optimizer/optimizers/SubexpressionOptimizerTest.java b/optimizer/src/test/java/dev/cel/optimizer/optimizers/SubexpressionOptimizerTest.java
@@ -827,10 +827,17 @@ private CelAbstractSyntaxTree compileUsingInternalFunctions(String expression, b
               indexExpr.ident().setName(internalIdentName);
             });
 
+    CelAbstractSyntaxTree parsedAst =
+        CelAbstractSyntaxTree.newParsedAst(
+            mutableAst.toParsedAst().getExpr(),
+            astToModify.getSource().toBuilder()
+                .addAllExtensions(
+                    Extension.create("cel_block", Version.of(1L, 1L), Component.COMPONENT_RUNTIME))
+                .build());
     if (parsedOnly) {
-      return mutableAst.toParsedAst();
+      return parsedAst;
     }
-    return celForEvaluatingBlock.check(mutableAst.toParsedAst()).getAst();
+    return celForEvaluatingBlock.check(parsedAst).getAst();
   }
 
   private CelAbstractSyntaxTree compileUsingInternalFunctions(String expression)

diff --git a/runtime/src/main/java/dev/cel/runtime/planner/BUILD.bazel b/runtime/src/main/java/dev/cel/runtime/planner/BUILD.bazel
@@ -46,6 +46,7 @@ java_library(
         ":planner_helpers",
         "//:auto_value",
         "//common:cel_ast",
+        "//common:cel_source",
         "//common:container",
         "//common:operator",
         "//common:options",
@@ -555,16 +556,13 @@ java_library(
         ":planned_interpretable",
         ":planner_helpers",
         "//common/ast",
-        "//common/types",
         "//common/types:cel_types",
-        "//common/types:type_providers",
         "//common/values",
         "//common/values:cel_byte_string",
         "//common/values:optimized_select_traversal",
         "//common/values:select_field",
         "@maven//:com_google_errorprone_error_prone_annotations",
         "@maven//:com_google_guava_guava",
-        "@maven//:org_jspecify_jspecify",
     ],
 )
 
@@ -720,6 +718,7 @@ cel_android_library(
         ":planner_helpers_android",
         "//:auto_value",
         "//common:cel_ast_android",
+        "//common:cel_source_android",
         "//common:container_android",
         "//common:operator_android",
         "//common:options",
@@ -1232,14 +1231,11 @@ cel_android_library(
         ":planner_helpers_android",
         "//common/ast:ast_android",
         "//common/types:cel_types_android",
-        "//common/types:type_providers_android",
-        "//common/types:types_android",
         "//common/values:cel_byte_string",
         "//common/values:optimized_select_traversal_android",
         "//common/values:select_field_android",
         "//common/values:values_android",
         "@maven//:com_google_errorprone_error_prone_annotations",
-        "@maven//:org_jspecify_jspecify",
         "@maven_android//:com_google_guava_guava",
     ],
 )

diff --git a/runtime/src/main/java/dev/cel/runtime/planner/ProgramPlanner.java b/runtime/src/main/java/dev/cel/runtime/planner/ProgramPlanner.java
@@ -14,6 +14,7 @@
 
 package dev.cel.runtime.planner;
 
+import static com.google.common.base.Preconditions.checkArgument;
 import static com.google.common.base.Preconditions.checkNotNull;
 
 import com.google.auto.value.AutoValue;
@@ -28,6 +29,9 @@
 import dev.cel.common.CelAbstractSyntaxTree;
 import dev.cel.common.CelContainer;
 import dev.cel.common.CelOptions;
+import dev.cel.common.CelSource.Extension;
+import dev.cel.common.CelSource.Extension.Component;
+import dev.cel.common.CelSource.Extension.Version;
 import dev.cel.common.Operator;
 import dev.cel.common.annotations.Internal;
 import dev.cel.common.ast.CelBlock;
@@ -60,6 +64,7 @@
 import dev.cel.runtime.RuntimeEquality;
 import java.util.Arrays;
 import java.util.HashMap;
+import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Optional;
 import org.jspecify.annotations.Nullable;
@@ -72,6 +77,15 @@
 @Internal
 public final class ProgramPlanner {
   private static final String MAP_INSERT_FUNCTION = "cel.@mapInsert";
+  private static final String CEL_BLOCK_EXTENSION = "cel_block";
+  private static final String JSON_NAME_EXTENSION = "json_name";
+  private static final String SELECT_OPTIMIZATION_EXTENSION = "select_optimization";
+
+  private static final ImmutableMap<String, Version> SUPPORTED_RUNTIME_EXTENSIONS =
+      ImmutableMap.of(
+          CEL_BLOCK_EXTENSION, Version.of(1, 1),
+          JSON_NAME_EXTENSION, Version.of(1, 1),
+          SELECT_OPTIMIZATION_EXTENSION, Version.of(1, 0));
 
   private final CelTypeProvider typeProvider;
   private final CelValueProvider valueProvider;
@@ -102,7 +116,7 @@ public PlannedProgram plan(CelAbstractSyntaxTree ast) throws CelEvaluationExcept
     ErrorMetadata errorMetadata =
         ErrorMetadata.create(ast.getSource().getPositionsMap(), ast.getSource().getDescription());
     try {
-      PlannerContext ctx = PlannerContext.create(ast);
+      PlannerContext ctx = PlannerContext.create(ast, options);
       plannedInterpretable =
           CelBlock.extract(ast)
               .map(celBlock -> planBlock(celBlock, ctx))
@@ -248,6 +262,11 @@ private PlannedInterpretable planCall(CelExpr expr, PlannerContext ctx) {
     // map key lookup on Map, and SelectableValue fallback).
     if (functionName.equals(OptimizedSelectPlanner.CEL_ATTRIBUTE_FUNCTION_NAME)
         || functionName.equals(OptimizedSelectPlanner.CEL_HAS_FIELD_FUNCTION_NAME)) {
+      checkArgument(
+          ctx.runtimeExtensions.contains(SELECT_OPTIMIZATION_EXTENSION),
+          "%s requires the %s AST extension",
+          functionName,
+          SELECT_OPTIMIZATION_EXTENSION);
       return optimizedSelectPlanner.plan(expr, functionName, operandExpr -> plan(operandExpr, ctx));
     }
 
@@ -382,6 +401,11 @@ private PlannedInterpretable planCall(CelExpr expr, PlannerContext ctx) {
   }
 
   private PlannedInterpretable planBlock(CelBlock celBlock, PlannerContext ctx) {
+    checkArgument(
+        ctx.runtimeExtensions.contains(CEL_BLOCK_EXTENSION),
+        "%s requires the %s AST extension",
+        CelBlock.FUNCTION_NAME,
+        CEL_BLOCK_EXTENSION);
     ImmutableList<CelExpr> indices = celBlock.indices();
 
     PlannedInterpretable[] slotExprs = new PlannedInterpretable[indices.size()];
@@ -716,23 +740,20 @@ private static Builder newBuilder() {
     }
   }
 
-  static final class PlannerContext {
+  private static final class PlannerContext {
     private final CelAbstractSyntaxTree ast;
-    private final HashMap<String, Integer> localVars = new HashMap<>();
-
-    CelAbstractSyntaxTree ast() {
-      return ast;
-    }
+    private final ImmutableSet<String> runtimeExtensions;
+    private final Map<String, Integer> localVars;
 
-    ImmutableMap<Long, CelReference> referenceMap() {
+    private ImmutableMap<Long, CelReference> referenceMap() {
       return ast.getReferenceMap();
     }
 
-    ImmutableMap<Long, CelType> typeMap() {
+    private ImmutableMap<Long, CelType> typeMap() {
       return ast.getTypeMap();
     }
 
-    boolean isChecked() {
+    private boolean isChecked() {
       return ast.isChecked();
     }
 
@@ -766,12 +787,35 @@ private boolean isLocalVar(String name) {
       return localVars.containsKey(name);
     }
 
-    static PlannerContext create(CelAbstractSyntaxTree ast) {
-      return new PlannerContext(ast);
+    private static PlannerContext create(CelAbstractSyntaxTree ast, CelOptions options) {
+      ImmutableSet.Builder<String> runtimeExtensions = ImmutableSet.builder();
+      for (Extension extension : ast.getSource().getExtensions()) {
+        if (!extension.affectedComponents().contains(Component.COMPONENT_RUNTIME)) {
+          continue;
+        }
+        Version version = extension.version();
+        Version supportedVersion = SUPPORTED_RUNTIME_EXTENSIONS.get(extension.id());
+        checkArgument(
+            supportedVersion != null
+                && version.major() == supportedVersion.major()
+                && version.minor() <= supportedVersion.minor(),
+            "unsupported CEL extension: %s@%s.%s",
+            extension.id(),
+            version.major(),
+            version.minor());
+        runtimeExtensions.add(extension.id());
+      }
+      ImmutableSet<String> extensions = runtimeExtensions.build();
+      checkArgument(
+          !extensions.contains(JSON_NAME_EXTENSION) || options.enableJsonFieldNames(),
+          "json_name extension requires CelOptions.enableJsonFieldNames(true)");
+      return new PlannerContext(ast, extensions);
     }
 
-    private PlannerContext(CelAbstractSyntaxTree ast) {
+    private PlannerContext(CelAbstractSyntaxTree ast, ImmutableSet<String> runtimeExtensions) {
       this.ast = checkNotNull(ast);
+      this.runtimeExtensions = runtimeExtensions;
+      this.localVars = new HashMap<>();
     }
   }
 

diff --git a/runtime/src/test/java/dev/cel/runtime/BUILD.bazel b/runtime/src/test/java/dev/cel/runtime/BUILD.bazel
@@ -40,6 +40,7 @@ java_library(
         "//common:container",
         "//common:error_codes",
         "//common:options",
+        "//common:proto_ast",
         "//common:proto_v1alpha1_ast",
         "//common/ast",
         "//common/ast:cel_block",
@@ -111,6 +112,7 @@ java_library(
         "//testing/protos:single_file_java_proto",
         "//testing/protos:test_all_types_cel_java_proto2",
         "//testing/protos:test_all_types_cel_java_proto3",
+        "@cel_spec//proto/cel/expr:checked_java_proto",
         "@cel_spec//proto/cel/expr/conformance/proto2:test_all_types_java_proto",
         "@cel_spec//proto/cel/expr/conformance/proto3:test_all_types_java_proto",
         "@com_google_googleapis//google/api/expr/v1alpha1:expr_java_proto",

diff --git a/runtime/src/test/java/dev/cel/runtime/CelLiteRuntimeVersionSkewTest.java b/runtime/src/test/java/dev/cel/runtime/CelLiteRuntimeVersionSkewTest.java
@@ -18,7 +18,7 @@
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.junit.Assert.assertThrows;
 
-import com.google.api.expr.v1alpha1.CheckedExpr;
+import dev.cel.expr.CheckedExpr;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableMap;
 import com.google.common.collect.ImmutableSet;
@@ -40,7 +40,7 @@
 import dev.cel.common.CelFunctionDecl;
 import dev.cel.common.CelOptions;
 import dev.cel.common.CelOverloadDecl;
-import dev.cel.common.CelProtoV1Alpha1AbstractSyntaxTree;
+import dev.cel.common.CelProtoAbstractSyntaxTree;
 import dev.cel.common.ast.CelBlock;
 import dev.cel.common.internal.ProtoTimeUtils;
 import dev.cel.common.types.ListType;
@@ -1879,11 +1879,11 @@ public void checkedExprWireRoundTrip_preservesOptimizedSelectsUnderVersionSkew()
             .getAst();
     CelAbstractSyntaxTree optimizedAst = serverOptimizer.optimize(ast);
     byte[] serializedCheckedExpr =
-        CelProtoV1Alpha1AbstractSyntaxTree.fromCelAst(optimizedAst).toCheckedExpr().toByteArray();
+        CelProtoAbstractSyntaxTree.fromCelAst(optimizedAst).toCheckedExpr().toByteArray();
     CheckedExpr deserializedCheckedExpr =
         CheckedExpr.parseFrom(serializedCheckedExpr, ExtensionRegistryLite.getEmptyRegistry());
     CelAbstractSyntaxTree deserializedAst =
-        CelProtoV1Alpha1AbstractSyntaxTree.fromCheckedExpr(deserializedCheckedExpr).getAst();
+        CelProtoAbstractSyntaxTree.fromCheckedExpr(deserializedCheckedExpr).getAst();
 
     Object result =
         clientRuntime