diff --git a/wire-compiler/src/test/java/com/squareup/wire/schema/WireRunTest.kt b/wire-compiler/src/test/java/com/squareup/wire/schema/WireRunTest.kt
index 5a45d8e520..f2b0c384ff 100644
--- a/wire-compiler/src/test/java/com/squareup/wire/schema/WireRunTest.kt
+++ b/wire-compiler/src/test/java/com/squareup/wire/schema/WireRunTest.kt
@@ -1811,6 +1811,14 @@ class WireRunTest {
         |message Any {}
       """.trimMargin(),
     )
+    fs.add(
+      "google/src/main/proto/google/protobuf/api.proto",
+      """
+        |syntax = "proto2";
+        |package google.protobuf;
+        |message Api {}
+      """.trimMargin(),
+    )
     fs.add(
       "google/src/main/proto/google/protobuf/duration.proto",
       """
@@ -1827,6 +1835,14 @@ class WireRunTest {
         |message Empty {}
       """.trimMargin(),
     )
+    fs.add(
+      "google/src/main/proto/google/protobuf/source_context.proto",
+      """
+        |syntax = "proto2";
+        |package google.protobuf;
+        |message SourceContext {}
+      """.trimMargin(),
+    )
     fs.add(
       "google/src/main/proto/google/protobuf/struct.proto",
       """
@@ -1843,6 +1859,14 @@ class WireRunTest {
         |message Timestamp {}
       """.trimMargin(),
     )
+    fs.add(
+      "google/src/main/proto/google/protobuf/type.proto",
+      """
+        |syntax = "proto2";
+        |package google.protobuf;
+        |message Type {}
+      """.trimMargin(),
+    )
     fs.add(
       "google/src/main/proto/google/protobuf/wrappers.proto",
       """
diff --git a/wire-schema/src/commonMain/kotlin/com/squareup/wire/schema/CoreLoader.kt b/wire-schema/src/commonMain/kotlin/com/squareup/wire/schema/CoreLoader.kt
index d251d75503..86f78d1cd3 100644
--- a/wire-schema/src/commonMain/kotlin/com/squareup/wire/schema/CoreLoader.kt
+++ b/wire-schema/src/commonMain/kotlin/com/squareup/wire/schema/CoreLoader.kt
@@ -33,23 +33,29 @@ fun isWireRuntimeProto(location: Location): Boolean {
 /** Returns true if [path] is bundled in the wire runtime. */
 fun isWireRuntimeProto(path: String): Boolean {
   return path == ANY_PROTO ||
+    path == API_PROTO ||
     path == DESCRIPTOR_PROTO ||
     path == DURATION_PROTO ||
     path == EMPTY_PROTO ||
+    path == SOURCE_CONTEXT_PROTO ||
     path == STRUCT_PROTO ||
     path == TIMESTAMP_PROTO ||
-    path == WRAPPERS_PROTO ||
-    path == WIRE_EXTENSIONS_PROTO
+    path == TYPE_PROTO ||
+    path == WIRE_EXTENSIONS_PROTO ||
+    path == WRAPPERS_PROTO
 }
 
 internal const val DESCRIPTOR_PROTO = "google/protobuf/descriptor.proto"
 internal const val WIRE_EXTENSIONS_PROTO = "wire/extensions.proto"
 
 private const val ANY_PROTO = "google/protobuf/any.proto"
+private const val API_PROTO = "google/protobuf/api.proto"
 private const val DURATION_PROTO = "google/protobuf/duration.proto"
 private const val EMPTY_PROTO = "google/protobuf/empty.proto"
+private const val SOURCE_CONTEXT_PROTO = "google/protobuf/source_context.proto"
 private const val STRUCT_PROTO = "google/protobuf/struct.proto"
 private const val TIMESTAMP_PROTO = "google/protobuf/timestamp.proto"
+private const val TYPE_PROTO = "google/protobuf/type.proto"
 private const val WRAPPERS_PROTO = "google/protobuf/wrappers.proto"
 
 /** A special base directory used for Wire's built-in .proto files. */
diff --git a/wire-schema/src/jvmMain/resources/google/protobuf/api.proto b/wire-schema/src/jvmMain/resources/google/protobuf/api.proto
new file mode 100644
index 0000000000..afc9cc1562
--- /dev/null
+++ b/wire-schema/src/jvmMain/resources/google/protobuf/api.proto
@@ -0,0 +1,207 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+syntax = "proto3";
+
+package google.protobuf;
+
+import "google/protobuf/source_context.proto";
+import "google/protobuf/type.proto";
+
+option java_package = "com.google.protobuf";
+option java_outer_classname = "ApiProto";
+option java_multiple_files = true;
+option objc_class_prefix = "GPB";
+option csharp_namespace = "Google.Protobuf.WellKnownTypes";
+option go_package = "google.golang.org/protobuf/types/known/apipb";
+
+// Api is a light-weight descriptor for an API Interface.
+//
+// Interfaces are also described as "protocol buffer services" in some contexts,
+// such as by the "service" keyword in a .proto file, but they are different
+// from API Services, which represent a concrete implementation of an interface
+// as opposed to simply a description of methods and bindings. They are also
+// sometimes simply referred to as "APIs" in other contexts, such as the name of
+// this message itself. See https://cloud.google.com/apis/design/glossary for
+// detailed terminology.
+message Api {
+  // The fully qualified name of this interface, including package name
+  // followed by the interface's simple name.
+  string name = 1;
+
+  // The methods of this interface, in unspecified order.
+  repeated Method methods = 2;
+
+  // Any metadata attached to the interface.
+  repeated Option options = 3;
+
+  // A version string for this interface. If specified, must have the form
+  // `major-version.minor-version`, as in `1.10`. If the minor version is
+  // omitted, it defaults to zero. If the entire version field is empty, the
+  // major version is derived from the package name, as outlined below. If the
+  // field is not empty, the version in the package name will be verified to be
+  // consistent with what is provided here.
+  //
+  // The versioning schema uses [semantic
+  // versioning](http://semver.org) where the major version number
+  // indicates a breaking change and the minor version an additive,
+  // non-breaking change. Both version numbers are signals to users
+  // what to expect from different versions, and should be carefully
+  // chosen based on the product plan.
+  //
+  // The major version is also reflected in the package name of the
+  // interface, which must end in `v<major-version>`, as in
+  // `google.feature.v1`. For major versions 0 and 1, the suffix can
+  // be omitted. Zero major versions must only be used for
+  // experimental, non-GA interfaces.
+  //
+  string version = 4;
+
+  // Source context for the protocol buffer service represented by this
+  // message.
+  SourceContext source_context = 5;
+
+  // Included interfaces. See [Mixin][].
+  repeated Mixin mixins = 6;
+
+  // The source syntax of the service.
+  Syntax syntax = 7;
+}
+
+// Method represents a method of an API interface.
+message Method {
+  // The simple name of this method.
+  string name = 1;
+
+  // A URL of the input message type.
+  string request_type_url = 2;
+
+  // If true, the request is streamed.
+  bool request_streaming = 3;
+
+  // The URL of the output message type.
+  string response_type_url = 4;
+
+  // If true, the response is streamed.
+  bool response_streaming = 5;
+
+  // Any metadata attached to the method.
+  repeated Option options = 6;
+
+  // The source syntax of this method.
+  Syntax syntax = 7;
+}
+
+// Declares an API Interface to be included in this interface. The including
+// interface must redeclare all the methods from the included interface, but
+// documentation and options are inherited as follows:
+//
+// - If after comment and whitespace stripping, the documentation
+//   string of the redeclared method is empty, it will be inherited
+//   from the original method.
+//
+// - Each annotation belonging to the service config (http,
+//   visibility) which is not set in the redeclared method will be
+//   inherited.
+//
+// - If an http annotation is inherited, the path pattern will be
+//   modified as follows. Any version prefix will be replaced by the
+//   version of the including interface plus the [root][] path if
+//   specified.
+//
+// Example of a simple mixin:
+//
+//     package google.acl.v1;
+//     service AccessControl {
+//       // Get the underlying ACL object.
+//       rpc GetAcl(GetAclRequest) returns (Acl) {
+//         option (google.api.http).get = "/v1/{resource=**}:getAcl";
+//       }
+//     }
+//
+//     package google.storage.v2;
+//     service Storage {
+//       rpc GetAcl(GetAclRequest) returns (Acl);
+//
+//       // Get a data record.
+//       rpc GetData(GetDataRequest) returns (Data) {
+//         option (google.api.http).get = "/v2/{resource=**}";
+//       }
+//     }
+//
+// Example of a mixin configuration:
+//
+//     apis:
+//     - name: google.storage.v2.Storage
+//       mixins:
+//       - name: google.acl.v1.AccessControl
+//
+// The mixin construct implies that all methods in `AccessControl` are
+// also declared with same name and request/response types in
+// `Storage`. A documentation generator or annotation processor will
+// see the effective `Storage.GetAcl` method after inheriting
+// documentation and annotations as follows:
+//
+//     service Storage {
+//       // Get the underlying ACL object.
+//       rpc GetAcl(GetAclRequest) returns (Acl) {
+//         option (google.api.http).get = "/v2/{resource=**}:getAcl";
+//       }
+//       ...
+//     }
+//
+// Note how the version in the path pattern changed from `v1` to `v2`.
+//
+// If the `root` field in the mixin is specified, it should be a
+// relative path under which inherited HTTP paths are placed. Example:
+//
+//     apis:
+//     - name: google.storage.v2.Storage
+//       mixins:
+//       - name: google.acl.v1.AccessControl
+//         root: acls
+//
+// This implies the following inherited HTTP annotation:
+//
+//     service Storage {
+//       // Get the underlying ACL object.
+//       rpc GetAcl(GetAclRequest) returns (Acl) {
+//         option (google.api.http).get = "/v2/acls/{resource=**}:getAcl";
+//       }
+//       ...
+//     }
+message Mixin {
+  // The fully qualified name of the interface which is included.
+  string name = 1;
+
+  // If non-empty specifies a path under which inherited HTTP paths
+  // are rooted.
+  string root = 2;
+}
diff --git a/wire-schema/src/jvmMain/resources/google/protobuf/source_context.proto b/wire-schema/src/jvmMain/resources/google/protobuf/source_context.proto
new file mode 100644
index 0000000000..135f50fea5
--- /dev/null
+++ b/wire-schema/src/jvmMain/resources/google/protobuf/source_context.proto
@@ -0,0 +1,48 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+syntax = "proto3";
+
+package google.protobuf;
+
+option java_package = "com.google.protobuf";
+option java_outer_classname = "SourceContextProto";
+option java_multiple_files = true;
+option objc_class_prefix = "GPB";
+option csharp_namespace = "Google.Protobuf.WellKnownTypes";
+option go_package = "google.golang.org/protobuf/types/known/sourcecontextpb";
+
+// `SourceContext` represents information about the source of a
+// protobuf element, like the file in which it is defined.
+message SourceContext {
+  // The path-qualified name of the .proto file that contained the associated
+  // protobuf element.  For example: `"google/protobuf/source_context.proto"`.
+  string file_name = 1;
+}
diff --git a/wire-schema/src/jvmMain/resources/google/protobuf/type.proto b/wire-schema/src/jvmMain/resources/google/protobuf/type.proto
new file mode 100644
index 0000000000..48cb11e755
--- /dev/null
+++ b/wire-schema/src/jvmMain/resources/google/protobuf/type.proto
@@ -0,0 +1,193 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+syntax = "proto3";
+
+package google.protobuf;
+
+import "google/protobuf/any.proto";
+import "google/protobuf/source_context.proto";
+
+option cc_enable_arenas = true;
+option java_package = "com.google.protobuf";
+option java_outer_classname = "TypeProto";
+option java_multiple_files = true;
+option objc_class_prefix = "GPB";
+option csharp_namespace = "Google.Protobuf.WellKnownTypes";
+option go_package = "google.golang.org/protobuf/types/known/typepb";
+
+// A protocol buffer message type.
+message Type {
+  // The fully qualified message name.
+  string name = 1;
+  // The list of fields.
+  repeated Field fields = 2;
+  // The list of types appearing in `oneof` definitions in this type.
+  repeated string oneofs = 3;
+  // The protocol buffer options.
+  repeated Option options = 4;
+  // The source context.
+  SourceContext source_context = 5;
+  // The source syntax.
+  Syntax syntax = 6;
+  // The source edition string, only valid when syntax is SYNTAX_EDITIONS.
+  string edition = 7;
+}
+
+// A single field of a message type.
+message Field {
+  // Basic field types.
+  enum Kind {
+    // Field type unknown.
+    TYPE_UNKNOWN = 0;
+    // Field type double.
+    TYPE_DOUBLE = 1;
+    // Field type float.
+    TYPE_FLOAT = 2;
+    // Field type int64.
+    TYPE_INT64 = 3;
+    // Field type uint64.
+    TYPE_UINT64 = 4;
+    // Field type int32.
+    TYPE_INT32 = 5;
+    // Field type fixed64.
+    TYPE_FIXED64 = 6;
+    // Field type fixed32.
+    TYPE_FIXED32 = 7;
+    // Field type bool.
+    TYPE_BOOL = 8;
+    // Field type string.
+    TYPE_STRING = 9;
+    // Field type group. Proto2 syntax only, and deprecated.
+    TYPE_GROUP = 10;
+    // Field type message.
+    TYPE_MESSAGE = 11;
+    // Field type bytes.
+    TYPE_BYTES = 12;
+    // Field type uint32.
+    TYPE_UINT32 = 13;
+    // Field type enum.
+    TYPE_ENUM = 14;
+    // Field type sfixed32.
+    TYPE_SFIXED32 = 15;
+    // Field type sfixed64.
+    TYPE_SFIXED64 = 16;
+    // Field type sint32.
+    TYPE_SINT32 = 17;
+    // Field type sint64.
+    TYPE_SINT64 = 18;
+  }
+
+  // Whether a field is optional, required, or repeated.
+  enum Cardinality {
+    // For fields with unknown cardinality.
+    CARDINALITY_UNKNOWN = 0;
+    // For optional fields.
+    CARDINALITY_OPTIONAL = 1;
+    // For required fields. Proto2 syntax only.
+    CARDINALITY_REQUIRED = 2;
+    // For repeated fields.
+    CARDINALITY_REPEATED = 3;
+  }
+
+  // The field type.
+  Kind kind = 1;
+  // The field cardinality.
+  Cardinality cardinality = 2;
+  // The field number.
+  int32 number = 3;
+  // The field name.
+  string name = 4;
+  // The field type URL, without the scheme, for message or enumeration
+  // types. Example: `"type.googleapis.com/google.protobuf.Timestamp"`.
+  string type_url = 6;
+  // The index of the field type in `Type.oneofs`, for message or enumeration
+  // types. The first type has index 1; zero means the type is not in the list.
+  int32 oneof_index = 7;
+  // Whether to use alternative packed wire representation.
+  bool packed = 8;
+  // The protocol buffer options.
+  repeated Option options = 9;
+  // The field JSON name.
+  string json_name = 10;
+  // The string value of the default value of this field. Proto2 syntax only.
+  string default_value = 11;
+}
+
+// Enum type definition.
+message Enum {
+  // Enum type name.
+  string name = 1;
+  // Enum value definitions.
+  repeated EnumValue enumvalue = 2;
+  // Protocol buffer options.
+  repeated Option options = 3;
+  // The source context.
+  SourceContext source_context = 4;
+  // The source syntax.
+  Syntax syntax = 5;
+  // The source edition string, only valid when syntax is SYNTAX_EDITIONS.
+  string edition = 6;
+}
+
+// Enum value definition.
+message EnumValue {
+  // Enum value name.
+  string name = 1;
+  // Enum value number.
+  int32 number = 2;
+  // Protocol buffer options.
+  repeated Option options = 3;
+}
+
+// A protocol buffer option, which can be attached to a message, field,
+// enumeration, etc.
+message Option {
+  // The option's name. For protobuf built-in options (options defined in
+  // descriptor.proto), this is the short name. For example, `"map_entry"`.
+  // For custom options, it should be the fully-qualified name. For example,
+  // `"google.api.http"`.
+  string name = 1;
+  // The option's value packed in an Any message. If the value is a primitive,
+  // the corresponding wrapper type defined in google/protobuf/wrappers.proto
+  // should be used. If the value is an enum, it should be stored as an int32
+  // value using the google.protobuf.Int32Value type.
+  Any value = 2;
+}
+
+// The syntax in which a protocol buffer element is defined.
+enum Syntax {
+  // Syntax `proto2`.
+  SYNTAX_PROTO2 = 0;
+  // Syntax `proto3`.
+  SYNTAX_PROTO3 = 1;
+  // Syntax `editions`.
+  SYNTAX_EDITIONS = 2;
+}