diff --git a/tools/src/cmd/cts/common/cmds.go b/tools/src/cmd/cts/common/cmds.go
new file mode 100644
index 0000000000..00a655ae24
--- /dev/null
+++ b/tools/src/cmd/cts/common/cmds.go
@@ -0,0 +1,31 @@
+// Copyright 2022 The Dawn Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package common
+
+import (
+	"dawn.googlesource.com/dawn/tools/src/subcmd"
+)
+
+// The registered commands
+var commands []Command
+
+// Command is the type of a single cts command
+type Command = subcmd.Command[Config]
+
+// Register registers the command for use by the 'cts' tool
+func Register(c Command) { commands = append(commands, c) }
+
+// Commands returns all the commands registered
+func Commands() []Command { return commands }
diff --git a/tools/src/cmd/cts/common/paths.go b/tools/src/cmd/cts/common/paths.go
new file mode 100644
index 0000000000..fda05ed20d
--- /dev/null
+++ b/tools/src/cmd/cts/common/paths.go
@@ -0,0 +1,38 @@
+// Copyright 2022 The Dawn Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package common
+
+import (
+	"os"
+	"path/filepath"
+
+	"dawn.googlesource.com/dawn/tools/src/utils"
+)
+
+const (
+	// RelativeExpectationsPath is the dawn-root relative path to the
+	// expectations.txt file.
+	RelativeExpectationsPath = "webgpu-cts/expectations.txt"
+)
+
+// DefaultExpectationsPath returns the default path to the expectations.txt
+// file. Returns an empty string if the file cannot be found.
+func DefaultExpectationsPath() string {
+	path := filepath.Join(utils.DawnRoot(), RelativeExpectationsPath)
+	if _, err := os.Stat(path); err != nil {
+		return ""
+	}
+	return path
+}
diff --git a/tools/src/cmd/cts/format/format.go b/tools/src/cmd/cts/format/format.go
new file mode 100644
index 0000000000..823e1bea1c
--- /dev/null
+++ b/tools/src/cmd/cts/format/format.go
@@ -0,0 +1,55 @@
+// Copyright 2022 The Dawn Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package format
+
+import (
+	"context"
+	"flag"
+
+	"dawn.googlesource.com/dawn/tools/src/cmd/cts/common"
+	"dawn.googlesource.com/dawn/tools/src/cts/expectations"
+)
+
+func init() {
+	common.Register(&cmd{})
+}
+
+type cmd struct {
+	flags struct {
+		expectations string // expectations file path
+	}
+}
+
+func (cmd) Name() string {
+	return "format"
+}
+
+func (cmd) Desc() string {
+	return "formats a WebGPUExpectation file"
+}
+
+func (c *cmd) RegisterFlags(ctx context.Context, cfg common.Config) ([]string, error) {
+	defaultExpectations := common.DefaultExpectationsPath()
+	flag.StringVar(&c.flags.expectations, "expectations", defaultExpectations, "path to CTS expectations file to update")
+	return nil, nil
+}
+
+func (c *cmd) Run(ctx context.Context, cfg common.Config) error {
+	ex, err := expectations.Load(c.flags.expectations)
+	if err != nil {
+		return err
+	}
+	return ex.Save(c.flags.expectations)
+}
diff --git a/tools/src/cmd/cts/main.go b/tools/src/cmd/cts/main.go
new file mode 100644
index 0000000000..542ae40f34
--- /dev/null
+++ b/tools/src/cmd/cts/main.go
@@ -0,0 +1,49 @@
+// Copyright 2022 The Dawn Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// cts is a collection of sub-commands for operating on the WebGPU CTS.
+//
+// To view available commands run: '<dawn>/tools/run cts --help'
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"dawn.googlesource.com/dawn/tools/src/cmd/cts/common"
+	"dawn.googlesource.com/dawn/tools/src/subcmd"
+	"dawn.googlesource.com/dawn/tools/src/utils"
+
+	// Register sub-commands
+	_ "dawn.googlesource.com/dawn/tools/src/cmd/cts/format"
+)
+
+func main() {
+	ctx := context.Background()
+
+	cfg, err := common.LoadConfig(filepath.Join(utils.ThisDir(), "config.json"))
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+
+	if err := subcmd.Run(ctx, *cfg, common.Commands()...); err != nil {
+		if err != subcmd.ErrInvalidCLA {
+			fmt.Fprintln(os.Stderr, err)
+		}
+		os.Exit(1)
+	}
+}