diff --git a/bigquery/storage/managedwriter/client.go b/bigquery/storage/managedwriter/client.go
new file mode 100644
index 00000000000..4d0bd68bdc0
--- /dev/null
+++ b/bigquery/storage/managedwriter/client.go
@@ -0,0 +1,161 @@
+// Copyright 2021 Google LLC
+//
+// 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
+//
+//     https://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 managedwriter
+
+import (
+	"context"
+	"fmt"
+	"runtime"
+	"strings"
+
+	storage "cloud.google.com/go/bigquery/storage/apiv1beta2"
+	"google.golang.org/api/option"
+	storagepb "google.golang.org/genproto/googleapis/cloud/bigquery/storage/v1beta2"
+)
+
+// Client is a managed BigQuery Storage write client scoped to a single project.
+type Client struct {
+	rawClient *storage.BigQueryWriteClient
+	projectID string
+}
+
+// NewClient instantiates a new client.
+func NewClient(ctx context.Context, projectID string, opts ...option.ClientOption) (c *Client, err error) {
+	numConns := runtime.GOMAXPROCS(0)
+	if numConns > 4 {
+		numConns = 4
+	}
+	o := []option.ClientOption{
+		option.WithGRPCConnectionPool(numConns),
+	}
+	o = append(o, opts...)
+
+	rawClient, err := storage.NewBigQueryWriteClient(ctx, o...)
+	if err != nil {
+		return nil, err
+	}
+
+	return &Client{
+		rawClient: rawClient,
+		projectID: projectID,
+	}, nil
+}
+
+// NewManagedStream establishes a new managed stream for appending data into a table.
+func (c *Client) NewManagedStream(ctx context.Context, opts ...WriterOption) (*ManagedStream, error) {
+
+	ms := &ManagedStream{
+		streamSettings: defaultStreamSettings(),
+		c:              c,
+	}
+
+	// apply writer options
+	for _, opt := range opts {
+		opt(ms)
+	}
+
+	if err := c.validateOptions(ctx, ms); err != nil {
+		return nil, err
+	}
+
+	if ms.streamSettings.streamID == "" {
+		// not instantiated with a stream, construct one.
+		streamName := fmt.Sprintf("%s/_default", ms.destinationTable)
+		if ms.streamSettings.streamType != DefaultStream {
+			// For everything but a default stream, we create a new stream on behalf of the user.
+			req := &storagepb.CreateWriteStreamRequest{
+				Parent: ms.destinationTable,
+				WriteStream: &storagepb.WriteStream{
+					Type: streamTypeToEnum(ms.streamSettings.streamType),
+				}}
+			resp, err := ms.c.rawClient.CreateWriteStream(ctx, req)
+			if err != nil {
+				return nil, fmt.Errorf("couldn't create write stream: %v", err)
+			}
+			streamName = resp.GetName()
+		}
+		ms.streamSettings.streamID = streamName
+		// TODO(followup CLs): instantiate an appendstream client, flow controller, etc.
+	}
+
+	return ms, nil
+}
+
+// validateOptions is used to validate that we received a sane/compatible set of WriterOptions
+// for constructing a new managed stream.
+func (c *Client) validateOptions(ctx context.Context, ms *ManagedStream) error {
+	if ms == nil {
+		return fmt.Errorf("no managed stream definition")
+	}
+	if ms.streamSettings.streamID != "" {
+		// User supplied a stream, we need to verify it exists.
+		info, err := c.getWriteStream(ctx, ms.streamSettings.streamID)
+		if err != nil {
+			return fmt.Errorf("a streamname was specified, but lookup of stream failed: %v", err)
+		}
+		// update type and destination based on stream metadata
+		ms.streamSettings.streamType = StreamType(info.Type.String())
+		ms.destinationTable = tableParentFromStreamName(ms.streamSettings.streamID)
+	}
+	if ms.destinationTable == "" {
+		return fmt.Errorf("no destination table specified")
+	}
+	// we could auto-select DEFAULT here, but let's force users to be specific for now.
+	if ms.StreamType() == "" {
+		return fmt.Errorf("stream type wasn't specified")
+	}
+	return nil
+}
+
+// BatchCommit is used to commit one or more PendingStream streams belonging to the same table
+// as a single transaction.  Streams must be finalized before committing.
+//
+// TODO: this currently exposes the raw proto response, but a future CL will wrap this with a nicer type.
+func (c *Client) BatchCommit(ctx context.Context, parentTable string, streamNames []string) (*storagepb.BatchCommitWriteStreamsResponse, error) {
+
+	// determine table from first streamName, as all must share the same table.
+	if len(streamNames) <= 0 {
+		return nil, fmt.Errorf("no streamnames provided")
+	}
+
+	req := &storagepb.BatchCommitWriteStreamsRequest{
+		Parent:       tableParentFromStreamName(streamNames[0]),
+		WriteStreams: streamNames,
+	}
+	return c.rawClient.BatchCommitWriteStreams(ctx, req)
+}
+
+// getWriteStream returns information about a given write stream.
+//
+// It's primarily used for setup validation, and not exposed directly to end users.
+func (c *Client) getWriteStream(ctx context.Context, streamName string) (*storagepb.WriteStream, error) {
+	req := &storagepb.GetWriteStreamRequest{
+		Name: streamName,
+	}
+	return c.rawClient.GetWriteStream(ctx, req)
+}
+
+// tableParentFromStreamName return the corresponding parent table
+// identifier given a fully qualified streamname.
+func tableParentFromStreamName(streamName string) string {
+	// Stream IDs have the following prefix:
+	// projects/{project}/datasets/{dataset}/tables/{table}/blah
+	parts := strings.SplitN(streamName, "/", 7)
+	if len(parts) < 7 {
+		// invalid; just pass back the input
+		return streamName
+	}
+	return strings.Join(parts[:6], "/")
+}
diff --git a/bigquery/storage/managedwriter/client_test.go b/bigquery/storage/managedwriter/client_test.go
new file mode 100644
index 00000000000..81d91e5ca13
--- /dev/null
+++ b/bigquery/storage/managedwriter/client_test.go
@@ -0,0 +1,48 @@
+// Copyright 2021 Google LLC
+//
+// 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
+//
+//     https://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 managedwriter
+
+import "testing"
+
+func TestTableParentFromStreamName(t *testing.T) {
+	testCases := []struct {
+		in   string
+		want string
+	}{
+		{
+			"bad",
+			"bad",
+		},
+		{
+			"projects/foo/datasets/bar/tables/baz",
+			"projects/foo/datasets/bar/tables/baz",
+		},
+		{
+			"projects/foo/datasets/bar/tables/baz/zip/zam/zoomie",
+			"projects/foo/datasets/bar/tables/baz",
+		},
+		{
+			"projects/foo/datasets/bar/tables/baz/_default",
+			"projects/foo/datasets/bar/tables/baz",
+		},
+	}
+
+	for _, tc := range testCases {
+		got := tableParentFromStreamName(tc.in)
+		if got != tc.want {
+			t.Errorf("mismatch on %s: got %s want %s", tc.in, got, tc.want)
+		}
+	}
+}
diff --git a/bigquery/storage/managedwriter/managed_stream.go b/bigquery/storage/managedwriter/managed_stream.go
new file mode 100644
index 00000000000..93854911300
--- /dev/null
+++ b/bigquery/storage/managedwriter/managed_stream.go
@@ -0,0 +1,142 @@
+// Copyright 2021 Google LLC
+//
+// 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
+//
+//     https://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 managedwriter
+
+import (
+	"context"
+
+	storagepb "google.golang.org/genproto/googleapis/cloud/bigquery/storage/v1beta2"
+	"google.golang.org/protobuf/types/known/wrapperspb"
+)
+
+// StreamType indicates the type of stream this write client is managing.
+type StreamType string
+
+var (
+	// DefaultStream most closely mimics the legacy bigquery
+	// tabledata.insertAll semantics.  Successful inserts are
+	// committed immediately, and there's no tracking offsets as
+	// all writes go into a "default" stream that always exists
+	// for a table.
+	DefaultStream StreamType = "DEFAULT"
+
+	// CommittedStream appends data immediately, but creates a
+	// discrete stream for the work so that offset tracking can
+	// be used to track writes.
+	CommittedStream StreamType = "COMMITTED"
+
+	// BufferedStream is a form of checkpointed stream, that allows
+	// you to advance the offset of visible rows via Flush operations.
+	BufferedStream StreamType = "BUFFERED"
+
+	// PendingStream is a stream in which no data is made visible to
+	// readers until the stream is finalized and committed explicitly.
+	PendingStream StreamType = "PENDING"
+)
+
+func streamTypeToEnum(t StreamType) storagepb.WriteStream_Type {
+	switch t {
+	case CommittedStream:
+		return storagepb.WriteStream_COMMITTED
+	case PendingStream:
+		return storagepb.WriteStream_PENDING
+	case BufferedStream:
+		return storagepb.WriteStream_BUFFERED
+	default:
+		return storagepb.WriteStream_TYPE_UNSPECIFIED
+	}
+}
+
+// ManagedStream is the abstraction over a single write stream.
+type ManagedStream struct {
+	streamSettings   *streamSettings
+	destinationTable string
+	c                *Client
+}
+
+// streamSettings govern behavior of the append stream RPCs.
+type streamSettings struct {
+
+	// streamID contains the reference to the destination stream.
+	streamID string
+
+	// streamType governs behavior of the client, such as how
+	// offset handling is managed.
+	streamType StreamType
+
+	// MaxInflightRequests governs how many unacknowledged
+	// append writes can be outstanding into the system.
+	MaxInflightRequests int
+
+	// MaxInflightBytes governs how many unacknowledged
+	// request bytes can be outstanding into the system.
+	MaxInflightBytes int
+
+	// TracePrefix sets a suitable prefix for the trace ID set on
+	// append requests.  Useful for diagnostic purposes.
+	TracePrefix string
+}
+
+func defaultStreamSettings() *streamSettings {
+	return &streamSettings{
+		streamType:          DefaultStream,
+		MaxInflightRequests: 1000,
+		MaxInflightBytes:    0,
+		TracePrefix:         "defaultManagedWriter",
+	}
+}
+
+// StreamName returns the corresponding write stream ID being managed by this writer.
+func (ms *ManagedStream) StreamName() string {
+	return ms.streamSettings.streamID
+}
+
+// StreamType returns the configured type for this stream.
+func (ms *ManagedStream) StreamType() StreamType {
+	return ms.streamSettings.streamType
+}
+
+// FlushRows advances the offset at which rows in a BufferedStream are visible.  Calling
+// this method for other stream types yields an error.
+func (ms *ManagedStream) FlushRows(ctx context.Context, offset int64) (int64, error) {
+	req := &storagepb.FlushRowsRequest{
+		WriteStream: ms.streamSettings.streamID,
+		Offset: &wrapperspb.Int64Value{
+			Value: offset,
+		},
+	}
+	resp, err := ms.c.rawClient.FlushRows(ctx, req)
+	if err != nil {
+		return 0, err
+	}
+	return resp.GetOffset(), nil
+}
+
+// Finalize is used to mark a stream as complete, and thus ensure no further data can
+// be appended to the stream.  You cannot finalize a DefaultStream, as it always exists.
+//
+// Finalizing does not advance the current offset of a BufferedStream, nor does it commit
+// data in a PendingStream.
+func (ms *ManagedStream) Finalize(ctx context.Context) (int64, error) {
+	// TODO: consider blocking for in-flight appends once we have an appendStream plumbed in.
+	req := &storagepb.FinalizeWriteStreamRequest{
+		Name: ms.streamSettings.streamID,
+	}
+	resp, err := ms.c.rawClient.FinalizeWriteStream(ctx, req)
+	if err != nil {
+		return 0, err
+	}
+	return resp.GetRowCount(), nil
+}
diff --git a/bigquery/storage/managedwriter/writer_option.go b/bigquery/storage/managedwriter/writer_option.go
new file mode 100644
index 00000000000..e0032788436
--- /dev/null
+++ b/bigquery/storage/managedwriter/writer_option.go
@@ -0,0 +1,69 @@
+// Copyright 2021 Google LLC
+//
+// 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
+//
+//     https://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 managedwriter
+
+// WriterOption is used to configure a ManagedWriteClient.
+type WriterOption func(*ManagedStream)
+
+// WithType sets the write type of the new writer.
+func WithType(st StreamType) WriterOption {
+	return func(ms *ManagedStream) {
+		ms.streamSettings.streamType = st
+	}
+}
+
+// WithStreamName allows users to set the stream name this writer will
+// append to explicitly.  By default, the managed client will create the
+// stream when instantiated.
+//
+// Note:  Supplying this option causes other options such as WithStreamType
+// and WithDestinationTable to be ignored.
+func WithStreamName(name string) WriterOption {
+	return func(ms *ManagedStream) {
+		ms.streamSettings.streamID = name
+	}
+}
+
+// WithDestinationTable specifies the destination table to which a created
+// stream will append rows.  Format of the table:
+//
+//   projects/{projectid}/datasets/{dataset}/tables/{table}
+func WithDestinationTable(destTable string) WriterOption {
+	return func(ms *ManagedStream) {
+		ms.destinationTable = destTable
+	}
+}
+
+// WithMaxInflightRequests bounds the inflight appends on the write connection.
+func WithMaxInflightRequests(n int) WriterOption {
+	return func(ms *ManagedStream) {
+		ms.streamSettings.MaxInflightRequests = n
+	}
+}
+
+// WithMaxInflightBytes bounds the inflight append request bytes on the write connection.
+func WithMaxInflightBytes(n int) WriterOption {
+	return func(ms *ManagedStream) {
+		ms.streamSettings.MaxInflightBytes = n
+	}
+}
+
+// WithTracePrefix allows instruments requests to the service with a custom trace prefix.
+// This is generally for diagnostic purposes only.
+func WithTracePrefix(prefix string) WriterOption {
+	return func(ms *ManagedStream) {
+		ms.streamSettings.TracePrefix = prefix
+	}
+}
diff --git a/bigquery/storage/managedwriter/writer_option_test.go b/bigquery/storage/managedwriter/writer_option_test.go
new file mode 100644
index 00000000000..c1e754fed1a
--- /dev/null
+++ b/bigquery/storage/managedwriter/writer_option_test.go
@@ -0,0 +1,117 @@
+// Copyright 2021 Google LLC
+//
+// 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
+//
+//     https://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 managedwriter
+
+import (
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func TestWriterOptions(t *testing.T) {
+
+	testCases := []struct {
+		desc    string
+		options []WriterOption
+		want    *ManagedStream
+	}{
+		{
+			desc:    "WithType",
+			options: []WriterOption{WithType(BufferedStream)},
+			want: func() *ManagedStream {
+				ms := &ManagedStream{
+					streamSettings: defaultStreamSettings(),
+				}
+				ms.streamSettings.streamType = BufferedStream
+				return ms
+			}(),
+		},
+		{
+			desc:    "WithMaxInflightRequests",
+			options: []WriterOption{WithMaxInflightRequests(2)},
+			want: func() *ManagedStream {
+				ms := &ManagedStream{
+					streamSettings: defaultStreamSettings(),
+				}
+				ms.streamSettings.MaxInflightRequests = 2
+				return ms
+			}(),
+		},
+		{
+			desc:    "WithMaxInflightBytes",
+			options: []WriterOption{WithMaxInflightBytes(5)},
+			want: func() *ManagedStream {
+				ms := &ManagedStream{
+					streamSettings: defaultStreamSettings(),
+				}
+				ms.streamSettings.MaxInflightBytes = 5
+				return ms
+			}(),
+		},
+		{
+			desc:    "WithTracePrefix",
+			options: []WriterOption{WithTracePrefix("foo")},
+			want: func() *ManagedStream {
+				ms := &ManagedStream{
+					streamSettings: defaultStreamSettings(),
+				}
+				ms.streamSettings.TracePrefix = "foo"
+				return ms
+			}(),
+		},
+		{
+			desc:    "WithDestinationTable",
+			options: []WriterOption{WithDestinationTable("foo")},
+			want: func() *ManagedStream {
+				ms := &ManagedStream{
+					streamSettings:   defaultStreamSettings(),
+					destinationTable: "foo",
+				}
+				return ms
+			}(),
+		},
+		{
+			desc: "multiple",
+			options: []WriterOption{
+				WithType(PendingStream),
+				WithMaxInflightBytes(5),
+				WithTracePrefix("pre"),
+			},
+			want: func() *ManagedStream {
+				ms := &ManagedStream{
+					streamSettings: defaultStreamSettings(),
+				}
+				ms.streamSettings.MaxInflightBytes = 5
+				ms.streamSettings.streamType = PendingStream
+				ms.streamSettings.TracePrefix = "pre"
+				return ms
+			}(),
+		},
+	}
+
+	for _, tc := range testCases {
+		got := &ManagedStream{
+			streamSettings: defaultStreamSettings(),
+		}
+		for _, o := range tc.options {
+			o(got)
+		}
+
+		if diff := cmp.Diff(got, tc.want,
+			cmp.AllowUnexported(ManagedStream{}, streamSettings{})); diff != "" {
+			t.Errorf("diff in case (%s):\n%v", tc.desc, diff)
+		}
+	}
+}