diff --git a/client/client_test.go b/client/client_test.go
index 9c9738c4..4ae64959 100644
--- a/client/client_test.go
+++ b/client/client_test.go
@@ -94,6 +94,7 @@ func TestIntegration(t *testing.T) {
 		testExtraHosts,
 		testNetworkMode,
 		testFrontendMetadataReturn,
+		testFrontendUseSolveResults,
 		testSSHMount,
 		testStdinClosed,
 		testHostnameLookup,
@@ -1461,6 +1462,72 @@ func testFrontendMetadataReturn(t *testing.T, sb integration.Sandbox) {
 	checkAllReleasable(t, c, sb, true)
 }
 
+func testFrontendUseSolveResults(t *testing.T, sb integration.Sandbox) {
+	requiresLinux(t)
+	c, err := New(context.TODO(), sb.Address())
+	require.NoError(t, err)
+	defer c.Close()
+
+	frontend := func(ctx context.Context, c gateway.Client) (*gateway.Result, error) {
+		st := llb.Scratch().File(
+			llb.Mkfile("foo", 0600, []byte("data")),
+		)
+
+		def, err := st.Marshal()
+		if err != nil {
+			return nil, err
+		}
+
+		res, err := c.Solve(ctx, gateway.SolveRequest{
+			Definition: def.ToPB(),
+		})
+		if err != nil {
+			return nil, err
+		}
+
+		ref, err := res.SingleRef()
+		if err != nil {
+			return nil, err
+		}
+
+		st2, err := ref.ToState()
+		if err != nil {
+			return nil, err
+		}
+
+		st = llb.Scratch().File(
+			llb.Copy(st2, "foo", "foo2"),
+		)
+
+		def, err = st.Marshal()
+		if err != nil {
+			return nil, err
+		}
+
+		return c.Solve(ctx, gateway.SolveRequest{
+			Definition: def.ToPB(),
+		})
+	}
+
+	destDir, err := ioutil.TempDir("", "buildkit")
+	require.NoError(t, err)
+	defer os.RemoveAll(destDir)
+
+	_, err = c.Build(context.TODO(), SolveOpt{
+		Exports: []ExportEntry{
+			{
+				Type:      ExporterLocal,
+				OutputDir: destDir,
+			},
+		},
+	}, "", frontend, nil)
+	require.NoError(t, err)
+
+	dt, err := ioutil.ReadFile(filepath.Join(destDir, "foo2"))
+	require.NoError(t, err)
+	require.Equal(t, dt, []byte("data"))
+}
+
 func testExporterTargetExists(t *testing.T, sb integration.Sandbox) {
 	requiresLinux(t)
 	c, err := New(context.TODO(), sb.Address())
diff --git a/client/llb/definition.go b/client/llb/definition.go
new file mode 100644
index 00000000..643a7f66
--- /dev/null
+++ b/client/llb/definition.go
@@ -0,0 +1,158 @@
+package llb
+
+import (
+	"github.com/moby/buildkit/solver/pb"
+	digest "github.com/opencontainers/go-digest"
+	specs "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
+)
+
+// DefinitionOp implements llb.Vertex using a marshalled definition.
+//
+// For example, after marshalling a LLB state and sending over the wire, the
+// LLB state can be reconstructed from the definition.
+type DefinitionOp struct {
+	MarshalCache
+	ops       map[digest.Digest]*pb.Op
+	defs      map[digest.Digest][]byte
+	metas     map[digest.Digest]pb.OpMetadata
+	platforms map[digest.Digest]*specs.Platform
+	dgst      digest.Digest
+	index     pb.OutputIndex
+}
+
+// NewDefinitionOp returns a new operation from a marshalled definition.
+func NewDefinitionOp(def *pb.Definition) (*DefinitionOp, error) {
+	ops := make(map[digest.Digest]*pb.Op)
+	defs := make(map[digest.Digest][]byte)
+
+	var dgst digest.Digest
+
+	for _, dt := range def.Def {
+		var op pb.Op
+		if err := (&op).Unmarshal(dt); err != nil {
+			return nil, errors.Wrap(err, "failed to parse llb proto op")
+		}
+		dgst = digest.FromBytes(dt)
+		ops[dgst] = &op
+		defs[dgst] = dt
+	}
+
+	if dgst != "" {
+		dgst = ops[dgst].Inputs[0].Digest
+	}
+
+	return &DefinitionOp{
+		ops:       ops,
+		defs:      defs,
+		metas:     def.Metadata,
+		platforms: make(map[digest.Digest]*specs.Platform),
+		dgst:      dgst,
+	}, nil
+}
+
+func (d *DefinitionOp) ToInput(c *Constraints) (*pb.Input, error) {
+	return d.Output().ToInput(c)
+}
+
+func (d *DefinitionOp) Vertex() Vertex {
+	return d
+}
+
+func (d *DefinitionOp) Validate() error {
+	// Scratch state has no digest, ops or metas.
+	if d.dgst == "" {
+		return nil
+	}
+
+	if len(d.ops) == 0 || len(d.defs) == 0 || len(d.metas) == 0 {
+		return errors.Errorf("invalid definition op with no ops %d %d", len(d.ops), len(d.metas))
+	}
+
+	_, ok := d.ops[d.dgst]
+	if !ok {
+		return errors.Errorf("invalid definition op with unknown op %q", d.dgst)
+	}
+
+	_, ok = d.defs[d.dgst]
+	if !ok {
+		return errors.Errorf("invalid definition op with unknown def %q", d.dgst)
+	}
+
+	_, ok = d.metas[d.dgst]
+	if !ok {
+		return errors.Errorf("invalid definition op with unknown metas %q", d.dgst)
+	}
+
+	// It is possible for d.index >= len(d.ops[d.dgst]) when depending on scratch
+	// images.
+	if d.index < 0 {
+		return errors.Errorf("invalid definition op with invalid index")
+	}
+
+	return nil
+}
+
+func (d *DefinitionOp) Marshal(c *Constraints) (digest.Digest, []byte, *pb.OpMetadata, error) {
+	if d.dgst == "" {
+		return "", nil, nil, errors.Errorf("cannot marshal empty definition op")
+	}
+
+	if err := d.Validate(); err != nil {
+		return "", nil, nil, err
+	}
+
+	meta := d.metas[d.dgst]
+	return d.dgst, d.defs[d.dgst], &meta, nil
+
+}
+
+func (d *DefinitionOp) Output() Output {
+	if d.dgst == "" {
+		return nil
+	}
+
+	return &output{vertex: d, platform: d.platform(), getIndex: func() (pb.OutputIndex, error) {
+		return d.index, nil
+	}}
+}
+
+func (d *DefinitionOp) Inputs() []Output {
+	if d.dgst == "" {
+		return nil
+	}
+
+	var inputs []Output
+
+	op := d.ops[d.dgst]
+	for _, input := range op.Inputs {
+		vtx := &DefinitionOp{
+			ops:   d.ops,
+			defs:  d.defs,
+			metas: d.metas,
+			dgst:  input.Digest,
+			index: input.Index,
+		}
+		inputs = append(inputs, &output{vertex: vtx, platform: d.platform(), getIndex: func() (pb.OutputIndex, error) {
+			return pb.OutputIndex(vtx.index), nil
+		}})
+	}
+
+	return inputs
+}
+
+func (d *DefinitionOp) platform() *specs.Platform {
+	platform, ok := d.platforms[d.dgst]
+	if ok {
+		return platform
+	}
+
+	op := d.ops[d.dgst]
+	if op.Platform != nil {
+		spec := op.Platform.Spec()
+		platform = &spec
+	}
+
+	d.platforms[d.dgst] = platform
+	return platform
+}
diff --git a/client/llb/definition_test.go b/client/llb/definition_test.go
new file mode 100644
index 00000000..6a77a538
--- /dev/null
+++ b/client/llb/definition_test.go
@@ -0,0 +1,65 @@
+package llb
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/containerd/containerd/platforms"
+	"github.com/stretchr/testify/require"
+)
+
+func TestDefinitionEquivalence(t *testing.T) {
+	for _, tc := range []struct {
+		name  string
+		state State
+	}{
+		{"scratch", Scratch()},
+		{"image op", Image("ref")},
+		{"exec op", Image("ref").Run(Shlex("args")).Root()},
+		{"local op", Local("name")},
+		{"git op", Git("remote", "ref")},
+		{"http op", HTTP("url")},
+		{"file op", Scratch().File(Mkdir("foo", 0600).Mkfile("foo/bar", 0600, []byte("data")).Copy(Scratch(), "src", "dst"))},
+		{"platform constraint", Image("ref", LinuxArm64)},
+	} {
+		tc := tc
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			def, err := tc.state.Marshal()
+			require.NoError(t, err)
+
+			op, err := NewDefinitionOp(def.ToPB())
+			require.NoError(t, err)
+
+			err = op.Validate()
+			require.NoError(t, err)
+
+			st2 := NewState(op.Output())
+
+			def2, err := st2.Marshal()
+			require.NoError(t, err)
+			require.Equal(t, len(def.Def), len(def2.Def))
+			require.Equal(t, len(def.Metadata), len(def2.Metadata))
+
+			for i := 0; i < len(def.Def); i++ {
+				res := bytes.Compare(def.Def[i], def2.Def[i])
+				require.Equal(t, res, 0)
+			}
+
+			for dgst := range def.Metadata {
+				require.Equal(t, def.Metadata[dgst], def2.Metadata[dgst])
+			}
+
+			expectedPlatform := tc.state.GetPlatform()
+			actualPlatform := st2.GetPlatform()
+
+			if expectedPlatform == nil && actualPlatform != nil {
+				defaultPlatform := platforms.Normalize(platforms.DefaultSpec())
+				expectedPlatform = &defaultPlatform
+			}
+
+			require.Equal(t, expectedPlatform, actualPlatform)
+		})
+	}
+}
diff --git a/client/llb/imagemetaresolver/resolver.go b/client/llb/imagemetaresolver/resolver.go
index 201f8cd7..0dbd4737 100644
--- a/client/llb/imagemetaresolver/resolver.go
+++ b/client/llb/imagemetaresolver/resolver.go
@@ -10,7 +10,6 @@ import (
 	"github.com/containerd/containerd/remotes/docker"
 	"github.com/docker/docker/pkg/locker"
 	"github.com/moby/buildkit/client/llb"
-	gw "github.com/moby/buildkit/frontend/gateway/client"
 	"github.com/moby/buildkit/util/contentutil"
 	"github.com/moby/buildkit/util/imageutil"
 	digest "github.com/opencontainers/go-digest"
@@ -72,7 +71,7 @@ type resolveResult struct {
 	dgst   digest.Digest
 }
 
-func (imr *imageMetaResolver) ResolveImageConfig(ctx context.Context, ref string, opt gw.ResolveImageConfigOpt) (digest.Digest, []byte, error) {
+func (imr *imageMetaResolver) ResolveImageConfig(ctx context.Context, ref string, opt llb.ResolveImageConfigOpt) (digest.Digest, []byte, error) {
 	imr.locker.Lock(ref)
 	defer imr.locker.Unlock(ref)
 
diff --git a/client/llb/resolver.go b/client/llb/resolver.go
index d670a991..73d89e19 100644
--- a/client/llb/resolver.go
+++ b/client/llb/resolver.go
@@ -3,8 +3,8 @@ package llb
 import (
 	"context"
 
-	gw "github.com/moby/buildkit/frontend/gateway/client"
 	digest "github.com/opencontainers/go-digest"
+	specs "github.com/opencontainers/image-spec/specs-go/v1"
 )
 
 // WithMetaResolver adds a metadata resolver to an image
@@ -16,5 +16,11 @@ func WithMetaResolver(mr ImageMetaResolver) ImageOption {
 
 // ImageMetaResolver can resolve image config metadata from a reference
 type ImageMetaResolver interface {
-	ResolveImageConfig(ctx context.Context, ref string, opt gw.ResolveImageConfigOpt) (digest.Digest, []byte, error)
+	ResolveImageConfig(ctx context.Context, ref string, opt ResolveImageConfigOpt) (digest.Digest, []byte, error)
+}
+
+type ResolveImageConfigOpt struct {
+	Platform    *specs.Platform
+	ResolveMode string
+	LogName     string
 }
diff --git a/client/llb/source.go b/client/llb/source.go
index 52d40be8..662966e3 100644
--- a/client/llb/source.go
+++ b/client/llb/source.go
@@ -9,7 +9,6 @@ import (
 	"strings"
 
 	"github.com/docker/distribution/reference"
-	gw "github.com/moby/buildkit/frontend/gateway/client"
 	"github.com/moby/buildkit/solver/pb"
 	"github.com/moby/buildkit/util/apicaps"
 	digest "github.com/opencontainers/go-digest"
@@ -119,7 +118,7 @@ func Image(ref string, opts ...ImageOption) State {
 		src.err = err
 	}
 	if info.metaResolver != nil {
-		_, dt, err := info.metaResolver.ResolveImageConfig(context.TODO(), ref, gw.ResolveImageConfigOpt{
+		_, dt, err := info.metaResolver.ResolveImageConfig(context.TODO(), ref, ResolveImageConfigOpt{
 			Platform:    info.Constraints.Platform,
 			ResolveMode: info.resolveMode.String(),
 		})
diff --git a/frontend/dockerfile/dockerfile2llb/convert.go b/frontend/dockerfile/dockerfile2llb/convert.go
index 2077eb8a..b911938a 100644
--- a/frontend/dockerfile/dockerfile2llb/convert.go
+++ b/frontend/dockerfile/dockerfile2llb/convert.go
@@ -22,7 +22,6 @@ import (
 	"github.com/moby/buildkit/frontend/dockerfile/instructions"
 	"github.com/moby/buildkit/frontend/dockerfile/parser"
 	"github.com/moby/buildkit/frontend/dockerfile/shell"
-	gw "github.com/moby/buildkit/frontend/gateway/client"
 	"github.com/moby/buildkit/solver/pb"
 	"github.com/moby/buildkit/util/apicaps"
 	"github.com/moby/buildkit/util/system"
@@ -240,7 +239,7 @@ func Dockerfile2LLB(ctx context.Context, dt []byte, opt ConvertOpt) (*llb.State,
 							prefix += platforms.Format(*platform) + " "
 						}
 						prefix += "internal]"
-						dgst, dt, err := metaResolver.ResolveImageConfig(ctx, d.stage.BaseName, gw.ResolveImageConfigOpt{
+						dgst, dt, err := metaResolver.ResolveImageConfig(ctx, d.stage.BaseName, llb.ResolveImageConfigOpt{
 							Platform:    platform,
 							ResolveMode: opt.ImageResolveMode.String(),
 							LogName:     fmt.Sprintf("%s load metadata for %s", prefix, d.stage.BaseName),
diff --git a/frontend/dockerfile/dockerfile_test.go b/frontend/dockerfile/dockerfile_test.go
index e7f05d50..efe70493 100644
--- a/frontend/dockerfile/dockerfile_test.go
+++ b/frontend/dockerfile/dockerfile_test.go
@@ -31,6 +31,7 @@ import (
 	"github.com/moby/buildkit/client/llb"
 	"github.com/moby/buildkit/frontend/dockerfile/builder"
 	"github.com/moby/buildkit/frontend/dockerfile/dockerfile2llb"
+	gateway "github.com/moby/buildkit/frontend/gateway/client"
 	"github.com/moby/buildkit/identity"
 	"github.com/moby/buildkit/session"
 	"github.com/moby/buildkit/session/upload/uploadprovider"
@@ -93,6 +94,7 @@ var allTests = []integration.Test{
 	testEnvEmptyFormatting,
 	testCacheMultiPlatformImportExport,
 	testOnBuildCleared,
+	testFrontendUseForwardedSolveResults,
 }
 
 var fileOpTests = []integration.Test{
@@ -4400,6 +4402,77 @@ COPY foo bar
 	require.Equal(t, string(dt), "contents")
 }
 
+func testFrontendUseForwardedSolveResults(t *testing.T, sb integration.Sandbox) {
+	c, err := client.New(context.TODO(), sb.Address())
+	require.NoError(t, err)
+	defer c.Close()
+
+	dockerfile := []byte(`
+FROM scratch
+COPY foo foo2
+`)
+	dir, err := tmpdir(
+		fstest.CreateFile("Dockerfile", dockerfile, 0600),
+		fstest.CreateFile("foo", []byte("data"), 0600),
+	)
+	require.NoError(t, err)
+	defer os.RemoveAll(dir)
+
+	frontend := func(ctx context.Context, c gateway.Client) (*gateway.Result, error) {
+		res, err := c.Solve(ctx, gateway.SolveRequest{
+			Frontend: "dockerfile.v0",
+		})
+		if err != nil {
+			return nil, err
+		}
+
+		ref, err := res.SingleRef()
+		if err != nil {
+			return nil, err
+		}
+
+		st2, err := ref.ToState()
+		if err != nil {
+			return nil, err
+		}
+
+		st := llb.Scratch().File(
+			llb.Copy(st2, "foo2", "foo3"),
+		)
+
+		def, err := st.Marshal()
+		if err != nil {
+			return nil, err
+		}
+
+		return c.Solve(ctx, gateway.SolveRequest{
+			Definition: def.ToPB(),
+		})
+	}
+
+	destDir, err := ioutil.TempDir("", "buildkit")
+	require.NoError(t, err)
+	defer os.RemoveAll(destDir)
+
+	_, err = c.Build(context.TODO(), client.SolveOpt{
+		Exports: []client.ExportEntry{
+			{
+				Type:      client.ExporterLocal,
+				OutputDir: destDir,
+			},
+		},
+		LocalDirs: map[string]string{
+			builder.DefaultLocalNameDockerfile: dir,
+			builder.DefaultLocalNameContext:    dir,
+		},
+	}, "", frontend, nil)
+	require.NoError(t, err)
+
+	dt, err := ioutil.ReadFile(filepath.Join(destDir, "foo3"))
+	require.NoError(t, err)
+	require.Equal(t, dt, []byte("data"))
+}
+
 func tmpdir(appliers ...fstest.Applier) (string, error) {
 	tmpdir, err := ioutil.TempDir("", "buildkit-dockerfile")
 	if err != nil {
diff --git a/frontend/frontend.go b/frontend/frontend.go
index 27c1d81a..573b1927 100644
--- a/frontend/frontend.go
+++ b/frontend/frontend.go
@@ -6,6 +6,7 @@ import (
 
 	"github.com/moby/buildkit/cache"
 	"github.com/moby/buildkit/client"
+	"github.com/moby/buildkit/client/llb"
 	"github.com/moby/buildkit/executor"
 	gw "github.com/moby/buildkit/frontend/gateway/client"
 	digest "github.com/opencontainers/go-digest"
@@ -17,7 +18,7 @@ type Frontend interface {
 
 type FrontendLLBBridge interface {
 	Solve(ctx context.Context, req SolveRequest) (*Result, error)
-	ResolveImageConfig(ctx context.Context, ref string, opt gw.ResolveImageConfigOpt) (digest.Digest, []byte, error)
+	ResolveImageConfig(ctx context.Context, ref string, opt llb.ResolveImageConfigOpt) (digest.Digest, []byte, error)
 	Exec(ctx context.Context, meta executor.Meta, rootfs cache.ImmutableRef, stdin io.ReadCloser, stdout, stderr io.WriteCloser) error
 }
 
diff --git a/frontend/gateway/client/client.go b/frontend/gateway/client/client.go
index 02c9c949..e8f5cbe5 100644
--- a/frontend/gateway/client/client.go
+++ b/frontend/gateway/client/client.go
@@ -3,6 +3,7 @@ package client
 import (
 	"context"
 
+	"github.com/moby/buildkit/client/llb"
 	"github.com/moby/buildkit/solver/pb"
 	"github.com/moby/buildkit/util/apicaps"
 	digest "github.com/opencontainers/go-digest"
@@ -12,11 +13,12 @@ import (
 
 type Client interface {
 	Solve(ctx context.Context, req SolveRequest) (*Result, error)
-	ResolveImageConfig(ctx context.Context, ref string, opt ResolveImageConfigOpt) (digest.Digest, []byte, error)
+	ResolveImageConfig(ctx context.Context, ref string, opt llb.ResolveImageConfigOpt) (digest.Digest, []byte, error)
 	BuildOpts() BuildOpts
 }
 
 type Reference interface {
+	ToState() (llb.State, error)
 	ReadFile(ctx context.Context, req ReadRequest) ([]byte, error)
 	StatFile(ctx context.Context, req StatRequest) (*fstypes.Stat, error)
 	ReadDir(ctx context.Context, req ReadDirRequest) ([]*fstypes.Stat, error)
@@ -68,9 +70,3 @@ type BuildOpts struct {
 	LLBCaps   apicaps.CapSet
 	Caps      apicaps.CapSet
 }
-
-type ResolveImageConfigOpt struct {
-	Platform    *specs.Platform
-	ResolveMode string
-	LogName     string
-}
diff --git a/frontend/gateway/forwarder/forward.go b/frontend/gateway/forwarder/forward.go
index 0bb0cf53..70899d8d 100644
--- a/frontend/gateway/forwarder/forward.go
+++ b/frontend/gateway/forwarder/forward.go
@@ -7,6 +7,7 @@ import (
 	"github.com/moby/buildkit/cache"
 	cacheutil "github.com/moby/buildkit/cache/util"
 	clienttypes "github.com/moby/buildkit/client"
+	"github.com/moby/buildkit/client/llb"
 	"github.com/moby/buildkit/frontend"
 	"github.com/moby/buildkit/frontend/gateway/client"
 	gwpb "github.com/moby/buildkit/frontend/gateway/pb"
@@ -54,12 +55,18 @@ func (c *bridgeClient) Solve(ctx context.Context, req client.SolveRequest) (*cli
 	cRes := &client.Result{}
 	c.mu.Lock()
 	for k, r := range res.Refs {
-		rr := &ref{r}
+		rr, err := newRef(r)
+		if err != nil {
+			return nil, err
+		}
 		c.refs = append(c.refs, rr)
 		cRes.AddRef(k, rr)
 	}
 	if r := res.Ref; r != nil {
-		rr := &ref{r}
+		rr, err := newRef(r)
+		if err != nil {
+			return nil, err
+		}
 		c.refs = append(c.refs, rr)
 		cRes.SetRef(rr)
 	}
@@ -131,6 +138,24 @@ func (c *bridgeClient) discard(err error) {
 
 type ref struct {
 	solver.CachedResult
+	def *opspb.Definition
+}
+
+func newRef(r solver.CachedResult) (*ref, error) {
+	wref, ok := r.Sys().(*worker.WorkerRef)
+	if !ok {
+		return nil, errors.Errorf("invalid ref: %T", r.Sys())
+	}
+
+	return &ref{CachedResult: r, def: wref.Definition}, nil
+}
+
+func (r *ref) ToState() (st llb.State, err error) {
+	defop, err := llb.NewDefinitionOp(r.def)
+	if err != nil {
+		return st, err
+	}
+	return llb.NewState(defop), nil
 }
 
 func (r *ref) ReadFile(ctx context.Context, req client.ReadRequest) ([]byte, error) {
diff --git a/frontend/gateway/gateway.go b/frontend/gateway/gateway.go
index 5587f45e..f7b0f09d 100644
--- a/frontend/gateway/gateway.go
+++ b/frontend/gateway/gateway.go
@@ -21,7 +21,6 @@ import (
 	"github.com/moby/buildkit/executor"
 	"github.com/moby/buildkit/exporter/containerimage/exptypes"
 	"github.com/moby/buildkit/frontend"
-	gw "github.com/moby/buildkit/frontend/gateway/client"
 	pb "github.com/moby/buildkit/frontend/gateway/pb"
 	"github.com/moby/buildkit/identity"
 	"github.com/moby/buildkit/session"
@@ -113,7 +112,7 @@ func (gf *gatewayFrontend) Solve(ctx context.Context, llbBridge frontend.Fronten
 			return nil, err
 		}
 
-		dgst, config, err := llbBridge.ResolveImageConfig(ctx, reference.TagNameOnly(sourceRef).String(), gw.ResolveImageConfigOpt{})
+		dgst, config, err := llbBridge.ResolveImageConfig(ctx, reference.TagNameOnly(sourceRef).String(), llb.ResolveImageConfigOpt{})
 		if err != nil {
 			return nil, err
 		}
@@ -405,7 +404,7 @@ func (lbf *llbBridgeForwarder) ResolveImageConfig(ctx context.Context, req *pb.R
 			OSFeatures:   p.OSFeatures,
 		}
 	}
-	dgst, dt, err := lbf.llbBridge.ResolveImageConfig(ctx, req.Ref, gw.ResolveImageConfigOpt{
+	dgst, dt, err := lbf.llbBridge.ResolveImageConfig(ctx, req.Ref, llb.ResolveImageConfigOpt{
 		Platform:    platform,
 		ResolveMode: req.ResolveMode,
 		LogName:     req.LogName,
@@ -466,6 +465,7 @@ func (lbf *llbBridgeForwarder) Solve(ctx context.Context, req *pb.SolveRequest)
 	lbf.mu.Lock()
 	if res.Refs != nil {
 		ids := make(map[string]string, len(res.Refs))
+		defs := make(map[string]*opspb.Definition, len(res.Refs))
 		for k, ref := range res.Refs {
 			id := identity.NewID()
 			if ref == nil {
@@ -474,28 +474,43 @@ func (lbf *llbBridgeForwarder) Solve(ctx context.Context, req *pb.SolveRequest)
 				lbf.refs[id] = ref
 			}
 			ids[k] = id
+
+			wref, ok := ref.Sys().(*worker.WorkerRef)
+			if !ok {
+				return nil, errors.Errorf("invalid ref: %T", ref.Sys())
+			}
+			defs[k] = wref.Definition
 		}
 
 		if req.AllowResultArrayRef {
 			refMap := make(map[string]*pb.Ref, len(res.Refs))
 			for k, id := range ids {
-				refMap[k] = pb.NewRef(id)
+				refMap[k] = pb.NewRef(id, defs[k])
 			}
 			pbRes.Result = &pb.Result_Refs{Refs: &pb.RefMap{Refs: refMap}}
 		} else {
 			pbRes.Result = &pb.Result_RefsDeprecated{RefsDeprecated: &pb.RefMapDeprecated{Refs: ids}}
 		}
 	} else {
+		ref := res.Ref
 		id := identity.NewID()
-		if res.Ref == nil {
+
+		var def *opspb.Definition
+		if ref == nil {
 			id = ""
 		} else {
-			lbf.refs[id] = res.Ref
+			wref, ok := ref.Sys().(*worker.WorkerRef)
+			if !ok {
+				return nil, errors.Errorf("invalid ref: %T", ref.Sys())
+			}
+			def = wref.Definition
+
+			lbf.refs[id] = ref
 		}
 		defaultID = id
 
 		if req.AllowResultArrayRef {
-			pbRes.Result = &pb.Result_Ref{Ref: pb.NewRef(id)}
+			pbRes.Result = &pb.Result_Ref{Ref: pb.NewRef(id, def)}
 		} else {
 			pbRes.Result = &pb.Result_RefDeprecated{RefDeprecated: id}
 		}
diff --git a/frontend/gateway/grpcclient/client.go b/frontend/gateway/grpcclient/client.go
index 12c7c754..1ad7daeb 100644
--- a/frontend/gateway/grpcclient/client.go
+++ b/frontend/gateway/grpcclient/client.go
@@ -10,6 +10,7 @@ import (
 	"time"
 
 	"github.com/gogo/googleapis/google/rpc"
+	"github.com/moby/buildkit/client/llb"
 	"github.com/moby/buildkit/frontend/gateway/client"
 	pb "github.com/moby/buildkit/frontend/gateway/pb"
 	opspb "github.com/moby/buildkit/solver/pb"
@@ -68,15 +69,15 @@ func current() (GrpcClient, error) {
 	return New(ctx, opts(), sessionID(), product(), pb.NewLLBBridgeClient(conn), workers())
 }
 
-func convertRef(ref client.Reference) (string, error) {
+func convertRef(ref client.Reference) (*pb.Ref, error) {
 	if ref == nil {
-		return "", nil
+		return &pb.Ref{}, nil
 	}
 	r, ok := ref.(*reference)
 	if !ok {
-		return "", errors.Errorf("invalid return reference type %T", ref)
+		return nil, errors.Errorf("invalid return reference type %T", ref)
 	}
-	return r.id, nil
+	return &pb.Ref{Ids: []string{r.id}, Defs: []*opspb.Definition{r.def}}, nil
 }
 
 func RunFromEnvironment(ctx context.Context, f client.BuildFunc) error {
@@ -108,34 +109,47 @@ func (c *grpcClient) Run(ctx context.Context, f client.BuildFunc) (retError erro
 					if c.caps.Supports(pb.CapProtoRefArray) == nil {
 						m := map[string]*pb.Ref{}
 						for k, r := range res.Refs {
-							id, err := convertRef(r)
+							pbRef, err := convertRef(r)
 							if err != nil {
 								retError = err
 								continue
 							}
-							m[k] = pb.NewRef(id)
+							m[k] = pbRef
 						}
 						pbRes.Result = &pb.Result_Refs{Refs: &pb.RefMap{Refs: m}}
 					} else {
+						// Server doesn't support the new wire format for refs, so we construct
+						// a deprecated result ref map.
 						m := map[string]string{}
 						for k, r := range res.Refs {
-							id, err := convertRef(r)
+							pbRef, err := convertRef(r)
 							if err != nil {
 								retError = err
 								continue
 							}
+
+							var id string
+							if len(pbRef.Ids) > 0 {
+								id = pbRef.Ids[0]
+							}
 							m[k] = id
 						}
 						pbRes.Result = &pb.Result_RefsDeprecated{RefsDeprecated: &pb.RefMapDeprecated{Refs: m}}
 					}
 				} else {
-					id, err := convertRef(res.Ref)
+					pbRef, err := convertRef(res.Ref)
 					if err != nil {
 						retError = err
 					} else {
 						if c.caps.Supports(pb.CapProtoRefArray) == nil {
-							pbRes.Result = &pb.Result_Ref{Ref: pb.NewRef(id)}
+							pbRes.Result = &pb.Result_Ref{Ref: pbRef}
 						} else {
+							// Server doesn't support the new wire format for refs, so we construct
+							// a deprecated result ref.
+							var id string
+							if len(pbRef.Ids) > 0 {
+								id = pbRef.Ids[0]
+							}
 							pbRes.Result = &pb.Result_RefDeprecated{RefDeprecated: id}
 						}
 					}
@@ -343,19 +357,21 @@ func (c *grpcClient) Solve(ctx context.Context, creq client.SolveRequest) (*clie
 		case *pb.Result_Ref:
 			ids := pbRes.Ref.Ids
 			if len(ids) > 0 {
-				if len(ids) > 1 {
-					return nil, errors.Errorf("solve returned multi-result array")
+				ref, err := newReference(c, pbRes.Ref)
+				if err != nil {
+					return nil, err
 				}
-				res.SetRef(&reference{id: ids[0], c: c})
+
+				res.SetRef(ref)
 			}
 		case *pb.Result_Refs:
 			for k, v := range pbRes.Refs.Refs {
 				var ref *reference
 				if len(v.Ids) > 0 {
-					if len(v.Ids) > 1 {
-						return nil, errors.Errorf("solve returned multi-result array")
+					ref, err = newReference(c, v)
+					if err != nil {
+						return nil, err
 					}
-					ref = &reference{id: v.Ids[0], c: c}
 				}
 				res.AddRef(k, ref)
 			}
@@ -365,7 +381,7 @@ func (c *grpcClient) Solve(ctx context.Context, creq client.SolveRequest) (*clie
 	return res, nil
 }
 
-func (c *grpcClient) ResolveImageConfig(ctx context.Context, ref string, opt client.ResolveImageConfigOpt) (digest.Digest, []byte, error) {
+func (c *grpcClient) ResolveImageConfig(ctx context.Context, ref string, opt llb.ResolveImageConfigOpt) (digest.Digest, []byte, error) {
 	var p *opspb.Platform
 	if platform := opt.Platform; platform != nil {
 		p = &opspb.Platform{
@@ -395,8 +411,44 @@ func (c *grpcClient) BuildOpts() client.BuildOpts {
 }
 
 type reference struct {
-	id string
-	c  *grpcClient
+	c      *grpcClient
+	id     string
+	def    *opspb.Definition
+	output llb.Output
+}
+
+func newReference(c *grpcClient, ref *pb.Ref) (*reference, error) {
+	if len(ref.Ids) == 0 {
+		return nil, errors.Errorf("reference has no ids")
+	}
+
+	if len(ref.Ids) > 1 {
+		return nil, errors.Errorf("cannot create multi-result array reference")
+	}
+
+	if len(ref.Ids) != len(ref.Defs) {
+		return nil, errors.Errorf("reference ids and definitions mismatch length")
+	}
+
+	return &reference{c: c, id: ref.Ids[0], def: ref.Defs[0]}, nil
+}
+
+func (r *reference) ToState() (st llb.State, err error) {
+	err = r.c.caps.Supports(pb.CapReferenceOutput)
+	if err != nil {
+		return st, err
+	}
+
+	if r.def == nil {
+		return st, errors.Errorf("gateway did not return reference with definition")
+	}
+
+	defop, err := llb.NewDefinitionOp(r.def)
+	if err != nil {
+		return st, err
+	}
+
+	return llb.NewState(defop), nil
 }
 
 func (r *reference) ReadFile(ctx context.Context, req client.ReadRequest) ([]byte, error) {
diff --git a/frontend/gateway/pb/caps.go b/frontend/gateway/pb/caps.go
index da94ea73..2f5b779c 100644
--- a/frontend/gateway/pb/caps.go
+++ b/frontend/gateway/pb/caps.go
@@ -24,6 +24,10 @@ const (
 	// refs. This capability is only for the wire format change and shouldn't be
 	// used in frontends for feature detection.
 	CapProtoRefArray apicaps.CapID = "proto.refarray"
+
+	// CapReferenceOutput is a capability to use a reference of a solved result as
+	// an llb.Output.
+	CapReferenceOutput apicaps.CapID = "reference.output"
 )
 
 func init() {
@@ -104,4 +108,11 @@ func init() {
 		Enabled: true,
 		Status:  apicaps.CapStatusExperimental,
 	})
+
+	Caps.Init(apicaps.Cap{
+		ID:      CapReferenceOutput,
+		Name:    "reference output",
+		Enabled: true,
+		Status:  apicaps.CapStatusExperimental,
+	})
 }
diff --git a/frontend/gateway/pb/gateway.pb.go b/frontend/gateway/pb/gateway.pb.go
index 444fb169..1d50feeb 100644
--- a/frontend/gateway/pb/gateway.pb.go
+++ b/frontend/gateway/pb/gateway.pb.go
@@ -50,7 +50,7 @@ func (m *Result) Reset()         { *m = Result{} }
 func (m *Result) String() string { return proto.CompactTextString(m) }
 func (*Result) ProtoMessage()    {}
 func (*Result) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{0}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{0}
 }
 func (m *Result) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -264,7 +264,7 @@ func (m *RefMapDeprecated) Reset()         { *m = RefMapDeprecated{} }
 func (m *RefMapDeprecated) String() string { return proto.CompactTextString(m) }
 func (*RefMapDeprecated) ProtoMessage()    {}
 func (*RefMapDeprecated) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{1}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{1}
 }
 func (m *RefMapDeprecated) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -301,17 +301,18 @@ func (m *RefMapDeprecated) GetRefs() map[string]string {
 }
 
 type Ref struct {
-	Ids                  []string `protobuf:"bytes,1,rep,name=ids,proto3" json:"ids,omitempty"`
-	XXX_NoUnkeyedLiteral struct{} `json:"-"`
-	XXX_unrecognized     []byte   `json:"-"`
-	XXX_sizecache        int32    `json:"-"`
+	Ids                  []string         `protobuf:"bytes,1,rep,name=ids,proto3" json:"ids,omitempty"`
+	Defs                 []*pb.Definition `protobuf:"bytes,2,rep,name=defs,proto3" json:"defs,omitempty"`
+	XXX_NoUnkeyedLiteral struct{}         `json:"-"`
+	XXX_unrecognized     []byte           `json:"-"`
+	XXX_sizecache        int32            `json:"-"`
 }
 
 func (m *Ref) Reset()         { *m = Ref{} }
 func (m *Ref) String() string { return proto.CompactTextString(m) }
 func (*Ref) ProtoMessage()    {}
 func (*Ref) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{2}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{2}
 }
 func (m *Ref) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -347,6 +348,13 @@ func (m *Ref) GetIds() []string {
 	return nil
 }
 
+func (m *Ref) GetDefs() []*pb.Definition {
+	if m != nil {
+		return m.Defs
+	}
+	return nil
+}
+
 type RefMap struct {
 	Refs                 map[string]*Ref `protobuf:"bytes,1,rep,name=refs,proto3" json:"refs,omitempty" protobuf_key:"bytes,1,opt,name=key,proto3" protobuf_val:"bytes,2,opt,name=value,proto3"`
 	XXX_NoUnkeyedLiteral struct{}        `json:"-"`
@@ -358,7 +366,7 @@ func (m *RefMap) Reset()         { *m = RefMap{} }
 func (m *RefMap) String() string { return proto.CompactTextString(m) }
 func (*RefMap) ProtoMessage()    {}
 func (*RefMap) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{3}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{3}
 }
 func (m *RefMap) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -406,7 +414,7 @@ func (m *ReturnRequest) Reset()         { *m = ReturnRequest{} }
 func (m *ReturnRequest) String() string { return proto.CompactTextString(m) }
 func (*ReturnRequest) ProtoMessage()    {}
 func (*ReturnRequest) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{4}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{4}
 }
 func (m *ReturnRequest) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -459,7 +467,7 @@ func (m *ReturnResponse) Reset()         { *m = ReturnResponse{} }
 func (m *ReturnResponse) String() string { return proto.CompactTextString(m) }
 func (*ReturnResponse) ProtoMessage()    {}
 func (*ReturnResponse) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{5}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{5}
 }
 func (m *ReturnResponse) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -502,7 +510,7 @@ func (m *ResolveImageConfigRequest) Reset()         { *m = ResolveImageConfigReq
 func (m *ResolveImageConfigRequest) String() string { return proto.CompactTextString(m) }
 func (*ResolveImageConfigRequest) ProtoMessage()    {}
 func (*ResolveImageConfigRequest) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{6}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{6}
 }
 func (m *ResolveImageConfigRequest) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -571,7 +579,7 @@ func (m *ResolveImageConfigResponse) Reset()         { *m = ResolveImageConfigRe
 func (m *ResolveImageConfigResponse) String() string { return proto.CompactTextString(m) }
 func (*ResolveImageConfigResponse) ProtoMessage()    {}
 func (*ResolveImageConfigResponse) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{7}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{7}
 }
 func (m *ResolveImageConfigResponse) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -633,7 +641,7 @@ func (m *SolveRequest) Reset()         { *m = SolveRequest{} }
 func (m *SolveRequest) String() string { return proto.CompactTextString(m) }
 func (*SolveRequest) ProtoMessage()    {}
 func (*SolveRequest) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{8}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{8}
 }
 func (m *SolveRequest) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -738,7 +746,7 @@ func (m *CacheOptionsEntry) Reset()         { *m = CacheOptionsEntry{} }
 func (m *CacheOptionsEntry) String() string { return proto.CompactTextString(m) }
 func (*CacheOptionsEntry) ProtoMessage()    {}
 func (*CacheOptionsEntry) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{9}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{9}
 }
 func (m *CacheOptionsEntry) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -795,7 +803,7 @@ func (m *SolveResponse) Reset()         { *m = SolveResponse{} }
 func (m *SolveResponse) String() string { return proto.CompactTextString(m) }
 func (*SolveResponse) ProtoMessage()    {}
 func (*SolveResponse) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{10}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{10}
 }
 func (m *SolveResponse) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -851,7 +859,7 @@ func (m *ReadFileRequest) Reset()         { *m = ReadFileRequest{} }
 func (m *ReadFileRequest) String() string { return proto.CompactTextString(m) }
 func (*ReadFileRequest) ProtoMessage()    {}
 func (*ReadFileRequest) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{11}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{11}
 }
 func (m *ReadFileRequest) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -913,7 +921,7 @@ func (m *FileRange) Reset()         { *m = FileRange{} }
 func (m *FileRange) String() string { return proto.CompactTextString(m) }
 func (*FileRange) ProtoMessage()    {}
 func (*FileRange) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{12}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{12}
 }
 func (m *FileRange) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -967,7 +975,7 @@ func (m *ReadFileResponse) Reset()         { *m = ReadFileResponse{} }
 func (m *ReadFileResponse) String() string { return proto.CompactTextString(m) }
 func (*ReadFileResponse) ProtoMessage()    {}
 func (*ReadFileResponse) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{13}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{13}
 }
 func (m *ReadFileResponse) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -1016,7 +1024,7 @@ func (m *ReadDirRequest) Reset()         { *m = ReadDirRequest{} }
 func (m *ReadDirRequest) String() string { return proto.CompactTextString(m) }
 func (*ReadDirRequest) ProtoMessage()    {}
 func (*ReadDirRequest) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{14}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{14}
 }
 func (m *ReadDirRequest) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -1077,7 +1085,7 @@ func (m *ReadDirResponse) Reset()         { *m = ReadDirResponse{} }
 func (m *ReadDirResponse) String() string { return proto.CompactTextString(m) }
 func (*ReadDirResponse) ProtoMessage()    {}
 func (*ReadDirResponse) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{15}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{15}
 }
 func (m *ReadDirResponse) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -1125,7 +1133,7 @@ func (m *StatFileRequest) Reset()         { *m = StatFileRequest{} }
 func (m *StatFileRequest) String() string { return proto.CompactTextString(m) }
 func (*StatFileRequest) ProtoMessage()    {}
 func (*StatFileRequest) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{16}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{16}
 }
 func (m *StatFileRequest) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -1179,7 +1187,7 @@ func (m *StatFileResponse) Reset()         { *m = StatFileResponse{} }
 func (m *StatFileResponse) String() string { return proto.CompactTextString(m) }
 func (*StatFileResponse) ProtoMessage()    {}
 func (*StatFileResponse) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{17}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{17}
 }
 func (m *StatFileResponse) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -1225,7 +1233,7 @@ func (m *PingRequest) Reset()         { *m = PingRequest{} }
 func (m *PingRequest) String() string { return proto.CompactTextString(m) }
 func (*PingRequest) ProtoMessage()    {}
 func (*PingRequest) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{18}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{18}
 }
 func (m *PingRequest) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -1267,7 +1275,7 @@ func (m *PongResponse) Reset()         { *m = PongResponse{} }
 func (m *PongResponse) String() string { return proto.CompactTextString(m) }
 func (*PongResponse) ProtoMessage()    {}
 func (*PongResponse) Descriptor() ([]byte, []int) {
-	return fileDescriptor_gateway_f66b6a1c7ba3b979, []int{19}
+	return fileDescriptor_gateway_b7e6dbfe1a84b4d2, []int{19}
 }
 func (m *PongResponse) XXX_Unmarshal(b []byte) error {
 	return m.Unmarshal(b)
@@ -1794,6 +1802,18 @@ func (m *Ref) MarshalTo(dAtA []byte) (int, error) {
 			i += copy(dAtA[i:], s)
 		}
 	}
+	if len(m.Defs) > 0 {
+		for _, msg := range m.Defs {
+			dAtA[i] = 0x12
+			i++
+			i = encodeVarintGateway(dAtA, i, uint64(msg.Size()))
+			n, err := msg.MarshalTo(dAtA[i:])
+			if err != nil {
+				return 0, err
+			}
+			i += n
+		}
+	}
 	if m.XXX_unrecognized != nil {
 		i += copy(dAtA[i:], m.XXX_unrecognized)
 	}
@@ -2620,6 +2640,12 @@ func (m *Ref) Size() (n int) {
 			n += 1 + l + sovGateway(uint64(l))
 		}
 	}
+	if len(m.Defs) > 0 {
+		for _, e := range m.Defs {
+			l = e.Size()
+			n += 1 + l + sovGateway(uint64(l))
+		}
+	}
 	if m.XXX_unrecognized != nil {
 		n += len(m.XXX_unrecognized)
 	}
@@ -3541,6 +3567,37 @@ func (m *Ref) Unmarshal(dAtA []byte) error {
 			}
 			m.Ids = append(m.Ids, string(dAtA[iNdEx:postIndex]))
 			iNdEx = postIndex
+		case 2:
+			if wireType != 2 {
+				return fmt.Errorf("proto: wrong wireType = %d for field Defs", wireType)
+			}
+			var msglen int
+			for shift := uint(0); ; shift += 7 {
+				if shift >= 64 {
+					return ErrIntOverflowGateway
+				}
+				if iNdEx >= l {
+					return io.ErrUnexpectedEOF
+				}
+				b := dAtA[iNdEx]
+				iNdEx++
+				msglen |= (int(b) & 0x7F) << shift
+				if b < 0x80 {
+					break
+				}
+			}
+			if msglen < 0 {
+				return ErrInvalidLengthGateway
+			}
+			postIndex := iNdEx + msglen
+			if postIndex > l {
+				return io.ErrUnexpectedEOF
+			}
+			m.Defs = append(m.Defs, &pb.Definition{})
+			if err := m.Defs[len(m.Defs)-1].Unmarshal(dAtA[iNdEx:postIndex]); err != nil {
+				return err
+			}
+			iNdEx = postIndex
 		default:
 			iNdEx = preIndex
 			skippy, err := skipGateway(dAtA[iNdEx:])
@@ -5906,91 +5963,92 @@ var (
 	ErrIntOverflowGateway   = fmt.Errorf("proto: integer overflow")
 )
 
-func init() { proto.RegisterFile("gateway.proto", fileDescriptor_gateway_f66b6a1c7ba3b979) }
+func init() { proto.RegisterFile("gateway.proto", fileDescriptor_gateway_b7e6dbfe1a84b4d2) }
 
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+	0xfb, 0x0b, 0x78, 0x4a, 0x09, 0xda, 0x81, 0x0a, 0x27, 0x61, 0xab, 0xa2, 0x74, 0x6d, 0x94, 0xeb,
+	0xda, 0x5f, 0xc0, 0x52, 0x18, 0xed, 0x42, 0x55, 0x6a, 0x69, 0x55, 0x15, 0xe8, 0xbf, 0x33, 0x09,
+	0xec, 0x2f, 0x60, 0x05, 0x40, 0x9f, 0xc1, 0xca, 0x80, 0x08, 0x3f, 0xf0, 0x85, 0xdf, 0x82, 0xcd,
+	0x4a, 0x7b, 0x75, 0xc7, 0x2b, 0x05, 0xcb, 0x00, 0xb9, 0x47, 0x06, 0xf1, 0x24, 0x11, 0x7c, 0x84,
+	0x4f, 0x14, 0xd8, 0xf7, 0x61, 0x6d, 0xe2, 0x13, 0x6a, 0x42, 0xe5, 0x35, 0x19, 0xe9, 0xf8, 0x61,
+	0xb9, 0x44, 0xff, 0x86, 0xda, 0x1b, 0x3f, 0x1e, 0x12, 0x15, 0xaa, 0x06, 0xd6, 0x9b, 0x7b, 0x8b,
+	0x77, 0xad, 0xce, 0x0a, 0x2c, 0x71, 0xa5, 0xde, 0xf9, 0xc5, 0x82, 0xe6, 0x74, 0x9c, 0xd0, 0x81,
+	0xf1, 0xd0, 0x52, 0x24, 0xef, 0xcc, 0x11, 0x62, 0x79, 0x90, 0x69, 0xaa, 0x4a, 0x85, 0xbd, 0x0b,
+	0xf5, 0x93, 0xa3, 0x59, 0x14, 0xeb, 0x05, 0x8a, 0xce, 0x7d, 0xa8, 0x60, 0x12, 0x4a, 0x08, 0x0d,
+	0x34, 0x93, 0x3a, 0x96, 0x4b, 0xe4, 0x40, 0x35, 0x90, 0xe4, 0x16, 0x15, 0xb9, 0x75, 0x37, 0xed,
+	0xb9, 0x7b, 0x24, 0xa4, 0x09, 0x15, 0x94, 0x25, 0x58, 0x7d, 0x73, 0x7e, 0xb3, 0x64, 0x81, 0x49,
+	0x6a, 0xe8, 0xe1, 0x84, 0x2f, 0xb3, 0xcb, 0xe5, 0x94, 0x07, 0x2f, 0xca, 0x3d, 0xb8, 0x5d, 0xf4,
+	0x60, 0x66, 0x0d, 0x15, 0x3d, 0x14, 0xb0, 0x86, 0x89, 0x18, 0xf2, 0x04, 0x93, 0x6f, 0x87, 0x24,
+	0x13, 0xe8, 0xa3, 0x3c, 0x2b, 0x4a, 0xff, 0xac, 0xd2, 0x92, 0x82, 0xd8, 0x00, 0x50, 0x1b, 0x6a,
+	0x84, 0x73, 0xc6, 0x0d, 0x0b, 0xe4, 0xea, 0xe9, 0xe1, 0xf2, 0xb4, 0xef, 0x3e, 0x57, 0xd3, 0x03,
+	0x6b, 0x01, 0xa7, 0x09, 0xeb, 0xb9, 0xd5, 0x2c, 0x65, 0x49, 0x46, 0x9c, 0x9f, 0x2d, 0xb8, 0x82,
+	0x89, 0x1a, 0x1e, 0x07, 0x03, 0x3f, 0x22, 0x8f, 0x59, 0x12, 0xd2, 0x28, 0x27, 0xd5, 0x54, 0x79,
+	0xc8, 0x3d, 0x96, 0x29, 0x69, 0xc3, 0x4a, 0x37, 0xf6, 0x45, 0xc8, 0xf8, 0xc0, 0x98, 0x6b, 0xc8,
+	0x24, 0xe4, 0x67, 0xf8, 0xe4, 0x2b, 0xda, 0x84, 0x55, 0xa3, 0xf8, 0x88, 0x05, 0x44, 0x75, 0x59,
+	0x1d, 0x17, 0x8f, 0x50, 0x0b, 0x96, 0x0f, 0x59, 0xf4, 0xb9, 0x3f, 0x20, 0xaa, 0x9d, 0xea, 0x38,
+	0xdf, 0x3a, 0x3f, 0x58, 0x60, 0x9f, 0xc5, 0x4a, 0x93, 0x46, 0x9f, 0xc2, 0xd2, 0x1e, 0x8d, 0x48,
+	0xa6, 0x63, 0x55, 0xef, 0xec, 0xbc, 0x7b, 0x7f, 0x75, 0xe1, 0xaf, 0xf7, 0x57, 0xaf, 0x17, 0x26,
+	0x11, 0x4b, 0x49, 0xd2, 0x67, 0x89, 0xf0, 0x69, 0x42, 0xb8, 0x1c, 0xa8, 0x37, 0x03, 0x05, 0x71,
+	0x35, 0x12, 0x1b, 0x0d, 0xe8, 0x3f, 0xb0, 0xa4, 0xb5, 0x9b, 0x46, 0x31, 0x3b, 0xe7, 0xd7, 0x2a,
+	0x34, 0x9e, 0x4b, 0x02, 0x79, 0x2c, 0x5c, 0x80, 0x71, 0xa9, 0x99, 0x24, 0x4d, 0x17, 0x60, 0x41,
+	0x02, 0xd9, 0xb0, 0xf2, 0xd4, 0x24, 0xcc, 0x14, 0xf8, 0xc9, 0x1e, 0xbd, 0x84, 0xd5, 0x7c, 0xfd,
+	0x2c, 0x15, 0xad, 0x8a, 0x2a, 0xcf, 0xbb, 0x25, 0x19, 0x2f, 0x32, 0x71, 0x0b, 0x50, 0x5d, 0xab,
+	0x45, 0x65, 0xe8, 0x63, 0xb8, 0x72, 0x30, 0x48, 0x19, 0x17, 0x8f, 0xfd, 0xfe, 0x2b, 0x82, 0x27,
+	0xe7, 0x66, 0x55, 0xb5, 0xd2, 0xf9, 0x02, 0x68, 0x1b, 0x2e, 0xfb, 0x71, 0xcc, 0xde, 0x9a, 0x12,
+	0x53, 0xc5, 0xd2, 0xaa, 0x6d, 0x5a, 0xed, 0x15, 0x7c, 0xfa, 0x03, 0xfa, 0x00, 0xfe, 0x55, 0x38,
+	0x7c, 0xc4, 0xb9, 0x3f, 0x92, 0xf5, 0xb2, 0xa4, 0xe4, 0xcf, 0xfa, 0x24, 0x7b, 0xfe, 0x29, 0x4d,
+	0xfc, 0xb8, 0x05, 0x4a, 0x46, 0x6f, 0x90, 0x03, 0x8d, 0x27, 0xdf, 0x49, 0x4a, 0x84, 0x3f, 0x12,
+	0x82, 0xb7, 0x56, 0x55, 0x2a, 0x26, 0xce, 0x50, 0x17, 0x1a, 0x8a, 0xb0, 0xe6, 0x9e, 0xb5, 0x1a,
+	0x2a, 0x68, 0xdb, 0x25, 0x41, 0x53, 0xe2, 0xcf, 0x52, 0x99, 0x0d, 0xd3, 0xd4, 0x13, 0x1a, 0xec,
+	0x07, 0xd0, 0x9c, 0x0e, 0xe5, 0x5c, 0x53, 0xea, 0x77, 0x0b, 0x2e, 0x9f, 0xb2, 0x81, 0x10, 0x54,
+	0xbf, 0x18, 0xa5, 0xc4, 0xa8, 0x50, 0x6b, 0x74, 0x04, 0x35, 0xe9, 0x43, 0x3e, 0xb7, 0x76, 0xe7,
+	0x21, 0xed, 0x2a, 0xa4, 0xe6, 0xaf, 0xb5, 0xd8, 0x77, 0x01, 0xc6, 0x87, 0x73, 0x51, 0xfe, 0x0a,
+	0xd6, 0x4c, 0x29, 0x99, 0x56, 0x6a, 0xea, 0x3b, 0xd0, 0x80, 0xe5, 0x0d, 0x37, 0x1e, 0x44, 0x95,
+	0x39, 0x07, 0x91, 0xf3, 0x3d, 0x5c, 0xc2, 0xc4, 0x0f, 0x9e, 0xd2, 0x98, 0x9c, 0x3f, 0x41, 0x64,
+	0x5f, 0xd0, 0x98, 0x74, 0x7d, 0xf1, 0xea, 0xa4, 0x2f, 0xcc, 0x1e, 0xdd, 0x83, 0x1a, 0xf6, 0x93,
+	0x88, 0x18, 0xd3, 0xff, 0x2b, 0x31, 0xad, 0x8c, 0x48, 0x59, 0xac, 0x21, 0xce, 0x7d, 0xa8, 0x9f,
+	0x9c, 0xc9, 0xae, 0x7e, 0x16, 0x86, 0x19, 0xd1, 0x13, 0xa2, 0x82, 0xcd, 0x4e, 0x9e, 0x1f, 0x92,
+	0x24, 0x32, 0xa6, 0x2b, 0xd8, 0xec, 0x9c, 0x2d, 0x79, 0x11, 0xe6, 0xcc, 0x4d, 0x68, 0x10, 0x54,
+	0xf7, 0xe4, 0x6d, 0x6d, 0xa9, 0x62, 0x54, 0x6b, 0x27, 0x90, 0x03, 0xd4, 0x0f, 0xf6, 0x28, 0x3f,
+	0xdf, 0xc1, 0x16, 0x2c, 0xef, 0x51, 0x5e, 0xf0, 0x2f, 0xdf, 0xa2, 0x2d, 0x58, 0x3f, 0x48, 0xfa,
+	0xf1, 0x30, 0x90, 0xde, 0x0a, 0xc2, 0x13, 0x33, 0x15, 0xa7, 0x4e, 0x9d, 0x87, 0x3a, 0x8e, 0xca,
+	0x8a, 0x21, 0xb3, 0x0d, 0xcb, 0x24, 0x11, 0x9c, 0x92, 0xfc, 0x32, 0x43, 0xae, 0x7e, 0x60, 0xb9,
+	0xea, 0x81, 0xa5, 0xe6, 0x3c, 0xce, 0x45, 0x9c, 0x5d, 0xb8, 0x24, 0x0f, 0xca, 0x13, 0x81, 0xa0,
+	0x5a, 0x20, 0xa9, 0xd6, 0xce, 0x3d, 0x68, 0x8e, 0x81, 0xc6, 0xf4, 0x16, 0x54, 0xe5, 0xf3, 0xcd,
+	0x8c, 0xbc, 0xb3, 0xec, 0xaa, 0xef, 0xce, 0x1a, 0xac, 0x76, 0x69, 0x92, 0xdf, 0x1d, 0xce, 0xb1,
+	0x05, 0x8d, 0x2e, 0x4b, 0xc6, 0x53, 0xbb, 0x0b, 0x97, 0xf2, 0x76, 0x7b, 0xd4, 0x3d, 0x78, 0xec,
+	0xa7, 0xb9, 0x2b, 0x9b, 0xa7, 0xd3, 0x6c, 0x5e, 0x9a, 0xae, 0x16, 0xec, 0x54, 0xe5, 0x80, 0xc7,
+	0xd3, 0x70, 0xf4, 0x09, 0x2c, 0x1f, 0x1e, 0x76, 0x94, 0xa6, 0xc5, 0xb9, 0x34, 0xe5, 0x30, 0xf4,
+	0x00, 0x96, 0x5f, 0xa8, 0x07, 0x70, 0x66, 0x86, 0xf0, 0x19, 0x25, 0xa7, 0x1d, 0xd5, 0x62, 0x98,
+	0xf4, 0x19, 0x0f, 0x70, 0x0e, 0xda, 0xf9, 0xa3, 0x06, 0xf5, 0xc3, 0xc3, 0x4e, 0x87, 0xd3, 0x20,
+	0x22, 0xe8, 0x47, 0x0b, 0xd0, 0xe9, 0x6b, 0x0b, 0xdd, 0x2e, 0xef, 0xa0, 0xb3, 0xef, 0x5e, 0xfb,
+	0xce, 0x9c, 0x28, 0x13, 0xe5, 0x97, 0x50, 0x53, 0x1d, 0x8e, 0xfe, 0x7f, 0xc1, 0xeb, 0xc4, 0x6e,
+	0xcf, 0x16, 0x34, 0xba, 0xfb, 0xb0, 0x92, 0x77, 0x09, 0xba, 0x5e, 0x4a, 0x6f, 0x62, 0x08, 0xd8,
+	0x37, 0x2e, 0x24, 0x6b, 0x8c, 0x7c, 0x03, 0xcb, 0xa6, 0xf8, 0xd1, 0xb5, 0x19, 0xb8, 0x71, 0x1b,
+	0xda, 0xd7, 0x2f, 0x22, 0x3a, 0x76, 0x23, 0x2f, 0xf2, 0x52, 0x37, 0xa6, 0x5a, 0xa8, 0xd4, 0x8d,
+	0x53, 0x5d, 0xf3, 0x02, 0xaa, 0xb2, 0x1b, 0xd0, 0x56, 0x09, 0xa8, 0xd0, 0x2e, 0x76, 0x59, 0xba,
+	0x26, 0xda, 0xe8, 0x6b, 0xf9, 0xba, 0x55, 0xb7, 0x6f, 0xbb, 0xd4, 0xe7, 0xc2, 0xe3, 0xd2, 0xbe,
+	0x76, 0x01, 0x49, 0xad, 0xbe, 0xd3, 0x78, 0x77, 0xbc, 0x61, 0xfd, 0x79, 0xbc, 0x61, 0xfd, 0x7d,
+	0xbc, 0x61, 0xf5, 0x96, 0xd4, 0x7f, 0xb6, 0x5b, 0xff, 0x04, 0x00, 0x00, 0xff, 0xff, 0x6d, 0x93,
+	0xbb, 0x7e, 0x05, 0x0f, 0x00, 0x00,
 }
diff --git a/frontend/gateway/pb/gateway.proto b/frontend/gateway/pb/gateway.proto
index 0a395152..54e5b275 100644
--- a/frontend/gateway/pb/gateway.proto
+++ b/frontend/gateway/pb/gateway.proto
@@ -46,6 +46,7 @@ message RefMapDeprecated {
 
 message Ref {
 	repeated string ids = 1;
+	repeated pb.Definition defs = 2;
 }
 
 message RefMap {
diff --git a/frontend/gateway/pb/ref.go b/frontend/gateway/pb/ref.go
index 882fae57..0132c0d7 100644
--- a/frontend/gateway/pb/ref.go
+++ b/frontend/gateway/pb/ref.go
@@ -1,9 +1,14 @@
 package moby_buildkit_v1_frontend
 
-func NewRef(id string) *Ref {
+import "github.com/moby/buildkit/solver/pb"
+
+func NewRef(id string, def *pb.Definition) *Ref {
 	var ref Ref
 	if id != "" {
 		ref.Ids = append(ref.Ids, id)
 	}
+	if def != nil {
+		ref.Defs = append(ref.Defs, def)
+	}
 	return &ref
 }
diff --git a/frontend/result.go b/frontend/result.go
index 37715de8..676262bc 100644
--- a/frontend/result.go
+++ b/frontend/result.go
@@ -1,6 +1,8 @@
 package frontend
 
-import "github.com/moby/buildkit/solver"
+import (
+	"github.com/moby/buildkit/solver"
+)
 
 type Result struct {
 	Ref      solver.CachedResult
diff --git a/solver/llbsolver/bridge.go b/solver/llbsolver/bridge.go
index 0905f983..98e1f183 100644
--- a/solver/llbsolver/bridge.go
+++ b/solver/llbsolver/bridge.go
@@ -11,6 +11,7 @@ import (
 	"github.com/containerd/containerd/platforms"
 	"github.com/moby/buildkit/cache"
 	"github.com/moby/buildkit/cache/remotecache"
+	"github.com/moby/buildkit/client/llb"
 	"github.com/moby/buildkit/executor"
 	"github.com/moby/buildkit/frontend"
 	gw "github.com/moby/buildkit/frontend/gateway/client"
@@ -116,6 +117,12 @@ func (b *llbBridge) Solve(ctx context.Context, req frontend.SolveRequest) (res *
 			return nil, errors.Wrap(err, "failed to build LLB")
 		}
 
+		wref, ok := ref.Sys().(*worker.WorkerRef)
+		if !ok {
+			return nil, errors.Errorf("invalid ref: %T", ref.Sys())
+		}
+		wref.Definition = req.Definition
+
 		res = &frontend.Result{Ref: ref}
 	} else if req.Frontend != "" {
 		f, ok := b.frontends[req.Frontend]
@@ -158,7 +165,7 @@ func (s *llbBridge) Exec(ctx context.Context, meta executor.Meta, root cache.Imm
 	return err
 }
 
-func (s *llbBridge) ResolveImageConfig(ctx context.Context, ref string, opt gw.ResolveImageConfigOpt) (dgst digest.Digest, config []byte, err error) {
+func (s *llbBridge) ResolveImageConfig(ctx context.Context, ref string, opt llb.ResolveImageConfigOpt) (dgst digest.Digest, config []byte, err error) {
 	w, err := s.resolveWorker()
 	if err != nil {
 		return "", nil, err
diff --git a/source/containerimage/pull.go b/source/containerimage/pull.go
index aa817e2d..d665ccc8 100644
--- a/source/containerimage/pull.go
+++ b/source/containerimage/pull.go
@@ -13,7 +13,7 @@ import (
 	"github.com/containerd/containerd/platforms"
 	"github.com/docker/distribution/reference"
 	"github.com/moby/buildkit/cache"
-	gw "github.com/moby/buildkit/frontend/gateway/client"
+	"github.com/moby/buildkit/client/llb"
 	"github.com/moby/buildkit/session"
 	"github.com/moby/buildkit/snapshot"
 	"github.com/moby/buildkit/source"
@@ -60,7 +60,7 @@ func (is *imageSource) ID() string {
 	return source.DockerImageScheme
 }
 
-func (is *imageSource) ResolveImageConfig(ctx context.Context, ref string, opt gw.ResolveImageConfigOpt, sm *session.Manager) (digest.Digest, []byte, error) {
+func (is *imageSource) ResolveImageConfig(ctx context.Context, ref string, opt llb.ResolveImageConfigOpt, sm *session.Manager) (digest.Digest, []byte, error) {
 	type t struct {
 		dgst digest.Digest
 		dt   []byte
diff --git a/worker/base/worker.go b/worker/base/worker.go
index 158f3423..f0803d60 100644
--- a/worker/base/worker.go
+++ b/worker/base/worker.go
@@ -21,6 +21,7 @@ import (
 	"github.com/moby/buildkit/cache/blobs"
 	"github.com/moby/buildkit/cache/metadata"
 	"github.com/moby/buildkit/client"
+	"github.com/moby/buildkit/client/llb"
 	"github.com/moby/buildkit/executor"
 	"github.com/moby/buildkit/exporter"
 	imageexporter "github.com/moby/buildkit/exporter/containerimage"
@@ -28,7 +29,6 @@ import (
 	ociexporter "github.com/moby/buildkit/exporter/oci"
 	tarexporter "github.com/moby/buildkit/exporter/tar"
 	"github.com/moby/buildkit/frontend"
-	gw "github.com/moby/buildkit/frontend/gateway/client"
 	"github.com/moby/buildkit/identity"
 	"github.com/moby/buildkit/session"
 	"github.com/moby/buildkit/snapshot"
@@ -274,7 +274,7 @@ func (w *Worker) PruneCacheMounts(ctx context.Context, ids []string) error {
 	return nil
 }
 
-func (w *Worker) ResolveImageConfig(ctx context.Context, ref string, opt gw.ResolveImageConfigOpt, sm *session.Manager) (digest.Digest, []byte, error) {
+func (w *Worker) ResolveImageConfig(ctx context.Context, ref string, opt llb.ResolveImageConfigOpt, sm *session.Manager) (digest.Digest, []byte, error) {
 	// ImageSource is typically source/containerimage
 	resolveImageConfig, ok := w.ImageSource.(resolveImageConfig)
 	if !ok {
@@ -284,7 +284,7 @@ func (w *Worker) ResolveImageConfig(ctx context.Context, ref string, opt gw.Reso
 }
 
 type resolveImageConfig interface {
-	ResolveImageConfig(ctx context.Context, ref string, opt gw.ResolveImageConfigOpt, sm *session.Manager) (digest.Digest, []byte, error)
+	ResolveImageConfig(ctx context.Context, ref string, opt llb.ResolveImageConfigOpt, sm *session.Manager) (digest.Digest, []byte, error)
 }
 
 func (w *Worker) Exec(ctx context.Context, meta executor.Meta, rootFS cache.ImmutableRef, stdin io.ReadCloser, stdout, stderr io.WriteCloser) error {
diff --git a/worker/result.go b/worker/result.go
index 9aa6af41..02303ce8 100644
--- a/worker/result.go
+++ b/worker/result.go
@@ -5,6 +5,7 @@ import (
 
 	"github.com/moby/buildkit/cache"
 	"github.com/moby/buildkit/solver"
+	"github.com/moby/buildkit/solver/pb"
 )
 
 func NewWorkerRefResult(ref cache.ImmutableRef, worker Worker) solver.Result {
@@ -14,6 +15,7 @@ func NewWorkerRefResult(ref cache.ImmutableRef, worker Worker) solver.Result {
 type WorkerRef struct {
 	ImmutableRef cache.ImmutableRef
 	Worker       Worker
+	Definition   *pb.Definition
 }
 
 func (wr *WorkerRef) ID() string {
diff --git a/worker/worker.go b/worker/worker.go
index 2c3c616e..50196530 100644
--- a/worker/worker.go
+++ b/worker/worker.go
@@ -7,10 +7,10 @@ import (
 	"github.com/containerd/containerd/content"
 	"github.com/moby/buildkit/cache"
 	"github.com/moby/buildkit/client"
+	"github.com/moby/buildkit/client/llb"
 	"github.com/moby/buildkit/executor"
 	"github.com/moby/buildkit/exporter"
 	"github.com/moby/buildkit/frontend"
-	gw "github.com/moby/buildkit/frontend/gateway/client"
 	"github.com/moby/buildkit/session"
 	"github.com/moby/buildkit/solver"
 	digest "github.com/opencontainers/go-digest"
@@ -26,7 +26,7 @@ type Worker interface {
 	LoadRef(id string, hidden bool) (cache.ImmutableRef, error)
 	// ResolveOp resolves Vertex.Sys() to Op implementation.
 	ResolveOp(v solver.Vertex, s frontend.FrontendLLBBridge, sm *session.Manager) (solver.Op, error)
-	ResolveImageConfig(ctx context.Context, ref string, opt gw.ResolveImageConfigOpt, sm *session.Manager) (digest.Digest, []byte, error)
+	ResolveImageConfig(ctx context.Context, ref string, opt llb.ResolveImageConfigOpt, sm *session.Manager) (digest.Digest, []byte, error)
 	// Exec is similar to executor.Exec but without []mount.Mount
 	Exec(ctx context.Context, meta executor.Meta, rootFS cache.ImmutableRef, stdin io.ReadCloser, stdout, stderr io.WriteCloser) error
 	DiskUsage(ctx context.Context, opt client.DiskUsageInfo) ([]*client.UsageInfo, error)