diff --git a/entity/request.go b/entity/request.go
index 0dd33f4d..d73604ca 100644
--- a/entity/request.go
+++ b/entity/request.go
@@ -33,13 +33,17 @@ const (
 	RequestStateError RequestState = "error"
 )
 
-// Change represents a set of related code changes identified by one or more IDs from a particular code change provider, like Github Pull Requests.
-// The object is immutable after creation.
+// Change represents a code change identified by URIs from a code change provider (e.g., GitHub Pull Request, Phabricator Diff).
+// The provider is extracted from the URI scheme. The object is immutable after creation.
 type Change struct {
-	// Source is the code change provider (e.g., "github", "gerrit", "phabricator").
-	Source string `json:"source"`
-	// IDs is a list of change IDs, in a format specific to the code change provider, that should be landed together.
-	IDs []string `json:"ids"`
+	// URIs identifies the change(s) to land (RFC 3986 compliant).
+	// The scheme identifies the change provider, and the path contains provider-specific resource identifiers.
+	//
+	// GitHub is supported by default (though other providers can be added):
+	//   Template: "github://<org>/<repo>/pull/<pr>/<hash>"
+	//   Example: "github://uber/submitqueue/pull/123/abc123def"
+	//
+	URIs []string `json:"uris"`
 }
 
 // Request defines a request to land (merge into target branch of the source control repository) a set of code changes.
diff --git a/entity/request_test.go b/entity/request_test.go
index 74bf2a00..d7233ce5 100644
--- a/entity/request_test.go
+++ b/entity/request_test.go
@@ -11,7 +11,7 @@ func TestRequest_ToBytes(t *testing.T) {
 	req := Request{
 		ID:           "test-queue/123",
 		Queue:        "test-queue",
-		Change:       Change{Source: "github", IDs: []string{"PR-456", "PR-789"}},
+		Change:       Change{URIs: []string{"github://uber/submitqueue/pull/456/abc123def", "github://uber/submitqueue/pull/789/def456abc"}},
 		LandStrategy: RequestLandStrategyRebase,
 		State:        RequestStateNew,
 		Version:      1,
@@ -24,8 +24,7 @@ func TestRequest_ToBytes(t *testing.T) {
 	// Verify JSON contains expected fields
 	jsonStr := string(data)
 	assert.Contains(t, jsonStr, "test-queue/123")
-	assert.Contains(t, jsonStr, "github")
-	assert.Contains(t, jsonStr, "PR-456")
+	assert.Contains(t, jsonStr, "github://uber/submitqueue/pull/456/abc123def")
 	assert.Contains(t, jsonStr, "rebase")
 	assert.Contains(t, jsonStr, "new")
 }
@@ -34,7 +33,7 @@ func TestRequestFromBytes(t *testing.T) {
 	original := Request{
 		ID:           "my-queue/999",
 		Queue:        "my-queue",
-		Change:       Change{Source: "gerrit", IDs: []string{"CL-111"}},
+		Change:       Change{URIs: []string{"code.uber.internal.com/D111"}},
 		LandStrategy: RequestLandStrategyMerge,
 		State:        RequestStateProcessing,
 		Version:      3,
@@ -51,8 +50,7 @@ func TestRequestFromBytes(t *testing.T) {
 	// Verify all fields match
 	assert.Equal(t, original.ID, deserialized.ID)
 	assert.Equal(t, original.Queue, deserialized.Queue)
-	assert.Equal(t, original.Change.Source, deserialized.Change.Source)
-	assert.Equal(t, original.Change.IDs, deserialized.Change.IDs)
+	assert.Equal(t, original.Change.URIs, deserialized.Change.URIs)
 	assert.Equal(t, original.LandStrategy, deserialized.LandStrategy)
 	assert.Equal(t, original.State, deserialized.State)
 	assert.Equal(t, original.Version, deserialized.Version)
@@ -85,33 +83,33 @@ func TestRequest_SerializationRoundTrip(t *testing.T) {
 		req  Request
 	}{
 		{
-			name: "full request",
+			name: "github stacked diff",
 			req: Request{
 				ID:           "queue1/100",
 				Queue:        "queue1",
-				Change:       Change{Source: "github", IDs: []string{"PR-1", "PR-2", "PR-3"}},
+				Change:       Change{URIs: []string{"github://uber/repo-a/pull/101/aaa111", "github://uber/repo-a/pull/102/bbb222", "github://uber/repo-a/pull/103/ccc333"}},
 				LandStrategy: RequestLandStrategySquashRebase,
 				State:        RequestStateLanded,
 				Version:      5,
 			},
 		},
 		{
-			name: "minimal request",
+			name: "phabricator revision",
 			req: Request{
 				ID:           "queue2/200",
 				Queue:        "queue2",
-				Change:       Change{Source: "phabricator", IDs: []string{"D123"}},
+				Change:       Change{URIs: []string{"code.uber.internal.com/D12345"}},
 				LandStrategy: RequestLandStrategyRebase,
 				State:        RequestStateNew,
 				Version:      1,
 			},
 		},
 		{
-			name: "error state request",
+			name: "github enterprise request",
 			req: Request{
 				ID:           "queue3/300",
 				Queue:        "queue3",
-				Change:       Change{Source: "github", IDs: []string{"PR-999"}},
+				Change:       Change{URIs: []string{"github.uber.com/internal/service/999/deadbeef12"}},
 				LandStrategy: RequestLandStrategyMerge,
 				State:        RequestStateError,
 				Version:      10,
diff --git a/extension/changeprovider/BUILD.bazel b/extension/changeprovider/BUILD.bazel
new file mode 100644
index 00000000..61b2e095
--- /dev/null
+++ b/extension/changeprovider/BUILD.bazel
@@ -0,0 +1,9 @@
+load("@rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "changeprovider",
+    srcs = ["change_provider.go"],
+    importpath = "github.com/uber/submitqueue/extension/changeprovider",
+    visibility = ["//visibility:public"],
+    deps = ["//entity"],
+)
diff --git a/extension/changeprovider/change_provider.go b/extension/changeprovider/change_provider.go
new file mode 100644
index 00000000..90cfe635
--- /dev/null
+++ b/extension/changeprovider/change_provider.go
@@ -0,0 +1,47 @@
+package changeprovider
+
+import (
+	"context"
+
+	"github.com/uber/submitqueue/entity"
+)
+
+// User represents the author of a change.
+type User struct {
+	// Name is the display name of the user.
+	Name string
+	// Email is the email address of the user.
+	Email string
+}
+
+// ChangedFile represents a single file modification in a change.
+type ChangedFile struct {
+	// Path is the file path relative to the repository root.
+	Path string
+	// Patch is the diff patch content for this file.
+	Patch string
+	// LinesAdded is the number of lines added in this file.
+	LinesAdded int
+	// LinesDeleted is the number of lines deleted in this file.
+	LinesDeleted int
+	// LinesModified is the number of lines modified in this file.
+	LinesModified int
+}
+
+// ChangeInfo contains metadata and file changes for a code change.
+type ChangeInfo struct {
+	// ID is the change identifier (e.g., "PR: uber-code/go-code/1" or "diff: uber-code/go-code/D1").
+	ID string
+	// User is the author of the change.
+	User User
+	// ChangedFiles is the list of files modified in this change. Order is unspecified.
+	ChangedFiles []ChangedFile
+}
+
+// ChangeProvider fetches change metadata from external systems
+// Each implementation is configured for a specific provider (GitHub, GitLab, Phabricator).
+type ChangeProvider interface {
+	// Get retrieves change information for the provided Change.
+	// Returns the change info containing metadata and file changes.
+	Get(ctx context.Context, change entity.Change) (ChangeInfo, error)
+}
diff --git a/extension/storage/mysql/request_store.go b/extension/storage/mysql/request_store.go
index 8f9841a8..4937066f 100644
--- a/extension/storage/mysql/request_store.go
+++ b/extension/storage/mysql/request_store.go
@@ -25,12 +25,12 @@ func NewRequestStore(db *sql.DB) storage.RequestStore {
 // Get retrieves a land request by ID. Returns ErrNotFound if the request is not found.
 func (r *requestStore) Get(ctx context.Context, id string) (entity.Request, error) {
 	var req entity.Request
-	var changeIDsJSON []byte
+	var changeURIsJSON []byte
 
 	err := r.db.QueryRowContext(ctx,
-		"SELECT id, queue, change_source, change_ids, land_strategy, state, version FROM request WHERE id = ?",
+		"SELECT id, queue, change_uri, land_strategy, state, version FROM request WHERE id = ?",
 		id,
-	).Scan(&req.ID, &req.Queue, &req.Change.Source, &changeIDsJSON, &req.LandStrategy, &req.State, &req.Version)
+	).Scan(&req.ID, &req.Queue, &changeURIsJSON, &req.LandStrategy, &req.State, &req.Version)
 
 	if errors.Is(err, sql.ErrNoRows) {
 		return entity.Request{}, storage.WrapNotFound(err)
@@ -39,8 +39,9 @@ func (r *requestStore) Get(ctx context.Context, id string) (entity.Request, erro
 		return entity.Request{}, fmt.Errorf("failed to get request entity id=%s from the database: %w", id, err)
 	}
 
-	if err := json.Unmarshal(changeIDsJSON, &req.Change.IDs); err != nil {
-		return entity.Request{}, fmt.Errorf("failed to unmarshal change IDs for request entity id=%s from the database: %w", id, err)
+	// Unmarshal the change URIs from JSON
+	if err := json.Unmarshal(changeURIsJSON, &req.Change.URIs); err != nil {
+		return entity.Request{}, fmt.Errorf("failed to unmarshal change URIs for request id=%s: %w", id, err)
 	}
 
 	return req, nil
@@ -48,14 +49,15 @@ func (r *requestStore) Get(ctx context.Context, id string) (entity.Request, erro
 
 // Create creates a new land request. The request must have a unique ID already assigned. Returns ErrAlreadyExists if the request ID already exists.
 func (r *requestStore) Create(ctx context.Context, request entity.Request) error {
-	changeIDsJSON, err := json.Marshal(request.Change.IDs)
+	// Marshal the change URIs to JSON
+	changeURIsJSON, err := json.Marshal(request.Change.URIs)
 	if err != nil {
-		return fmt.Errorf("failed to marshal change IDs=%v id=%s for Create request entity: %w", request.Change.IDs, request.ID, err)
+		return fmt.Errorf("failed to marshal change URIs for request id=%s: %w", request.ID, err)
 	}
 
 	_, err = r.db.ExecContext(ctx,
-		"INSERT INTO request (id, queue, change_source, change_ids, land_strategy, state, version) VALUES (?, ?, ?, ?, ?, ?, ?)",
-		request.ID, request.Queue, request.Change.Source, changeIDsJSON, request.LandStrategy, request.State, request.Version,
+		"INSERT INTO request (id, queue, change_uri, land_strategy, state, version) VALUES (?, ?, ?, ?, ?, ?)",
+		request.ID, request.Queue, changeURIsJSON, request.LandStrategy, request.State, request.Version,
 	)
 	if err != nil {
 		var mysqlErr *mysql.MySQLError
diff --git a/extension/storage/mysql/schema/request.sql b/extension/storage/mysql/schema/request.sql
index 5011f094..e19a575f 100644
--- a/extension/storage/mysql/schema/request.sql
+++ b/extension/storage/mysql/schema/request.sql
@@ -1,8 +1,7 @@
 CREATE TABLE IF NOT EXISTS request (
     id VARCHAR(255) NOT NULL,
     queue VARCHAR(255) NOT NULL,
-    change_source VARCHAR(255) NOT NULL,
-    change_ids JSON NOT NULL,
+    change_uri JSON NOT NULL,
     land_strategy VARCHAR(64) NOT NULL,
     state VARCHAR(64) NOT NULL,
     version INT NOT NULL,
diff --git a/gateway/controller/land.go b/gateway/controller/land.go
index 27fe58e6..9e0f70c4 100644
--- a/gateway/controller/land.go
+++ b/gateway/controller/land.go
@@ -61,16 +61,12 @@ func (c *LandController) Land(ctx context.Context, req *pb.LandRequest) (*pb.Lan
 	if req.Queue == "" {
 		return nil, fmt.Errorf("LandController requires the request to have a queue name specified: %w", ErrInvalidRequest)
 	}
-	if req.Change == nil || req.Change.Source == "" {
-		return nil, fmt.Errorf("LandController requires the request to have a change source specified: %w", ErrInvalidRequest)
-	}
-	if len(req.Change.GetIds()) == 0 {
-		return nil, fmt.Errorf("LandController requires the request to have at least one change ID specified: %w", ErrInvalidRequest)
+	if req.Change == nil || len(req.Change.Uris) == 0 {
+		return nil, fmt.Errorf("LandController requires the request to have at least one change URI specified: %w", ErrInvalidRequest)
 	}
 
 	change := entity.Change{
-		Source: req.Change.GetSource(),
-		IDs:    req.Change.GetIds(),
+		URIs: req.Change.GetUris(),
 	}
 
 	// TODO: validate that queue is configured. Return error if not.
@@ -104,8 +100,8 @@ func (c *LandController) Land(ctx context.Context, req *pb.LandRequest) (*pb.Lan
 	c.logger.Debugw("land request created",
 		"queue", req.Queue,
 		"sqid", request.ID,
-		"change_source", change.Source,
-		"change_ids", change.IDs,
+		"change_uris", change.URIs,
+		"change_count", len(change.URIs),
 		"strategy", string(strategy),
 	)
 
diff --git a/gateway/controller/land_test.go b/gateway/controller/land_test.go
index 9154e160..c0f425f9 100644
--- a/gateway/controller/land_test.go
+++ b/gateway/controller/land_test.go
@@ -248,7 +248,7 @@ func TestLand_ReturnsSqid(t *testing.T) {
 
 	req := &pb.LandRequest{
 		Queue:  "test-queue",
-		Change: &pb.Change{Source: "github", Ids: []string{"123"}},
+		Change: &pb.Change{Uris: []string{"github://uber/test-repo/pull/123/abc123def"}},
 	}
 	resp, err := controller.Land(ctx, req)
 
@@ -280,7 +280,7 @@ func TestLand_PassesCorrectParametersToStore(t *testing.T) {
 
 	req := &pb.LandRequest{
 		Queue:    "my-queue",
-		Change:   &pb.Change{Source: "github", Ids: []string{"pr-1", "pr-2"}},
+		Change:   &pb.Change{Uris: []string{"github://uber/myservice/pull/1/abc111", "github://uber/myservice/pull/2/def222"}},
 		Strategy: pb.Strategy_REBASE,
 	}
 	resp, err := controller.Land(ctx, req)
@@ -288,8 +288,7 @@ func TestLand_PassesCorrectParametersToStore(t *testing.T) {
 	require.NoError(t, err)
 	assert.Equal(t, "my-queue/42", capturedRequest.ID)
 	assert.Equal(t, "my-queue", capturedRequest.Queue)
-	assert.Equal(t, "github", capturedRequest.Change.Source)
-	assert.Equal(t, []string{"pr-1", "pr-2"}, capturedRequest.Change.IDs)
+	assert.Equal(t, []string{"github://uber/myservice/pull/1/abc111", "github://uber/myservice/pull/2/def222"}, capturedRequest.Change.URIs)
 	assert.Equal(t, entity.RequestLandStrategyRebase, capturedRequest.LandStrategy)
 	assert.Equal(t, entity.RequestStateNew, capturedRequest.State)
 	assert.Equal(t, int32(1), capturedRequest.Version)
@@ -317,7 +316,7 @@ func TestLand_ReturnsErrorOnStorageFailure(t *testing.T) {
 
 	req := &pb.LandRequest{
 		Queue:  "test-queue",
-		Change: &pb.Change{Source: "github", Ids: []string{"123"}},
+		Change: &pb.Change{Uris: []string{"github://uber/test-repo/pull/123/abc123def"}},
 	}
 	_, err := controller.Land(ctx, req)
 
@@ -345,7 +344,7 @@ func TestLand_ReturnsErrorOnCounterFailure(t *testing.T) {
 
 	req := &pb.LandRequest{
 		Queue:  "test-queue",
-		Change: &pb.Change{Source: "github", Ids: []string{"123"}},
+		Change: &pb.Change{Uris: []string{"github://uber/test-repo/pull/123/abc123def"}},
 	}
 	_, err := controller.Land(ctx, req)
 
@@ -376,7 +375,7 @@ func TestLand_CounterDomainIncludesQueue(t *testing.T) {
 
 	req := &pb.LandRequest{
 		Queue:  "my-queue",
-		Change: &pb.Change{Source: "github", Ids: []string{"123"}},
+		Change: &pb.Change{Uris: []string{"github://uber/test-repo/pull/123/abc123def"}},
 	}
 	_, err := controller.Land(ctx, req)
 
@@ -398,7 +397,7 @@ func TestLand_ReturnsErrorOnEmptyQueue(t *testing.T) {
 
 	req := &pb.LandRequest{
 		Queue:  "",
-		Change: &pb.Change{Source: "github", Ids: []string{"123"}},
+		Change: &pb.Change{Uris: []string{"github://uber/test-repo/pull/123/abc123def"}},
 	}
 	_, err := controller.Land(ctx, req)
 
@@ -406,7 +405,7 @@ func TestLand_ReturnsErrorOnEmptyQueue(t *testing.T) {
 	assert.True(t, IsInvalidRequest(err))
 }
 
-func TestLand_ReturnsErrorOnEmptyChangeSource(t *testing.T) {
+func TestLand_ReturnsErrorOnEmptyChangeUri(t *testing.T) {
 	store := &mockStorage{requestStore: &mockRequestStore{
 		createFunc: func(ctx context.Context, request entity.Request) error {
 			return nil
@@ -420,7 +419,7 @@ func TestLand_ReturnsErrorOnEmptyChangeSource(t *testing.T) {
 
 	req := &pb.LandRequest{
 		Queue:  "test-queue",
-		Change: &pb.Change{Source: "", Ids: []string{"123"}},
+		Change: &pb.Change{Uris: []string{}},
 	}
 	_, err := controller.Land(ctx, req)
 
@@ -450,28 +449,6 @@ func TestLand_ReturnsErrorOnNilChange(t *testing.T) {
 	assert.True(t, IsInvalidRequest(err))
 }
 
-func TestLand_ReturnsErrorOnEmptyChangeIDs(t *testing.T) {
-	store := &mockStorage{requestStore: &mockRequestStore{
-		createFunc: func(ctx context.Context, request entity.Request) error {
-			return nil
-		},
-	}}
-	cnt := &mockCounter{nextFunc: func(ctx context.Context, domain string) (int64, error) {
-		return 1, nil
-	}}
-	controller := NewLandController(zap.NewNop().Sugar(), tally.NoopScope, store, cnt, noopPublisher(), "request")
-	ctx := context.Background()
-
-	req := &pb.LandRequest{
-		Queue:  "test-queue",
-		Change: &pb.Change{Source: "github", Ids: []string{}},
-	}
-	_, err := controller.Land(ctx, req)
-
-	require.Error(t, err)
-	assert.True(t, IsInvalidRequest(err))
-}
-
 func TestLand_PublishesToQueue(t *testing.T) {
 	var publishedTopic string
 	var publishedMessage queue.Message
@@ -495,7 +472,7 @@ func TestLand_PublishesToQueue(t *testing.T) {
 
 	req := &pb.LandRequest{
 		Queue:    "test-queue",
-		Change:   &pb.Change{Source: "github", Ids: []string{"PR-456"}},
+		Change:   &pb.Change{Uris: []string{"github://uber/backend/pull/456/fed987cba"}},
 		Strategy: pb.Strategy_REBASE,
 	}
 	resp, err := controller.Land(ctx, req)
@@ -513,8 +490,7 @@ func TestLand_PublishesToQueue(t *testing.T) {
 	require.NoError(t, err)
 	assert.Equal(t, "test-queue/123", deserializedReq.ID)
 	assert.Equal(t, "test-queue", deserializedReq.Queue)
-	assert.Equal(t, "github", deserializedReq.Change.Source)
-	assert.Equal(t, []string{"PR-456"}, deserializedReq.Change.IDs)
+	assert.Equal(t, []string{"github://uber/backend/pull/456/fed987cba"}, deserializedReq.Change.URIs)
 	assert.Equal(t, entity.RequestLandStrategyRebase, deserializedReq.LandStrategy)
 	assert.Equal(t, entity.RequestStateNew, deserializedReq.State)
 	assert.Equal(t, int32(1), deserializedReq.Version)
@@ -538,7 +514,7 @@ func TestLand_ContinuesWhenPublishFails(t *testing.T) {
 
 	req := &pb.LandRequest{
 		Queue:  "test-queue",
-		Change: &pb.Change{Source: "github", Ids: []string{"PR-1"}},
+		Change: &pb.Change{Uris: []string{"github://uber/service/pull/1/abc123def"}},
 	}
 	_, err := controller.Land(ctx, req)
 
diff --git a/gateway/proto/gateway.proto b/gateway/proto/gateway.proto
index 44a2a10b..e1495193 100644
--- a/gateway/proto/gateway.proto
+++ b/gateway/proto/gateway.proto
@@ -41,14 +41,20 @@ enum Strategy {
     MERGE = 3;
 }
 
-// Change represents a set of related code changes identified by one or more IDs from a particular code change provider, like Github Pull Requests.
+// Change represents a code change identified by URIs from a code change provider (e.g., GitHub Pull Request, Phabricator Diff).
+// The provider is extracted from the URI scheme.
 message Change {
-    // The code change provider (e.g., "github", "gerrit", "phabricator").
-    string source = 1;
-    // List of change IDs, in a format specific to the code change provider, that should be landed together. SubmitQueue guarantees that the changes are landed in the order of the list,
-    // and no other changes are landed in between. SubmitQueue does not guarantee that each change is individually valid, but produces a special validity
-    // marker on such changes. The user is responsible to include all changes in a change stack in the order of the list, starting from the earlist change.
-    repeated string ids = 2;
+    // URIs identifying the change(s) to land (RFC 3986 compliant).
+    // The scheme identifies the change provider, and the path contains provider-specific resource identifiers.
+    //
+    // GitHub is supported by default (though other providers can be added):
+    //   Template: "github://<org>/<repo>/pull/<pr>/<hash>"
+    //   Example: "github://uber/submitqueue/pull/123/abc123def"
+    //
+    // SubmitQueue guarantees changes are landed in order with no other changes in between.
+    // SubmitQueue does not guarantee each change is individually valid, but produces a validity marker on such changes.
+    // The user is responsible for including all changes in a stack in order, starting from the earliest change.
+    repeated string uris = 1;
 }
 
 // LandRequest defines a request to land (merge into target branch of the source control repository) a set of code changes.
diff --git a/gateway/protopb/gateway.pb.go b/gateway/protopb/gateway.pb.go
index 175058b8..cfc144d5 100644
--- a/gateway/protopb/gateway.pb.go
+++ b/gateway/protopb/gateway.pb.go
@@ -197,15 +197,22 @@ func (x *PingResponse) GetHostname() string {
 	return ""
 }
 
-// Change represents a set of related code changes identified by one or more IDs from a particular code change provider, like Github Pull Requests.
+// Change represents a code change identified by URIs from a code change provider (e.g., GitHub Pull Request, Phabricator Diff).
+// The provider is extracted from the URI scheme.
 type Change struct {
 	state protoimpl.MessageState `protogen:"open.v1"`
-	// The code change provider (e.g., "github", "gerrit", "phabricator").
-	Source string `protobuf:"bytes,1,opt,name=source,proto3" json:"source,omitempty"`
-	// List of change IDs, in a format specific to the code change provider, that should be landed together. SubmitQueue guarantees that the changes are landed in the order of the list,
-	// and no other changes are landed in between. SubmitQueue does not guarantee that each change is individually valid, but produces a special validity
-	// marker on such changes. The user is responsible to include all changes in a change stack in the order of the list, starting from the earlist change.
-	Ids           []string `protobuf:"bytes,2,rep,name=ids,proto3" json:"ids,omitempty"`
+	// URIs identifying the change(s) to land (RFC 3986 compliant).
+	// The scheme identifies the change provider, and the path contains provider-specific resource identifiers.
+	//
+	// GitHub is supported by default (though other providers can be added):
+	//
+	//	Template: "github://<org>/<repo>/pull/<pr>/<hash>"
+	//	Example: "github://uber/submitqueue/pull/123/abc123def"
+	//
+	// SubmitQueue guarantees changes are landed in order with no other changes in between.
+	// SubmitQueue does not guarantee each change is individually valid, but produces a validity marker on such changes.
+	// The user is responsible for including all changes in a stack in order, starting from the earliest change.
+	Uris          []string `protobuf:"bytes,1,rep,name=uris,proto3" json:"uris,omitempty"`
 	unknownFields protoimpl.UnknownFields
 	sizeCache     protoimpl.SizeCache
 }
@@ -240,16 +247,9 @@ func (*Change) Descriptor() ([]byte, []int) {
 	return file_gateway_proto_rawDescGZIP(), []int{2}
 }
 
-func (x *Change) GetSource() string {
+func (x *Change) GetUris() []string {
 	if x != nil {
-		return x.Source
-	}
-	return ""
-}
-
-func (x *Change) GetIds() []string {
-	if x != nil {
-		return x.Ids
+		return x.Uris
 	}
 	return nil
 }
@@ -476,10 +476,9 @@ const file_gateway_proto_rawDesc = "" +
 	"\amessage\x18\x01 \x01(\tR\amessage\x12!\n" +
 	"\fservice_name\x18\x02 \x01(\tR\vserviceName\x12\x1c\n" +
 	"\ttimestamp\x18\x03 \x01(\x03R\ttimestamp\x12\x1a\n" +
-	"\bhostname\x18\x04 \x01(\tR\bhostname\"2\n" +
-	"\x06Change\x12\x16\n" +
-	"\x06source\x18\x01 \x01(\tR\x06source\x12\x10\n" +
-	"\x03ids\x18\x02 \x03(\tR\x03ids\"\xab\x01\n" +
+	"\bhostname\x18\x04 \x01(\tR\bhostname\"\x1c\n" +
+	"\x06Change\x12\x12\n" +
+	"\x04uris\x18\x01 \x03(\tR\x04uris\"\xab\x01\n" +
 	"\vLandRequest\x12\x14\n" +
 	"\x05queue\x18\x01 \x01(\tR\x05queue\x12?\n" +
 	"\x06change\x18\x02 \x01(\v2'.uber.devexp.submitqueue.gateway.ChangeR\x06change\x12E\n" +
diff --git a/gateway/protopb/gateway.pb.yarpc.go b/gateway/protopb/gateway.pb.yarpc.go
index c1cbe323..17760cd6 100644
--- a/gateway/protopb/gateway.pb.yarpc.go
+++ b/gateway/protopb/gateway.pb.yarpc.go
@@ -283,37 +283,36 @@ var (
 var yarpcFileDescriptorClosuref1a937782ebbded5 = [][]byte{
 	// gateway.proto
 	[]byte{
-		0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x8c, 0x93, 0xcd, 0x6e, 0xd3, 0x4e,
-		0x14, 0xc5, 0xe3, 0x38, 0x71, 0x93, 0xeb, 0xf4, 0xaf, 0xfc, 0x47, 0xa8, 0xb2, 0x2a, 0x24, 0x52,
-		0x23, 0xd1, 0xf0, 0xe5, 0x48, 0x66, 0x8b, 0x84, 0x12, 0x30, 0x65, 0x51, 0x50, 0x6a, 0x93, 0x0d,
-		0x9b, 0xca, 0x1f, 0x57, 0x8e, 0x25, 0xec, 0x71, 0x66, 0xc6, 0x85, 0xb2, 0xe7, 0x69, 0x78, 0x2b,
-		0x9e, 0x04, 0x79, 0x3c, 0x69, 0xbd, 0x01, 0x67, 0x77, 0xef, 0xf8, 0xfe, 0x7c, 0xce, 0x9c, 0x99,
-		0x81, 0xe3, 0x34, 0x14, 0xf8, 0x2d, 0xbc, 0x75, 0x4a, 0x46, 0x05, 0x25, 0x8f, 0xaa, 0x08, 0x99,
-		0x93, 0xe0, 0x0d, 0x7e, 0x2f, 0x1d, 0x5e, 0x45, 0x79, 0x26, 0x76, 0x15, 0x56, 0xe8, 0xa8, 0x31,
-		0xfb, 0x1c, 0xcc, 0x75, 0x56, 0xa4, 0x3e, 0xee, 0x2a, 0xe4, 0x82, 0x58, 0x70, 0x94, 0x23, 0xe7,
-		0x61, 0x8a, 0x96, 0x36, 0xd3, 0xe6, 0x63, 0x7f, 0xdf, 0xda, 0x3f, 0x35, 0x98, 0x34, 0x93, 0xbc,
-		0xa4, 0x05, 0xc7, 0xbf, 0x8f, 0x92, 0x33, 0x98, 0x70, 0x64, 0x37, 0x59, 0x8c, 0xd7, 0x45, 0x98,
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-		0x22, 0xcc, 0x4b, 0x4b, 0x9f, 0x69, 0x73, 0xdd, 0xbf, 0x5f, 0x20, 0xa7, 0x30, 0xda, 0x52, 0x2e,
-		0x24, 0x3c, 0x90, 0xf0, 0x5d, 0x6f, 0xbb, 0x60, 0xbc, 0xdd, 0x86, 0x45, 0x8a, 0xe4, 0x04, 0x0c,
-		0x4e, 0x2b, 0x16, 0xef, 0xf5, 0x55, 0x47, 0xa6, 0xa0, 0x67, 0x09, 0xb7, 0xfa, 0x33, 0x7d, 0x3e,
-		0xf6, 0xeb, 0xd2, 0xfe, 0xa5, 0x81, 0x79, 0x19, 0x16, 0xc9, 0x7e, 0x97, 0x0f, 0x60, 0x28, 0x53,
-		0x50, 0x60, 0xd3, 0x90, 0x37, 0x60, 0xc4, 0xf2, 0xcf, 0xd2, 0xb0, 0xe9, 0x9e, 0x3b, 0x1d, 0xe1,
-		0x39, 0x8d, 0x11, 0x5f, 0x61, 0xc4, 0x83, 0x11, 0x17, 0x2c, 0x14, 0x98, 0xde, 0x4a, 0xdb, 0xff,
-		0xb9, 0x4f, 0x3b, 0x7f, 0x11, 0x28, 0xc0, 0xbf, 0x43, 0x6d, 0x1b, 0x26, 0x8d, 0x59, 0x15, 0x34,
-		0x81, 0x01, 0xdf, 0x65, 0x89, 0x32, 0x2b, 0x6b, 0xfb, 0x0c, 0x86, 0x1e, 0x63, 0x94, 0xfd, 0xe3,
-		0xc0, 0xbe, 0xc2, 0xc9, 0xa6, 0x60, 0x18, 0xd3, 0xb4, 0xc8, 0x7e, 0x60, 0x72, 0x55, 0xcb, 0x36,
-		0xcc, 0x6b, 0x18, 0x62, 0x5d, 0x48, 0xc2, 0x74, 0x9f, 0x74, 0x9a, 0x94, 0x98, 0xdf, 0x40, 0xf7,
-		0xe1, 0xf5, 0x5b, 0xe1, 0x3d, 0x5b, 0xc2, 0x68, 0xbf, 0x15, 0x62, 0xc2, 0xd1, 0x3b, 0xef, 0xfd,
-		0x72, 0x73, 0xf9, 0x79, 0xda, 0x23, 0x00, 0x86, 0xef, 0xad, 0x96, 0x81, 0x37, 0xd5, 0xc8, 0xff,
-		0x70, 0x1c, 0x5c, 0x6d, 0x96, 0xc1, 0x87, 0x6b, 0xb5, 0xd4, 0x27, 0x63, 0x18, 0x7e, 0xf4, 0xfc,
-		0x0b, 0x6f, 0xaa, 0xbb, 0xbf, 0x35, 0x20, 0x81, 0x54, 0x97, 0x5e, 0x2f, 0x1a, 0x71, 0x82, 0x30,
-		0xa8, 0xef, 0x1d, 0x79, 0xd1, 0x69, 0xb3, 0x75, 0x91, 0x4f, 0x5f, 0x1e, 0x38, 0xdd, 0x64, 0x6c,
-		0xf7, 0x6a, 0x99, 0x3a, 0xf5, 0x03, 0x64, 0x5a, 0x37, 0xe9, 0x00, 0x99, 0xf6, 0x51, 0xda, 0xbd,
-		0x55, 0x04, 0x8f, 0x63, 0x9a, 0x77, 0x51, 0xab, 0x89, 0xda, 0xfd, 0xba, 0x7e, 0xc5, 0x6b, 0xed,
-		0xcb, 0xf3, 0x34, 0x13, 0xdb, 0x2a, 0x72, 0x62, 0x9a, 0x2f, 0x6a, 0x76, 0xd1, 0x82, 0x16, 0x0a,
-		0x5a, 0xc8, 0x27, 0x5f, 0x46, 0x91, 0x21, 0x8b, 0x57, 0x7f, 0x02, 0x00, 0x00, 0xff, 0xff, 0x20,
-		0x51, 0xf6, 0x91, 0x0c, 0x04, 0x00, 0x00,
+		0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0xff, 0x8c, 0x93, 0x5d, 0x6f, 0xd3, 0x3e,
+		0x14, 0xc6, 0x9b, 0xbe, 0xad, 0x3d, 0xe9, 0xfe, 0xea, 0xdf, 0x42, 0x28, 0x9a, 0x26, 0xd1, 0x19,
+		0x89, 0x95, 0xb7, 0x54, 0x2a, 0xb7, 0x48, 0xa8, 0x85, 0x30, 0x2e, 0x06, 0xea, 0x1c, 0x7a, 0xc3,
+		0xcd, 0xe4, 0xa4, 0x47, 0x69, 0x24, 0xf2, 0x52, 0xdb, 0x19, 0x8c, 0x7b, 0x3e, 0x0d, 0xdf, 0x8a,
+		0x4f, 0x82, 0xe2, 0xb8, 0x5b, 0x6e, 0x20, 0xbd, 0x3b, 0x76, 0xce, 0x2f, 0xcf, 0x73, 0x1e, 0xdb,
+		0x70, 0x1c, 0x71, 0x85, 0xdf, 0xf8, 0xad, 0x9b, 0x8b, 0x4c, 0x65, 0xe4, 0x51, 0x11, 0xa0, 0x70,
+		0x37, 0x78, 0x83, 0xdf, 0x73, 0x57, 0x16, 0x41, 0x12, 0xab, 0x5d, 0x81, 0x05, 0xba, 0xa6, 0x8d,
+		0x9e, 0x83, 0xbd, 0x8a, 0xd3, 0x88, 0xe1, 0xae, 0x40, 0xa9, 0x88, 0x03, 0x47, 0x09, 0x4a, 0xc9,
+		0x23, 0x74, 0xac, 0x89, 0x35, 0x1d, 0xb2, 0xfd, 0x92, 0xfe, 0xb4, 0x60, 0x54, 0x75, 0xca, 0x3c,
+		0x4b, 0x25, 0xfe, 0xbd, 0x95, 0x9c, 0xc1, 0x48, 0xa2, 0xb8, 0x89, 0x43, 0xbc, 0x4e, 0x79, 0x82,
+		0x4e, 0x5b, 0x7f, 0xb6, 0xcd, 0xde, 0x27, 0x9e, 0x20, 0x39, 0x85, 0xa1, 0x8a, 0x13, 0x94, 0x8a,
+		0x27, 0xb9, 0xd3, 0x99, 0x58, 0xd3, 0x0e, 0xbb, 0xdf, 0x20, 0x27, 0x30, 0xd8, 0x66, 0x52, 0x69,
+		0xb8, 0xab, 0xe1, 0xbb, 0x35, 0x3d, 0x85, 0xfe, 0xdb, 0x2d, 0x4f, 0x23, 0x24, 0x04, 0xba, 0x85,
+		0x88, 0xa5, 0x63, 0x4d, 0x3a, 0xd3, 0x21, 0xd3, 0x35, 0xfd, 0x65, 0x81, 0x7d, 0xc9, 0xd3, 0xcd,
+		0x7e, 0x9e, 0x07, 0xd0, 0xd3, 0xf3, 0x1a, 0x8b, 0xd5, 0x82, 0xbc, 0x81, 0x7e, 0xa8, 0xff, 0xa1,
+		0xad, 0xd9, 0xf3, 0x73, 0xb7, 0x21, 0x26, 0xb7, 0x92, 0x64, 0x06, 0x23, 0x1e, 0x0c, 0xa4, 0x12,
+		0x5c, 0x61, 0x74, 0xab, 0x0d, 0xfe, 0x37, 0x7f, 0xda, 0xf8, 0x0b, 0xdf, 0x00, 0xec, 0x0e, 0xa5,
+		0x14, 0x46, 0x95, 0x59, 0x13, 0x29, 0x81, 0xae, 0xdc, 0xc5, 0x1b, 0x63, 0x56, 0xd7, 0xf4, 0x0c,
+		0x7a, 0x9e, 0x10, 0x99, 0xf8, 0xc7, 0xd1, 0x7c, 0x85, 0x87, 0xeb, 0x54, 0x60, 0x98, 0x45, 0x69,
+		0xfc, 0x03, 0x37, 0x57, 0xa5, 0x6c, 0xc5, 0xbc, 0x86, 0x1e, 0x96, 0x85, 0x26, 0xec, 0xf9, 0x93,
+		0x46, 0x93, 0x1a, 0x63, 0x15, 0x74, 0x1f, 0x5e, 0xbb, 0x16, 0xde, 0xb3, 0x05, 0x0c, 0xf6, 0xa3,
+		0x10, 0x1b, 0x8e, 0xde, 0x79, 0xef, 0x17, 0xeb, 0xcb, 0xcf, 0xe3, 0x16, 0x01, 0xe8, 0x33, 0x6f,
+		0xb9, 0xf0, 0xbd, 0xb1, 0x45, 0xfe, 0x87, 0x63, 0xff, 0x6a, 0xbd, 0xf0, 0x3f, 0x5c, 0x9b, 0xad,
+		0x36, 0x19, 0x42, 0xef, 0xa3, 0xc7, 0x2e, 0xbc, 0x71, 0x67, 0xfe, 0xdb, 0x02, 0xe2, 0x6b, 0x75,
+		0xed, 0xf5, 0xa2, 0x12, 0x27, 0x08, 0xdd, 0xf2, 0x86, 0x91, 0x17, 0x8d, 0x36, 0x6b, 0x57, 0xf6,
+		0xe4, 0xe5, 0x81, 0xdd, 0x55, 0xc6, 0xb4, 0x55, 0xca, 0x94, 0xa9, 0x1f, 0x20, 0x53, 0xbb, 0x49,
+		0x07, 0xc8, 0xd4, 0x8f, 0x92, 0xb6, 0x96, 0x01, 0x3c, 0x0e, 0xb3, 0xa4, 0x89, 0x5a, 0x8e, 0xcc,
+		0xf4, 0xab, 0xf2, 0xbd, 0xae, 0xac, 0x2f, 0xcf, 0xa3, 0x58, 0x6d, 0x8b, 0xc0, 0x0d, 0xb3, 0x64,
+		0x56, 0xb2, 0xb3, 0x1a, 0x34, 0x33, 0xd0, 0x4c, 0x3f, 0xee, 0x3c, 0x08, 0xfa, 0xba, 0x78, 0xf5,
+		0x27, 0x00, 0x00, 0xff, 0xff, 0xe8, 0x4d, 0xf1, 0x97, 0xf6, 0x03, 0x00, 0x00,
 	},
 }
 
diff --git a/orchestrator/controller/batch/batch_test.go b/orchestrator/controller/batch/batch_test.go
index 2383e6db..3b35167f 100644
--- a/orchestrator/controller/batch/batch_test.go
+++ b/orchestrator/controller/batch/batch_test.go
@@ -57,7 +57,7 @@ func TestController_Process_Success(t *testing.T) {
 	request := entity.Request{
 		ID:           "test-queue/123",
 		Queue:        "test-queue",
-		Change:       entity.Change{Source: "github", IDs: []string{"PR-456"}},
+		Change:       entity.Change{URIs: []string{"github://uber/service/pull/456/abc123def"}},
 		LandStrategy: entity.RequestLandStrategyRebase,
 		State:        entity.RequestStateNew,
 		Version:      1,
@@ -100,7 +100,7 @@ func TestController_Process_PublishFailure(t *testing.T) {
 	request := entity.Request{
 		ID:           "test-queue/123",
 		Queue:        "test-queue",
-		Change:       entity.Change{Source: "github", IDs: []string{"PR-1"}},
+		Change:       entity.Change{URIs: []string{"github://uber/service/pull/1/xyz789abc"}},
 		LandStrategy: entity.RequestLandStrategyRebase,
 		State:        entity.RequestStateNew,
 		Version:      1,
diff --git a/orchestrator/controller/build/build_test.go b/orchestrator/controller/build/build_test.go
index fa7b8d36..97fbd67e 100644
--- a/orchestrator/controller/build/build_test.go
+++ b/orchestrator/controller/build/build_test.go
@@ -57,7 +57,7 @@ func TestController_Process_Success(t *testing.T) {
 	request := entity.Request{
 		ID:           "test-queue/123",
 		Queue:        "test-queue",
-		Change:       entity.Change{Source: "github", IDs: []string{"PR-456"}},
+		Change:       entity.Change{URIs: []string{"github://uber/service/pull/456/abc123def"}},
 		LandStrategy: entity.RequestLandStrategyRebase,
 		State:        entity.RequestStateNew,
 		Version:      1,
@@ -100,7 +100,7 @@ func TestController_Process_PublishFailure(t *testing.T) {
 	request := entity.Request{
 		ID:           "test-queue/123",
 		Queue:        "test-queue",
-		Change:       entity.Change{Source: "github", IDs: []string{"PR-1"}},
+		Change:       entity.Change{URIs: []string{"github://uber/service/pull/1/xyz789abc"}},
 		LandStrategy: entity.RequestLandStrategyRebase,
 		State:        entity.RequestStateNew,
 		Version:      1,
diff --git a/orchestrator/controller/buildsignal/buildsignal_test.go b/orchestrator/controller/buildsignal/buildsignal_test.go
index 41792c59..b8f4cc6b 100644
--- a/orchestrator/controller/buildsignal/buildsignal_test.go
+++ b/orchestrator/controller/buildsignal/buildsignal_test.go
@@ -42,7 +42,7 @@ func TestController_Process_Success(t *testing.T) {
 	request := entity.Request{
 		ID:           "test-queue/123",
 		Queue:        "test-queue",
-		Change:       entity.Change{Source: "github", IDs: []string{"PR-456"}},
+		Change:       entity.Change{URIs: []string{"github://uber/service/pull/456/abc123def"}},
 		LandStrategy: entity.RequestLandStrategyRebase,
 		State:        entity.RequestStateNew,
 		Version:      1,
diff --git a/orchestrator/controller/finalize/finalize_test.go b/orchestrator/controller/finalize/finalize_test.go
index 609c0011..1f2fe7a7 100644
--- a/orchestrator/controller/finalize/finalize_test.go
+++ b/orchestrator/controller/finalize/finalize_test.go
@@ -42,7 +42,7 @@ func TestController_Process_Success(t *testing.T) {
 	request := entity.Request{
 		ID:           "test-queue/123",
 		Queue:        "test-queue",
-		Change:       entity.Change{Source: "github", IDs: []string{"PR-456"}},
+		Change:       entity.Change{URIs: []string{"github://uber/service/pull/456/abc123def"}},
 		LandStrategy: entity.RequestLandStrategyRebase,
 		State:        entity.RequestStateNew,
 		Version:      1,
diff --git a/orchestrator/controller/merge/merge_test.go b/orchestrator/controller/merge/merge_test.go
index efbe4146..1ff56e54 100644
--- a/orchestrator/controller/merge/merge_test.go
+++ b/orchestrator/controller/merge/merge_test.go
@@ -57,7 +57,7 @@ func TestController_Process_Success(t *testing.T) {
 	request := entity.Request{
 		ID:           "test-queue/123",
 		Queue:        "test-queue",
-		Change:       entity.Change{Source: "github", IDs: []string{"PR-456"}},
+		Change:       entity.Change{URIs: []string{"github://uber/service/pull/456/abc123def"}},
 		LandStrategy: entity.RequestLandStrategyRebase,
 		State:        entity.RequestStateNew,
 		Version:      1,
@@ -100,7 +100,7 @@ func TestController_Process_PublishFailure(t *testing.T) {
 	request := entity.Request{
 		ID:           "test-queue/123",
 		Queue:        "test-queue",
-		Change:       entity.Change{Source: "github", IDs: []string{"PR-1"}},
+		Change:       entity.Change{URIs: []string{"github://uber/service/pull/1/xyz789abc"}},
 		LandStrategy: entity.RequestLandStrategyRebase,
 		State:        entity.RequestStateNew,
 		Version:      1,
diff --git a/orchestrator/controller/mergesignal/mergesignal_test.go b/orchestrator/controller/mergesignal/mergesignal_test.go
index 228d4f42..a7f2f06e 100644
--- a/orchestrator/controller/mergesignal/mergesignal_test.go
+++ b/orchestrator/controller/mergesignal/mergesignal_test.go
@@ -42,7 +42,7 @@ func TestController_Process_Success(t *testing.T) {
 	request := entity.Request{
 		ID:           "test-queue/123",
 		Queue:        "test-queue",
-		Change:       entity.Change{Source: "github", IDs: []string{"PR-456"}},
+		Change:       entity.Change{URIs: []string{"github://uber/service/pull/456/abc123def"}},
 		LandStrategy: entity.RequestLandStrategyRebase,
 		State:        entity.RequestStateNew,
 		Version:      1,
diff --git a/orchestrator/controller/request/request.go b/orchestrator/controller/request/request.go
index 3b6f9a9e..71749bae 100644
--- a/orchestrator/controller/request/request.go
+++ b/orchestrator/controller/request/request.go
@@ -69,8 +69,8 @@ func (c *Controller) Process(ctx context.Context, delivery consumer.Delivery) er
 		"queue", request.Queue,
 		"state", string(request.State),
 		"land_strategy", string(request.LandStrategy),
-		"change_source", request.Change.Source,
-		"change_ids", request.Change.IDs,
+		"change_uris", request.Change.URIs,
+		"change_count", len(request.Change.URIs),
 		"version", request.Version,
 		"attempt", delivery.Attempt(),
 		"partition_key", msg.PartitionKey,
diff --git a/orchestrator/controller/request/request_test.go b/orchestrator/controller/request/request_test.go
index 1752d192..e08f1c77 100644
--- a/orchestrator/controller/request/request_test.go
+++ b/orchestrator/controller/request/request_test.go
@@ -57,7 +57,7 @@ func TestController_Process_Success(t *testing.T) {
 	request := entity.Request{
 		ID:           "test-queue/123",
 		Queue:        "test-queue",
-		Change:       entity.Change{Source: "github", IDs: []string{"PR-456"}},
+		Change:       entity.Change{URIs: []string{"github://uber/service/pull/456/abc123def"}},
 		LandStrategy: entity.RequestLandStrategyRebase,
 		State:        entity.RequestStateNew,
 		Version:      1,
@@ -115,7 +115,7 @@ func TestController_Process_AllRequestStates(t *testing.T) {
 			request := entity.Request{
 				ID:           fmt.Sprintf("queue/%s", tt.state),
 				Queue:        "test-queue",
-				Change:       entity.Change{Source: "github", IDs: []string{"PR-1"}},
+				Change:       entity.Change{URIs: []string{"github://uber/service/pull/1/aaa111bbb"}},
 				LandStrategy: tt.strategy,
 				State:        tt.state,
 				Version:      1,
@@ -144,8 +144,11 @@ func TestController_Process_MultipleChanges(t *testing.T) {
 		ID:    "queue/999",
 		Queue: "test-queue",
 		Change: entity.Change{
-			Source: "github",
-			IDs:    []string{"PR-1", "PR-2", "PR-3"},
+			URIs: []string{
+				"github://uber/monorepo/pull/1/aaa111",
+				"github://uber/monorepo/pull/2/bbb222",
+				"github://uber/monorepo/pull/3/ccc333",
+			},
 		},
 		LandStrategy: entity.RequestLandStrategySquashRebase,
 		State:        entity.RequestStateNew,
@@ -172,7 +175,7 @@ func TestController_Process_PublishFailure(t *testing.T) {
 	request := entity.Request{
 		ID:           "test-queue/123",
 		Queue:        "test-queue",
-		Change:       entity.Change{Source: "github", IDs: []string{"PR-1"}},
+		Change:       entity.Change{URIs: []string{"github://uber/service/pull/1/xyz789abc"}},
 		LandStrategy: entity.RequestLandStrategyRebase,
 		State:        entity.RequestStateNew,
 		Version:      1,
diff --git a/orchestrator/controller/speculate/speculate_test.go b/orchestrator/controller/speculate/speculate_test.go
index 56e38de3..452ca70a 100644
--- a/orchestrator/controller/speculate/speculate_test.go
+++ b/orchestrator/controller/speculate/speculate_test.go
@@ -60,7 +60,7 @@ func TestController_Process_Success(t *testing.T) {
 	request := entity.Request{
 		ID:           "test-queue/123",
 		Queue:        "test-queue",
-		Change:       entity.Change{Source: "github", IDs: []string{"PR-456"}},
+		Change:       entity.Change{URIs: []string{"github://uber/service/pull/456/abc123def"}},
 		LandStrategy: entity.RequestLandStrategyRebase,
 		State:        entity.RequestStateNew,
 		Version:      1,
@@ -103,7 +103,7 @@ func TestController_Process_PublishFailure(t *testing.T) {
 	request := entity.Request{
 		ID:           "test-queue/123",
 		Queue:        "test-queue",
-		Change:       entity.Change{Source: "github", IDs: []string{"PR-1"}},
+		Change:       entity.Change{URIs: []string{"github://uber/service/pull/1/xyz789abc"}},
 		LandStrategy: entity.RequestLandStrategyRebase,
 		State:        entity.RequestStateNew,
 		Version:      1,
diff --git a/test/e2e/suite_test.go b/test/e2e/suite_test.go
index 97539b4e..5cc7035d 100644
--- a/test/e2e/suite_test.go
+++ b/test/e2e/suite_test.go
@@ -111,16 +111,16 @@ func (s *E2EIntegrationSuite) TestPingOrchestrator() {
 	s.log.Logf("Orchestrator ping: %s", resp.Message)
 }
 
-func (s *E2EIntegrationSuite) TestLandRequest() {
+func (s *E2EIntegrationSuite) TestLandRequest_SinglePR() {
 	req := &gatewaypb.LandRequest{
 		Queue:    "e2e-test-queue",
-		Change:   &gatewaypb.Change{Source: "github", Ids: []string{"pr-100", "pr-101"}},
+		Change:   &gatewaypb.Change{Uris: []string{"github://uber/e2e-service/pull/123/abc123def"}},
 		Strategy: gatewaypb.Strategy_REBASE,
 	}
 
-	s.log.Logf("Sending Land request for queue=%s", req.Queue)
+	s.log.Logf("Sending Land request (single PR) for queue=%s", req.Queue)
 	resp, err := s.gatewayClient.Land(s.ctx, req)
 	require.NoError(s.T(), err, "Land request failed")
 	require.NotEmpty(s.T(), resp.Sqid, "SQID should not be empty")
-	s.log.Logf("Land request succeeded: sqid=%s", resp.Sqid)
+	s.log.Logf("Land request (single PR) succeeded: sqid=%s", resp.Sqid)
 }
diff --git a/test/integration/extension/storage/suite.go b/test/integration/extension/storage/suite.go
index 4a7df35b..5771b4dc 100644
--- a/test/integration/extension/storage/suite.go
+++ b/test/integration/extension/storage/suite.go
@@ -46,8 +46,7 @@ func (s *StorageContractSuite) TestStorage_CreateAndGet() {
 		Queue: "test-queue",
 		State: entity.RequestStateNew,
 		Change: entity.Change{
-			Source: "github",
-			IDs:    []string{"123"},
+			URIs: []string{"github://uber/storage-test/pull/123/abc123def"},
 		},
 		LandStrategy: entity.RequestLandStrategyMerge,
 		Version:      1,
@@ -65,14 +64,53 @@ func (s *StorageContractSuite) TestStorage_CreateAndGet() {
 	assert.Equal(t, request.ID, retrieved.ID)
 	assert.Equal(t, request.Queue, retrieved.Queue)
 	assert.Equal(t, request.State, retrieved.State)
-	assert.Equal(t, request.Change.Source, retrieved.Change.Source)
-	assert.Equal(t, request.Change.IDs, retrieved.Change.IDs)
+	assert.Equal(t, request.Change.URIs, retrieved.Change.URIs)
 	assert.Equal(t, request.LandStrategy, retrieved.LandStrategy)
 	assert.Equal(t, request.Version, retrieved.Version)
 
 	s.log.Logf("CreateAndGet test passed: created and retrieved request %s", request.ID)
 }
 
+// TestStorage_CreateAndGet_StackedPRs tests creating and retrieving a request with stacked PRs
+func (s *StorageContractSuite) TestStorage_CreateAndGet_StackedPRs() {
+	t := s.T()
+	ctx := s.ctx
+
+	// Stacked PRs as separate URIs
+	stackedURIs := []string{
+		"github://uber/monorepo/pull/101/aaa111bbb",
+		"github://uber/monorepo/pull/102/ccc222ddd",
+		"github://uber/monorepo/pull/103/eee333fff",
+		"github://uber/monorepo/pull/104/ggg444hhh",
+	}
+
+	request := entity.Request{
+		ID:    "test/stacked-prs",
+		Queue: "test-queue",
+		State: entity.RequestStateNew,
+		Change: entity.Change{
+			URIs: stackedURIs,
+		},
+		LandStrategy: entity.RequestLandStrategySquashRebase,
+		Version:      1,
+	}
+
+	// Create request
+	err := s.storage.GetRequestStore().Create(ctx, request)
+	require.NoError(t, err, "failed to create request with stacked PRs")
+
+	// Get request back
+	retrieved, err := s.storage.GetRequestStore().Get(ctx, request.ID)
+	require.NoError(t, err, "failed to get request with stacked PRs")
+
+	// Verify the stacked URIs are preserved
+	assert.Equal(t, stackedURIs, retrieved.Change.URIs, "stacked PR URIs should be preserved exactly")
+	assert.Equal(t, request.ID, retrieved.ID)
+	assert.Equal(t, request.LandStrategy, retrieved.LandStrategy)
+
+	s.log.Logf("CreateAndGet_StackedPRs test passed: %d stacked URIs", len(stackedURIs))
+}
+
 // TestStorage_UpdateState tests updating request state
 func (s *StorageContractSuite) TestStorage_UpdateState() {
 	t := s.T()
diff --git a/test/integration/gateway/suite_test.go b/test/integration/gateway/suite_test.go
index c16cf931..d7c65238 100644
--- a/test/integration/gateway/suite_test.go
+++ b/test/integration/gateway/suite_test.go
@@ -111,7 +111,7 @@ func (s *GatewayIntegrationSuite) TestLandAPI() {
 
 	req := &pb.LandRequest{
 		Queue:    "test-queue",
-		Change:   &pb.Change{Source: "github", Ids: []string{"PR-123"}},
+		Change:   &pb.Change{Uris: []string{"github://uber/integration-test/pull/123/abc123def"}},
 		Strategy: pb.Strategy_REBASE,
 	}