Merge branch 'nv/delete-v2-dashboard' into nv/patch-dashboard

ee/modules/dashboard/impldashboard/module.go

@@ -211,6 +211,10 @@ func (module *module) UpdateV2(ctx context.Context, orgID valuer.UUID, id valuer
 	return module.pkgDashboardModule.UpdateV2(ctx, orgID, id, updatedBy, updateable)
 }
 
+func (module *module) PatchV2(ctx context.Context, orgID valuer.UUID, id valuer.UUID, updatedBy string, patch dashboardtypes.PatchableDashboardV2) (*dashboardtypes.DashboardV2, error) {
+	return module.pkgDashboardModule.PatchV2(ctx, orgID, id, updatedBy, patch)
+}
+
 func (module *module) LockUnlockV2(ctx context.Context, orgID valuer.UUID, id valuer.UUID, updatedBy string, isAdmin bool, lock bool) error {
 	return module.pkgDashboardModule.LockUnlockV2(ctx, orgID, id, updatedBy, isAdmin, lock)
 }

go.mod

@@ -88,6 +88,7 @@ require (
 	gonum.org/v1/gonum v0.17.0
 	google.golang.org/api v0.265.0
 	google.golang.org/protobuf v1.36.11
+	gopkg.in/evanphx/json-patch.v4 v4.13.0
 	gopkg.in/yaml.v2 v2.4.0
 	gopkg.in/yaml.v3 v3.0.1
 	k8s.io/apimachinery v0.35.2

pkg/apiserver/signozapiserver/dashboard.go

@@ -64,6 +64,29 @@ func (provider *provider) addDashboardRoutes(router *mux.Router) error {
 		return err
 	}
 
+	if err := router.Handle("/api/v2/dashboards/{id}", handler.New(provider.authZ.EditAccess(provider.dashboardHandler.PatchV2), handler.OpenAPIDef{
+		ID:                  "PatchDashboardV2",
+		Tags:                []string{"dashboard"},
+		Summary:             "Patch dashboard (v2)",
+		Description:         "This endpoint applies an RFC 6902 JSON Patch to a v2-shape dashboard. The patch is applied against the postable view of the dashboard (metadata, data, tags), so individual panels, queries, variables, layouts, or tags can be updated without re-sending the rest of the dashboard. Locked dashboards are rejected.",
+		Request:             new(dashboardtypes.JSONPatchDocument),
+		// Strictly per RFC 6902 the content type is `application/json-patch+json`,
+		// but our OpenAPI generator only reflects schemas for content types it
+		// understands (application/json, form-urlencoded, multipart) — anything
+		// else degrades to `type: string`. Declaring application/json here keeps
+		// the array-of-ops schema visible to spec consumers; the runtime decoder
+		// parses JSON regardless of the request's actual Content-Type header.
+		RequestContentType:  "application/json",
+		Response:            new(dashboardtypes.GettableDashboardV2),
+		ResponseContentType: "application/json",
+		SuccessStatusCode:   http.StatusOK,
+		ErrorStatusCodes:    []int{},
+		Deprecated:          false,
+		SecuritySchemes:     newSecuritySchemes(types.RoleEditor),
+	})).Methods(http.MethodPatch).GetError(); err != nil {
+		return err
+	}
+
 	if err := router.Handle("/api/v2/dashboards/{id}/lock", handler.New(provider.authZ.EditAccess(provider.dashboardHandler.LockV2), handler.OpenAPIDef{
 		ID:                  "LockDashboardV2",
 		Tags:                []string{"dashboard"},

pkg/modules/dashboard/dashboard.go

@@ -63,6 +63,8 @@ type Module interface {
 
 	UpdateV2(ctx context.Context, orgID valuer.UUID, id valuer.UUID, updatedBy string, updateable dashboardtypes.UpdateableDashboardV2) (*dashboardtypes.DashboardV2, error)
 
+	PatchV2(ctx context.Context, orgID valuer.UUID, id valuer.UUID, updatedBy string, patch dashboardtypes.PatchableDashboardV2) (*dashboardtypes.DashboardV2, error)
+
 	LockUnlockV2(ctx context.Context, orgID valuer.UUID, id valuer.UUID, updatedBy string, isAdmin bool, lock bool) error
 
 	CreatePublicV2(ctx context.Context, orgID valuer.UUID, id valuer.UUID, postable dashboardtypes.PostablePublicDashboard) (*dashboardtypes.DashboardV2, error)
@@ -102,6 +104,8 @@ type Handler interface {
 
 	UpdateV2(http.ResponseWriter, *http.Request)
 
+	PatchV2(http.ResponseWriter, *http.Request)
+
 	LockV2(http.ResponseWriter, *http.Request)
 
 	UnlockV2(http.ResponseWriter, *http.Request)

pkg/modules/dashboard/impldashboard/v2_handler.go

@@ -182,6 +182,48 @@ func (handler *handler) UpdateV2(rw http.ResponseWriter, r *http.Request) {
 	render.Success(rw, http.StatusOK, dashboardtypes.NewGettableDashboardV2FromDashboardV2(dashboard))
 }
 
+func (handler *handler) PatchV2(rw http.ResponseWriter, r *http.Request) {
+	ctx, cancel := context.WithTimeout(r.Context(), 10*time.Second)
+	defer cancel()
+
+	claims, err := authtypes.ClaimsFromContext(ctx)
+	if err != nil {
+		render.Error(rw, err)
+		return
+	}
+
+	orgID, err := valuer.NewUUID(claims.OrgID)
+	if err != nil {
+		render.Error(rw, err)
+		return
+	}
+
+	id := mux.Vars(r)["id"]
+	if id == "" {
+		render.Error(rw, errors.Newf(errors.TypeInvalidInput, errors.CodeInvalidInput, "id is missing in the path"))
+		return
+	}
+	dashboardID, err := valuer.NewUUID(id)
+	if err != nil {
+		render.Error(rw, err)
+		return
+	}
+
+	req := dashboardtypes.PatchableDashboardV2{}
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		render.Error(rw, err)
+		return
+	}
+
+	dashboard, err := handler.module.PatchV2(ctx, orgID, dashboardID, claims.Email, req)
+	if err != nil {
+		render.Error(rw, err)
+		return
+	}
+
+	render.Success(rw, http.StatusOK, dashboardtypes.NewGettableDashboardV2FromDashboardV2(dashboard))
+}
+
 func (handler *handler) CreatePublicV2(rw http.ResponseWriter, r *http.Request) {
 	ctx, cancel := context.WithTimeout(r.Context(), 10*time.Second)
 	defer cancel()

pkg/modules/dashboard/impldashboard/v2_module.go

@@ -111,6 +111,51 @@ func (module *module) UpdateV2(ctx context.Context, orgID valuer.UUID, id valuer
 	return existing, nil
 }
 
+func (module *module) PatchV2(ctx context.Context, orgID valuer.UUID, id valuer.UUID, updatedBy string, patch dashboardtypes.PatchableDashboardV2) (*dashboardtypes.DashboardV2, error) {
+	existing, err := module.GetV2(ctx, orgID, id)
+	if err != nil {
+		return nil, err
+	}
+	if err := existing.CanUpdate(); err != nil {
+		return nil, err
+	}
+
+	updateable, err := patch.Apply(existing)
+	if err != nil {
+		return nil, err
+	}
+
+	resolvedTags, err := module.tagModule.CreateMany(ctx, orgID, updateable.Tags, updatedBy)
+	if err != nil {
+		return nil, err
+	}
+	tagIDs := make([]valuer.UUID, len(resolvedTags))
+	for i, t := range resolvedTags {
+		tagIDs[i] = t.ID
+	}
+
+	if err := existing.Update(*updateable, updatedBy, resolvedTags); err != nil {
+		return nil, err
+	}
+
+	storable, err := existing.ToStorableDashboard()
+	if err != nil {
+		return nil, err
+	}
+
+	err = module.sqlstore.RunInTxCtx(ctx, nil, func(ctx context.Context) error {
+		if err := module.tagModule.SyncLinksForEntity(ctx, orgID, dashboardtypes.EntityTypeDashboard, id, tagIDs); err != nil {
+			return err
+		}
+		return module.store.UpdateV2(ctx, orgID, id, updatedBy, storable.Data)
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return existing, nil
+}
+
 // CreatePublicV2 is not supported in the community build.
 func (module *module) CreatePublicV2(_ context.Context, _ valuer.UUID, _ valuer.UUID, _ dashboardtypes.PostablePublicDashboard) (*dashboardtypes.DashboardV2, error) {
 	return nil, errors.Newf(errors.TypeUnsupported, dashboardtypes.ErrCodePublicDashboardUnsupported, "not implemented")

pkg/types/dashboardtypes/perses_dashboard.go

@@ -9,6 +9,8 @@ import (
 	"github.com/SigNoz/signoz/pkg/types"
 	"github.com/SigNoz/signoz/pkg/types/tagtypes"
 	"github.com/SigNoz/signoz/pkg/valuer"
+	"github.com/swaggest/jsonschema-go"
+	jsonpatch "gopkg.in/evanphx/json-patch.v4"
 )
 
 const (
@@ -52,6 +54,88 @@ type PostableDashboardV2 struct {
 
 type UpdateableDashboardV2 = PostableDashboardV2
 
+// PatchableDashboardV2 is an RFC 6902 JSON Patch document applied against a
+// PostableDashboardV2-shaped view of an existing dashboard. Patch ops can
+// target any field — including individual entries inside `data.panels`,
+// `data.panels.<id>.spec.queries`, or `tags` — without re-sending the rest of
+// the dashboard.
+type PatchableDashboardV2 struct {
+	patch jsonpatch.Patch
+}
+
+// JSONPatchDocument is the OpenAPI-facing schema for an RFC 6902 patch body.
+// PatchableDashboardV2 has only an internal `jsonpatch.Patch` field, so the
+// reflector would emit an empty schema; the handler def points at this type
+// instead so consumers see the array-of-ops shape.
+type JSONPatchDocument []JSONPatchOperation
+
+// JSONPatchOperation is one RFC 6902 op. Not every field is valid on every
+// op kind (e.g. `value` is required for add/replace/test, ignored for remove;
+// `from` is required for move/copy) — the JSON Patch RFC governs that.
+type JSONPatchOperation struct {
+	Op    string `json:"op" required:"true"`
+	Path  string `json:"path" required:"true" description:"JSON Pointer (RFC 6901) into the dashboard's postable shape — e.g. /data/display/name, /data/panels/<id>, /data/panels/<id>/spec/queries/0, /tags/-."`
+	Value any    `json:"value,omitempty" description:"Value to add/replace/test against. The expected type depends on the path — a string for /data/display/name, a Panel for /data/panels/<id>, a PostableTag for /tags/-, etc. Required for add/replace/test; ignored for remove/move/copy."`
+	From  string `json:"from,omitempty" description:"Source JSON Pointer for move/copy ops; ignored for other ops."`
+}
+
+// PrepareJSONSchema constrains the `op` field to the six RFC 6902 verbs.
+func (JSONPatchOperation) PrepareJSONSchema(s *jsonschema.Schema) error {
+	op, ok := s.Properties["op"]
+	if !ok || op.TypeObject == nil {
+		return errors.NewInternalf(errors.CodeInternal, "JSONPatchOperation schema missing `op` property")
+	}
+	op.TypeObject.WithEnum("add", "remove", "replace", "move", "copy", "test")
+	s.Properties["op"] = op
+	return nil
+}
+
+func (p *PatchableDashboardV2) UnmarshalJSON(data []byte) error {
+	patch, err := jsonpatch.DecodePatch(data)
+	if err != nil {
+		return errors.WrapInvalidInputf(err, ErrCodeDashboardInvalidInput, "%s", err.Error())
+	}
+	p.patch = patch
+	return nil
+}
+
+// patchableDashboardV2View is the JSON shape a patch is applied against.
+// It mirrors PostableDashboardV2 except `tags` is always emitted (even when
+// empty) — RFC 6902 `add /tags/-` requires the array to exist in the target
+// document, and PostableDashboardV2's own `omitempty` on tags would drop it.
+type patchableDashboardV2View struct {
+	StoredDashboardInfo
+	Tags []tagtypes.PostableTag `json:"tags"`
+}
+
+// Apply runs the patch against the existing dashboard. The dashboard is
+// projected into the postable JSON shape, the patch is applied, and the
+// result is decoded back into an UpdateableDashboardV2 — which re-runs
+// the full v2 validation chain.
+func (p PatchableDashboardV2) Apply(existing *DashboardV2) (*UpdateableDashboardV2, error) {
+	postableTags := make([]tagtypes.PostableTag, len(existing.Info.Tags))
+	for i, t := range existing.Info.Tags {
+		postableTags[i] = tagtypes.PostableTag{Name: t.Name}
+	}
+	base := patchableDashboardV2View{
+		StoredDashboardInfo: existing.Info.StoredDashboardInfo,
+		Tags:                postableTags,
+	}
+	raw, err := json.Marshal(base)
+	if err != nil {
+		return nil, errors.WrapInternalf(err, errors.CodeInternal, "marshal existing dashboard for patch")
+	}
+	patched, err := p.patch.Apply(raw)
+	if err != nil {
+		return nil, errors.WrapInvalidInputf(err, ErrCodeDashboardInvalidInput, "%s", err.Error())
+	}
+	out := &UpdateableDashboardV2{}
+	if err := json.Unmarshal(patched, out); err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
 func (p *PostableDashboardV2) UnmarshalJSON(data []byte) error {
 	dec := json.NewDecoder(bytes.NewReader(data))
 	dec.DisallowUnknownFields()

pkg/types/dashboardtypes/perses_dashboard_patch_test.go

@@ -0,0 +1,521 @@
+package dashboardtypes
+
+import (
+	"encoding/json"
+	"strings"
+	"testing"
+
+	"github.com/SigNoz/signoz/pkg/types/tagtypes"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+// basePostableJSON is the postable shape of a small but realistic v2
+// dashboard used as the base document for patch tests. Each panel carries
+// one builder query in the same shape production dashboards use
+// (aggregations, filter, groupBy populated), and the dashboard has one
+// variable — the variable is not patched in any test here, that's
+// covered in a separate variable-focused suite.
+const basePostableJSON = `{
+	"metadata": {"schemaVersion": "v6"},
+	"data": {
+		"display": {"name": "Service overview"},
+		"variables": [
+			{
+				"kind": "ListVariable",
+				"spec": {
+					"name": "service",
+					"allowAllValue": true,
+					"allowMultiple": false,
+					"plugin": {
+						"kind": "signoz/DynamicVariable",
+						"spec": {"name": "service.name", "signal": "metrics"}
+					}
+				}
+			}
+		],
+		"panels": {
+			"p1": {
+				"kind": "Panel",
+				"spec": {
+					"plugin": {"kind": "signoz/TimeSeriesPanel", "spec": {}},
+					"queries": [
+						{
+							"kind": "TimeSeriesQuery",
+							"spec": {"plugin": {"kind": "signoz/BuilderQuery", "spec": {
+								"name": "A",
+								"signal": "metrics",
+								"aggregations": [{
+									"metricName": "signoz_calls_total",
+									"temporality": "cumulative",
+									"timeAggregation": "rate",
+									"spaceAggregation": "sum"
+								}],
+								"filter": {"expression": "service.name IN $service"},
+								"groupBy": [{"name": "service.name", "fieldDataType": "string", "fieldContext": "tag"}]
+							}}}
+						}
+					]
+				}
+			},
+			"p2": {
+				"kind": "Panel",
+				"spec": {
+					"plugin": {"kind": "signoz/NumberPanel", "spec": {}},
+					"queries": [
+						{
+							"kind": "TimeSeriesQuery",
+							"spec": {"plugin": {"kind": "signoz/BuilderQuery", "spec": {
+								"name": "X",
+								"signal": "metrics",
+								"aggregations": [{
+									"metricName": "signoz_latency_count",
+									"temporality": "cumulative",
+									"timeAggregation": "rate",
+									"spaceAggregation": "sum"
+								}]
+							}}}
+						}
+					]
+				}
+			}
+		},
+		"layouts": [
+			{
+				"kind": "Grid",
+				"spec": {
+					"display": {"title": "Row 1"},
+					"items": [
+						{"x": 0, "y": 0, "width": 6, "height": 6, "content": {"$ref": "#/spec/panels/p1"}},
+						{"x": 6, "y": 0, "width": 6, "height": 6, "content": {"$ref": "#/spec/panels/p2"}}
+					]
+				}
+			}
+		],
+		"duration": "1h"
+	},
+	"tags": [{"name": "team/alpha"}, {"name": "env/prod"}]
+}`
+
+func TestPatchableDashboardV2_Apply(t *testing.T) {
+	// Apply doesn't mutate the input *DashboardV2 — it marshals it to
+	// JSON, applies the patch, and unmarshals the result into a fresh
+	// struct. Sharing one base across subtests is safe.
+	var p PostableDashboardV2
+	require.NoError(t, json.Unmarshal([]byte(basePostableJSON), &p), "base postable JSON must validate")
+	base := &DashboardV2{
+		Info: DashboardInfo{
+			StoredDashboardInfo: p.StoredDashboardInfo,
+			Tags: []*tagtypes.Tag{
+				{Name: "team/alpha", InternalName: "team::alpha"},
+				{Name: "env/prod", InternalName: "env::prod"},
+			},
+		},
+	}
+
+	decode := func(t *testing.T, body string) PatchableDashboardV2 {
+		t.Helper()
+		var patch PatchableDashboardV2
+		require.NoError(t, json.Unmarshal([]byte(body), &patch))
+		return patch
+	}
+
+	// jsonOf marshals the patched dashboard back to JSON so subtests can
+	// assert on field values without reaching into the typed plugin specs.
+	jsonOf := func(t *testing.T, out *UpdateableDashboardV2) string {
+		t.Helper()
+		raw, err := json.Marshal(out)
+		require.NoError(t, err)
+		return string(raw)
+	}
+
+	// ─────────────────────────────────────────────────────────────────
+	// Successful patches
+	// ─────────────────────────────────────────────────────────────────
+
+	t.Run("no-op preserves all fields", func(t *testing.T) {
+		out, err := decode(t, `[]`).Apply(base)
+		require.NoError(t, err)
+		assert.Equal(t, base.Info.Metadata, out.Metadata)
+		assert.Equal(t, base.Info.Data.Display.Name, out.Data.Display.Name)
+		require.Equal(t, len(base.Info.Data.Panels), len(out.Data.Panels))
+		for k, panel := range base.Info.Data.Panels {
+			require.Contains(t, out.Data.Panels, k)
+			assert.Equal(t, panel.Spec.Plugin.Kind, out.Data.Panels[k].Spec.Plugin.Kind)
+		}
+		assert.Len(t, out.Tags, len(base.Info.Tags))
+		assert.Len(t, out.Data.Variables, len(base.Info.Data.Variables))
+		assert.Len(t, out.Data.Layouts, len(base.Info.Data.Layouts))
+	})
+
+	t.Run("add metadata image", func(t *testing.T) {
+		out, err := decode(t, `[{"op": "add", "path": "/metadata/image", "value": "https://example.com/img.png"}]`).Apply(base)
+		require.NoError(t, err)
+		assert.Equal(t, "https://example.com/img.png", out.Metadata.Image)
+		assert.Equal(t, SchemaVersion, out.Metadata.SchemaVersion, "schemaVersion preserved")
+	})
+
+	t.Run("replace display name", func(t *testing.T) {
+		out, err := decode(t, `[{"op": "replace", "path": "/data/display/name", "value": "Renamed"}]`).Apply(base)
+		require.NoError(t, err)
+		assert.Equal(t, "Renamed", out.Data.Display.Name)
+	})
+
+	// Per RFC 6902 § 4.1, `add` on an existing object member replaces the
+	// existing value rather than erroring — same effect as `replace`.
+	t.Run("add overwrites existing display name", func(t *testing.T) {
+		out, err := decode(t, `[{"op": "add", "path": "/data/display/name", "value": "Overwritten"}]`).Apply(base)
+		require.NoError(t, err)
+		assert.Equal(t, "Overwritten", out.Data.Display.Name)
+	})
+
+	t.Run("add data refreshInterval", func(t *testing.T) {
+		out, err := decode(t, `[{"op": "add", "path": "/data/refreshInterval", "value": "30s"}]`).Apply(base)
+		require.NoError(t, err)
+		assert.Equal(t, "30s", string(out.Data.RefreshInterval))
+	})
+
+	t.Run("add panel leaves others untouched", func(t *testing.T) {
+		out, err := decode(t, `[{
+			"op": "add",
+			"path": "/data/panels/p3",
+			"value": {
+				"kind": "Panel",
+				"spec": {
+					"plugin": {"kind": "signoz/TablePanel", "spec": {}},
+					"queries": [{
+						"kind": "TimeSeriesQuery",
+						"spec": {"plugin": {"kind": "signoz/BuilderQuery", "spec": {
+							"name": "A",
+							"signal": "logs",
+							"aggregations": [{"expression": "count()"}]
+						}}}
+					}]
+				}
+			}
+		}]`).Apply(base)
+		require.NoError(t, err)
+		assert.Len(t, out.Data.Panels, 3)
+		assert.Contains(t, out.Data.Panels, "p1")
+		assert.Contains(t, out.Data.Panels, "p2")
+		assert.Contains(t, out.Data.Panels, "p3")
+	})
+
+	t.Run("replace single panel", func(t *testing.T) {
+		out, err := decode(t, `[{
+			"op": "replace",
+			"path": "/data/panels/p2",
+			"value": {
+				"kind": "Panel",
+				"spec": {
+					"plugin": {"kind": "signoz/BarChartPanel", "spec": {}},
+					"queries": [{
+						"kind": "TimeSeriesQuery",
+						"spec": {"plugin": {"kind": "signoz/BuilderQuery", "spec": {
+							"name": "A",
+							"signal": "metrics",
+							"aggregations": [{
+								"metricName": "signoz_calls_total",
+								"temporality": "cumulative",
+								"timeAggregation": "rate",
+								"spaceAggregation": "sum"
+							}]
+						}}}
+					}]
+				}
+			}
+		}]`).Apply(base)
+		require.NoError(t, err)
+		assert.Equal(t, PanelPluginKind("signoz/BarChartPanel"), out.Data.Panels["p2"].Spec.Plugin.Kind)
+		assert.Equal(t, PanelPluginKind("signoz/TimeSeriesPanel"), out.Data.Panels["p1"].Spec.Plugin.Kind, "p1 untouched")
+	})
+
+	// Removing a panel realistically also drops its layout item — exercise
+	// the multi-op shape the UI sends.
+	t.Run("remove panel and its layout item", func(t *testing.T) {
+		out, err := decode(t, `[
+			{"op": "remove", "path": "/data/panels/p2"},
+			{"op": "remove", "path": "/data/layouts/0/spec/items/1"}
+		]`).Apply(base)
+		require.NoError(t, err)
+		assert.Len(t, out.Data.Panels, 1)
+		assert.Contains(t, out.Data.Panels, "p1")
+		assert.NotContains(t, out.Data.Panels, "p2")
+		raw := jsonOf(t, out)
+		assert.NotContains(t, raw, `"$ref":"#/spec/panels/p2"`)
+		assert.Contains(t, raw, `"$ref":"#/spec/panels/p1"`)
+	})
+
+	// The headline use case: edit a single field of a single query inside
+	// one panel without re-sending any other part of the dashboard.
+	t.Run("rename single query inside panel", func(t *testing.T) {
+		out, err := decode(t, `[{
+			"op": "replace",
+			"path": "/data/panels/p1/spec/queries/0/spec/plugin/spec/name",
+			"value": "renamed"
+		}]`).Apply(base)
+		require.NoError(t, err)
+
+		require.Len(t, out.Data.Panels["p1"].Spec.Queries, 1)
+		assert.Contains(t, jsonOf(t, out), `"name":"renamed"`)
+	})
+
+	// Replace a query at a specific index — swaps query "A" out for "B"
+	// without re-sending the rest of the panel.
+	t.Run("replace query at index", func(t *testing.T) {
+		out, err := decode(t, `[{
+			"op": "replace",
+			"path": "/data/panels/p1/spec/queries/0",
+			"value": {
+				"kind": "TimeSeriesQuery",
+				"spec": {"plugin": {"kind": "signoz/BuilderQuery", "spec": {
+					"name": "B",
+					"signal": "metrics",
+					"aggregations": [{
+						"metricName": "signoz_db_calls_total",
+						"temporality": "cumulative",
+						"timeAggregation": "rate",
+						"spaceAggregation": "sum"
+					}]
+				}}}
+			}
+		}]`).Apply(base)
+		require.NoError(t, err)
+		require.Len(t, out.Data.Panels["p1"].Spec.Queries, 1)
+		raw := jsonOf(t, out)
+		assert.Contains(t, raw, `"name":"B"`)
+		assert.NotContains(t, raw, `"name":"A"`)
+	})
+
+	// ─────────────────────────────────────────────────────────────────
+	// Layout edits
+	// ─────────────────────────────────────────────────────────────────
+
+	t.Run("move panel by editing layout x coordinate", func(t *testing.T) {
+		out, err := decode(t, `[{"op": "replace", "path": "/data/layouts/0/spec/items/0/x", "value": 6}]`).Apply(base)
+		require.NoError(t, err)
+		raw := jsonOf(t, out)
+		// The first item used to live at x=0, now lives at x=6.
+		assert.Contains(t, raw, `"x":6,"y":0,"width":6,"height":6,"content":{"$ref":"#/spec/panels/p1"}`)
+	})
+
+	t.Run("resize panel by editing layout width", func(t *testing.T) {
+		out, err := decode(t, `[{"op": "replace", "path": "/data/layouts/0/spec/items/0/width", "value": 12}]`).Apply(base)
+		require.NoError(t, err)
+		raw := jsonOf(t, out)
+		assert.Contains(t, raw, `"width":12`)
+	})
+
+	t.Run("rename layout row title", func(t *testing.T) {
+		out, err := decode(t, `[{"op": "replace", "path": "/data/layouts/0/spec/display/title", "value": "Latency"}]`).Apply(base)
+		require.NoError(t, err)
+		assert.Contains(t, jsonOf(t, out), `"title":"Latency"`)
+	})
+
+	t.Run("append layout item", func(t *testing.T) {
+		out, err := decode(t, `[{
+			"op": "add",
+			"path": "/data/layouts/0/spec/items/-",
+			"value": {"x": 0, "y": 6, "width": 12, "height": 6, "content": {"$ref": "#/spec/panels/p1"}}
+		}]`).Apply(base)
+		require.NoError(t, err)
+		// Item count went 2 → 3.
+		raw := jsonOf(t, out)
+		assert.Equal(t, 3, strings.Count(raw, `"$ref":"#/spec/panels/`))
+	})
+
+	// Composing add-panel + add-layout-item is the realistic shape of the
+	// "add a new chart to my dashboard" UI flow — exercise it end-to-end.
+	t.Run("add panel and corresponding layout item", func(t *testing.T) {
+		out, err := decode(t, `[
+			{
+				"op": "add",
+				"path": "/data/panels/p3",
+				"value": {
+					"kind": "Panel",
+					"spec": {
+						"plugin": {"kind": "signoz/TablePanel", "spec": {}},
+						"queries": [{
+							"kind": "TimeSeriesQuery",
+							"spec": {"plugin": {"kind": "signoz/BuilderQuery", "spec": {
+								"name": "A",
+								"signal": "logs",
+								"aggregations": [{"expression": "count()"}]
+							}}}
+						}]
+					}
+				}
+			},
+			{
+				"op": "add",
+				"path": "/data/layouts/0/spec/items/-",
+				"value": {"x": 0, "y": 6, "width": 12, "height": 6, "content": {"$ref": "#/spec/panels/p3"}}
+			}
+		]`).Apply(base)
+		require.NoError(t, err)
+		assert.Len(t, out.Data.Panels, 3)
+		raw := jsonOf(t, out)
+		assert.Contains(t, raw, `"$ref":"#/spec/panels/p3"`)
+	})
+
+	t.Run("append tag", func(t *testing.T) {
+		out, err := decode(t, `[{"op": "add", "path": "/tags/-", "value": {"name": "env/staging"}}]`).Apply(base)
+		require.NoError(t, err)
+		require.Len(t, out.Tags, 3)
+		assert.Equal(t, "env/staging", out.Tags[2].Name)
+	})
+
+	t.Run("append tag when none exist", func(t *testing.T) {
+		noTagsBase := &DashboardV2{
+			Info: DashboardInfo{
+				StoredDashboardInfo: base.Info.StoredDashboardInfo,
+				Tags:                nil,
+			},
+		}
+		out, err := decode(t, `[{"op": "add", "path": "/tags/-", "value": {"name": "team/new"}}]`).Apply(noTagsBase)
+		require.NoError(t, err)
+		require.Len(t, out.Tags, 1)
+		assert.Equal(t, "team/new", out.Tags[0].Name)
+	})
+
+	t.Run("replace tag name", func(t *testing.T) {
+		out, err := decode(t, `[{"op": "replace", "path": "/tags/0/name", "value": "team/beta"}]`).Apply(base)
+		require.NoError(t, err)
+		require.Len(t, out.Tags, 2)
+		assert.Equal(t, "team/beta", out.Tags[0].Name)
+		assert.Equal(t, "env/prod", out.Tags[1].Name, "tag at index 1 untouched")
+		for _, tag := range out.Tags {
+			assert.NotEqual(t, "team/alpha", tag.Name, "old tag name must be gone")
+		}
+	})
+
+	t.Run("multiple ops applied in order", func(t *testing.T) {
+		out, err := decode(t, `[
+			{"op": "replace", "path": "/data/display/name", "value": "Multi-step"},
+			{"op": "remove",  "path": "/data/panels/p2"},
+			{"op": "add",     "path": "/tags/-", "value": {"name": "env/staging"}}
+		]`).Apply(base)
+		require.NoError(t, err)
+		assert.Equal(t, "Multi-step", out.Data.Display.Name)
+		assert.Len(t, out.Data.Panels, 1)
+		assert.Len(t, out.Tags, 3)
+	})
+
+	// `test` is an RFC 6902 precondition op: aborts the patch if the value
+	// at the path doesn't equal the supplied value. Used for optimistic
+	// concurrency. Here it matches, so the subsequent ops apply.
+	t.Run("test op passes", func(t *testing.T) {
+		out, err := decode(t, `[
+			{"op": "test",    "path": "/data/display/name", "value": "Service overview"},
+			{"op": "replace", "path": "/data/display/name", "value": "Confirmed"}
+		]`).Apply(base)
+		require.NoError(t, err)
+		assert.Equal(t, "Confirmed", out.Data.Display.Name)
+	})
+
+	// ─────────────────────────────────────────────────────────────────
+	// Failure cases
+	// ─────────────────────────────────────────────────────────────────
+
+	t.Run("decode rejects non-array body", func(t *testing.T) {
+		var patch PatchableDashboardV2
+		err := json.Unmarshal([]byte(`{"op": "replace"}`), &patch)
+		require.Error(t, err)
+	})
+
+	t.Run("decode rejects malformed JSON", func(t *testing.T) {
+		var patch PatchableDashboardV2
+		// Outer json.Unmarshal rejects non-JSON before PatchableDashboardV2's
+		// UnmarshalJSON runs, so the error is a stdlib SyntaxError rather
+		// than the InvalidInput-classified wrap.
+		err := json.Unmarshal([]byte(`not json`), &patch)
+		require.Error(t, err)
+	})
+
+	// `test` precondition fails — the whole patch is rejected, including
+	// the subsequent replace.
+	t.Run("test op failure rejected", func(t *testing.T) {
+		_, err := decode(t, `[
+			{"op": "test", "path": "/data/display/name", "value": "Wrong"},
+			{"op": "replace", "path": "/data/display/name", "value": "Should not apply"}
+		]`).Apply(base)
+		require.Error(t, err)
+	})
+
+	t.Run("remove at missing path rejected", func(t *testing.T) {
+		_, err := decode(t, `[{"op": "remove", "path": "/data/panels/does-not-exist"}]`).Apply(base)
+		require.Error(t, err)
+	})
+
+	t.Run("remove schemaVersion rejected", func(t *testing.T) {
+		_, err := decode(t, `[{"op": "remove", "path": "/metadata/schemaVersion"}]`).Apply(base)
+		require.Error(t, err)
+	})
+
+	t.Run("wrong schemaVersion rejected", func(t *testing.T) {
+		_, err := decode(t, `[{"op": "replace", "path": "/metadata/schemaVersion", "value": "v5"}]`).Apply(base)
+		require.Error(t, err)
+		require.Contains(t, err.Error(), SchemaVersion)
+	})
+
+	t.Run("empty display name rejected", func(t *testing.T) {
+		_, err := decode(t, `[{"op": "replace", "path": "/data/display/name", "value": ""}]`).Apply(base)
+		require.Error(t, err)
+		require.Contains(t, err.Error(), "data.display.name is required")
+	})
+
+	t.Run("unknown top-level field rejected", func(t *testing.T) {
+		_, err := decode(t, `[{"op": "add", "path": "/bogus", "value": 42}]`).Apply(base)
+		require.Error(t, err)
+		require.Contains(t, err.Error(), "bogus")
+	})
+
+	t.Run("invalid panel kind rejected", func(t *testing.T) {
+		_, err := decode(t, `[{
+			"op": "replace",
+			"path": "/data/panels/p1",
+			"value": {
+				"kind": "Panel",
+				"spec": {"plugin": {"kind": "signoz/NotAPanel", "spec": {}}}
+			}
+		}]`).Apply(base)
+		require.Error(t, err)
+		require.Contains(t, err.Error(), "NotAPanel")
+	})
+
+	t.Run("query kind incompatible with panel rejected", func(t *testing.T) {
+		// PromQLQuery is not allowed on ListPanel — verify the cross-check
+		// in Validate still runs after a patch.
+		_, err := decode(t, `[{
+			"op": "replace",
+			"path": "/data/panels/p2",
+			"value": {
+				"kind": "Panel",
+				"spec": {
+					"plugin": {"kind": "signoz/ListPanel", "spec": {}},
+					"queries": [{"kind": "TimeSeriesQuery", "spec": {"plugin": {"kind": "signoz/PromQLQuery", "spec": {"name": "A", "query": "up"}}}}]
+				}
+			}
+		}]`).Apply(base)
+		require.Error(t, err)
+	})
+
+	t.Run("removing only query rejected", func(t *testing.T) {
+		// p2 has exactly one query in the base; removing it would strand
+		// the panel queryless, which Validate now rejects.
+		_, err := decode(t, `[{"op": "remove", "path": "/data/panels/p2/spec/queries/0"}]`).Apply(base)
+		require.Error(t, err)
+		require.Contains(t, err.Error(), "at least one query")
+	})
+
+	t.Run("too many tags rejected", func(t *testing.T) {
+		_, err := decode(t, `[
+			{"op": "add", "path": "/tags/-", "value": {"name": "t1"}},
+			{"op": "add", "path": "/tags/-", "value": {"name": "t2"}},
+			{"op": "add", "path": "/tags/-", "value": {"name": "t3"}},
+			{"op": "add", "path": "/tags/-", "value": {"name": "t4"}}
+		]`).Apply(base)
+		require.Error(t, err)
+		require.Contains(t, err.Error(), "at most")
+	})
+}