diff --git a/pkg/report/datasource.go b/pkg/report/datasource.go
index a59900241..9faf73af5 100644
--- a/pkg/report/datasource.go
+++ b/pkg/report/datasource.go
@@ -21,6 +21,7 @@ type (
 	Datasource    interface {
 		Name() string
 		Load(context.Context, ...*FrameDefinition) (Loader, Closer, error)
+		Describe() FrameDescriptionSet
 	}
 
 	// GroupableDatasource is able to provide groupped data
diff --git a/pkg/report/frame.go b/pkg/report/frame.go
index e99b0611e..1c4d409b3 100644
--- a/pkg/report/frame.go
+++ b/pkg/report/frame.go
@@ -54,6 +54,15 @@ type (
 		Paging  *filter.Paging     `json:"paging"`
 		Sorting filter.SortExprSet `json:"sorting"`
 	}
+
+	FrameDescriptionSet []*FrameDescription
+	FrameDescription    struct {
+		Source  string         `json:"source"`
+		Ref     string         `json:"ref,omitempty"`
+		Columns FrameColumnSet `json:"columns"`
+
+		// @todo size and other shape related bits
+	}
 )
 
 const (
diff --git a/pkg/report/model.go b/pkg/report/model.go
index b66f94657..312530f37 100644
--- a/pkg/report/model.go
+++ b/pkg/report/model.go
@@ -19,6 +19,7 @@ type (
 		Add(...Step) M
 		Run(context.Context) error
 		Load(context.Context, ...*FrameDefinition) ([]*Frame, error)
+		Describe(source string) (FrameDescriptionSet, error)
 	}
 
 	StepSet []Step
@@ -130,6 +131,15 @@ func (m *model) Run(ctx context.Context) (err error) {
 	return nil
 }
 
+func (m *model) Describe(source string) (out FrameDescriptionSet, err error) {
+	ds := m.datasources.Find(source)
+	if ds == nil {
+		return nil, fmt.Errorf("model does not contain the datasource: %s", source)
+	}
+
+	return ds.Describe(), nil
+}
+
 func (m *model) Load(ctx context.Context, dd ...*FrameDefinition) ([]*Frame, error) {
 	var err error
 
diff --git a/pkg/report/step_join.go b/pkg/report/step_join.go
index bce04f0ac..fe3898a6c 100644
--- a/pkg/report/step_join.go
+++ b/pkg/report/step_join.go
@@ -93,6 +93,34 @@ func (d *joinedDataset) Name() string {
 	return d.def.Name
 }
 
+func (d *joinedDataset) Describe() FrameDescriptionSet {
+	out := make(FrameDescriptionSet, 0, 2)
+
+	local := d.base.Describe()
+	for _, l := range local {
+		out = append(out,
+			&FrameDescription{
+				Source:  d.Name(),
+				Ref:     l.Source,
+				Columns: l.Columns,
+			},
+		)
+	}
+
+	foreign := d.foreign.Describe()
+	for _, f := range foreign {
+		out = append(out,
+			&FrameDescription{
+				Source:  d.Name(),
+				Ref:     f.Source,
+				Columns: f.Columns,
+			},
+		)
+	}
+
+	return out
+}
+
 // @todo allow x-join filtering
 func (d *joinedDataset) Load(ctx context.Context, dd ...*FrameDefinition) (Loader, Closer, error) {
 	// to hold closer references for all underlying datasources
diff --git a/store/rdbms/compose_record_datasource.go b/store/rdbms/compose_record_datasource.go
index 51edfec10..eb16414a0 100644
--- a/store/rdbms/compose_record_datasource.go
+++ b/store/rdbms/compose_record_datasource.go
@@ -174,6 +174,15 @@ func (r *recordDatasource) Group(d report.GroupDefinition, name string) (bool, e
 	return true, nil
 }
 
+func (r *recordDatasource) Describe() report.FrameDescriptionSet {
+	return report.FrameDescriptionSet{
+		&report.FrameDescription{
+			Source:  r.Name(),
+			Columns: r.cols,
+		},
+	}
+}
+
 func (r *recordDatasource) Load(ctx context.Context, dd ...*report.FrameDefinition) (l report.Loader, c report.Closer, err error) {
 	def := dd[0]
 
diff --git a/system/rest.yaml b/system/rest.yaml
index f950f080e..31a239d2a 100644
--- a/system/rest.yaml
+++ b/system/rest.yaml
@@ -1435,6 +1435,16 @@ endpoints:
         name: reportID
         required: true
         title: Report ID
+  - name: describe
+    method: POST
+    title: Describe report (fresh)
+    path: "/describe"
+    parameters:
+      post:
+      - { name: sources,  type: "types.ReportDataSourceSet",  title: Report steps definition }
+      - { name: steps,    type: "report.StepDefinitionSet",   title: Report steps definition  }
+      - { name: describe, type: "[]string",                   title: The source descriptions to generate }
+
     # @todo better name
   - name: runFresh
     method: POST
diff --git a/system/rest/handlers/report.go b/system/rest/handlers/report.go
index 8e72d8a5d..2758b4663 100644
--- a/system/rest/handlers/report.go
+++ b/system/rest/handlers/report.go
@@ -25,6 +25,7 @@ type (
 		Read(context.Context, *request.ReportRead) (interface{}, error)
 		Delete(context.Context, *request.ReportDelete) (interface{}, error)
 		Undelete(context.Context, *request.ReportUndelete) (interface{}, error)
+		Describe(context.Context, *request.ReportDescribe) (interface{}, error)
 		RunFresh(context.Context, *request.ReportRunFresh) (interface{}, error)
 		Run(context.Context, *request.ReportRun) (interface{}, error)
 	}
@@ -37,6 +38,7 @@ type (
 		Read     func(http.ResponseWriter, *http.Request)
 		Delete   func(http.ResponseWriter, *http.Request)
 		Undelete func(http.ResponseWriter, *http.Request)
+		Describe func(http.ResponseWriter, *http.Request)
 		RunFresh func(http.ResponseWriter, *http.Request)
 		Run      func(http.ResponseWriter, *http.Request)
 	}
@@ -140,6 +142,22 @@ func NewReport(h ReportAPI) *Report {
 
 			api.Send(w, r, value)
 		},
+		Describe: func(w http.ResponseWriter, r *http.Request) {
+			defer r.Body.Close()
+			params := request.NewReportDescribe()
+			if err := params.Fill(r); err != nil {
+				api.Send(w, r, err)
+				return
+			}
+
+			value, err := h.Describe(r.Context(), params)
+			if err != nil {
+				api.Send(w, r, err)
+				return
+			}
+
+			api.Send(w, r, value)
+		},
 		RunFresh: func(w http.ResponseWriter, r *http.Request) {
 			defer r.Body.Close()
 			params := request.NewReportRunFresh()
@@ -184,6 +202,7 @@ func (h Report) MountRoutes(r chi.Router, middlewares ...func(http.Handler) http
 		r.Get("/reports/{reportID}", h.Read)
 		r.Delete("/reports/{reportID}", h.Delete)
 		r.Post("/reports/{reportID}/undelete", h.Undelete)
+		r.Post("/reports/describe", h.Describe)
 		r.Post("/reports/run", h.RunFresh)
 		r.Post("/reports/{reportID}/run", h.Run)
 	})
diff --git a/system/rest/report.go b/system/rest/report.go
index 509f34480..689295a63 100644
--- a/system/rest/report.go
+++ b/system/rest/report.go
@@ -30,6 +30,7 @@ type (
 		// @todo
 		// Run(ctx context.Context, ID uint64, dd report.DatasetDefinitionSet) (rr *report.Matrix, err error)
 		RunFresh(ctx context.Context, src types.ReportDataSourceSet, st report.StepDefinitionSet, dd report.FrameDefinitionSet) (rr []*report.Frame, err error)
+		DescribeFresh(ctx context.Context, src types.ReportDataSourceSet, st report.StepDefinitionSet, sources ...string) (out report.FrameDescriptionSet, err error)
 	}
 
 	reportAccessController interface {
@@ -139,6 +140,10 @@ func (ctrl *Report) Run(ctx context.Context, r *request.ReportRun) (interface{},
 	return nil, nil
 }
 
+func (ctrl *Report) Describe(ctx context.Context, r *request.ReportDescribe) (interface{}, error) {
+	return ctrl.report.DescribeFresh(ctx, r.Sources, r.Steps, r.Describe...)
+}
+
 func (ctrl *Report) RunFresh(ctx context.Context, r *request.ReportRunFresh) (interface{}, error) {
 	rr, err := ctrl.report.RunFresh(ctx, r.Sources, r.Steps, r.Frames)
 	return ctrl.makeReportFramePayload(ctx, rr, err)
diff --git a/system/rest/request/report.go b/system/rest/request/report.go
index 3691ac590..74962bc50 100644
--- a/system/rest/request/report.go
+++ b/system/rest/request/report.go
@@ -148,6 +148,23 @@ type (
 		ReportID uint64 `json:",string"`
 	}
 
+	ReportDescribe struct {
+		// Sources POST parameter
+		//
+		// Report steps definition
+		Sources types.ReportDataSourceSet
+
+		// Steps POST parameter
+		//
+		// Report steps definition
+		Steps report.StepDefinitionSet
+
+		// Describe POST parameter
+		//
+		// The source descriptions to generate
+		Describe []string
+	}
+
 	ReportRunFresh struct {
 		// Sources POST parameter
 		//
@@ -623,6 +640,81 @@ func (r *ReportUndelete) Fill(req *http.Request) (err error) {
 	return err
 }
 
+// NewReportDescribe request
+func NewReportDescribe() *ReportDescribe {
+	return &ReportDescribe{}
+}
+
+// Auditable returns all auditable/loggable parameters
+func (r ReportDescribe) Auditable() map[string]interface{} {
+	return map[string]interface{}{
+		"sources":  r.Sources,
+		"steps":    r.Steps,
+		"describe": r.Describe,
+	}
+}
+
+// Auditable returns all auditable/loggable parameters
+func (r ReportDescribe) GetSources() types.ReportDataSourceSet {
+	return r.Sources
+}
+
+// Auditable returns all auditable/loggable parameters
+func (r ReportDescribe) GetSteps() report.StepDefinitionSet {
+	return r.Steps
+}
+
+// Auditable returns all auditable/loggable parameters
+func (r ReportDescribe) GetDescribe() []string {
+	return r.Describe
+}
+
+// Fill processes request and fills internal variables
+func (r *ReportDescribe) Fill(req *http.Request) (err error) {
+
+	if strings.ToLower(req.Header.Get("content-type")) == "application/json" {
+		err = json.NewDecoder(req.Body).Decode(r)
+
+		switch {
+		case err == io.EOF:
+			err = nil
+		case err != nil:
+			return fmt.Errorf("error parsing http request body: %w", err)
+		}
+	}
+
+	{
+		if err = req.ParseForm(); err != nil {
+			return err
+		}
+
+		// POST params
+
+		//if val, ok := req.Form["sources[]"]; ok && len(val) > 0  {
+		//    r.Sources, err = types.ReportDataSourceSet(val), nil
+		//    if err != nil {
+		//        return err
+		//    }
+		//}
+
+		//if val, ok := req.Form["steps[]"]; ok && len(val) > 0  {
+		//    r.Steps, err = report.StepDefinitionSet(val), nil
+		//    if err != nil {
+		//        return err
+		//    }
+		//}
+
+		//if val, ok := req.Form["describe[]"]; ok && len(val) > 0  {
+		//    r.Describe, err = val, nil
+		//    if err != nil {
+		//        return err
+		//    }
+		//}
+	}
+
+	return err
+}
+
 // NewReportRunFresh request
 func NewReportRunFresh() *ReportRunFresh {
 	return &ReportRunFresh{}
diff --git a/system/service/report.go b/system/service/report.go
index ec23b5828..6489f1c7a 100644
--- a/system/service/report.go
+++ b/system/service/report.go
@@ -288,6 +288,45 @@ func (svc *report) Run(ctx context.Context, ID uint64, dd rep.FrameDefinitionSet
 	return nil, nil
 }
 
+// actionlog?
+func (svc *report) DescribeFresh(ctx context.Context, src types.ReportDataSourceSet, st rep.StepDefinitionSet, sources ...string) (out rep.FrameDescriptionSet, err error) {
+	// var (
+	// 	aaProps = &reportActionProps{}
+	// )
+
+	out = make(rep.FrameDescriptionSet, 0, len(sources)*2)
+
+	err = func() (err error) {
+		ss := src.ModelSteps()
+		ss = append(ss, st...)
+
+		// Model the report
+		model, err := rep.Model(ctx, reporters, ss...)
+		if err != nil {
+			return
+		}
+
+		err = model.Run(ctx)
+		if err != nil {
+			return
+		}
+
+		var auxOut rep.FrameDescriptionSet
+		for _, s := range sources {
+			auxOut, err = model.Describe(s)
+			if err != nil {
+				return err
+			}
+
+			out = append(out, auxOut...)
+		}
+
+		return nil
+	}()
+
+	return out, err
+}
+
 func (svc *report) RunFresh(ctx context.Context, src types.ReportDataSourceSet, st rep.StepDefinitionSet, dd rep.FrameDefinitionSet) (out []*rep.Frame, err error) {
 	var (
 		aaProps = &reportActionProps{}