diff --git a/src/core/opentelemetry.ml b/src/core/opentelemetry.ml
index 0b303f7..6908d98 100644
--- a/src/core/opentelemetry.ml
+++ b/src/core/opentelemetry.ml
@@ -782,7 +782,12 @@ module Span_link : sig
     unit ->
     t
 
-  val of_span_ctx : ?attrs:key_value list -> Span_ctx.t -> t
+  val of_span_ctx :
+    ?trace_state:string ->
+    ?attrs:key_value list ->
+    ?dropped_attributes_count:int ->
+    Span_ctx.t ->
+    t
 end = struct
   open Proto.Trace
 
@@ -799,9 +804,10 @@ end = struct
       ~span_id:(Span_id.to_bytes span_id) ?trace_state ~attributes
       ?dropped_attributes_count ()
 
-  let[@inline] of_span_ctx ?attrs (ctx : Span_ctx.t) : t =
+  let[@inline] of_span_ctx ?trace_state ?attrs ?dropped_attributes_count
+      (ctx : Span_ctx.t) : t =
     make ~trace_id:(Span_ctx.trace_id ctx) ~span_id:(Span_ctx.parent_id ctx)
-      ?attrs ()
+      ?trace_state ?attrs ?dropped_attributes_count ()
 end
 
 module Span_status : sig
@@ -834,6 +840,29 @@ end = struct
   let make ~message ~code = { message; code }
 end
 
+(** @since NEXT_RELEASE *)
+module Span_kind : sig
+  open Proto.Trace
+
+  type t = span_span_kind =
+    | Span_kind_unspecified
+    | Span_kind_internal
+    | Span_kind_server
+    | Span_kind_client
+    | Span_kind_producer
+    | Span_kind_consumer
+end = struct
+  open Proto.Trace
+
+  type t = span_span_kind =
+    | Span_kind_unspecified
+    | Span_kind_internal
+    | Span_kind_server
+    | Span_kind_client
+    | Span_kind_producer
+    | Span_kind_consumer
+end
+
 (** {2 Scopes} *)
 
 (** Scopes.
@@ -857,6 +886,8 @@ module Scope : sig
 
   val status : t -> Span_status.t option
 
+  val kind : t -> Span_kind.t option
+
   val make :
     trace_id:Trace_id.t ->
     span_id:Span_id.t ->
@@ -867,6 +898,14 @@ module Scope : sig
     unit ->
     t
 
+  val to_span_link :
+    ?trace_state:string ->
+    ?attrs:key_value list ->
+    ?dropped_attributes_count:int ->
+    t ->
+    Span_link.t
+  (** Turn the scope into a span link *)
+
   val to_span_ctx : t -> Span_ctx.t
   (** Turn the scope into a span context *)
 
@@ -896,6 +935,10 @@ module Scope : sig
   Note that this function will be
   called only if there is an instrumentation backend. *)
 
+  val set_kind : t -> Span_kind.t -> unit
+  (** Set the span's kind.
+      @since NEXT_RELEASE *)
+
   val ambient_scope_key : t Ambient_context.key
   (** The opaque key necessary to access/set the ambient scope with
   {!Ambient_context}. *)
@@ -916,6 +959,7 @@ end = struct
     | Attr of key_value * item_list
     | Span_link of Span_link.t * item_list
     | Span_status of Span_status.t * item_list
+    | Span_kind of Span_kind.t * item_list
 
   type t = {
     trace_id: Trace_id.t;
@@ -927,7 +971,8 @@ end = struct
     let rec loop acc = function
       | Nil -> acc
       | Attr (attr, l) -> loop (attr :: acc) l
-      | Ev (_, l) | Span_link (_, l) | Span_status (_, l) -> loop acc l
+      | Ev (_, l) | Span_kind (_, l) | Span_link (_, l) | Span_status (_, l) ->
+        loop acc l
     in
     loop [] scope.items
 
@@ -935,7 +980,9 @@ end = struct
     let rec loop acc = function
       | Nil -> acc
       | Ev (event, l) -> loop (event :: acc) l
-      | Attr (_, l) | Span_link (_, l) | Span_status (_, l) -> loop acc l
+      | Attr (_, l) | Span_kind (_, l) | Span_link (_, l) | Span_status (_, l)
+        ->
+        loop acc l
     in
     loop [] scope.items
 
@@ -943,17 +990,27 @@ end = struct
     let rec loop acc = function
       | Nil -> acc
       | Span_link (span_link, l) -> loop (span_link :: acc) l
-      | Ev (_, l) | Attr (_, l) | Span_status (_, l) -> loop acc l
+      | Ev (_, l) | Span_kind (_, l) | Attr (_, l) | Span_status (_, l) ->
+        loop acc l
     in
     loop [] scope.items
 
   let status scope =
-    let rec loop acc = function
-      | Nil -> acc
+    let rec loop = function
+      | Nil -> None
       | Span_status (status, _) -> Some status
-      | Ev (_, l) | Attr (_, l) | Span_link (_, l) -> loop acc l
+      | Ev (_, l) | Attr (_, l) | Span_kind (_, l) | Span_link (_, l) -> loop l
+    in
+    loop scope.items
+
+  let kind scope =
+    let rec loop = function
+      | Nil -> None
+      | Span_kind (k, _) -> Some k
+      | Ev (_, l) | Span_status (_, l) | Attr (_, l) | Span_link (_, l) ->
+        loop l
     in
-    loop None scope.items
+    loop scope.items
 
   let make ~trace_id ~span_id ?(events = []) ?(attrs = []) ?(links = []) ?status
       () : t =
@@ -971,6 +1028,11 @@ end = struct
     in
     { trace_id; span_id; items }
 
+  let[@inline] to_span_link ?trace_state ?attrs ?dropped_attributes_count
+      (self : t) : Span_link.t =
+    Span_link.make ?trace_state ?attrs ?dropped_attributes_count
+      ~trace_id:self.trace_id ~span_id:self.span_id ()
+
   let[@inline] to_span_ctx (self : t) : Span_ctx.t =
     Span_ctx.make ~trace_id:self.trace_id ~parent_id:self.span_id ()
 
@@ -1008,6 +1070,9 @@ end = struct
     if Collector.has_backend () then
       scope.items <- Span_status (status, scope.items)
 
+  let set_kind (scope : t) (k : Span_kind.t) : unit =
+    if Collector.has_backend () then scope.items <- Span_kind (k, scope.items)
+
   let ambient_scope_key : t Ambient_context.key = Ambient_context.create_key ()
 
   let get_ambient_scope ?scope () : t option =
@@ -1034,7 +1099,7 @@ module Span : sig
 
   type id = Span_id.t
 
-  type nonrec kind = span_span_kind =
+  type kind = Span_kind.t =
     | Span_kind_unspecified
     | Span_kind_internal
     | Span_kind_server
@@ -1079,7 +1144,7 @@ end = struct
 
   type id = Span_id.t
 
-  type nonrec kind = span_span_kind =
+  type kind = Span_kind.t =
     | Span_kind_unspecified
     | Span_kind_internal
     | Span_kind_server
diff --git a/src/trace/opentelemetry_trace.ml b/src/trace/opentelemetry_trace.ml
index ebf9328..09b29d7 100644
--- a/src/trace/opentelemetry_trace.ml
+++ b/src/trace/opentelemetry_trace.ml
@@ -53,6 +53,11 @@ open Well_known
 let on_internal_error =
   ref (fun msg -> Printf.eprintf "error in Opentelemetry_trace: %s\n%!" msg)
 
+type Otrace.extension_event +=
+  | Ev_link_span of Otrace.explicit_span * Otrace.explicit_span
+  | Ev_set_span_kind of Otrace.explicit_span * Otel.Span_kind.t
+  | Ev_record_exn of Otrace.explicit_span * exn * Printexc.raw_backtrace
+
 module Internal = struct
   type span_begin = {
     start_time: int64;
@@ -193,6 +198,9 @@ module Internal = struct
       Active_span_tbl.remove active_spans.tbl otrace_id;
       Some (exit_span_ otel_span_begin)
 
+  let[@inline] get_scope (span : Otrace.explicit_span) : Otel.Scope.t option =
+    Otrace.Meta_map.find k_explicit_scope span.meta
+
   module M = struct
     let with_span ~__FUNCTION__ ~__FILE__ ~__LINE__ ~data name cb =
       let otrace_id, sb =
@@ -259,10 +267,10 @@ module Internal = struct
       | Some sb -> Otel.Scope.add_attrs sb.scope (fun () -> data)
 
     let add_data_to_manual_span (span : Otrace.explicit_span) data : unit =
-      match Otrace.Meta_map.find_exn k_explicit_scope span.meta with
-      | exception _ ->
+      match get_scope span with
+      | None ->
         !on_internal_error (spf "manual span does not a contain an OTEL scope")
-      | scope -> Otel.Scope.add_attrs scope (fun () -> data)
+      | Some scope -> Otel.Scope.add_attrs scope (fun () -> data)
 
     let message ?span ~data:_ msg : unit =
       (* gather information from context *)
@@ -293,9 +301,35 @@ module Internal = struct
       let _kind, attrs = otel_attrs_of_otrace_data data in
       let m = Otel.Metrics.(gauge ~name [ float ~attrs cur_val ]) in
       Otel.Metrics.emit [ m ]
+
+    let extension_event = function
+      | Ev_link_span (sp1, sp2) ->
+        (match get_scope sp1, get_scope sp2 with
+        | Some sc1, Some sc2 ->
+          Otel.Scope.add_links sc1 (fun () -> [ Otel.Scope.to_span_link sc2 ])
+        | _ -> !on_internal_error "could not find scope for OTEL span")
+      | Ev_set_span_kind (sp, k) ->
+        (match get_scope sp with
+        | None -> !on_internal_error "could not find scope for OTEL span"
+        | Some sc -> Otel.Scope.set_kind sc k)
+      | Ev_record_exn (sp, exn, bt) ->
+        (match get_scope sp with
+        | None -> !on_internal_error "could not find scope for OTEL span"
+        | Some sc -> Otel.Scope.record_exception sc exn bt)
+      | _ -> ()
   end
 end
 
+let link_spans (sp1 : Otrace.explicit_span) (sp2 : Otrace.explicit_span) : unit
+    =
+  if Otrace.enabled () then Otrace.extension_event @@ Ev_link_span (sp1, sp2)
+
+let set_span_kind sp k : unit =
+  if Otrace.enabled () then Otrace.extension_event @@ Ev_set_span_kind (sp, k)
+
+let record_exception sp exn bt : unit =
+  if Otrace.enabled () then Otrace.extension_event @@ Ev_record_exn (sp, exn, bt)
+
 let collector () : Otrace.collector = (module Internal.M)
 
 let setup () = Otrace.setup_collector @@ collector ()
diff --git a/src/trace/opentelemetry_trace.mli b/src/trace/opentelemetry_trace.mli
index 0834960..da8f848 100644
--- a/src/trace/opentelemetry_trace.mli
+++ b/src/trace/opentelemetry_trace.mli
@@ -48,6 +48,19 @@ val setup_with_otel_backend : Opentelemetry.Collector.backend -> unit
 val collector : unit -> Trace_core.collector
 (** Make a Trace collector that uses the OTEL backend to send spans and logs *)
 
+val link_spans : Otrace.explicit_span -> Otrace.explicit_span -> unit
+(** [link_spans sp1 sp2] modifies [sp1] by adding a span link to [sp2].
+  @since NEXT_RELEASE *)
+
+val set_span_kind : Otrace.explicit_span -> Otel.Span.kind -> unit
+(** [set_span_kind sp k] sets the span's kind.
+  @since NEXT_RELEASE *)
+
+val record_exception :
+  Otrace.explicit_span -> exn -> Printexc.raw_backtrace -> unit
+(** Record exception in the current span.
+  @since NEXT_RELEASE *)
+
 (** Static references for well-known identifiers; see {!label-wellknown}. *)
 module Well_known : sig
   val spankind_key : string
@@ -68,6 +81,7 @@ module Well_known : sig
     (string * Otrace.user_data) list ->
     Otel.Span.kind * Otel.Span.key_value list
 end
+[@@deprecated "use the regular functions for this"]
 
 (**/**)