return completed span

app/schema.graphql

@@ -65,8 +65,6 @@ enum AuthMethod {
 
 union Bin = NominalBin | IntervalBin | MissingValueBin
 
-union ChatCompletionChunk = TextChunk | ToolCallChunk
-
 input ChatCompletionInput {
   messages: [ChatCompletionMessageInput!]!
   model: GenerativeModelInput!
@@ -90,6 +88,8 @@ enum ChatCompletionMessageRole {
   AI
 }
 
+union ChatCompletionSubscriptionPayload = TextChunk | ToolCallChunk | FinishedChatCompletion
+
 input ClearProjectInput {
   id: GlobalID!
 
@@ -821,6 +821,10 @@ type ExportedFile {
   fileName: String!
 }
 
+type FinishedChatCompletion {
+  span: Span!
+}
+
 type FunctionCallChunk {
   name: String!
   arguments: String!
@@ -1442,7 +1446,7 @@ enum SpanStatusCode {
 }
 
 type Subscription {
-  chatCompletion(input: ChatCompletionInput!): ChatCompletionChunk!
+  chatCompletion(input: ChatCompletionInput!): ChatCompletionSubscriptionPayload!
 }
 
 type SystemApiKey implements ApiKey & Node {

src/phoenix/server/api/subscriptions.py

@@ -34,6 +34,7 @@
 from opentelemetry.sdk.trace.export.in_memory_span_exporter import InMemorySpanExporter
 from opentelemetry.trace import StatusCode
 from sqlalchemy import insert, select
+from sqlalchemy.orm import joinedload
 from strawberry import UNSET
 from strawberry.scalars import JSON as JSONScalarType
 from strawberry.types import Info
@@ -45,6 +46,7 @@
 from phoenix.server.api.input_types.InvocationParameters import InvocationParameters
 from phoenix.server.api.types.ChatCompletionMessageRole import ChatCompletionMessageRole
 from phoenix.server.api.types.GenerativeProvider import GenerativeProviderKey
+from phoenix.server.api.types.Span import Span, to_gql_span
 from phoenix.server.dml_event import SpanInsertEvent
 from phoenix.trace.attributes import unflatten
 from phoenix.utilities.json import jsonify
@@ -94,8 +96,14 @@ class ToolCallChunk:
     function: FunctionCallChunk
 
 
-ChatCompletionChunk: TypeAlias = Annotated[
-    Union[TextChunk, ToolCallChunk], strawberry.union("ChatCompletionChunk")
+@strawberry.type
+class FinishedChatCompletion:
+    span: Span
+
+
+ChatCompletionSubscriptionPayload: TypeAlias = Annotated[
+    Union[TextChunk, ToolCallChunk, FinishedChatCompletion],
+    strawberry.union("ChatCompletionSubscriptionPayload"),
 ]
 
 
@@ -160,7 +168,7 @@ class Subscription:
     @strawberry.subscription
     async def chat_completion(
         self, info: Info[Context, None], input: ChatCompletionInput
-    ) -> AsyncIterator[ChatCompletionChunk]:
+    ) -> AsyncIterator[ChatCompletionSubscriptionPayload]:
         from openai import NOT_GIVEN, AsyncAzureOpenAI, AsyncOpenAI
         from openai.types.chat import ChatCompletionStreamOptionsParam
 
@@ -294,8 +302,10 @@ async def chat_completion(
                     end_time=end_time,
                 )
             )
-            await session.execute(
-                insert(models.Span).values(
+            span_id = await session.scalar(
+                insert(models.Span)
+                .returning(models.Span.id)
+                .values(
                     trace_rowid=trace_rowid,
                     span_id=span_id,
                     parent_id=None,
@@ -314,6 +324,15 @@ async def chat_completion(
                     llm_token_count_completion=completion_tokens,
                 )
             )
+            playground_span = await session.scalar(
+                select(models.Span)
+                .where(models.Span.id == span_id)
+                .options(
+                    joinedload(models.Span.trace, innerjoin=True).load_only(models.Trace.trace_id)
+                )
+            )
+            assert playground_span is not None
+            yield FinishedChatCompletion(span=to_gql_span(playground_span))
         info.context.event_queue.put(SpanInsertEvent(ids=(playground_project_id,)))