From 5eca4e3cabad9c92ccbf290d8406fbe7c110a680 Mon Sep 17 00:00:00 2001
From: Thomas LECONTE <161708450+thom-dev-fr@users.noreply.github.com>
Date: Tue, 7 Jul 2026 16:13:03 +0200
Subject: [PATCH] server : add timings and progress to /responses API stream
 (#25348)

---
 tools/server/server-task.cpp                  | 34 ++++++++++++++-
 tools/server/server-task.h                    |  2 +
 .../tests/unit/test_compat_oai_responses.py   | 41 +++++++++++++++++++
 3 files changed, 76 insertions(+), 1 deletion(-)

diff --git a/tools/server/server-task.cpp b/tools/server/server-task.cpp
index 54fa949dfa..8d611e520d 100644
--- a/tools/server/server-task.cpp
+++ b/tools/server/server-task.cpp
@@ -730,6 +730,10 @@ json server_task_result_cmpl_final::to_json_oaicompat_resp_stream() {
         }}
     });
 
+    if (timings.prompt_n >= 0) {
+        server_sent_events.back().at("data").push_back({"timings", timings.to_json()});
+    }
+
     return server_sent_events;
 }
 
@@ -1016,6 +1020,7 @@ void server_task_result_cmpl_partial::update(task_result_state & state) {
     thinking_block_started = state.thinking_block_started;
     text_block_started     = state.text_block_started;
 
+    oai_resp_created       = state.oai_resp_created;
     oai_resp_id            = state.oai_resp_id;
     oai_resp_reasoning_id  = state.oai_resp_reasoning_id;
     oai_resp_message_id    = state.oai_resp_message_id;
@@ -1024,6 +1029,10 @@ void server_task_result_cmpl_partial::update(task_result_state & state) {
     // track if the accumulated message has any reasoning content
     anthropic_has_reasoning = !state.chat_msg.reasoning_content.empty();
 
+    if (res_type == TASK_RESPONSE_TYPE_OAI_RESP && !state.oai_resp_created && (is_progress || n_decoded == 1)) {
+        state.oai_resp_created = true;
+    }
+
     // Pre-compute state updates based on diffs (for next chunk)
     for (const common_chat_msg_diff & diff : oaicompat_msg_diffs) {
         if (!diff.reasoning_content_delta.empty() && !state.thinking_block_started) {
@@ -1181,7 +1190,7 @@ json server_task_result_cmpl_partial::to_json_oaicompat_chat() {
 json server_task_result_cmpl_partial::to_json_oaicompat_resp() {
     std::vector<json> events;
 
-    if (n_decoded == 1) {
+    if (!oai_resp_created) {
         events.push_back(json {
             {"event", "response.created"},
             {"data", json {
@@ -1204,6 +1213,18 @@ json server_task_result_cmpl_partial::to_json_oaicompat_resp() {
                 }},
             }},
         });
+    } else if (is_progress) {
+        events.push_back(json {
+            {"event", "response.in_progress"},
+            {"data", json {
+                {"type", "response.in_progress"},
+                {"response", json {
+                    {"id",     oai_resp_id},
+                    {"object", "response"},
+                    {"status", "in_progress"},
+                }},
+            }},
+        });
     }
 
     for (const common_chat_msg_diff & diff : oaicompat_msg_diffs) {
@@ -1302,6 +1323,17 @@ json server_task_result_cmpl_partial::to_json_oaicompat_resp() {
             });
         }
     }
+
+    if (!events.empty()) {
+        json & data = events.back().at("data");
+        if (timings.prompt_n >= 0) {
+            data.push_back({"timings", timings.to_json()});
+        }
+        if (is_progress) {
+            data.push_back({"prompt_progress", progress.to_json()});
+        }
+    }
+
     return events;
 }
 
diff --git a/tools/server/server-task.h b/tools/server/server-task.h
index 49f62d3866..dc6b2dac1e 100644
--- a/tools/server/server-task.h
+++ b/tools/server/server-task.h
@@ -117,6 +117,7 @@ struct task_result_state {
     bool text_block_started = false;
 
     // for OpenAI Responses streaming API
+    bool oai_resp_created = false;
     const std::string oai_resp_id;
     const std::string oai_resp_reasoning_id;
     const std::string oai_resp_message_id;
@@ -440,6 +441,7 @@ struct server_task_result_cmpl_partial : server_task_result {
     bool text_block_started     = false;
 
     // for OpenAI Responses API
+    bool oai_resp_created = false;
     std::string oai_resp_id;
     std::string oai_resp_reasoning_id;
     std::string oai_resp_message_id;
diff --git a/tools/server/tests/unit/test_compat_oai_responses.py b/tools/server/tests/unit/test_compat_oai_responses.py
index 7aab4a8ba6..14528b4874 100644
--- a/tools/server/tests/unit/test_compat_oai_responses.py
+++ b/tools/server/tests/unit/test_compat_oai_responses.py
@@ -71,3 +71,44 @@ def test_responses_stream_with_openai_library():
             assert r.response.output[0].id.startswith("msg_")
             assert gathered_text == r.response.output_text
             assert match_regex("(Suddenly)+", r.response.output_text)
+
+
+def test_responses_stream_with_llama_telemetry():
+    global server
+    server.n_ctx = 256
+    server.n_batch = 32
+    server.n_slots = 1
+    server.start()
+
+    saw_progress = False
+    saw_delta_timings = False
+    completed = None
+
+    res = server.make_stream_request("POST", "/responses", data={
+        "input": "This is a test" * 10,
+        "max_output_tokens": 8,
+        "temperature": 0.8,
+        "stream": True,
+        "timings_per_token": True,
+        "return_progress": True,
+    })
+
+    for data in res:
+        if "prompt_progress" in data:
+            assert data["type"] == "response.in_progress"
+            assert data["prompt_progress"]["total"] > 0
+            assert data["prompt_progress"]["processed"] >= data["prompt_progress"]["cache"]
+            saw_progress = True
+        if "timings" in data:
+            assert "prompt_per_second" in data["timings"]
+            assert "predicted_per_second" in data["timings"]
+            if data["type"] == "response.output_text.delta":
+                saw_delta_timings = True
+        if data["type"] == "response.completed":
+            completed = data
+
+    assert saw_progress
+    assert saw_delta_timings
+    assert completed is not None
+    assert "usage" in completed["response"]
+    assert "timings" in completed