diff --git a/comfy/api/openapi.yaml b/comfy/api/openapi.yaml
index 1e983a6c4..bcfe29d8f 100644
--- a/comfy/api/openapi.yaml
+++ b/comfy/api/openapi.yaml
@@ -354,19 +354,29 @@ paths:
           required: true
           description: |
             The ID of the prompt to query.
-    responses:
-      204:
-        description: |
-          The prompt is still in progress
-      200:
-        description: |
-          Prompt outputs
-        content:
-          application/json:
-            $ref: "#/components/schemas/Outputs"
-      404:
-        description: |
-          The prompt was not found
+      responses:
+        204:
+          description: |
+            The prompt is still in progress
+        200:
+          description: |
+            Prompt outputs
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Outputs"
+        404:
+          description: |
+            The prompt was not found
+        500:
+          description: |
+            An execution error occurred while processing the prompt.
+          content:
+            application/json:
+              description:
+                An execution status directly from the workers
+              schema:
+                $ref: "#/components/schemas/ExecutionStatusAsDict"
   /api/v1/prompts:
     get:
       operationId: list_prompts
diff --git a/comfy/client/aio_client.py b/comfy/client/aio_client.py
index cdf16e0f1..68ac7d1e3 100644
--- a/comfy/client/aio_client.py
+++ b/comfy/client/aio_client.py
@@ -65,16 +65,21 @@ class AsyncRemoteComfyClient:
             else:
                 raise RuntimeError(f"unexpected response: {response.status}: {await response.text()}")
 
-    async def queue_and_forget_prompt_api(self, prompt: PromptDict) -> str:
+    async def queue_and_forget_prompt_api(self, prompt: PromptDict, prefer_header: Optional[str] = "respond-async", accept_header: str = "application/json") -> str:
         """
         Calls the API to queue a prompt, and forgets about it
         :param prompt:
+        :param prefer_header: The Prefer header value (e.g., "respond-async" or None)
+        :param accept_header: The Accept header value (e.g., "application/json", "application/json+respond-async")
         :return: the task ID
         """
         prompt_json = AsyncRemoteComfyClient.__json_encoder.encode(prompt)
         response: ClientResponse
+        headers = {'Content-Type': 'application/json', 'Accept': accept_header}
+        if prefer_header:
+            headers['Prefer'] = prefer_header
         async with self.session.post(urljoin(self.server_address, "/api/v1/prompts"), data=prompt_json,
-                                     headers={'Content-Type': 'application/json', 'Accept': 'application/json', 'Prefer': 'respond-async'}) as response:
+                                     headers=headers) as response:
 
             if 200 <= response.status < 400:
                 response_json = await response.json()
@@ -82,16 +87,21 @@ class AsyncRemoteComfyClient:
             else:
                 raise RuntimeError(f"could not prompt: {response.status}: {await response.text()}")
 
-    async def queue_prompt_api(self, prompt: PromptDict) -> V1QueuePromptResponse:
+    async def queue_prompt_api(self, prompt: PromptDict, prefer_header: Optional[str] = None, accept_header: str = "application/json") -> V1QueuePromptResponse:
         """
         Calls the API to queue a prompt.
         :param prompt:
+        :param prefer_header: The Prefer header value (e.g., "respond-async" or None)
+        :param accept_header: The Accept header value (e.g., "application/json", "application/json+respond-async")
         :return: the API response from the server containing URLs and the outputs for the UI (nodes with OUTPUT_NODE == true)
         """
         prompt_json = AsyncRemoteComfyClient.__json_encoder.encode(prompt)
         response: ClientResponse
+        headers = {'Content-Type': 'application/json', 'Accept': accept_header}
+        if prefer_header:
+            headers['Prefer'] = prefer_header
         async with self.session.post(urljoin(self.server_address, "/api/v1/prompts"), data=prompt_json,
-                                     headers={'Content-Type': 'application/json', 'Accept': 'application/json'}) as response:
+                                     headers=headers) as response:
 
             if 200 <= response.status < 400:
                 return V1QueuePromptResponse(**(await response.json()))
@@ -160,3 +170,36 @@ class AsyncRemoteComfyClient:
         # images have filename, subfolder, type keys
         # todo: use the OpenAPI spec for this when I get around to updating it
         return history_json[prompt_id].outputs
+
+    async def get_prompt_status(self, prompt_id: str) -> ClientResponse:
+        """
+        Get the status of a prompt by ID using the API endpoint.
+        :param prompt_id: The prompt ID to query
+        :return: The ClientResponse object (caller should check status and read body)
+        """
+        return await self.session.get(urljoin(self.server_address, f"/api/v1/prompts/{prompt_id}"))
+
+    async def poll_prompt_until_done(self, prompt_id: str, max_attempts: int = 60, poll_interval: float = 1.0) -> tuple[int, dict | None]:
+        """
+        Poll a prompt until it's done (200), errors (500), or times out.
+        :param prompt_id: The prompt ID to poll
+        :param max_attempts: Maximum number of polling attempts
+        :param poll_interval: Time to wait between polls in seconds
+        :return: Tuple of (status_code, response_json or None)
+        """
+        for _ in range(max_attempts):
+            async with await self.get_prompt_status(prompt_id) as response:
+                if response.status == 200:
+                    return response.status, await response.json()
+                elif response.status == 500:
+                    return response.status, await response.json()
+                elif response.status == 404:
+                    return response.status, None
+                elif response.status == 204:
+                    # Still in progress
+                    await asyncio.sleep(poll_interval)
+                else:
+                    # Unexpected status
+                    return response.status, None
+        # Timeout
+        return 408, None
diff --git a/comfy/cmd/server.py b/comfy/cmd/server.py
index df37647d3..b346a711e 100644
--- a/comfy/cmd/server.py
+++ b/comfy/cmd/server.py
@@ -116,6 +116,24 @@ async def compress_body(request: web.Request, handler):
     return response
 
 
+@web.middleware
+async def opentelemetry_middleware(request: web.Request, handler):
+    """Middleware to extract and propagate OpenTelemetry context from request headers"""
+    from opentelemetry import propagate, context
+
+    # Extract OpenTelemetry context from headers
+    carrier = dict(request.headers)
+    ctx = propagate.extract(carrier)
+
+    # Attach context and execute handler
+    token = context.attach(ctx)
+    try:
+        response = await handler(request)
+        return response
+    finally:
+        context.detach(token)
+
+
 def create_cors_middleware(allowed_origin: str):
     @web.middleware
     async def cors_middleware(request: web.Request, handler):
@@ -127,7 +145,7 @@ def create_cors_middleware(allowed_origin: str):
 
         response.headers['Access-Control-Allow-Origin'] = allowed_origin
         response.headers['Access-Control-Allow-Methods'] = 'POST, GET, DELETE, PUT, OPTIONS'
-        response.headers['Access-Control-Allow-Headers'] = 'Content-Type, Authorization'
+        response.headers['Access-Control-Allow-Headers'] = 'Content-Type, Authorization, traceparent, tracestate'
         response.headers['Access-Control-Allow-Credentials'] = 'true'
         return response
 
@@ -224,7 +242,7 @@ class PromptServer(ExecutorToClientProgress):
         self._external_address: Optional[str] = None
         self.background_tasks: dict[str, Task] = dict()
 
-        middlewares = [cache_control, deprecation_warning]
+        middlewares = [opentelemetry_middleware, cache_control, deprecation_warning]
         if args.enable_compress_response_body:
             middlewares.append(compress_body)
 
@@ -867,9 +885,19 @@ class PromptServer(ExecutorToClientProgress):
                     return web.json_response(status=404)
             elif prompt_id in history_items:
                 history_entry = history_items[prompt_id]
+                # Check if execution resulted in an error
+                if "status" in history_entry:
+                    status = history_entry["status"]
+                    if isinstance(status, dict) and status.get("status_str") == "error":
+                        # Return ExecutionStatusAsDict format with status 500, matching POST /api/v1/prompts behavior
+                        return web.Response(
+                            body=json.dumps(status),
+                            status=500,
+                            content_type="application/json"
+                        )
                 return web.json_response(history_entry["outputs"])
             else:
-                return web.json_response(status=500)
+                return web.Response(status=404, reason="prompt not found in expected state")
 
         @routes.post("/api/v1/prompts")
         async def post_api_prompt(request: web.Request) -> web.Response | web.FileResponse:
diff --git a/tests/conftest.py b/tests/conftest.py
index 712cfc0dc..33ae98f9d 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -3,8 +3,6 @@ import multiprocessing
 import os
 import pathlib
 import subprocess
-import sys
-import time
 import urllib
 from contextvars import ContextVar
 from multiprocessing import Process
@@ -12,9 +10,9 @@ from typing import List, Any, Generator
 
 import pytest
 import requests
+import sys
+import time
 
-from comfy.cli_args import default_configuration
-from comfy.execution_context import context_configuration
 
 os.environ['OTEL_METRICS_EXPORTER'] = 'none'
 os.environ["OPENCV_IO_ENABLE_OPENEXR"] = "1"
@@ -22,6 +20,7 @@ os.environ["HF_XET_HIGH_PERFORMANCE"] = "True"
 # fixes issues with running the testcontainers rabbitmqcontainer on Windows
 os.environ["TC_HOST"] = "localhost"
 
+from comfy.cli_args import default_configuration
 from comfy.cli_args_types import Configuration
 
 logging.getLogger("pika").setLevel(logging.CRITICAL + 1)
diff --git a/tests/distributed/test_distributed_queue.py b/tests/distributed/test_distributed_queue.py
index 5aa28c722..098072645 100644
--- a/tests/distributed/test_distributed_queue.py
+++ b/tests/distributed/test_distributed_queue.py
@@ -243,3 +243,265 @@ async def test_two_workers_distinct_requests():
             all_workflows.update(worker.processed_workflows)
 
         assert len(all_workflows) == 2, f"Expected 2 distinct workflows, but got {len(all_workflows)}"
+
+
+# ============================================================================
+# API Error Reporting Tests
+# ============================================================================
+
+
+@pytest.mark.asyncio
+async def test_api_error_reporting_blocking_request(frontend_backend_worker_with_rabbitmq):
+    """Test error reporting with blocking request (no async preference)"""
+    async with AsyncRemoteComfyClient(server_address=frontend_backend_worker_with_rabbitmq) as client:
+        # Create an invalid prompt that will cause a validation error
+        prompt = sdxl_workflow_with_refiner("test", inference_steps=1, refiner_steps=1)
+        # Make the prompt invalid by referencing a non-existent checkpoint
+        prompt["4"]["inputs"]["ckpt_name"] = "nonexistent_checkpoint.safetensors"
+
+        # Post with blocking behavior (no prefer header for async)
+        prompt_json = client._AsyncRemoteComfyClient__json_encoder.encode(prompt)
+        async with client.session.post(
+            f"{frontend_backend_worker_with_rabbitmq}/api/v1/prompts",
+            data=prompt_json,
+            headers={'Content-Type': 'application/json', 'Accept': 'application/json'}
+        ) as response:
+            # Should return 400 for validation error (invalid checkpoint)
+            assert response.status == 400, f"Expected 400, got {response.status}"
+            error_body = await response.json()
+
+            # Verify ValidationErrorDict structure per OpenAPI spec
+            assert "type" in error_body, "Missing 'type' field in error response"
+            assert "message" in error_body, "Missing 'message' field in error response"
+            assert "details" in error_body, "Missing 'details' field in error response"
+            assert "extra_info" in error_body, "Missing 'extra_info' field in error response"
+
+
+@pytest.mark.asyncio
+async def test_api_error_reporting_async_prefer_header(frontend_backend_worker_with_rabbitmq):
+    """Test error reporting with Prefer: respond-async header"""
+    async with AsyncRemoteComfyClient(server_address=frontend_backend_worker_with_rabbitmq) as client:
+        # Create a valid prompt structure but with invalid checkpoint
+        prompt = sdxl_workflow_with_refiner("test", inference_steps=1, refiner_steps=1)
+        prompt["4"]["inputs"]["ckpt_name"] = "nonexistent.safetensors"
+
+        # Post with Prefer: respond-async header
+        prompt_json = client._AsyncRemoteComfyClient__json_encoder.encode(prompt)
+        async with client.session.post(
+            f"{frontend_backend_worker_with_rabbitmq}/api/v1/prompts",
+            data=prompt_json,
+            headers={
+                'Content-Type': 'application/json',
+                'Accept': 'application/json',
+                'Prefer': 'respond-async'
+            }
+        ) as response:
+            # Should return 400 immediately for validation error
+            assert response.status == 400, f"Expected 400 for validation error, got {response.status}"
+            error_body = await response.json()
+            assert "type" in error_body
+
+
+@pytest.mark.asyncio
+async def test_api_error_reporting_async_accept_mimetype(frontend_backend_worker_with_rabbitmq):
+    """Test error reporting with +respond-async in Accept mimetype"""
+    async with AsyncRemoteComfyClient(server_address=frontend_backend_worker_with_rabbitmq) as client:
+        # Create a prompt with validation error
+        prompt = sdxl_workflow_with_refiner("test", inference_steps=1, refiner_steps=1)
+        prompt["4"]["inputs"]["ckpt_name"] = "invalid_model.safetensors"
+
+        # Post with +respond-async in Accept header
+        prompt_json = client._AsyncRemoteComfyClient__json_encoder.encode(prompt)
+        async with client.session.post(
+            f"{frontend_backend_worker_with_rabbitmq}/api/v1/prompts",
+            data=prompt_json,
+            headers={
+                'Content-Type': 'application/json',
+                'Accept': 'application/json+respond-async'
+            }
+        ) as response:
+            # Should return 400 for validation error (happens before queuing)
+            assert response.status == 400, f"Expected 400, got {response.status}"
+            error_body = await response.json()
+            assert "type" in error_body
+
+
+@pytest.mark.asyncio
+async def test_api_get_prompt_status_success(frontend_backend_worker_with_rabbitmq):
+    """Test GET /api/v1/prompts/{prompt_id} returns 200 with Outputs on success"""
+    async with AsyncRemoteComfyClient(server_address=frontend_backend_worker_with_rabbitmq) as client:
+        # Create a valid prompt
+        prompt = sdxl_workflow_with_refiner("test", inference_steps=1, refiner_steps=1)
+
+        # Queue async to get prompt_id
+        task_id = await client.queue_and_forget_prompt_api(prompt, prefer_header="respond-async")
+        assert task_id is not None
+
+        # Poll until done
+        status_code, result = await client.poll_prompt_until_done(task_id, max_attempts=60, poll_interval=1.0)
+
+        # For a valid prompt, should get 200
+        assert status_code == 200, f"Expected 200 for successful execution, got {status_code}"
+        assert result is not None
+
+        # Verify it returns outputs structure (dict with node IDs)
+        assert isinstance(result, dict)
+        assert len(result) > 0, "Expected non-empty outputs"
+
+
+@pytest.mark.asyncio
+async def test_api_get_prompt_status_404(frontend_backend_worker_with_rabbitmq):
+    """Test GET /api/v1/prompts/{prompt_id} returns 404 for non-existent prompt"""
+    async with AsyncRemoteComfyClient(server_address=frontend_backend_worker_with_rabbitmq) as client:
+        # Request a non-existent prompt ID
+        fake_prompt_id = str(uuid.uuid4())
+
+        async with await client.get_prompt_status(fake_prompt_id) as response:
+            assert response.status == 404, f"Expected 404 for non-existent prompt, got {response.status}"
+
+
+@pytest.mark.asyncio
+async def test_api_get_prompt_status_204_in_progress(frontend_backend_worker_with_rabbitmq):
+    """Test GET /api/v1/prompts/{prompt_id} returns 204 while prompt is in progress"""
+    async with AsyncRemoteComfyClient(server_address=frontend_backend_worker_with_rabbitmq) as client:
+        # Create a prompt that takes some time to execute
+        prompt = sdxl_workflow_with_refiner("test", inference_steps=10, refiner_steps=10)
+
+        # Queue async
+        task_id = await client.queue_and_forget_prompt_api(prompt, prefer_header="respond-async")
+
+        # Immediately check status (should be 204 or 200 if very fast)
+        async with await client.get_prompt_status(task_id) as response:
+            # Should be either 204 (in progress) or 200 (completed very fast)
+            assert response.status in [200, 204], f"Expected 200 or 204, got {response.status}"
+
+            if response.status == 204:
+                # No content for in-progress
+                content = await response.read()
+                assert len(content) == 0 or content == b'', "Expected no content for 204 response"
+
+
+@pytest.mark.asyncio
+async def test_api_async_workflow_both_methods(frontend_backend_worker_with_rabbitmq):
+    """Test full async workflow: queue with respond-async, then poll for completion"""
+    async with AsyncRemoteComfyClient(server_address=frontend_backend_worker_with_rabbitmq) as client:
+        # Create a valid prompt
+        prompt = sdxl_workflow_with_refiner("test", inference_steps=1, refiner_steps=1)
+
+        # Method 1: Prefer header
+        task_id_1 = await client.queue_and_forget_prompt_api(prompt, prefer_header="respond-async")
+        assert task_id_1 is not None
+
+        # Method 2: +respond-async in Accept header
+        task_id_2 = await client.queue_and_forget_prompt_api(
+            prompt, prefer_header=None, accept_header="application/json+respond-async"
+        )
+        assert task_id_2 is not None
+
+        # Poll both until done
+        status_1, result_1 = await client.poll_prompt_until_done(task_id_1, max_attempts=60, poll_interval=1.0)
+        status_2, result_2 = await client.poll_prompt_until_done(task_id_2, max_attempts=60, poll_interval=1.0)
+
+        # Both should succeed
+        assert status_1 == 200, f"Task 1 failed with status {status_1}"
+        assert status_2 == 200, f"Task 2 failed with status {status_2}"
+
+        # Both should have outputs
+        assert result_1 is not None and len(result_1) > 0
+        assert result_2 is not None and len(result_2) > 0
+
+
+@pytest.mark.asyncio
+async def test_api_validation_error_structure(frontend_backend_worker_with_rabbitmq):
+    """Test that validation errors return proper ValidationErrorDict structure"""
+    async with AsyncRemoteComfyClient(server_address=frontend_backend_worker_with_rabbitmq) as client:
+        # Create an invalid prompt (invalid checkpoint name)
+        prompt = sdxl_workflow_with_refiner("test", 1, 1)
+        prompt["4"]["inputs"]["ckpt_name"] = "fake.safetensors"
+
+        prompt_json = client._AsyncRemoteComfyClient__json_encoder.encode(prompt)
+
+        async with client.session.post(
+            f"{frontend_backend_worker_with_rabbitmq}/api/v1/prompts",
+            data=prompt_json,
+            headers={'Content-Type': 'application/json', 'Accept': 'application/json'}
+        ) as response:
+            assert response.status == 400, f"Expected 400, got {response.status}"
+
+            error_body = await response.json()
+
+            # Verify ValidationErrorDict structure per OpenAPI spec
+            assert "type" in error_body, "Missing 'type'"
+            assert "message" in error_body, "Missing 'message'"
+            assert "details" in error_body, "Missing 'details'"
+            assert "extra_info" in error_body, "Missing 'extra_info'"
+
+            # extra_info should have exception_type and traceback
+            assert "exception_type" in error_body["extra_info"], "Missing 'exception_type' in extra_info"
+            assert "traceback" in error_body["extra_info"], "Missing 'traceback' in extra_info"
+            assert isinstance(error_body["extra_info"]["traceback"], list), "traceback should be a list"
+
+
+@pytest.mark.asyncio
+async def test_api_success_response_contract(frontend_backend_worker_with_rabbitmq):
+    """Test that successful execution returns proper response structure"""
+    async with AsyncRemoteComfyClient(server_address=frontend_backend_worker_with_rabbitmq) as client:
+        # Create a valid prompt
+        prompt = sdxl_workflow_with_refiner("test", inference_steps=1, refiner_steps=1)
+
+        # Queue and wait for blocking response
+        prompt_json = client._AsyncRemoteComfyClient__json_encoder.encode(prompt)
+        async with client.session.post(
+            f"{frontend_backend_worker_with_rabbitmq}/api/v1/prompts",
+            data=prompt_json,
+            headers={'Content-Type': 'application/json', 'Accept': 'application/json'}
+        ) as response:
+            assert response.status == 200, f"Expected 200, got {response.status}"
+
+            result = await response.json()
+
+            # Should have 'outputs' key (and deprecated 'urls' key)
+            assert "outputs" in result, "Missing 'outputs' in response"
+
+            # outputs should be a dict with node IDs as keys
+            outputs = result["outputs"]
+            assert isinstance(outputs, dict), "outputs should be a dict"
+            assert len(outputs) > 0, "outputs should not be empty"
+
+            # Each output should follow the Output schema
+            for node_id, output in outputs.items():
+                assert isinstance(output, dict), f"Output for node {node_id} should be a dict"
+                # Should have images or other output types
+                if "images" in output:
+                    assert isinstance(output["images"], list), f"images for node {node_id} should be a list"
+                    for image in output["images"]:
+                        assert "filename" in image, f"image missing 'filename' in node {node_id}"
+                        assert "subfolder" in image, f"image missing 'subfolder' in node {node_id}"
+                        assert "type" in image, f"image missing 'type' in node {node_id}"
+
+
+@pytest.mark.asyncio
+async def test_api_get_prompt_returns_outputs_directly(frontend_backend_worker_with_rabbitmq):
+    """Test GET /api/v1/prompts/{prompt_id} returns Outputs directly (not wrapped in history entry)"""
+    async with AsyncRemoteComfyClient(server_address=frontend_backend_worker_with_rabbitmq) as client:
+        # Create and queue a prompt
+        prompt = sdxl_workflow_with_refiner("test", inference_steps=1, refiner_steps=1)
+        task_id = await client.queue_and_forget_prompt_api(prompt)
+
+        # Poll until done
+        status_code, result = await client.poll_prompt_until_done(task_id, max_attempts=60, poll_interval=1.0)
+
+        assert status_code == 200, f"Expected 200, got {status_code}"
+        assert result is not None, "Result should not be None"
+
+        # Per OpenAPI spec, GET should return Outputs directly, not wrapped
+        # result should be a dict with node IDs as keys
+        assert isinstance(result, dict), "Result should be a dict (Outputs)"
+
+        # Should NOT have 'prompt', 'outputs', 'status' keys (those are in history entry)
+        # Should have node IDs directly
+        for key in result.keys():
+            # Node IDs are typically numeric strings like "4", "13", etc.
+            # Should not be "prompt", "outputs", "status"
+            assert key not in ["prompt", "status"], \
+                f"GET endpoint should return Outputs directly, not history entry. Found key: {key}"