add optional webhook after job finished, allow to send prompt_id with api request

api params to send:
```
{
   "prompt": "json - comfyui workflow exported as api format",
   "prompt_id": "uuidv4", # optional - you can use it to reference your db record for job - webhook will contain this uuid
   "webhook_url": "url to send results from comfyui after job is complete",
}
```

Comfyui will rspond to webhook url with params:
```
{
  "prompt_id": "uuidv4 you provided during job creation (or autogenerated in comfyui during job creation)",
  "execution_time": 32.7151094869987, # (in seconds)
  "status": "success/error",
  "result": {"outputs": {}} # same format as in history endpoint
}
```

main.py

@@ -7,7 +7,8 @@ import folder_paths
 import time
 from comfy.cli_args import args
 from app.logger import setup_logger
-
+import aiohttp
+import asyncio
 
 setup_logger(log_level=args.verbose)
 
@@ -104,6 +105,18 @@ def cuda_malloc_warning():
         if cuda_malloc_warning:
             logging.warning("\nWARNING: this card most likely does not support cuda-malloc, if you get \"CUDA error\" please run ComfyUI with: --disable-cuda-malloc\n")
 
+async def send_webhook(server, prompt_id, data):
+    webhook_url = server.webhooks.pop(prompt_id, None)
+    if webhook_url:
+        try:
+            async with aiohttp.ClientSession() as session:
+                logging.info(f"Sending webhook for prompt {prompt_id}")
+                async with session.post(webhook_url, json=data) as response:
+                    if response.status != 200:
+                        logging.warning(f"Webhook delivery failed for prompt {prompt_id}. Status: {response.status}")
+        except Exception as e:
+            logging.error(f"Error sending webhook for prompt {prompt_id}: {str(e)}")
+
 def prompt_worker(q, server):
     e = execution.PromptExecutor(server, lru_size=args.cache_lru)
     last_gc_collect = 0
@@ -137,6 +150,15 @@ def prompt_worker(q, server):
             execution_time = current_time - execution_start_time
             logging.info("Prompt executed in {:.2f} seconds".format(execution_time))
 
+            # Send webhook after execution is complete
+            webhook_data = {
+                "prompt_id": prompt_id,
+                "execution_time": execution_time,
+                "status": "success" if e.success else "error",
+                "result": e.history_result
+            }
+            asyncio.run_coroutine_threadsafe(send_webhook(server, prompt_id, webhook_data), server.loop)
+
         flags = q.get_flags()
         free_memory = flags.get("free_memory", False)
 

requirements.txt

@@ -14,7 +14,11 @@ scipy
 tqdm
 psutil
 
+#webhook handling
+aiohttp
+
 #non essential dependencies:
 kornia>=0.7.1
 spandrel
 soundfile
+

server.py

@@ -32,6 +32,10 @@ from app.user_manager import UserManager
 from model_filemanager import download_model, DownloadModelStatus
 from typing import Optional
 from api_server.routes.internal.internal_routes import InternalRoutes
+import requests
+import json
+from urllib.parse import urlparse, parse_qs, urlencode
+
 
 class BinaryEventTypes:
     PREVIEW_IMAGE = 1
@@ -159,6 +163,7 @@ class PromptServer():
         self.messages = asyncio.Queue()
         self.client_session:Optional[aiohttp.ClientSession] = None
         self.number = 0
+        self.webhooks = {}
 
         middlewares = [cache_control]
         if args.enable_cors_header:
@@ -623,8 +628,15 @@ class PromptServer():
                 if "client_id" in json_data:
                     extra_data["client_id"] = json_data["client_id"]
                 if valid[0]:
-                    prompt_id = str(uuid.uuid4())
+                    # allow to accept prompt_id from api caller to reference it in webhook handler if needed
+                    prompt_id = json_data.get("prompt_id", str(uuid.uuid4()))
                     outputs_to_execute = valid[2]
+                    
+                    # Add webhook URL to the webhooks dict if provided
+                    webhook_url = json_data.get("webhook_url")
+                    if webhook_url:
+                        self.webhooks[prompt_id] = webhook_url
+
                     self.prompt_queue.put((number, prompt_id, prompt, extra_data, outputs_to_execute))
                     response = {"prompt_id": prompt_id, "number": number, "node_errors": valid[3]}
                     return web.json_response(response)
@@ -864,4 +876,4 @@ class PromptServer():
                 logging.warning(f"[ERROR] An error occurred during the on_prompt_handler processing")
                 logging.warning(traceback.format_exc())
 
-        return json_data
+        return json_data