added openrouter api and called using simple http layer

app.py

@@ -345,20 +345,30 @@ def set_up_chat_ui():
                 )
                 return
 
-            for chunk in llm.stream(formatted_template):
-                if isinstance(chunk, str):
-                    response += chunk
-                else:
-                    response += chunk.content  # AIMessageChunk
-
-                # Update the progress bar with an approx progress percentage
-                progress_bar.progress(
-                    min(
-                        len(response) / gcfg.get_max_output_tokens(llm_provider_to_use),
-                        0.95
-                    ),
-                    text='Streaming content...this might take a while...'
-                )
+            if provider == GlobalConfig.PROVIDER_OPENROUTER:
+                # OpenRouter returns a function, not a LangChain LLM. Call it directly.
+                response_json = llm(formatted_template)
+                # Extract the text from the OpenAI-compatible response
+                try:
+                    response = response_json["choices"][0]["message"]["content"]
+                except Exception as ex:
+                    handle_error(f"Failed to parse OpenRouter response: {ex}\nRaw response: {response_json}", True)
+                    return
+            else:
+                for chunk in llm.stream(formatted_template):
+                    if isinstance(chunk, str):
+                        response += chunk
+                    else:
+                        response += chunk.content  # AIMessageChunk
+
+                    # Update the progress bar with an approx progress percentage
+                    progress_bar.progress(
+                        min(
+                            len(response) / gcfg.get_max_output_tokens(llm_provider_to_use),
+                            0.95
+                        ),
+                        text='Streaming content...this might take a while...'
+                    )
         except (httpx.ConnectError, requests.exceptions.ConnectionError):
             handle_error(
                 'A connection error occurred while streaming content from the LLM endpoint.'

global_config.py

@@ -23,6 +23,7 @@ class GlobalConfig:
     PROVIDER_OLLAMA = 'ol'
     PROVIDER_TOGETHER_AI = 'to'
     PROVIDER_AZURE_OPENAI = 'az'
+    PROVIDER_OPENROUTER = 'or'
     VALID_PROVIDERS = {
         PROVIDER_COHERE,
         PROVIDER_GOOGLE_GEMINI,
@@ -30,6 +31,7 @@ class GlobalConfig:
         PROVIDER_OLLAMA,
         PROVIDER_TOGETHER_AI,
         PROVIDER_AZURE_OPENAI,
+        PROVIDER_OPENROUTER,
     }
     VALID_MODELS = {
         '[az]azure/open-ai': {
@@ -72,6 +74,19 @@ class GlobalConfig:
             'max_new_tokens': 4096,
             'paid': True,
         },
+        '[or]openai/gpt-3.5-turbo': {
+            'description': 'OpenAI GPT-3.5 Turbo (via OpenRouter)',
+            'max_new_tokens': 2048,
+        },
+        '[or]openrouter/gpt-4-omni': {
+            'description': 'OpenRouter GPT-4 Omni',
+            'max_new_tokens': 8192,
+            'paid': True,
+        },
+        '[or]openrouter/mixtral-8x22b-instruct': {
+            'description': 'Mixtral 8x22B Instruct (via OpenRouter)',
+            'max_new_tokens': 2048,
+        },
     }
     LLM_PROVIDER_HELP = (
         'LLM provider codes:\n\n'
@@ -79,13 +94,14 @@ class GlobalConfig:
         '- **[co]**: Cohere\n'
         '- **[gg]**: Google Gemini API\n'
         '- **[hf]**: Hugging Face Inference API\n'
-        '- **[to]**: Together AI\n\n'
+        '- **[to]**: Together AI\n'
+        '- **[or]**: OpenRouter\n\n'
         '[Find out more](https://github.com/barun-saha/slide-deck-ai?tab=readme-ov-file#summary-of-the-llms)'
     )
     DEFAULT_MODEL_INDEX = int(os.environ.get('DEFAULT_MODEL_INDEX', '4'))
     LLM_MODEL_TEMPERATURE = 0.2
     LLM_MODEL_MIN_OUTPUT_LENGTH = 100
-    LLM_MODEL_MAX_INPUT_LENGTH = 400  # characters
+    LLM_MODEL_MAX_INPUT_LENGTH = 10000  # characters
     MAX_PAGE_COUNT = 50
 
     LOG_LEVEL = 'DEBUG'

helpers/llm_helper.py

@@ -188,6 +188,41 @@ def get_langchain_llm(
             api_key=api_key,
         )
 
+    if provider == GlobalConfig.PROVIDER_OPENROUTER:
+        logger.debug('Getting LLM via OpenRouter: %s', model)
+        OPENROUTER_API_URL = "https://openrouter.ai/api/v1/chat/completions"
+        OPENROUTER_API_KEY = api_key
+        import os
+        import requests
+
+        def openrouter_completion(prompt, model=model, api_key=OPENROUTER_API_KEY):
+            headers = {
+                "Authorization": f"Bearer {api_key}",
+                "Content-Type": "application/json",
+            }
+            # Optionally add analytics headers if available
+            site_url = os.getenv("OPENROUTER_SITE_URL")
+            app_name = os.getenv("OPENROUTER_SITE_NAME")
+            if site_url:
+                headers["HTTP-Referer"] = site_url
+            if app_name:
+                headers["X-Title"] = app_name
+            data = {
+                "model": model,
+                "messages": [
+                    {"role": "system", "content": "You are a helpful assistant summarizing technical support information. Provide a concise summary or key action points based on the provided context."},
+                    {"role": "user", "content": prompt},
+                ]
+            }
+            response = requests.post(
+                url=OPENROUTER_API_URL,
+                headers=headers,
+                json=data
+            )
+            response.raise_for_status()
+            return response.json()
+        return openrouter_completion
+
     if provider == GlobalConfig.PROVIDER_COHERE:
         from langchain_cohere.llms import Cohere