Add Managed Motorhead (#5507)

# Add Managed Motorhead
This change enabled MotorheadMemory to utilize Metal's managed version
of Motorhead. We can easily enable this by passing in a `api_key` and
`client_id` in order to hit the managed url and access the memory api on
Metal.

Twitter: [@softboyjimbo](https://twitter.com/softboyjimbo)

## Who can review?

Community members can review the PR once tests pass. Tag
maintainers/contributors who might be interested:

 @dev2049 @hwchase17

---------

Co-authored-by: Dev 2049 <dev.dev2049@gmail.com>

docs/modules/memory/examples/motorhead_memory_managed.ipynb

@@ -0,0 +1,198 @@
+{
+ "cells": [
+  {
+   "attachments": {},
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# Motörhead Memory (Managed)\n",
+    "[Motörhead](https://github.com/getmetal/motorhead) is a memory server implemented in Rust. It automatically handles incremental summarization in the background and allows for stateless applications.\n",
+    "\n",
+    "## Setup\n",
+    "\n",
+    "See instructions at [Motörhead](https://docs.getmetal.io/motorhead/introduction) for running the managed version of Motorhead. You can retrieve your `api_key` and `client_id` by creating an account on [Metal](https://getmetal.io).\n",
+    "\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 1,
+   "metadata": {},
+   "outputs": [],
+   "source": [
+    "from langchain.memory.motorhead_memory import MotorheadMemory\n",
+    "from langchain import OpenAI, LLMChain, PromptTemplate\n",
+    "\n",
+    "template = \"\"\"You are a chatbot having a conversation with a human.\n",
+    "\n",
+    "{chat_history}\n",
+    "Human: {human_input}\n",
+    "AI:\"\"\"\n",
+    "\n",
+    "prompt = PromptTemplate(\n",
+    "    input_variables=[\"chat_history\", \"human_input\"], \n",
+    "    template=template\n",
+    ")\n",
+    "memory = MotorheadMemory(\n",
+    "    api_key=\"YOUR_API_KEY\",\n",
+    "    client_id=\"YOUR_CLIENT_ID\"\n",
+    "    session_id=\"testing-1\",\n",
+    "    memory_key=\"chat_history\"\n",
+    ")\n",
+    "\n",
+    "await memory.init();  # loads previous state from Motörhead 🤘\n",
+    "\n",
+    "llm_chain = LLMChain(\n",
+    "    llm=OpenAI(), \n",
+    "    prompt=prompt, \n",
+    "    verbose=True, \n",
+    "    memory=memory,\n",
+    ")\n",
+    "\n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 2,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      "\n",
+      "\u001b[1m> Entering new LLMChain chain...\u001b[0m\n",
+      "Prompt after formatting:\n",
+      "\u001b[32;1m\u001b[1;3mYou are a chatbot having a conversation with a human.\n",
+      "\n",
+      "\n",
+      "Human: hi im bob\n",
+      "AI:\u001b[0m\n",
+      "\n",
+      "\u001b[1m> Finished chain.\u001b[0m\n"
+     ]
+    },
+    {
+     "data": {
+      "text/plain": [
+       "' Hi Bob, nice to meet you! How are you doing today?'"
+      ]
+     },
+     "execution_count": 2,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "llm_chain.run(\"hi im bob\")"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 3,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      "\n",
+      "\u001b[1m> Entering new LLMChain chain...\u001b[0m\n",
+      "Prompt after formatting:\n",
+      "\u001b[32;1m\u001b[1;3mYou are a chatbot having a conversation with a human.\n",
+      "\n",
+      "Human: hi im bob\n",
+      "AI:  Hi Bob, nice to meet you! How are you doing today?\n",
+      "Human: whats my name?\n",
+      "AI:\u001b[0m\n",
+      "\n",
+      "\u001b[1m> Finished chain.\u001b[0m\n"
+     ]
+    },
+    {
+     "data": {
+      "text/plain": [
+       "' You said your name is Bob. Is that correct?'"
+      ]
+     },
+     "execution_count": 3,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "llm_chain.run(\"whats my name?\")"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": 4,
+   "metadata": {},
+   "outputs": [
+    {
+     "name": "stdout",
+     "output_type": "stream",
+     "text": [
+      "\n",
+      "\n",
+      "\u001b[1m> Entering new LLMChain chain...\u001b[0m\n",
+      "Prompt after formatting:\n",
+      "\u001b[32;1m\u001b[1;3mYou are a chatbot having a conversation with a human.\n",
+      "\n",
+      "Human: hi im bob\n",
+      "AI:  Hi Bob, nice to meet you! How are you doing today?\n",
+      "Human: whats my name?\n",
+      "AI:  You said your name is Bob. Is that correct?\n",
+      "Human: whats for dinner?\n",
+      "AI:\u001b[0m\n",
+      "\n",
+      "\u001b[1m> Finished chain.\u001b[0m\n"
+     ]
+    },
+    {
+     "data": {
+      "text/plain": [
+       "\"  I'm sorry, I'm not sure what you're asking. Could you please rephrase your question?\""
+      ]
+     },
+     "execution_count": 4,
+     "metadata": {},
+     "output_type": "execute_result"
+    }
+   ],
+   "source": [
+    "llm_chain.run(\"whats for dinner?\")"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3 (ipykernel)",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.9.1"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}

langchain/memory/motorhead_memory.py

@@ -5,19 +5,47 @@ import requests
 from langchain.memory.chat_memory import BaseChatMemory
 from langchain.schema import get_buffer_string
 
+MANAGED_URL = "https://api.getmetal.io/v1/motorhead"
+# LOCAL_URL = "http://localhost:8080"
+
 
 class MotorheadMemory(BaseChatMemory):
-    url: str = "http://localhost:8080"
+    url: str = MANAGED_URL
     timeout = 3000
     memory_key = "history"
     session_id: str
     context: Optional[str] = None
 
+    # Managed Params
+    api_key: Optional[str] = None
+    client_id: Optional[str] = None
+
+    def __get_headers(self) -> Dict[str, str]:
+        is_managed = self.url == MANAGED_URL
+
+        headers = {
+            "Content-Type": "application/json",
+        }
+
+        if is_managed and not (self.api_key and self.client_id):
+            raise ValueError(
+                """
+                You must provide an API key or a client ID to use the managed
+                version of Motorhead. Visit https://getmetal.io for more information.
+                """
+            )
+
+        if is_managed and self.api_key and self.client_id:
+            headers["x-metal-api-key"] = self.api_key
+            headers["x-metal-client-id"] = self.client_id
+
+        return headers
+
     async def init(self) -> None:
         res = requests.get(
             f"{self.url}/sessions/{self.session_id}/memory",
             timeout=self.timeout,
-            headers={"Content-Type": "application/json"},
+            headers=self.__get_headers(),
         )
         res_data = res.json()
         messages = res_data.get("messages", [])
@@ -53,6 +81,6 @@ class MotorheadMemory(BaseChatMemory):
                     {"role": "AI", "content": f"{output_str}"},
                 ]
             },
-            headers={"Content-Type": "application/json"},
+            headers=self.__get_headers(),
         )
         super().save_context(inputs, outputs)