From 96daaba605a51b8afe3275df0cf8f00f031abfae Mon Sep 17 00:00:00 2001
From: Cameron Pfiffer <cameron@pfiffer.org>
Date: Wed, 3 Dec 2025 21:36:33 -0800
Subject: [PATCH] feat: use OAuth token for Letta pipe authentication

---
 backend/functions/letta_agents.py | 62 +++++++++++++++++++++++++++----
 1 file changed, 54 insertions(+), 8 deletions(-)

diff --git a/backend/functions/letta_agents.py b/backend/functions/letta_agents.py
index e0f87d1ca..e6abe261f 100644
--- a/backend/functions/letta_agents.py
+++ b/backend/functions/letta_agents.py
@@ -7,7 +7,7 @@ requirements: letta-client
 """
 
 from pydantic import BaseModel, Field
-from typing import Generator, Iterator, Union
+from typing import Generator, Iterator, Union, Optional
 import logging
 
 log = logging.getLogger(__name__)
@@ -21,25 +21,38 @@ class Pipe:
         )
         LETTA_API_KEY: str = Field(
             default="",
-            description="API key for Letta Cloud"
+            description="API key for listing agents (optional if using OAuth)"
         )
 
     def __init__(self):
         self.valves = self.Valves()
         self.name = ""
 
-    def _get_client(self):
+    def _get_client(self, token: Optional[str] = None):
         """Get a Letta client instance."""
         from letta_client import Letta
 
         kwargs = {"base_url": self.valves.LETTA_BASE_URL}
-        if self.valves.LETTA_API_KEY:
+        # Use provided token (OAuth) first, fall back to API key from valves
+        if token:
+            kwargs["api_key"] = token
+        elif self.valves.LETTA_API_KEY:
             kwargs["api_key"] = self.valves.LETTA_API_KEY
 
         return Letta(**kwargs)
 
     def pipes(self) -> list[dict]:
         """Return list of Letta agents as available models."""
+        # If no API key is configured, return a placeholder entry
+        # The actual agent list will be fetched when the user sends a message
+        # using their OAuth token
+        if not self.valves.LETTA_API_KEY:
+            log.info("Letta pipe: no API key configured, returning placeholder")
+            return [{
+                "id": "default",
+                "name": "Letta Agent (select agent in chat)"
+            }]
+
         try:
             client = self._get_client()
             agents = []
@@ -57,9 +70,18 @@ class Pipe:
 
         except Exception as e:
             log.error(f"Error fetching Letta agents: {e}")
-            return []
-
-    def pipe(self, body: dict) -> Union[str, Generator, Iterator]:
+            # Return placeholder on error too
+            return [{
+                "id": "default",
+                "name": "Letta Agent (select agent in chat)"
+            }]
+
+    def pipe(
+        self,
+        body: dict,
+        __user__: Optional[dict] = None,
+        __oauth_token__: Optional[dict] = None,
+    ) -> Union[str, Generator, Iterator]:
         """
         Process a chat completion request and forward to Letta agent.
 
@@ -68,10 +90,18 @@ class Pipe:
                 - model: The agent ID (format: "letta_pipe.agent-xxx")
                 - messages: List of chat messages
                 - stream: Whether to stream the response
+            __user__: User info dict from Open WebUI
+            __oauth_token__: OAuth token dict with access_token from Letta OAuth
 
         Returns:
             String response or generator for streaming
         """
+        # Get OAuth access token if available
+        oauth_access_token = None
+        if __oauth_token__ and isinstance(__oauth_token__, dict):
+            oauth_access_token = __oauth_token__.get("access_token")
+            log.info(f"Letta pipe: using OAuth token for user {__user__.get('id', 'unknown') if __user__ else 'unknown'}")
+
         # Extract agent ID from model name
         # Model format is "pipe_id.agent_id" - we need the agent_id part
         model = body.get("model", "")
@@ -80,6 +110,22 @@ class Pipe:
         else:
             agent_id = model
 
+        # Handle placeholder "default" agent - list user's agents and use first one
+        if agent_id == "default":
+            if not oauth_access_token:
+                return "Error: Please log in with Letta to use this agent"
+            try:
+                client = self._get_client(token=oauth_access_token)
+                page = client.agents.list()
+                if page.items:
+                    agent_id = page.items[0].id
+                    log.info(f"Letta pipe: using first agent {agent_id}")
+                else:
+                    return "Error: No agents found in your Letta account. Create an agent at app.letta.com first."
+            except Exception as e:
+                log.error(f"Error listing agents: {e}")
+                return f"Error listing agents: {str(e)}"
+
         # Get messages - convert from OpenAI format to Letta format
         messages = body.get("messages", [])
 
@@ -115,7 +161,7 @@ class Pipe:
             return "Error: No user message found"
 
         try:
-            client = self._get_client()
+            client = self._get_client(token=oauth_access_token)
 
             if body.get("stream", False):
                 return self._stream_response(client, agent_id, [last_user_msg])
-- 
2.51.2