diff --git a/.env.example b/.env.example
index 328413b209..0257d33e31 100644
--- a/.env.example
+++ b/.env.example
@@ -1,3 +1,6 @@
+# [Optional] Set the user for OpenAI and Helicone to track usage
+USER=
+
 # [Recommended for local deployments] Backend API key for OpenAI, so that users don't need one (UI > this > '')
 OPENAI_API_KEY=
 # [Optional] Sets the "OpenAI-Organization" header field to support organization users (UI > this > '')
diff --git a/src/common/types/env.d.ts b/src/common/types/env.d.ts
index c7fe31c01a..3843dbd197 100644
--- a/src/common/types/env.d.ts
+++ b/src/common/types/env.d.ts
@@ -4,6 +4,8 @@ declare namespace NodeJS {
 
   // available to the server-side
   interface ProcessEnv {
+    // OpenAI and Helicone
+    USER_ID: string;
 
     // LLM: OpenAI
     OPENAI_API_KEY: string;
diff --git a/src/modules/llms/openai/OpenAISourceSetup.tsx b/src/modules/llms/openai/OpenAISourceSetup.tsx
index 9bbbd6e34d..5603bf3088 100644
--- a/src/modules/llms/openai/OpenAISourceSetup.tsx
+++ b/src/modules/llms/openai/OpenAISourceSetup.tsx
@@ -1,7 +1,7 @@
 import * as React from 'react';
 
-import { Box, Button, FormControl, FormHelperText, FormLabel, Input, Switch } from '@mui/joy';
 import SyncIcon from '@mui/icons-material/Sync';
+import { Box, Button, FormControl, FormHelperText, FormLabel, Input, Switch } from '@mui/joy';
 
 import { apiQuery } from '~/modules/trpc/trpc.client';
 
@@ -12,9 +12,9 @@ import { Link } from '~/common/components/Link';
 import { settingsCol1Width, settingsGap } from '~/common/theme';
 
 import { DLLM, DModelSource, DModelSourceId } from '../llm.types';
-import { OpenAI } from './openai.types';
-import { hasServerKeyOpenAI, isValidOpenAIApiKey, LLMOptionsOpenAI, ModelVendorOpenAI } from './openai.vendor';
 import { useModelsStore, useSourceSetup } from '../store-llms';
+import { OpenAI } from './openai.types';
+import { LLMOptionsOpenAI, ModelVendorOpenAI, hasServerKeyOpenAI, isValidOpenAIApiKey } from './openai.vendor';
 
 
 export function OpenAISourceSetup(props: { sourceId: DModelSourceId }) {
@@ -25,7 +25,7 @@ export function OpenAISourceSetup(props: { sourceId: DModelSourceId }) {
   // external state
   const {
     source, sourceLLMs, updateSetup,
-    normSetup: { heliKey, oaiHost, oaiKey, oaiOrg, moderationCheck },
+    normSetup: { heliKey, oaiHost, oaiKey, oaiOrg, moderationCheck, userId },
   } = useSourceSetup(props.sourceId, ModelVendorOpenAI.normalizeSetup);
 
   const hasModels = !!sourceLLMs.length;
@@ -110,6 +110,23 @@ export function OpenAISourceSetup(props: { sourceId: DModelSourceId }) {
       />
     </FormControl>}
 
+    {showAdvanced && <FormControl orientation='horizontal' sx={{ flexWrap: 'wrap', justifyContent: 'space-between' }}>
+      <Box sx={{ minWidth: settingsCol1Width }}>
+        <FormLabel>
+          User ID
+        </FormLabel>
+        <FormHelperText sx={{ display: 'block' }}>
+            <Link level='body-sm' href='https://docs.helicone.ai/features/advanced-usage/user-metrics' target='_blank'>helicone</Link>, 
+            <Link level='body-sm' href='https://platform.openai.com/docs/guides/safety-best-practices/end-user-ids' target='_blank'>OpenAI</Link>
+        </FormHelperText>
+      </Box>
+      <Input
+        variant='outlined' placeholder='big-agi'
+        value={userId} onChange={event => updateSetup({ userId: event.target.value })}
+        sx={{ flexGrow: 1 }}
+      />
+    </FormControl>}
+
     {showAdvanced && <FormControl orientation='horizontal' sx={{ flexWrap: 'wrap', justifyContent: 'space-between' }}>
       <Box sx={{ minWidth: settingsCol1Width }}>
         <FormLabel>
diff --git a/src/modules/llms/openai/openai.router.ts b/src/modules/llms/openai/openai.router.ts
index 04ea7749c3..3ecc402e82 100644
--- a/src/modules/llms/openai/openai.router.ts
+++ b/src/modules/llms/openai/openai.router.ts
@@ -1,5 +1,5 @@
-import { z } from 'zod';
 import { TRPCError } from '@trpc/server';
+import { z } from 'zod';
 
 import { createTRPCRouter, publicProcedure } from '~/modules/trpc/trpc.server';
 import { fetchJsonOrTRPCError } from '~/modules/trpc/trpc.serverutils';
@@ -19,12 +19,14 @@ const accessSchema = z.object({
   oaiHost: z.string().trim(),
   heliKey: z.string().trim(),
   moderationCheck: z.boolean(),
+  userId: z.string().trim().optional(),
 });
 
 export const modelSchema = z.object({
   id: z.string(),
   temperature: z.number().min(0).max(1).optional(),
   maxTokens: z.number().min(1).max(1000000),
+  userId: z.string().optional()
 });
 
 export const historySchema = z.array(z.object({
@@ -202,6 +204,9 @@ export function openAIAccess(access: AccessSchema, apiPath: string): { headers:
   // Organization ID
   const oaiOrg = access.oaiOrg || process.env.OPENAI_API_ORG_ID || '';
 
+  // User ID
+  const userId = access.userId || process.env.USER_ID || '';
+
   // API host
   let oaiHost = access.oaiHost || process.env.OPENAI_API_HOST || DEFAULT_OPENAI_HOST;
   if (!oaiHost.startsWith('http'))
@@ -221,19 +226,23 @@ export function openAIAccess(access: AccessSchema, apiPath: string): { headers:
       ...(oaiKey && { Authorization: `Bearer ${oaiKey}` }),
       'Content-Type': 'application/json',
       ...(oaiOrg && { 'OpenAI-Organization': oaiOrg }),
-      ...(heliKey && { 'Helicone-Auth': `Bearer ${heliKey}` }),
+      ...(heliKey && { 'Helicone-Auth': `Bearer ${heliKey}`, 'Helicone-User-Id': userId }),
     },
     url: oaiHost + apiPath,
   };
 }
 
 export function openAIChatCompletionPayload(model: ModelSchema, history: HistorySchema, functions: FunctionsSchema | null, n: number, stream: boolean): OpenAI.Wire.ChatCompletion.Request {
+  // User ID
+  const userId = model.userId || process.env.USER_ID || '';
+
   return {
     model: model.id,
     messages: history,
     ...(functions && { functions: functions, function_call: 'auto' }),
     ...(model.temperature && { temperature: model.temperature }),
     ...(model.maxTokens && { max_tokens: model.maxTokens }),
+    ...(userId && { user: userId }),
     n,
     stream,
   };
diff --git a/src/modules/llms/openai/openai.vendor.ts b/src/modules/llms/openai/openai.vendor.ts
index d917b5c29c..ee1c48b1f2 100644
--- a/src/modules/llms/openai/openai.vendor.ts
+++ b/src/modules/llms/openai/openai.vendor.ts
@@ -1,7 +1,7 @@
 import { apiAsync } from '~/modules/trpc/trpc.client';
 
-import { DLLM, ModelVendor } from '../llm.types';
 import { VChatFunctionIn, VChatMessageIn, VChatMessageOrFunctionCallOut, VChatMessageOut } from '../llm.client';
+import { DLLM, ModelVendor } from '../llm.types';
 
 import { OpenAIIcon } from './OpenAIIcon';
 import { OpenAILLMOptions } from './OpenAILLMOptions';
@@ -19,6 +19,7 @@ export interface SourceSetupOpenAI {
   oaiHost: string;  // use OpenAI-compatible non-default hosts (full origin path)
   heliKey: string;  // helicone key (works in conjunction with oaiHost)
   moderationCheck: boolean;
+  userId: string; // user id for OpenAi and helicone if heliKey is present 
 }
 
 export interface LLMOptionsOpenAI {
@@ -45,6 +46,7 @@ export const ModelVendorOpenAI: ModelVendor<SourceSetupOpenAI, LLMOptionsOpenAI>
     oaiOrg: '',
     oaiHost: '',
     heliKey: '',
+    userId: '',
     moderationCheck: false,
     ...partialSetup,
   }),