Different user, Different prompt - Same assistant
# supports
sanskar
05/12/2025, 12:31 PMI want different users on my app have different system and user prompts for their voice agents. For that, I am making a patch call to /assistant and updating both the prompts when my user is about to make the call.
I am using a common assistant for the same. There would be an issue if:
for 2 users U1 and U2:
U1 triggers call --> vapi prompts are updated (as per U1) --> U2 triggers call --> vapi prompts are updated (as per U2) --> U1's call triggers (but vapi config has U2's prompt now)
Is there a way out?
v
Vapi Support Bot
05/12/2025, 12:31 PMThanks for describing your scenario in detail. Based on the information available, I don't have details on whether Vapi supports per-user or per-session prompts with a shared assistant, or if there's a built-in way to prevent prompt overwriting in this situation. If you have any other questions or need clarification on a different aspect, feel free to ask!
Vapi Support Bot
05/12/2025, 12:31 PMThanks for describing your scenario in detail. Based on the information available, I don't have details on whether Vapi supports per-user or per-session prompts with a shared assistant, or if there's a built-in way to prevent prompt overwriting in this situation. If you have any other questions or need clarification on a different aspect, feel free to ask!
s
sanskar
05/12/2025, 12:34 PM@User sorry for tagging here. in bit of a pickle here. have a customer demo in a couple of hours where I want to showcase parallel calls but with different prompts. in case this is not possible, any way out that is recommended?
i hope my usecase is clear based on the question.
sanskar
05/12/2025, 12:53 PMis
one assistant per userk
Kings_big💫
05/12/2025, 3:13 PMUse per-user assistants, create transient ones per call, or pass user-specific prompts via assistantOverrides at call time instead of patching the assistant.
s
sanskar
05/12/2025, 4:01 PMthanks @Kings_big💫 !!
if possible, can you please lead to the correct place in docs for this? really appreciate it
sanskar
05/12/2025, 4:07 PMchecking the documentation here: https://docs.vapi.ai/assistants/dynamic-variables
sanskar
05/12/2025, 4:08 PMseems like we can override variables. can we update the system and user prompts as well?
k
Kings_big💫
05/12/2025, 4:13 PMYes, you can override system and user prompts dynamically using assistantOverrides in the API call
https://docs.vapi.ai/assistants/dynamic-variables
s
sanskar
05/12/2025, 4:14 PM Copy code
{
"assistantId": "your-assistant-id",
"assistantOverrides": {
"variableValues": {
"name": "John"
}
},
"customer": {
"number": "+1xxxxxxxxxx"
},
"phoneNumberId": "your-phone-id"
}sanskar
05/12/2025, 4:14 PMso instead of
namesystemPromptuserPromptsanskar
05/12/2025, 4:21 PMsanskar
05/12/2025, 4:21 PMcouldn't see it in the api docs
sanskar
05/12/2025, 4:22 PMin the 35 possible inputs
sanskar
05/12/2025, 4:44 PMnvm found it, thanks :]
sanskar
05/12/2025, 4:44 PMits in models --> openai --> ...