langchain-ai/langserve
1
0
Fork 0
mirror of https://github.com/langchain-ai/langserve.git synced 2026-07-18 10:54:29 -04:00
Code Issues 136 Packages Projects Releases 10 Wiki Activity

How to do Human in Loop in /stream Endpoint #66

New Issue
Open
opened 2026-02-16 00:18:28 -05:00 by yindo · 1 comment
yindo commented 2026-02-16 00:18:28 -05:00
Owner
Copy Link
Copy Source

Originally created by @wolvever on GitHub (Dec 12, 2023).

LangServe can stream output using /stream Endpoint. However, if I want to send an event and wait for human feedback, wait for a parameter value or confirm, for example. It seems impossible to use SSE only. Users have to do some conversation keeping and implement coversations in two functions, one returns an generator, save conversation to cache and load them in another request handler.

Is there any demo to implement SSE and Human in Loop at the same time. If not, how do we implement that without websockets.

Originally created by @wolvever on GitHub (Dec 12, 2023). LangServe can stream output using `/stream` Endpoint. However, if I want to send an event and wait for human feedback, wait for a parameter value or confirm, for example. It seems impossible to use SSE only. Users have to do some conversation keeping and implement coversations in two functions, one returns an generator, save conversation to cache and load them in another request handler. Is there any demo to implement SSE and Human in Loop at the same time. If not, how do we implement that without websockets.
yindo added the streaming label 2026-02-16 00:18:28 -05:00
yindo commented 2026-02-16 00:18:28 -05:00
Author
Owner
Copy Link
Copy Source

@eyurtsev commented on GitHub (Dec 12, 2023):

We can't do it with the streaming endpoint right now since that's just one way communication from server to client.

Right now, the way to achieve this is by issuing a new request for every human in the loop action.

Options are either:

  1. Parameterize the inputs to the runnable to take the relevant context and store the session information on the client side
  2. Persist the relevant session on the backend

Also more context will be super helpful in terms of expanding support in langserve/langchain:

  1. What should the human in the loop be able to do? Approve/edit/change tools used?
  2. Should control be configurable per tool?
  3. Are you referencing any existing workflows supported by langchain?
@eyurtsev commented on GitHub (Dec 12, 2023): We can't do it with the `streaming` endpoint right now since that's just one way communication from server to client. Right now, the way to achieve this is by issuing a new request for every human in the loop action. Options are either: 1. Parameterize the inputs to the runnable to take the relevant context and store the session information on the client side 2. Persist the relevant session on the backend Also more context will be super helpful in terms of expanding support in langserve/langchain: 1) What should the human in the loop be able to do? Approve/edit/change tools used? 2) Should control be configurable per tool? 3) Are you referencing any existing workflows supported by langchain?
Sign in to join this conversation.
No Branch/Tag Specified
Branches Tags
Labels
Clear labels
bug
confirmed
duplicate
enhancement
help wanted
in-progress
investigate
not langserve
playground
pull-request
Mirrored from GitHub Pull Request
 question
stale
streaming
unable-to-reproduce
wontfix
No Label streaming
Milestone
No items
No Milestone
Projects
Clear projects
No project
Assignees
Clear assignees
yindo
No Assignees
1 Participants
Notifications
Due Date
No due date set.
Dependencies

No dependencies set.

Reference: langchain-ai/langserve#66
Delete Branch "%!s()"

Deleting a branch is permanent. Although the deleted branch may continue to exist for a short time before it actually gets removed, it CANNOT be undone in most cases. Continue?