Repository navigation
Child agent sessions produce isolated traces — no linkage to parent trace #8
Description
Problem
When a parent agent spawns child agents (sub-agents), each child session creates an independent
trace with its own traceId. There is no way to view the full parent → child orchestration as a
single connected trace in Langfuse.
Expected Behavior
Child agent sessions should be linked to the parent session's trace, so the entire multi-agent call
chain is visible as one trace in the Langfuse UI.
Current Behavior
A multi-agent workflow (e.g., 1 parent + 3 child agents) produces 4 completely disconnected traces.
There is no correlation between them — the parent trace has no reference to child traces, and vice
versa.
Environment
- OpenCode: 1.15.5
- Plugin: 0.1.0
- Langfuse: Self-hosted
Activity
bezbac commentedon Jul 17, 2026
Hi @x-xiang, thanks for the report! I already noticed this and am planning to spend some time next week updating the behavior here, along with making a few more general improvements.
x-xiang commentedon Jul 17, 2026
Thanks for the quick response! Glad to hear it's already on your radar. Looking forward to the update — happy to help test when it's ready.
bezbac commentedon Aug 7, 2026
Hi @x-xiang, just wanted to share an update here. I released v0.2.0, but it doesn’t yet include fixes for sub-agent tracing. I hope to find some time in the coming weeks to give it another go :)
x-xiang commentedon Aug 7, 2026
Thanks for the update, and no rush at all — really appreciate you keeping the issue posted.
I’d be happy to help test it whenever you get a chance to revisit it.
idityaGE commentedon Aug 9, 2026
Hi @bezbac, I worked on a fix for this issue and manually verified it against the Langfuse UI.
Proposed fix branch:
https://github.com/idityaGE/opencode-observability-plugin/tree/fix-child-session-parenting
Compare:
main...idityaGE:opencode-observability-plugin:fix-child-session-parenting
I tried to open a PR, but GitHub returned:
Could you please enable/allow PRs from my fork, or let me know the preferred way to contribute this change?
Summary of the fix:
session.created/session.updatedparent session IDs.opencode.turnspans under the active parent trace when available.session.idlefinalize only that session so child sessions do not clear parent trace state.Validation:
npx pnpm run formatnpx pnpm run buildnpx pnpm run test:integrationwith 14 passing testsBefore:
After:
bezbac commentedon Aug 18, 2026
Hi @idityaGE, I took the required steps to open up the plugin to external contributions. Could you open a PR, sounds like you're changes would be helpful!
idityaGE commentedon Aug 18, 2026
PR#27
bezbac commentedon Aug 20, 2026
This was released as part of v0.3.0.
You might need to update your OpenCode config to explicitly reference this version if you’ve already used a prior version.