Child agent sessions produce isolated traces — no linkage to parent trace

[x-xiang]

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

[bezbac]

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]

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.

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]

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]

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.