Tool observations can be parented to the previous generation within a trace

[csh-scl]

Problem

Within a single trace, tool observations can be parented to the previous assistant generation when generation lifecycle events arrive out of order.

This happens when a late lifecycle event from an earlier generation overwrites the current generation state.

Expected Behavior

Each tool observation should be parented to the assistant generation that requested it.

[1, 2, 3]

Current Behavior

The generation and tool observations share the same trace ID, but the tools are assigned the wrong parentObservationId.

For three consecutive generations and tool batches:

[1, 1, 2]

The tools execute in the correct order, but their parent relationships appear one generation behind in Langfuse.

Fix

I prepared and tested a fix:

• Branch: https://github.com/csh-scl/opencode-observability-plugin/tree/fix/tool-generation-parenting
• Commit: csh-scl@c4b30ba

The patched result is [1, 2, 3]. Formatting, build, and regression tests pass.

PR creation is currently limited to collaborators. Could a maintainer create a cross-fork PR from this branch or cherry-pick the commit?

Environment

• OpenCode: 1.16.2
• Plugin: 0.1.0
• Langfuse: Cloud

[bezbac]

This should be fixed in the newly released v0.2.0.

You might need to update your OpenCode config to explicitly reference this version if you’ve already used v0.1.0.

"plugin": [
  "@langfuse/opencode-observability-plugin@0.2.0",
]