W&B Weave — Cloud Observability & Experiment Tracking for DSPy

Guide the user through setting up W&B Weave for tracing DSPy calls, tracking optimization experiments, and collaborating with team dashboards.

What is W&B Weave

Weave is Weights & Biases' LLM observability and experiment tracking product. It provides cloud-hosted dashboards for tracing function calls, comparing optimization runs, and sharing results across teams.

• Cloud-hosted: Dashboards at wandb.ai
• Manual instrumentation: Uses @weave.op() decorator (not auto-instrument like Langtrace)
• Team collaboration: shared projects, comments, and run comparisons

Key difference from Langtrace/Phoenix

Weave uses a manual decorator (@weave.op()) — you choose which functions to trace. Langtrace and Phoenix auto-instrument all DSPy calls. This gives Weave more control over what gets tracked but requires more setup.

When to use Weave

Use Weave when: