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W&B Weave
LLM tracing and evaluation toolkit from Weights & Biases, integrated with the broader W&B experiment-tracking ecosystem.
| Category | Observability & Tracing |
| OpenTelemetry-native | Yes — no proprietary-SDK lock-in |
| Open source | Yes |
| Self-hostable | Yes |
| Pricing model | freemium |
| Pricing notes | Free tier on W&B cloud; usage-based ingestion pricing; enterprise self-hosting via W&B Server |
| Framework integrations | openai-sdk, anthropic, langchain, llamaindex, mistral |
| Funding / ownership | Weights & Biases acquired by CoreWeave (~$1.7B, 2025) |
| GitHub stars | 1,101 |
| Maintenance | active (commit 2026-06-13) |
| License (GitHub) | Apache-2.0 |
| Open issues | 426 |
| Maturity signal | 87/100 (Mature) — computed from public GitHub signals, see methodology |
Pricing/feature source: https://wandb.ai/site/pricing/
Maturity signal is computed from public GitHub data only. How it is calculated.
Frequently asked questions
Is W&B Weave open source?
Yes. Licensed under Apache-2.0.
Can I self-host W&B Weave?
Yes — W&B Weave can run in your own infrastructure.
Is W&B Weave OpenTelemetry-native?
Yes — W&B Weave speaks OpenTelemetry (OTLP) natively, so there is no proprietary-SDK lock-in.
How much does W&B Weave cost?
Freemium. Free tier on W&B cloud; usage-based ingestion pricing; enterprise self-hosting via W&B Server