# Pydantic Logfire vs W&B Weave (slim)

> W&B Weave scores 66.7 (B) to Pydantic Logfire's 64.9 (B) for agent tracing. Prices, MCP, x402, uptime and agent notes side by side.

- Full: https://www.anchorterminal.com/compare/pydantic-logfire-vs-wandb-weave.md (~2,850 tokens) · this version ~680 tokens · JSON https://www.anchorterminal.com/compare/pydantic-logfire-vs-wandb-weave.json · canonical https://www.anchorterminal.com/compare/pydantic-logfire-vs-wandb-weave
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-09

W&B Weave scores 66.7 (B) on agent readiness against Pydantic Logfire's 64.9 (B), and leads in 2 of 7 scored categories. Pydantic Logfire leads on schema & documentation, security & auth and payments & pricing. Both do agent tracing.

- Pydantic Logfire: B 64.9, rank #335 of 950 · https://www.anchorterminal.com/tools/pydantic-logfire.min.md
- W&B Weave: B 66.7, rank #280 of 950 · https://www.anchorterminal.com/tools/wandb-weave.min.md
- Pydantic Logfire, good for Teams that want agent traces alongside application logs and metrics in one OpenTelemetry store, queried by SQL from a coding assistant. Ahead on Schema & documentation, 81 against 74; Security & auth, 80 against 63; Payments & pricing, 40 against 35. Also Free to start without a card.
- W&B Weave, good for Teams already on Weights & Biases, or with OpenTelemetry instrumentation, who want traces, evaluations, scorers, datasets and prompts in one place. Ahead on Reliability, 68 against 34. Also Open source.

| Category | Pydantic Logfire | W&B Weave |
| --- | --- | --- |
| Reliability (16%) | 34 | 68 |
| Performance (10%) | pending | pending |
| Schema & documentation (13%) | 81 | 74 |
| Agent ergonomics (13%) | 72 | 71 |
| Security & auth (14%) | 80 | 63 |
| Payments & pricing (10%) | 40 | 35 |
| Task success (10%) | pending | pending |
| Maintenance & community (7%) | 90 | 87 |
| Transparency & trust (7%) | 73 | 75 |

| Fact (where they differ) | Pydantic Logfire | W&B Weave |
| --- | --- | --- |
| Vendor | Pydantic Services Inc. | Weights & Biases (CoreWeave) |
| Hosted endpoint | `https://logfire-us.pydantic.dev/mcp` | `https://trace.wandb.ai` |
| Auth | OAuth or key | API key |
| Licence | Proprietary hosted service under the Logfire Terms of Service. The Python, JavaScript and Rust SDKs and the Helm chart are open source, the Python SDK under MIT | Hosted service under the W&B Master Service Agreement. The Weave SDKs and trace server source on GitHub are Apache-2.0, and the W&B MCP server is MIT |
| Tools exposed | 51 | none |
| Last release | 2026-10-07 | 2026-09-25 |
| Terms last updated | no date given | 2026-09-30 |
| Privacy policy last updated | 2024-02-21 | 2026-02-24 |
| Terms restrict automated access | not found in the text | yes |
| Popularity | 4.5k stars, 24k npm/wk, 3.4M PyPI/wk | 624k npm/wk, 219k PyPI/wk |