PromptTools vs W&B Weave

PromptTools has no write-up on Specifiction yet; its figures are above.

W&B Weave provides observability and continuous-improvement tools for production AI agents. It structures traces as sessions and turns, with steps, tools, and sub-agents represented individually. Built-in and custom signals classify interactions, and alerts can be sent through Slack notifications or webhook automations. Its evaluation tools compare results and visualize regressions before deployment; the Playground lets teams compare models and prompting methods against production traces. Safety scorers cover toxicity, bias, personal information, and hallucinations, while quality scorers assess coherence, fluency, and context relevance. Weave works with LangChain and LlamaIndex and supports models from OpenAI, Meta, Amazon Bedrock, and Anthropic. Python and TypeScript libraries are available, as is OpenTelemetry trace submission through an OTLP endpoint. Weave runs on API, Linux, macOS, self-hosted, web, and Windows platforms. The Free plan costs nothing and includes 1 GB of monthly ingestion and 5 GB of storage. Pro costs $60 a month, with 1.5 GB of monthly ingestion; extra ingestion costs $0.10 per MB. A 30-day trial is listed.