Startup

Weights & Biases Weave

Observability and continuous improvement for production agents

W&B Weave is Weights & Biases' observability and evaluation product for production AI agents. Its traces are organized around sessions, turns, steps, tools and sub-agents. It adds behavior monitoring with alerts, an evaluation API, guardrail scorers and leaderboards. Coding agents such as Claude Code can connect through W&B skills and an MCP server to read production data and run evaluations.

Visit wandb.ai

Their open-source work

Python · ≈1.1k stars · Apache-2.0

W&B Weave

wandb/weave

Toolkit for developing AI-powered applications, by Weights & Biases

Maintained by wandb

San Francisco, CA · Est. 2022

Featured

LangChain

The de-facto standard toolkit for building LLM applications and agents.

LangChain makes the LangChain framework and LangGraph, the low-level orchestration standard for stateful, controllable agents, plus the LangSmith platform for tracing, evaluating and monitoring them in production.

~$75M raised

4 pros · 4 cons

San Francisco, CA · Est. 2023

Braintrust

Enterprise-grade evals, data and AI gateway.

Braintrust turns prompts and agent traces into testable datasets and CI, plus an inference gateway — helping teams measure whether harness changes actually improve agent quality.

4 pros · 4 cons

Berkeley, CA · Est. 2020

Arize AI

Observability and evaluation for AI — makers of OSS Phoenix.

Arize traces and evaluates LLM and agent systems in production; their open-source Phoenix tracer is a common instrumentation choice for agent harnesses that need to be debuggable.

4 pros · 5 cons