StartupLondon, UK · Est. 2024
Laminar
Open-source observability platform purpose-built for AI agents.
Laminar (YC S24) is an open-source observability platform for AI agents. Its OpenTelemetry-native SDK auto-traces Vercel AI SDK, Browser Use, Stagehand, LangChain, OpenAI, Anthropic and Gemini. Signals let teams describe behaviors in plain English, such as an agent stuck in a loop, and get Slack alerts when they occur. It also offers an evals SDK and CLI for local or CI runs, SQL-queryable traces via MCP and CLI so coding agents can debug from traces, custom dashboards, and dataset annotation. The backend is written in Rust and can be self-hosted with Docker Compose.
People
Co-founder & CEO
Evals & benchmarks
Co-founder & CTO
Evals & benchmarks
In the news
Open Source · Hacker News (MCP) · Oct 19, 2026
Hi HN, we’re Robert and Din from Laminar ( https://laminar.sh ). We’ve been building open-source observability for AI agents since 2024. Recently, we released flow-1, a model trained with RL to find errors in agent traces. On our benchmark ( https://laminar.sh/blog/flow-1 ), i...
Neighbours in the directory
San Francisco, CA · Est. 2022
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
San Francisco, CA · Est. 2023
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.
Berkeley, CA · Est. 2020
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.
Connections
Relations from the Harness Hub knowledge graph, as charted in the State of Harness reports.
Built on · 3
- LangChainProject
- Model Context ProtocolProject
- Vercel AI SDKProject
Similar entries · 6
- Arize AIStartup
- Bento LabsStartup
- LatitudeStartup
- OpenLITProject
- OpenLLMetryProject
- PhoenixProject
Sources
Verified Oct 29, 2026