Braintrust Data, Inc. · Prompting, evaluation & observability
Hosted observability and evaluation platform for AI agents with tracing, experiments, pattern detection, a CLI, MCP access and an AI assistant (Loop) that analyzes traces and builds evals
Distributed search and analytics engine on Apache Lucene with full-text, aggregations, vector search and ES|QL; triple-licensed AGPL, SSPL and Elastic License
AGPL-3.0-only OR SSPL-1.0 OR Elastic-2.0Open sourceFreeSelf-hostedNov 2, 2026
Langfuse (part of ClickHouse, Inc. since January 2026) · Prompting, evaluation & observability
In-depth entry
Open-source LLM observability and evaluation platform: tracing, LLM-as-judge and human evals, prompt management, datasets and cost dashboards, self-hostable or as Langfuse Cloud
LangChain, Inc. · Prompting, evaluation & observability
LangChain's hosted platform for tracing, evaluating and deploying LLM applications and agents, with prompt tooling, an LLM gateway and cloud, hybrid or self-hosted options
Open-source Python SDK and self-hosted AI gateway that calls 100+ LLM providers in the OpenAI format, with routing, fallbacks, virtual keys, budgets, spend tracking and logging callbacks
Self-hostable BI tool with a no-code question builder, SQL editor, dashboards and embedding; AGPL open-source edition plus commercial Pro and Enterprise