LangWatch

Lightweight server monitoring with Docker stats and alerts

Beszel is a lightweight, self-hosted server monitoring platform built in Go that tracks CPU, memory, disk, network, GPU, temperature, and Docker container metrics with historical data visualization and configurable alerts. Its simple hub-and-agent architecture deploys in minutes and consumes minimal resources compared to traditional monitoring stacks like Prometheus and Grafana.

Open-source LLM gateway with built-in optimization and A/B testing

TensorZero is an open-source LLMOps platform in Rust that unifies an LLM gateway, observability, prompt optimization, and A/B experimentation in a single binary. It routes requests across providers with sub-millisecond P99 latency at 10K+ QPS while capturing structured data for continuous improvement. Supports dynamic in-context learning, fine-tuning workflows, and production feedback loops. Backed by $7.3M seed funding, 11K+ GitHub stars.

Open-source observability platform for metrics, logs, and traces visualization.

Grafana is the leading open-source platform for monitoring and observability visualization. It connects to virtually any data source — Prometheus, Elasticsearch, InfluxDB, PostgreSQL, CloudWatch, Datadog, and 150+ others — to create beautiful, interactive dashboards. Used by millions of users at companies like Bloomberg, JPMorgan, eBay, and PayPal. Grafana Cloud offers a fully managed experience with generous free tier. The CNCF ecosystem standard for metrics visualization.

Cloud-scale monitoring, security, and analytics platform for modern infrastructure.

Datadog is a cloud observability and security platform that unifies metrics, traces, logs, RUM, synthetics, APM, and security signals. Current pricing pages list 1,000+ integrations for Infrastructure Monitoring, with Pro from $15/host/month and Enterprise from $23/host/month when billed annually.

Open-source product analytics, session replay, and feature flags

PostHog is an open-source product and data tools platform for analytics, session replay, feature flags, experiments, surveys, error tracking, web analytics, data warehouse, CDP and LLM observability workflows. It suits developer-led teams that want one integrated product OS instead of many separate tools.

Open-source LLM observability and evaluation

Phoenix by Arize is an open-source AI observability platform for tracing, evaluating, and debugging LLM applications. It captures prompt-response pairs, retrieval context, agent tool calls, and latency data through OpenTelemetry-based instrumentation. Provides experiment tracking, dataset management, and evaluation frameworks for systematically improving AI application quality. 10K+ GitHub stars.

Open-source LLM engineering platform for observability

Langfuse is an open-source LLM engineering platform with 29K+ GitHub stars for tracing, evaluating, and monitoring AI applications. Acquired by ClickHouse, it provides detailed traces of LLM calls, prompt management with versioning, dataset-based evaluation, user feedback collection, and cost tracking. Framework-agnostic with native integrations for LangChain, LlamaIndex, OpenAI SDK, and Vercel AI SDK. Offers both self-hosted deployment and a managed cloud service.

LLM evaluation and prompt engineering platform

Braintrust is an AI observability and evaluation platform for tracing LLM applications, building datasets, running prompt/model experiments, scoring outputs and turning production feedback into regression tests. It fits teams that need repeatable quality gates for AI releases rather than one-off prompt demos.