Open source Harness Engineering Platform
Trace LLMs and AI agents with OpenTelemetry, run LLM evaluations, manage prompts, compare models, store API keys in Vault, and self-host free under Apache 2.0.
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All the tools, one harness platform.
AI engineering tools for LLM tracing, prompt management, LLM evaluation, and model comparison from prototype to production.
LLM tracing
OpenTelemetry LLM tracing for every call, tool, and retrieval. Filter by user, session, cost, latency, or metadata.
$ pip install openlit
import openlit; openlit.init()
LLM evaluation
LLM evaluation with LLM-as-a-judge, heuristics, or human review on production traffic or experiments.
Evaluators
Prompt management
Prompt Hub for prompt management and versioning. Deploy and roll back prompts without shipping app code.
support-agent
v3 · prodYou are a helpful support agent. Answer using the docs context: {{context}}
Keep answers under 120 words. Cite sources when possible.
Variables
{{context}}
{{user_name}}
Deploy
prod · staging
rollback ready
v1
v2
v3
Model comparison
OpenGround model comparison playground. Test prompts on real inputs and compare LLMs side by side.
fable
Sol
AI agent monitoring
AI agent monitoring for coding agents and tool loops. See tools, cost, and outcomes in one view.
API key management
Vault for LLM API key management. Store and rotate OpenAI, Anthropic, and other secrets outside app code.
Cost & latency
Track spend, latency, and quality for AI workloads so you can improve cost and speed with real data.
218 traces
$12.40
p95 latency
842ms
avg cost
$0.057
Instrument once
Your way in. Every stack covered.
Use OpenLIT SDKs, the enterprise eBPF controller, the GPU collector, or send OTLP from OTel SDKs, OBI, OpenLLMetry, and other OpenTelemetry instrumentations.
Native SDKs
Drop in openlit.init() for OpenTelemetry LLM tracing at the app level.
pip install openliteBPF controller
Zero-code instrumentation for any language. No SDK, no app changes.
helm install ... openlit-controllerGPU collector
GPU monitoring for LLM inference: utilization, memory, temperature, and power via OpenTelemetry.
docker run ... otel-gpu-collectorAny OTel source
Already instrumented? Point OTel SDKs, OBI, OpenLLMetry, or any OTLP exporter at OpenLIT.
OTEL_EXPORTER_OTLP_ENDPOINT=https://your-openlit-url:431856+ integrations
LLMs, agent frameworks, vector DBs, and more.
Openai
Ollama
Anthropic
Deepseek
Gpt4all
Cohere
Mistral
Github Models
Vllm
Azure Openai
Azure Ai Inference
Huggingface
Amazon Bedrock
Vertex AIOpenaiOllamaAnthropicDeepseekGpt4allCohereMistralGithub ModelsVllmAzure OpenaiAzure Ai InferenceHuggingfaceAmazon BedrockVertex AI
Google Ai Studio
Groq
Nvidia Nim
Xai
Elevenlabs
Ai21
Together.ai
Assembly AI
Featherless
Reka AI
OLA Krutrim
Titan ML
Sarvam AI
Prem AIGoogle Ai StudioGroqNvidia NimXaiElevenlabsAi21Together.aiAssembly AIFeatherlessReka AIOLA KrutrimTitan MLSarvam AIPrem AI
Open platform. Open source.
Built on OpenTelemetry so your traces stay portable. Self-host under Apache 2.0, keep full ownership of your data, and never get locked into a proprietary format.
Self-host at scale
Apache 2.0 license
APIs and data you own
Active OSS community
Why use OpenLIT?
OpenLIT is an OpenTelemetry-native Harness Engineering platform. Trace, evaluate, and improve AI systems with production data, without locking telemetry into a proprietary format.
The full harness loop
Instrument, develop, manage, observe, and improve AI systems in one Harness Engineering platform from prototype to production.
Unified platform
LLM tracing, LLM evaluation, prompt management, Vault, OpenGround, and Otter work alone or together on the same production data.
Open source (Apache 2.0)
Inspect the code, self-host for free with no license key, and join a community with … GitHub stars.
OpenTelemetry-native
Standard OpenTelemetry tracing and metrics you can keep in OpenLIT or export to Grafana, Datadog, and any OTLP backend.
56+ integrations
LLMs, agent frameworks, vector databases, and GPUs, plus ingest from any OTel SDK, OBI, or OpenLLMetry source.
Built for scale
ClickHouse-backed storage for fast queries across high-volume LLM and agent telemetry.
Proxy-free by design
Instrument in-process with SDKs or zero-code tooling. No mandatory proxy on every LLM call.
GPU monitoring
OpenTelemetry GPU collector for NVIDIA, AMD, and Intel utilization, memory, temperature, and power during LLM inference.
Production-proven
Trusted by teams worldwide with … SDK downloads and … GitHub stars.
Your data, your infra
Self-host the UI and ClickHouse so prompts, traces, and secrets stay in your environment.