Discover / Token & Cost Optimization

LangWatch

by langwatchTypeScript

Monitoring and analytics platform for tracking LLM usage quality and cost.

Toolstable

Maturity: stable because 3y old, langwatch-3.7.0 released 8d ago. Derived from release and commit history, not a rating.

Stars
3.5k
Forks
340
Downloads / mo
Last commit
2026-08-03
License
Apache-2.0
Open issues
766

Market and trust evidence

Edition not yet matched

No exact skills.sh identity match is available for this repository. Repository adoption and freshness remain visible above; install momentum is not inferred.

Trust analysis is a screening signal, not a security warranty. Read the ranking and trust methodology.

In practice

Written by AI from this repository’s README · high confidence

Teams shipping agents have no systematic way to regression test them or to see what happened in production.

Use it when

Use it when you need traces, datasets, evaluations and prompt versions in one loop instead of stitching separate tools.

Not the right pick when

The local setup pulls postgres, redis, clickhouse and more into ~/.langwatch, so it is heavy for a quick experiment.

Capabilities

  • end to end agent simulations against your full stack
  • trace, dataset, evaluate and optimize loop
  • OpenTelemetry and OTLP native integration
  • AI gateway with virtual keys, budgets and guardrails
  • annotations and queues for human review
  • prompt versions linked to traces and kept in Git

Requirements

  • Node.js for the local CLI setup
  • Docker if you use the docker compose path

Cost: Open source with a paid cloud option

Install

Derived from the published package name in the repository, not from a model.

Video walkthroughs

Third-party YouTube uploads matched to this tool by title, channel and repository name on 2026-08-03. Not made, reviewed or endorsed by SkillPilot. View counts and publish months are as of the match date and the month is approximate. Nothing loads from YouTube until you press play.

What the repository ships

Ships CLAUDE.mdMCP manifestHas docsDocker imageCI configured

Detected from the actual files in the repository root.

Latest release langwatch-3.7.0

Published 2026-07-26

Helm chart for LangWatch application

Tags

README

<img width="1212" height="395" alt="012d1688-24ae-4759-ae70-5f8f81a13c0e" src="https://github.com/user-attachments/assets/27b6e50e-efde-41cf-9f7c-94b829b25a8c" />

<h3 align="center">

<a href="https://langwatch.ai">Website</a> · <a href="https://docs.langwatch.ai">Docs</a> · <a href="https://discord.gg/kT4PhDS2gH">Discord</a> · <a href="https://docs.langwatch.ai/self-hosting/overview">Self-hosting</a>

</h3>

<p align="center">

<a href="https://discord.gg/kT4PhDS2gH" target="_blank"><img src="https://img.shields.io/discord/1227886780536324106?logo=discord&labelColor=%20%235462eb&logoColor=%20%23f5f5f5&color=%20%235462eb" alt="chat on Discord"></a>

<a href="https://pypi.python.org/pypi/langwatch" target="_blank"><img src="https://img.shields.io/pypi/dm/langwatch?logo=python&logoColor=white&label=pypi%20langwatch&color=blue" alt="langwatch Python package on PyPi"></a>

<a href="https://www.npmjs.com/package/langwatch" target="_blank"><img src="https://img.shields.io/npm/dm/langwatch?logo=npm&logoColor=white&label=npm%20langwatch&color=blue" alt="langwatch npm package"></a>

<a href="https://twitter.com/intent/follow?screen_name=langwatchai" target="_blank">

<img src="https://img.shields.io/twitter/follow/langwatchai?logo=X&color=%20%23f5f5f5"

alt="follow on X"></a>

<img src="https://img.shields.io/badge/license-Apache%202.0%20%2B%20Enterprise-blue" alt="Open-core: Apache 2.0 floor + Enterprise extension">

</p>

<video src="https://github.com/user-attachments/assets/ff49882d-4e9d-4b7c-819b-be690fba9387" autoplay loop muted playsinline width="100%" style="display: block; aspect-ratio: 16 / 9;"></video>

Why LangWatch?

The platform for LLM evaluations and AI agent testing.

We help teams test, simulate, evaluate, and monitor LLM-powered agents end-to-end — before release and in production.

Built for teams that need regression testing, simulations, and production observability without building custom tooling.

Run realistic scenarios against your full stack (tools, state, user simulator, judge) and pinpoint where your agents break, and why? down to each decision.

  • Eval + observability + prompts in one loop

Tracedatasetevaluateoptimize prompts/models → re-test. No glue code, no tool sprawl.

OpenTelemetry/OTLP-native. Framework- and LLM-provider agnostic by design.

OpenAI/Anthropic-compatible proxy with virtual keys, hierarchical budgets, inline guardrails, automatic fallback across providers, and Anthropic cache_control passthrough. ~700 ns hot-path overhead. Ships as a separate Go binary (services/gateway/) + Helm sub-chart (charts/gateway/).

Review runs, annotate failures, and ship fixes faster. Let domain experts label edge cases with annotations & queues, keep prompts in Git with the GitHub integration, and link prompt versions to traces.

LangWatch gives you full visibility into agent behavior and the tools to systematically improve reliability, performance, and cost, while keeping you in control of your AI system

Getting Started

Cloud ☁️

The easiest way to get started with LangWatch.

Create a free account → create a project → get started/ copy your API key.

Local setup 💻

The fastest way to run LangWatch locally — only Node.js required:


npx @langwatch/server

The CLI installs uv, postgres, redis, clickhouse, the AI gateway binary, and the Langy assistant's runtime into ~/.langwatch/, scaffolds a .env with locally-generated secrets, then starts every service in parallel and opens http://localhost:5560. Everything lives under ~/.langwatch/; rm -rf ~/.langwatch is a clean reset.

Two pieces are yours to decide on, in ~/.langwatch/.env:

| Variable | Default | What it changes |

|---|---|---|

| LANGWATCH_ENABLE_LANGY | true | The Langy assistant. Adds ~45MB for its runtime; the workers run unsandboxed as you, on your own machine. |

| LANGWATCH_ENABLE_PRESIDIO | false | The PII detection evaluator. Adds ~670MB of language model, larger than the rest of the evaluator environment put together. LangWatch's own secret and PII redaction of your traces does not depend on it. |

| LANGWATCH_ENABLE_LINGUA | false | The language detection evaluator. Adds ~95MB of language models. |

| LANGWATCH_ENABLE_LEGACY_EVALUATORS | false | The deprecated legacy evaluators, kept only for evaluations saved long ago. Hidden from the product entirely while off. |

Every other evaluator is installed either way. Change any of these in ~/.langwatch/.env and restart the server.

Prefer Docker? You can still use docker compose:


git clone https://github.com/langwatch/langwatch.git
cd langwatch
cp langwatch/.env.example langwatch/.env
docker compose up -d --wait --build

Once running, LangWatch will be available at http://localhost:5560, where you can create your first project and API key.

Deployment options ⚓️

Run LangWatch on your own infrastructure:

  • Docker Compose - Run LangWatch on your own machine.
  • Kubernetes (Helm) - Run LangWatch on a Kubernetes cluster using Helm.
  • OnPrem - Cloud-specific setups for AWS, Google Cloud, and Azure.

<details>

<summary>Hybrid (OnPrem data) 🔀</summary>

For companies that have strict data residency and control requirements, without needing to go fully on-prem.

Read more about it on our docs.

</details>

<details>

<summary>Local Development 👩‍💻</summary>

You can also run LangWatch locally without docker to develop and help contribute to the project.

Start just the databases using docker and leave it running:


docker compose up redis postgres opensearch

Then, on another terminal, install the dependencies and start LangWatch:


make install
make start

</details>

🚀 Quick Start

Ship safer agents in minutes. Create a free account, then dive into these guides:

🗺️ Integrations

LangWatch builds and maintains several integrations listed below. Our tracing platform is built on top of OpenTelemetry, so we support any OpenTelemetry-compatible library out of the box.

Frameworks:

LangChain ·

LangGraph ·

Vercel AI SDK ·

Mastra ·

CrewAI ·

Google ADK

Model Providers:

OpenAI ·

Anthropic ·

Azure ·

Google Cloud ·

AWS ·

Groq ·

Ollama

Platforms

LangFlow · Flowise · n8n

and many more…

Are you using a platform that could benefit from a direct LangWatch integration? We'd love to hear from you, please fill out this very quick form.

💬 Support

Have questions or need help? We're here to support you in multiple ways:

  • Documentation: Our comprehensive documentation covers everything from getting started to advanced features.
  • Discord Community: Join our Discord server for real-time help from our team and community.
  • X (Twitter): Follow us on X for updates and announcements.
  • GitHub Issues: Report bugs or request features through our GitHub repository.
  • Enterprise Support: Enterprise customers receive priority support with dedicated response times. Our pricing page contains more information.

🤝 Collaborating

Contributions are what make the open-source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated.

Please read our Contribution Guidelines for details on our code of conduct, and the process for submitting pull requests.

✍️ License — open-core split

LangWatch is Apache 2.0, except for the enterprise modules (SCIM, audit logs, license and billing management, etc.) which live under langwatch/ee/ and need a commercial license for production use. The SDKs (typescript-sdk, python-sdk, mcp-server) are MIT.

See LICENSE.md, NOTICE, and langwatch/ee/LICENSE.md for the full text and the per-folder breakdown.

👮‍♀️ Security + Compliance

As a platform that has access to data that is highly likely to be sensitive, we take security incredibly seriously and treat it as a core part of our culture.

| Legal Framework | Current Status |

| --------------- | ------------------------------------------------------------------------------ |

| GDPR | Compliant. DPA available upon request. |

| ISO 27001 | Certified. Certification report available upon request on our Enterprise plan. |

Please refer to our Security page for more information. Contact us at security@langwatch.ai if you have any further questions.

Vulnerability Disclosure

If you need to do a responsible disclosure of a security vulnerability, you may do so by email to security@langwatch.ai, or if you prefer you can reach out to one of our team privately on Discord.

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