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LangWatch
Amsterdam
What it is
LangWatch is an AI agent engineering platform for teams developing agents for production. Simulations cover multi-turn conversations, tool use, recovery, and business outcomes before launch. Evaluations can run on datasets, production traffic, or in CI/CD to gate merges. Its tracing reports agent steps, cost, tokens, duration, errors, evaluations, and annotations.
Integrations include Python and TypeScript SDKs, OpenTelemetry, REST ingestion, model providers, and frameworks such as LangGraph, LangChain, CrewAI, and DSPy. Voice-agent testing supports OpenAI Realtime, Gemini, ElevenLabs, Google Live API, Pipecat, WebSocket bots, and Twilio. Deployment options include managed cloud, self-hosted, and hybrid; self-hosting uses Docker Compose and the customer's ClickHouse. LangWatch is open source under Apache 2.0. Its free Developer plan includes 50k events per month, 14-day data access, and two users. Growth costs €29 a month per core seat and includes 200k events, with additional events charged at €5 per 100k. LangWatch B.V. is based in Amsterdam.
For and against
For
- Simulates multi-turn agent conversations and tool use
- Evaluations can gate CI/CD merges
- Traces cost, tokens, errors, and duration
- Offers managed cloud, self-hosted, and hybrid deployment
- Free plan includes two users
Against
- Developer plan provides 14-day data access
- Growth includes 200k events before additional charges
- Self-hosting requires the customer's ClickHouse
The verdict
LangWatch combines agent simulations, evaluations, and observability with several deployment options. The free plan has event and data-access limits, while Growth charges for events beyond its included amount.
Who it suits
LangWatch suits AI teams working on agents, including developers, product owners, QA, and domain experts involved in evaluation workflows. It may fit teams that need simulations, production tracing, or CI/CD evaluation gates.
Plans and prices
Developer
50k events/month · 14-day data access · 2 users · 3 scenarios
Read 21 Oct 2026 · langwatch.ai
Growth
200k events included · €5/100k additional events · 30-day retention · €3/GB beyond retention
Read 21 Oct 2026 · langwatch.ai
Enterprise
hybrid/self-hosted/on-prem · custom retention · SSO/RBAC · audit logs and SLAs
Read 21 Oct 2026 · langwatch.ai
On the record
- Agent simulations
- It runs realistic multi-turn text and voice simulations with simulated users, judges, tool-call verification and visual run debugging.langwatch.ai · read 21 Oct 2026
- AI gateway
- The AI Gateway provides an OpenAI- and Anthropic-compatible endpoint with virtual keys, budgets, routing and provider fallbacks.github.com · read 21 Oct 2026
- AI governance
- Governance features include organization-wide policy controls, audit exports, spend dashboards and inventory of AI tools.github.com · read 21 Oct 2026
- CLI and MCP
- The project provides a CLI and an MCP server for use with coding assistants and other MCP clients.langwatch.ai · read 21 Oct 2026
- Company
- The site's footer identifies the maker as LangWatch B.V. and says it is built in Amsterdam.langwatch.ai · read 5 Oct 2026
- Company founded
- LinkedIn lists LangWatch as founded in 2023.linkedin.com · read 21 Oct 2026
- Company headquarters
- LinkedIn lists headquarters at Herengracht 551, Amsterdam, Netherlands.linkedin.com · read 21 Oct 2026
- Company legal name
- Crunchbase identifies the operating legal entity as Reasoning Engine B.V.crunchbase.com · read 21 Oct 2026
- Company size
- LinkedIn lists the company size as 11–50 employees.linkedin.com · read 21 Oct 2026
- Compliance
- LangWatch states ISO 27001 certification, GDPR compliance, EU data residency and SOC 2 coverage through AWS.langwatch.ai · read 21 Oct 2026
- Deployment
- LangWatch offers managed cloud, self-hosted, and hybrid deployment; its pricing page says self-hosting uses Docker Compose and the customer's ClickHouse.langwatch.ai · read 5 Oct 2026
- Documentation
- Documentation covers introduction, integrations, CLI, MCP, agent testing, observability, evaluations, datasets, prompt management, self-hosting and API reference.langwatch.ai · read 21 Oct 2026
- Evaluations
- The platform supports offline and online evaluations, CI/CD gates, multimodal scoring, built-in evaluators and custom workflows.langwatch.ai · read 21 Oct 2026
- Framework integrations
- Framework support includes OpenAI Agents, LangGraph, LangChain, CrewAI, Pydantic AI, Agno, Mastra, Vercel AI SDK, Google ADK, LangFlow and Flowise.langwatch.ai · read 21 Oct 2026
- Funding
- Crunchbase lists LangWatch as a private pre-seed company with two funding rounds and investors including Volta Ventures and Antler.crunchbase.com · read 21 Oct 2026
- Integrations
- Official integrations cover OpenAI, Anthropic, Google Gemini, Bedrock, Azure OpenAI, Vertex AI, Groq, Ollama and LiteLLM.langwatch.ai · read 21 Oct 2026
- Intended users
- The company says the platform is for AI teams shipping agents and describes evaluation workflows for developers, product owners, QA, and domain experts.langwatch.ai · read 5 Oct 2026
- Licence
- The core platform is Apache 2.0; enterprise modules require a commercial production licence and the SDKs are MIT licensed.github.com · read 21 Oct 2026
