LangWatch
Overview
Open-source and hosted observability, evaluation and simulation tools for LLM applications and agents.
Open-source and hosted observability, evaluation and simulation tools for LLM applications and agents.
Active LLM/agent observability and evaluation platform with traces, prompt management, Scenario simulations, Optimization Studio and Langy-assisted changes. Voice evaluation and AI gateway features extend the documented workflow.
Hosted onboarding and Python/TypeScript SDK documentation provide a manageable adoption path; Apache-2.0 source and enterprise self-hosting options are also available. Production instrumentation still requires application access.
Developer is €0 with 50,000 events/month and 14-day access. Growth is €29 per core seat/month with 200,000 events, then €5/100,000 events; extra retention is metered. These are events, not unique questions, and enterprise terms require a quote.
OpenTelemetry/REST ingestion, Python/TypeScript SDKs, major model providers, LangChain/LangGraph, CrewAI, DSPy and other documented frameworks provide broad relevant connections. GitHub prompt sync, Slack notifications and plan-specific webhooks are listed.
Historical 2024-05-13 video by LangWatch: LangWatch Quality Control & Analytics for GenAI. Watch-page/player metadata, publisher and product description/repository attribution checked; retained as historical media. No full video was watched.
Product overview
Capabilities, pricing and fit
Open-source and hosted observability, evaluation and simulation tools for LLM applications and agents.
Information as of October 5, 2026
What it can do
- Documented workflow
Active LLM/agent observability and evaluation platform with traces, prompt management, Scenario simulations, Optimization Studio and Langy-assisted changes. Voice evaluation and AI gateway features extend the documented workflow.[1], [2], [3], [4]
- Access and lifecycle
Hosted onboarding and Python/TypeScript SDK documentation provide a manageable adoption path; Apache-2.0 source and enterprise self-hosting options are also available. Production instrumentation still requires application access.[1], [2], [3], [4]
- Documented connections
OpenTelemetry/REST ingestion, Python/TypeScript SDKs, major model providers, LangChain/LangGraph, CrewAI, DSPy and other documented frameworks provide broad relevant connections. GitHub prompt sync, Slack notifications and plan-specific webhooks are listed.[1], [2], [3], [4]
Where it fits best
Pricing and availability
Developer is €0 with 50,000 events/month and 14-day access. Growth is €29 per core seat/month with 200,000 events, then €5/100,000 events; extra retention is metered. These are events, not unique questions, and enterprise terms require a quote.[1], [2], [3], [4]
Platforms: Hosted onboarding and Python/TypeScript SDK documentation provide a manageable a[1], [2], [3], [4]
Sources (4)
- Product evidence: langwatch.aiOfficial site · checked 2026-10-05
- Product evidence: langwatch.aiOfficial site · checked 2026-10-05
- Product evidence: langwatch.aiOfficial site · checked 2026-10-05
- Product evidence: github.comOfficial site · checked 2026-10-05
Autonomy level
47/100
Our subjective rating of how independently the product carries out its documented tasks, considering the human setup, input, approval and review it needs. This is not a measured success rate.
Comparisons
Custom Comparisons
Some of the use cases of LangWatch:
- Teams instrumenting agent traces, evaluations, simulations and prompt changes.
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Pricing model:
Code access:
Popularity level: 54%
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