Langtail

What is Langtail?

Langtail is a platform for developing and deploying LLM-powered applications. It combines prompt engineering, testing, monitoring, and deployment in one toolkit, with collaborative workflows built in for teams.

Key features include:

• No-code playground: Write and run prompts without code, tweaking parameters to fine-tune LLM behavior.
• Test suites: Catch unexpected issues with your prompts before deployment.
• Benchmarking: Compare prompt variations to find the best-performing versions.
• Deployment: Deploy prompts as API endpoints for easy integration and iteration.
• Logging and metrics: Detailed logs of performance data and costs, plus a metrics dashboard for an overview of prompt performance.
• Production monitoring: Detect problems by observing how users interact with your app in production.
• Team collaboration: A collaborative workflow for working on prompts together.

Who created Langtail?

Langtail was created by three co-founders: Petr Brzek (CEO), Tomas Rychlik (CTO), and Martin Duris (growth). They previously worked together at Avocode. The company is based in Prague, Czech Republic. Its mission is to simplify developing and testing AI by providing tools for prompt engineering, testing, observability, and deployment in one place.

What is Langtail used for?

Langtail is aimed at anyone building with LLMs. Typical uses include:

• Refining and debugging prompts
• Evaluating LLM application performance
• Testing LLM-powered apps for reliability
• Observing AI app behavior and monitoring production deployments
• Collaborating on prompts across a team

Pricing

Langtail offers flexible pricing:

• Free plan: Available for unlimited users.
• Pro plan: Unlimited prompts and 10,000 logs per month, suited to growing teams.
• Enterprise plan: Fully customizable, with unlimited logs, SAML Single-Sign-On (SSO), custom billing, dedicated support, and personalized onboarding for large organizations.