Langtail

Langtail is a web-based prompt management and LLMOps platform for product, engineering, and business teams building LLM-powered applications.

Key capabilities include:

• Centralized prompt registry and version control for collaborative editing, approvals, and rollback across teams
• Spreadsheet-like prompt builder and testing that supports non-technical contributors, plus experimentation across models and parameters
• Evaluation and regression testing using real-world data with natural-language evaluation, pattern matching, or custom code
• Deployment and observability with multi-environment management (preview, staging, production), centralized logs, and prompt performance analytics

Pricing: Freemium, including a free tier for prompt debugging and testing, with paid plans for advanced deployment, monitoring, and collaboration.

What makes it notable is its focus on production readiness, combining prompt experimentation and analytics with an AI Firewall designed to help block prompt injection, denial-of-service attacks, and information leakage. It also supports major LLM providers (including OpenAI, Anthropic, Gemini, and Mistral), offers self-hosting for tighter data control, and can deploy prompts as API endpoints (with TypeScript SDK and OpenAPI support).