Langtail

Langtail is a prompt management platform for product teams that build features on large language models. It gives developers, product managers and business teams one place to build, test, validate and deploy prompts, using a spreadsheet like interface that does not require code, so that behavior of an LLM feature is checked before it reaches users rather than discovered in production. It is designed for teams that need predictable LLM applications. Prompts can target models from OpenAI, Anthropic, Google Gemini, Meta and other providers. Evaluation tools include natural language evaluation, pattern matching and custom code validation, and performance insights report how prompts behave with real users. An AI Firewall, enabled with one click, blocks prompt injection, denial of service and information leakage. Developers get a TypeScript SDK and an OpenAPI specification, and the platform can be self hosted on the enterprise tier. Pricing is published in US dollars, plus VAT. Free is $0 per month with unlimited users, two prompts or assistants, 1,000 logs per month, 30 days of data retention and public shareable apps. Pro is $99 per month with one user, 20 prompts or assistants, unlimited logs and 90 days of retention. Team is $499 per month with ten users, unlimited prompts or assistants, unlimited logs, one year of retention, radars and alerts, and dedicated support. Enterprise is custom priced and adds unlimited users, custom data retention, the AI Firewall and self hosting.