Parlant

Parlant is an open-source, self-hosted conversational AI server designed to manage agent behavior through context-aware guidelines, ensuring that responses remain consistent and aligned at scale. The software is deployed as a server and provides a Python SDK for developers to build and maintain customer-facing AI agents for business-to-consumer and business-to-business interactions.

Unlike standard LLM implementations that rely on massive system prompts or rigid routed graphs, Parlant uses a specialized context engineering engine. This engine dynamically filters rules, knowledge, and tools in real-time, providing the model with only the information relevant to the current turn of the conversation. This approach prevents the model from becoming confused by excessive instructions as the complexity of the agent grows, solving the problem of prompt overload where models stop paying attention to instructions as they increase in volume.

Key features

• Dynamic context narrowing to keep LLMs focused on relevant instructions
• Behavioral control through guidelines and observations defined in code
• Support for domain-specific glossaries and retrievers
• Integration of standard operating procedures through Journeys
• Ability to set dependencies and exclusions between different agent behaviors
• Traceable and auditable response generation for compliant interactions
• Support for multiple LLM providers including OpenAI, Gemini, and Llama 3
• Fluid and strict output modes for generating messages or canned responses

The architecture focuses on conversational governance and behavioral consistency rather than general workflow automation. It is specifically designed for teams in regulated or high-stakes industries, such as finance, healthcare, and insurance, where brand voice, accuracy, and policy compliance are critical. By moving behavioral logic out of the prompt and into a structured engine, it allows for rapid iterations based on product feedback without requiring manual rewiring of conversation graphs or extensive fine-tuning of models.

Parlant is an interaction control harness for enterprise-grade AI agents that require a high degree of precision and auditability.