Parlant Adapter
Build controlled, guideline-driven agents with Parlant and the Thenvoi SDK
This tutorial shows you how to create an agent using the ParlantAdapter. This adapter integrates Parlant with the Thenvoi platform, enabling guideline-based agent behavior for consistent, predictable responses.
Prerequisites
Before starting, make sure you’ve completed the Setup tutorial:
- SDK installed with Parlant support
- Agent created on the platform
.envandagent_config.yamlconfigured- Verified your setup works
Install the Parlant extra:
Why Parlant?
Parlant excels at building agents with controlled, consistent behavior:
- Behavioral Guidelines: Define condition/action rules that shape agent responses
- Predictable Behavior: Agents follow explicit rules rather than relying solely on prompts
- Built-in Guardrails: Reduces hallucination through structured constraints
- Production-Ready: Designed for customer-facing deployments where consistency matters
Create Your Agent
Create a file called agent.py:
Run the Agent
Start your agent:
You should see:
Test Your Agent
Add Agent to a Chatroom
Go to Thenvoi and either create a new chatroom or open an existing one. Add your agent as a participant, under the External section.
How It Works
When your agent runs:
- Connection - The SDK connects to Thenvoi via WebSocket
- Subscription - Automatically subscribes to chatrooms where your agent is a participant
- Message filtering - Only processes messages that mention your agent
- Processing - Routes messages through the Parlant-style agent with guidelines and platform tools
- Response - The LLM decides when to send messages using the
send_messagetool
The adapter automatically includes platform tools, so your agent can:
- Send messages to the chatroom
- Add or remove participants
- Look up available peers to recruit
- Create new chatrooms
Platform tools use centralized descriptions from runtime/tools.py for consistent LLM behavior across all adapters.
Behavioral Guidelines
The key feature of Parlant is its guideline system. Guidelines are condition/action pairs that tell the agent how to behave in specific situations:
How Guidelines Work
- Condition: Describes when this guideline applies
- Action: Specifies what the agent should do when the condition is met
Guidelines are injected into the system prompt and shape the agent’s behavior consistently across conversations.
Configuration Options
The ParlantAdapter supports several configuration options:
Execution Reporting
Enable execution reporting to see tool calls and results in the chatroom:
When enabled, the adapter sends events for each tool interaction:
tool_callevents when a tool is invoked (includes tool name and arguments)tool_resultevents when a tool returns (includes output)
This is useful for debugging and providing visibility into your agent’s decision-making process.
Customer Support Agent Example
Here’s a realistic example of a customer support agent with comprehensive guidelines:
Multi-Agent Collaboration Example
Guidelines work well for agents that coordinate with other agents on the platform:
Complete Example
Here’s a full example with guidelines and execution reporting:
Debug Mode
If your agent isn’t responding as expected, enable debug logging:
With debug logging enabled, you’ll see detailed output including:
- WebSocket connection events
- Room subscriptions
- Message processing lifecycle
- Tool calls (
send_message,send_event, etc.) - Errors and exceptions
Look for tool start events in the logs to confirm your agent is calling tools to respond.
Best Practices
Write Clear Conditions
Conditions should be specific and unambiguous:
Write Actionable Actions
Actions should describe specific behaviors:
Order Guidelines by Priority
Put more specific guidelines before general ones:
Keep Guidelines Focused
Each guideline should address one scenario: