sessions

Session Examples

This directory contains examples of creating and customizing Mellea sessions.

Files

creating_a_new_type_of_session.py

Demonstrates how to create custom session types with specialized behavior.

Key Features:

• Extending the base session class
• Custom context types
• Specialized session methods
• Session configuration patterns

Concepts Demonstrated

• Session Customization: Creating domain-specific session types
• Context Management: Using different context types
• Backend Configuration: Setting up backends for sessions
• Session Lifecycle: Managing session state and resources

Basic Session Creation

from mellea import start_session

# Default session (Ollama backend, SimpleContext)
m = start_session()

# With specific model
m = start_session(model_id="ibm-granite/granite-3.2-8b-instruct")

# With chat context
from mellea.stdlib.context import ChatContext
m = start_session(ctx=ChatContext())

# With model options
from mellea.backends import ModelOption
m = start_session(model_options={
    ModelOption.MAX_NEW_TOKENS: 200,
    ModelOption.TEMPERATURE: 0.7
})

Custom Session Pattern

from mellea import MelleaSession
from mellea.backends.ollama import OllamaModelBackend
from mellea.stdlib.context import ChatContext

class MyCustomSession(MelleaSession):
    def __init__(self, **kwargs):
        backend = OllamaModelBackend(
            model_id="my-model",
            **kwargs
        )
        super().__init__(backend=backend, ctx=ChatContext())
    
    def custom_method(self, prompt: str):
        """Add custom functionality."""
        # Your custom logic here
        return self.instruct(prompt)

# Use custom session
m = MyCustomSession()
result = m.custom_method("Hello!")

Session Context Managers

# Automatic cleanup with context manager
with start_session() as m:
    result = m.instruct("Generate text")
    # Session automatically cleaned up

Backend Options

# Ollama (default)
from mellea.backends.ollama import OllamaModelBackend
backend = OllamaModelBackend(model_id="llama2")

# OpenAI
from mellea.backends.openai import OpenAIBackend
backend = OpenAIBackend(model_id="gpt-4")

# HuggingFace
from mellea.backends.huggingface import LocalHFBackend
backend = LocalHFBackend(model_id="ibm-granite/granite-3.2-8b-instruct")

# LiteLLM
from mellea.backends.litellm import LiteLLMBackend
backend = LiteLLMBackend(model_id="claude-3-opus")

# Create session with custom backend
m = MelleaSession(backend=backend, ctx=ChatContext())

Context Types

• SimpleContext: Basic linear context
• ChatContext: Multi-turn conversation context
• Custom: Create your own context types

Related Documentation

• See mellea/stdlib/session.py for session implementation
• See mellea/stdlib/context.py for context types
• See mellea/backends/ for backend options