Configuration

YouLab uses Pydantic Settings for type-safe environment configuration.

Quick Reference

Essential Variables

# Letta Server
LETTA_BASE_URL=http://localhost:8283

# LLM Provider (choose one)
OPENAI_API_KEY=sk-...
# or
ANTHROPIC_API_KEY=sk-ant-...

# HTTP Service
YOULAB_SERVICE_HOST=127.0.0.1
YOULAB_SERVICE_PORT=8100

Environment File

Copy the example and configure:

cp .env.example .env
vim .env

All Environment Variables

Letta Connection

Variable	Default	Description
`LETTA_BASE_URL`	`http://localhost:8283`	Letta server URL
`LETTA_API_KEY`	`null`	API key (if required)

LLM Provider

Variable	Default	Description
`LLM_PROVIDER`	`openai`	Provider: `openai`, `anthropic`, `local`
`LLM_MODEL`	`gpt-4`	Default model
`OPENAI_API_KEY`	`null`	OpenAI API key
`ANTHROPIC_API_KEY`	`null`	Anthropic API key

Observability

Variable	Default	Description
`LOG_LEVEL`	`INFO`	Level: `DEBUG`, `INFO`, `WARNING`, `ERROR`
`LOG_JSON`	`true`	JSON format (true for production)
`SERVICE_NAME`	`youlab`	Service identifier

Langfuse Tracing

Variable	Default	Description
`LANGFUSE_ENABLED`	`false`	Enable Langfuse
`LANGFUSE_PUBLIC_KEY`	`null`	Public API key
`LANGFUSE_SECRET_KEY`	`null`	Secret API key
`LANGFUSE_HOST`	`https://cloud.langfuse.com`	Langfuse host

Memory Settings

Variable	Default	Description
`CORE_MEMORY_MAX_CHARS`	`1500`	Max chars per memory block
`ARCHIVAL_ROTATION_THRESHOLD`	`0.8`	Rotation threshold (0-1)

Agent Defaults

Variable	Default	Description
`DEFAULT_AGENT_NAME`	`default`	Default agent name

HTTP Service Variables

All prefixed with YOULAB_SERVICE_:

Variable	Default	Description
`YOULAB_SERVICE_HOST`	`127.0.0.1`	Bind host
`YOULAB_SERVICE_PORT`	`8100`	Bind port
`YOULAB_SERVICE_API_KEY`	`null`	Service authentication
`YOULAB_SERVICE_LOG_LEVEL`	`INFO`	Service log level
`YOULAB_SERVICE_LETTA_BASE_URL`	`http://localhost:8283`	Letta URL
`YOULAB_SERVICE_LANGFUSE_ENABLED`	`true`	Enable tracing
`YOULAB_SERVICE_LANGFUSE_PUBLIC_KEY`	`null`	Langfuse public key
`YOULAB_SERVICE_LANGFUSE_SECRET_KEY`	`null`	Langfuse secret key
`YOULAB_SERVICE_LANGFUSE_HOST`	`https://cloud.langfuse.com`	Langfuse host

Honcho Message Persistence

Variable	Default	Description
`YOULAB_SERVICE_HONCHO_ENABLED`	`true`	Enable Honcho message persistence
`YOULAB_SERVICE_HONCHO_WORKSPACE_ID`	`youlab`	Honcho workspace identifier
`YOULAB_SERVICE_HONCHO_API_KEY`	`null`	Honcho API key (required for production)
`YOULAB_SERVICE_HONCHO_ENVIRONMENT`	`demo`	Environment: `demo`, `local`, or `production`

Example Configurations

Development

# .env for development
LETTA_BASE_URL=http://localhost:8283
OPENAI_API_KEY=sk-dev-key-here
LOG_LEVEL=DEBUG
LOG_JSON=false
LANGFUSE_ENABLED=false

Production

# .env for production
LETTA_BASE_URL=http://youlab-server:8283
OPENAI_API_KEY=sk-prod-key-here

LOG_LEVEL=INFO
LOG_JSON=true
SERVICE_NAME=youlab-production

LANGFUSE_ENABLED=true
LANGFUSE_PUBLIC_KEY=pk-lf-xxx
LANGFUSE_SECRET_KEY=sk-lf-xxx

# Honcho (Theory of Mind)
YOULAB_SERVICE_HONCHO_ENABLED=true
YOULAB_SERVICE_HONCHO_ENVIRONMENT=production
YOULAB_SERVICE_HONCHO_API_KEY=your-honcho-api-key

YOULAB_SERVICE_HOST=0.0.0.0
YOULAB_SERVICE_PORT=8100

Docker

# When OpenWebUI runs in Docker
YOULAB_SERVICE_HOST=0.0.0.0
# Pipe uses: http://host.docker.internal:8100

Settings Classes

YouLab uses two Pydantic settings classes for type-safe configuration.

Location: src/youlab_server/config/settings.py

Class	Prefix	Use Case
`Settings`	(none)	CLI and library
`ServiceSettings`	`YOULAB_SERVICE_`	HTTP service

Settings Class

General application settings, loaded from .env:

from youlab_server.config import get_settings

settings = get_settings()
print(settings.letta_base_url)

ServiceSettings Class

HTTP service-specific settings with YOULAB_SERVICE_ prefix:

from youlab_server.config.settings import ServiceSettings

settings = ServiceSettings()
uvicorn.run(app, host=settings.host, port=settings.port)

Testing with Settings

from unittest.mock import patch

def test_with_custom_settings():
    with patch.object(settings, "langfuse_enabled", False):
        result = get_langfuse()
        assert result is None

Development - Local setup
Quickstart - Getting started