pycelest
Python AI Agent Framework
A lightweight, provider-agnostic framework for building AI agents in Python. 10+ AI providers. Plugin system. Memory & RAG. Free and open source — forever.
pip install pycelestCode
Simple API. Powerful primitives.
Import as celest, not pycelest. Three lines to run your first agent.
from celest import SessionManager
session = SessionManager(
provider="anthropic",
model="claude-sonnet-4-6",
tools=["search_web", "scrape_page"],
)
result = await session.run(
"Find the top 5 AI tools in 2025"
)
print(result.response)from celest import SessionManager
from celest.plugins import SSEPlugin
sse = SSEPlugin()
session = SessionManager(
provider="openai",
model="gpt-4o",
plugins=[sse],
)
# Iterate over live tokens
async for token in session.stream_response("Explain RAG"):
print(token, end="", flush=True)from celest import SessionManager, MemoryConfig
from celest.memory import SQLiteMemory
session = SessionManager(
provider="ollama",
model="llama3.2",
memory=SQLiteMemory("agent.db"),
memory_config=MemoryConfig(
compression_enabled=True,
),
)
await session.run("Remember: my name is Eddy")Providers
Switch provider in one line
Change provider= and that's it. Cloud models for power, local models for privacy.
Anthropic
Claude 4.x / Opus / Sonnet / Haiku
OpenAI
GPT-4o, o1, o3, GPT-4o-mini
Gemini 2.0 Flash, Gemini Pro
Mistral
Mistral Large, Codestral
DeepSeek
DeepSeek-V3, DeepSeek-R1
Ollama
Llama 3.x, Phi-3, Gemma, Qwen…
LM Studio
Any GGUF model via server
vLLM
Self-hosted OpenAI-compat
LocalAI
Self-hosted OpenAI-compat
OllamaAdapter requires pip install pycelest[openai] — it speaks the OpenAI protocol under the hood.
Plugin System
Extend agents with hooks
Every plugin hooks into the agent lifecycle via CelestPlugin. Add streaming, notifications, firewalls — without changing agent logic.
SSEPlugin
from celest.plugins import SSEPluginStream tool_call / tool_result events via Server-Sent Events. Built-in for the FlyCelest API.
HttpFirewall
from celest.guardrails import HttpFirewallIntercepts dangerous tool calls and POSTs them to an HTTP endpoint for human approval before execution.
TelegramPlugin
from celest.plugins import TelegramPluginpip install pycelest[telegram]Sends the final agent response directly into a Telegram chat on session end.
WhatsAppPlugin
from celest.plugins import WhatsAppPluginpip install pycelest[whatsapp]Sends the final response via Twilio WhatsApp Business API.
MemoryPersistencePlugin
from celest.plugins import MemoryPersistencePluginLoads and saves facts across sessions using SQLiteMemory or JsonMemory backends.