Fastest way to build and deploy long-running AI agents—with durability, observability, and security.
Features
| Feature | Description | Docs |
|---|---|---|
| 🚀 MCP & tool security | The only full FastAPI compatible MCP Server with decorator API | Link |
| 🦾 Agent-to-agent | Multi-agent communication | Link |
| 📊 Observability | Agent tracing and monitoring | Link |
| 💾 Durable runs | Persist, resume, and fork agent runs | Durable runs docs |
| 🔍 Tool Search API | Reduced tool context bloat | Link |
🚅 Quick Start
Installation
The recommended method of installing agentor is with pip from PyPI.
pip install agentor
This installs the v0.1.0 line, built on Agentor's own agent engine — durable, forkable runs included.
Tools with heavy or vendor-specific dependencies ship as extras, so the base install stays small:
pip install "agentor[google]" # GmailTool, CalendarTool
pip install "agentor[all]" # every optional tool
Available extras: google, exa, git, github, slack, postgres, scrapegraph, all.
More ways...
You can also install the latest bleeding edge version (could be unstable) of agentor, should you feel motivated enough, as follows:
pip install git+https://github.com/celestoai/agentor@main
Build and Serve an Agent
Build an Agent, connect external tools or MCP Server and serve as an API in just a few lines of code:
from agentor.tools import GetWeatherTool
from agentor import Agentor
agent = Agentor(
name="Weather Agent",
model="gpt-5-mini", # Use any LLM provider - gemini/gemini-2.5-pro or anthropic/claude-3.5
tools=[GetWeatherTool()]
)
result = agent.run("What is the weather in London?") # Run the Agent
print(result)
# Serve Agent with a single line of code
agent.serve()
Any OpenAI-compatible provider
Point base_url at any provider that speaks OpenAI's /chat/completions — OpenRouter,
Groq, Together, Fireworks, DeepSeek, vLLM, Ollama, or Anthropic's and Gemini's compatible
endpoints — with no extra dependency:
agent = Agentor(
name="Assistant",
model="openrouter/auto",
base_url="https://openrouter.ai/api/v1",
api_key=os.environ["OPENROUTER_API_KEY"],
)
Run the following command to query the Agent server:
curl -X 'POST' \
'http://localhost:8000/chat' \
-H 'accept: application/json' \
-H 'Content-Type: application/json' \
-d '{
"input": "What is the weather in London?"
}'
agent.serve() gives you an ordinary ASGI app, so host it wherever you already
run Python services.
Durable Runs
Give the agent a store and every run becomes an append-only event log that survives process death. Resume an interrupted run, or fork any persisted run — even a completed one — into a new, independent run that keeps the full trace, the model's reasoning included when the provider returns it:
from agentor import Agentor
from agentor.engine.store import FileStore
agent = Agentor(name="Assistant", model="gpt-5-mini", store=FileStore("runs"))
result = agent.run("Draft a launch plan") # persisted under result.run_id
# Interrupted mid-run? agent.resume(result.run_id) picks up where it left off.
fork = agent.fork(result.run_id, "Make it punchier") # fork.run_id is a new run; parent untouched
fork and resume have async twins, afork and aresume.
Tracing
Tracing is off unless you ask for it. A trace carries prompts, tool arguments, tool results, and the model's reasoning when a provider returns it — so nothing leaves your process by default.
Turn it on for an agent:
agent = Agentor(name="Assistant", enable_tracing=True) # needs CELESTO_API_KEY
Or decide per run:
agent.run("public question")
agent.run("contains customer data", tracing=False) # this run sends nothing
agent.run("debug this", tracing=True) # trace just this one
tracing= is accepted by run, arun, chat and stream_chat. View traces at
celesto.ai/observe.
Agent Skills
Skills are folders of instructions, scripts, and resources that Claude loads dynamically to improve performance on specialized tasks.
Agent Skills help agents pull just the right context from simple Markdown files. The agent first sees only a skill’s name and short description. When the task matches, it loads the rest of SKILL.md, follows the steps, and can call a shell environment to run the commands the skill points to.
- Starts light: discover skills by name/description only
- Loads on demand: pull full instructions from
SKILL.mdwhen relevant - Executes safely: run skill-driven commands in an isolated shell
Skill layout example:
example-skill/
├── SKILL.md # required instructions + metadata
├── scripts/ # optional helpers the agent can call
├── assets/ # optional templates/resources
└── references/ # optional docs or checklists
Using a skill to create a GIF:
from agentor.tools import ShellTool
from agentor import Agentor
agent = Agentor(
name="Assistant",
model="gemini/gemini-3-flash-preview",
instructions="Your job is to create GIFs. Lean on the shell tool and any available skills.",
skills=[".skills/slack-gif-creator"],
tools=[ShellTool()],
)
async for chunk in await agent.chat("produce a cat gif", stream=True):
print(chunk)
Create an Agent from Markdown
Bootstrap an Agent directly from a markdown file with metadata for name, tools, model, and temperature:
---
name: WeatherBot
tools: [get_weather]
model: gpt-4o-mini
temperature: 0.3
---
You are a concise weather assistant.
Load it with:
from agentor import Agentor
agent = Agentor.from_md("agent.md")
result = agent.run("Weather in Paris?")
Build a custom MCP Server with LiteMCP
Agentor enables you to build a custom MCP Server using LiteMCP. You can run it inside a FastAPI application or as a standalone MCP server.
from agentor.mcp import LiteMCP, get_token
mcp = LiteMCP(name="my-server", version="1.0.0")
@mcp.tool(description="Get weather for a given location")
def get_weather(location: str) -> str:
# *********** Control authentication ***********
token = get_token()
if token != "SOME_SECRET":
return "Not authorized"
return f"Weather in {location}: Sunny, 72°F"
mcp.serve()
LiteMCP vs FastMCP
Key Difference: LiteMCP is a native ASGI app that integrates directly with FastAPI using standard patterns. FastMCP requires mounting as a sub-application, diverging from standard FastAPI primitives.
| Feature | LiteMCP | FastMCP |
|---|---|---|
| Integration | Native ASGI | Requires mounting |
| FastAPI Patterns | ✅ Standard | ⚠️ Diverges |
| Built-in CORS | ✅ | ❌ |
| Custom Methods | ✅ Full | ⚠️ Limited |
| With Existing Backend | ✅ Easy | ⚠️ Complex |
Agent-to-Agent (A2A) Protocol
The A2A Protocol defines standard specifications for agent communication and message formatting, enabling seamless interoperability between different AI agents.
Key Features:
- Standard Communication: JSON-RPC based messaging with support for both streaming and non-streaming responses
- Agent Discovery: Automatic agent card generation at
/.well-known/agent-card.jsondescribing agent capabilities, skills, and endpoints - Rich Interactions: Built-in support for tasks, status updates, and artifact sharing between agents
Agentor makes it easy to serve any agent as an A2A protocol.
from agentor import Agentor
agent = Agentor(
name="Weather Agent",
model="gpt-5-mini",
tools=["get_weather"],
)
# Serve agent with A2A protocol enabled automatically
agent.serve(port=8000)
# Agent card available at: http://localhost:8000/.well-known/agent-card.json
Any agent served with agent.serve() automatically becomes A2A-compatible with standardized endpoints for message sending, streaming, and task management.
🤝 Contributing
We'd love your help making Agentor even better! Please read our Contributing Guidelines and Code of Conduct.
📄 License
Apache 2.0 License - see LICENSE for details.
Release files for agentor 0.1.0
For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.
Source distribution (sdist)
| File | Size | Uploaded | |
|---|---|---|---|
| agentor-0.1.0.tar.gz | 139.1 kB | Details |
Built distribution (wheel)
| File | Interpreter | ABI | Platform | Reset |
|---|---|---|---|---|
| agentor-0.1.0-py3-none-any.whl | Python 3 | none | any | Details |
Total release size: 226.9 kB
Release files / agentor-0.1.0.tar.gz
| Download URL | agentor-0.1.0.tar.gz |
|---|---|
| Size | 139.1 kB |
| Tags | Source |
|
SHA-256 checksum How to use checksums |
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| Download URL | agentor-0.1.0-py3-none-any.whl |
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| Tags | Python 3 |
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Uploaded using Trusted Publishing? What is trusted publishing? |
Yes |
| Uploaded via |
twine/7.0.0 CPython/3.13.14
|
Provenance
Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.
PyPI Publish Attestation
PyPI verified that this artifact, at this checksum, originated from the publisher listed below.
Signed by GitHub Actions, verified by PyPI on Aug 25, 2026.
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