z4j-fastapi 1.0.1

z4j FastAPI framework adapter (Apache 2.0)

z4j-fastapi

License: Apache 2.0 Status: v1.0.0 - first public release.

FastAPI framework adapter for z4j. Integrates via FastAPI's lifespan hook - one context manager wraps the agent's lifecycle with your app's startup and shutdown.

Install

# FastAPI + arq (the most common async-native pairing)
pip install z4j-fastapi z4j-arq z4j-arqcron

# FastAPI + Celery (when the sync stack is preferred)
pip install z4j-fastapi z4j-celery z4j-celerybeat

# FastAPI + Dramatiq / RQ / Huey / taskiq - all supported
pip install z4j-fastapi z4j-dramatiq z4j-apscheduler
pip install z4j-fastapi z4j-taskiq z4j-taskiqscheduler

Configure

Mount the z4j lifespan in your FastAPI app:

from contextlib import asynccontextmanager
from fastapi import FastAPI
from z4j_fastapi import Z4JLifespan

z4j = Z4JLifespan(
    brain_url="https://z4j.internal",
    token="z4j_agent_...",        # minted in the brain dashboard
    project_id="my-project",
)

@asynccontextmanager
async def lifespan(app: FastAPI):
    async with z4j(app):
        yield

app = FastAPI(lifespan=lifespan)

Or, if you have no other lifespan logic:

from z4j_fastapi import Z4JLifespan

app = FastAPI(lifespan=Z4JLifespan(
    brain_url="https://z4j.internal",
    token="z4j_agent_...",
    project_id="my-project",
))

On uvicorn startup the agent connects to the brain and z4j's dashboard populates with every arq / Celery / Dramatiq / taskiq / Huey task your workers register.

What it does

Piece	Purpose
Z4JLifespan(...)	Async context manager matching FastAPI's lifespan contract
Graceful shutdown	Flushes the event buffer on await lifespan.aclose()
Async-native	Uses asyncio.create_task - never blocks the event loop

Reliability

z4j-fastapi follows the project-wide safety rule: z4j never breaks your FastAPI app. Agent failures are caught at the boundary and never propagate into your request handlers.

Documentation

• Quickstart (FastAPI)
• Install guide
• Architecture

License

Apache 2.0 - see LICENSE. Your FastAPI application is never AGPL-tainted by importing z4j_fastapi.

Links

• Homepage: https://z4j.com
• Documentation: https://z4j.dev
• Issues: https://github.com/z4jdev/z4j-fastapi/issues
• Changelog: CHANGELOG.md
• Security: [e-mail] (see SECURITY.md)