bussdcc 0.17.0

A cybernetic runtime for Python, providing a resilient core for managing devices, services, and processes in autonomous or IoT systems.

BussDCC

bussdcc (Bussdieker Durable Cybernetic Core) is a minimal, strongly-typed cybernetic runtime for Python.

It provides a resilient core for building systems that coordinate devices, processes, services, and interfaces through explicit lifecycles, event-driven communication, and strict typing.

The project is intentionally lightweight: it defines contracts and flow, not application policy.

Quick Start

from bussdcc import Runtime
from bussdcc.device import Device
from bussdcc.process import Process
from bussdcc.service import Service

class MySensor(Device):
    kind = "sensor"
    def connect(self): print("Sensor online")
    def disconnect(self): print("Sensor offline")

class MyProcess(Process):
    name = "logger"
    def on_event(self, ctx, evt):
        print(evt.name, evt.data)

class MyService(Service):
    name = "heartbeat"
    interval = 2.0
    def tick(self, ctx):
        ctx.events.emit("heartbeat.tick")

rt = Runtime()
rt.attach_device(MySensor(id="device1"))
rt.register_process(MyProcess())
rt.register_service(MyService())
rt.boot()

Design Philosophy

bussdcc is built around a few guiding principles:

• Cybernetics over frameworks — systems coordinate through feedback loops (events), not tight coupling.
• Protocols first — behavior is defined via typing.Protocol, not deep inheritance.
• Replaceable infrastructure — clocks, event engines, state stores, and runtimes are swappable.
• Explicit lifecycles — startup, attachment, execution, and shutdown are visible and ordered.
• Strict typing — compatible with mypy --strict without sacrificing flexibility.

This is not an automation framework. It is a kernel for building your own.

Core Concepts

Runtime

The Runtime coordinates the system:

• Manages devices, processes, services, and interfaces

• Constructs the shared Context

• Emits lifecycle events:

  • system.booting
  • system.booted
  • system.shutting_down
  • system.shutdown

Boot order is deterministic:

1. Devices attach
2. Processes attach
3. Interfaces attach
4. Services start (under supervision)

Shutdown reverses this order.

Context

A lightweight capability container shared by all components.

Provides access to:

• clock — monotonic + UTC time
• events — synchronous event bus
• state — thread-safe hierarchical state
• runtime — runtime introspection and lookup

The context is intentionally small and side-effect free.

Clock

Clocks are abstracted via a protocol.

Default: SystemClock, providing:

• now_utc()
• monotonic()
• uptime()
• sleep(seconds)

Custom clocks (simulated, deterministic, test clocks) can be injected into the runtime.

Events

Synchronous, in-process, thread-safe event engine.

• Events are named strings with structured payloads
• Handlers run in the emitter’s thread
• Subscriber failures are isolated and reported as event.subscriber_error
• Subscriptions are cancellable

This is coordination, not messaging middleware.

State

Thread-safe hierarchical state engine with dot-path access:

ctx.state.set("system.clock.uptime", 42)
ctx.state.get("system.clock.uptime")

• No schema enforcement
• No persistence (by design)
• Intended for coordination and observation, not storage

Devices

Devices represent hardware, external resources, or system boundaries.

Lifecycle:

attach(ctx) → connect()
detach()   → disconnect()

Events emitted:

• device.attached
• device.detached
• device.failed

Devices are expected to be honest about failure.

Processes

Processes are event-driven units of work.

They:

• Subscribe to the event engine
• React synchronously to events
• May emit new events or update state

Lifecycle hooks:

• attach(ctx)
• on_start(ctx)
• on_event(ctx, evt)
• on_stop(ctx)
• detach()

Errors are isolated and reported as process.error.

Interfaces

Interfaces are processes by role, not by mechanism.

They typically:

• Translate human, network, or UI inputs into events
• Present system state outward
• Remain event-driven like any other process

They attach and detach alongside processes but are registered separately for clarity.

Services

Services are long-running, time-driven components, managed by the ServiceSupervisor.

Characteristics:

• Run in their own threads
• Execute tick(ctx) on an interval
• Can restart automatically on failure
• May be marked critical

Lifecycle:

• start(ctx)
• tick(ctx) (loop)
• stop(ctx)

Supervisor events:

• service.started
• service.stopped
• service.error
• service.restart
• service.critical_failure

Policies

Policies answer a single question:

“Should this happen?”

They are pure evaluators, not controllers.

class MyPolicy:
    name = "office_hours"

    def evaluate(self, ctx, evt=None) -> bool:
        hour = ctx.clock.now_utc().hour
        return 9 <= hour < 17

Key properties:

• No lifecycle
• No side effects
• No authority
• Callable by any component

Policies are consulted, never enforced by the runtime.

What bussdcc Is (and Isn’t)

It is:

• A cybernetic coordination kernel
• A foundation for durable, event-driven systems
• Suitable for IoT, automation, robotics, and control planes

It is not:

• An application framework
• A scheduler or cron replacement
• A rules engine or policy engine
• Batteries included

Status

Pre-alpha. APIs may evolve, but core concepts are stabilizing.

License

MIT License

Durable systems start with clear contracts, explicit lifecycles, and honest boundaries.

Links

• Repository: https://github.com/jbussdieker/bussdcc
• Issues: https://github.com/jbussdieker/bussdcc/issues
• Changelog: https://github.com/jbussdieker/bussdcc/blob/main/CHANGELOG.md