kontiki 2.1.0

Part of the Kontiki suite — Python runtime, registry, terminal UI, and fleet monitoring for distributed services.

Full suite overview → https://kontiki-org.github.io/

Ops demo → kontiki-monitor Quickstart.

Overview

Kontiki is a Python runtime for distributed services on RabbitMQ. You write @http, @rpc, @on_event, and @task. The decorators are the visible API; most of the leverage sits one layer deeper — identity, routing, delivery, fleet health, configuration, and testing. You express intentions in Kontiki terms, not broker topology by hand.

This repository is the runtime. Together with the registry, KontikiTUI, and kontiki-monitor, every Python workload — API, worker, cron job, ops service — is the same operable, testable, and observable unit.

Most applications don't need the full depth of a specialized ops stack. Kontiki takes the commonly useful part and aims to integrate it into the same service model, instead of giving you another platform to assemble and tune.

Why conventions

Services should differ primarily because of what they do, not because each one introduces another way of being built and operated.

• An ops job fails months later: find the service in KontikiTUI instead of rediscovering its crontab, script, and log file.
• A request failed after crossing several services: follow its flow_id tree in KontikiTUI instead of correlating timestamps across logs by hand.
• Adding a new service — including a monitor: identity, configuration, lifecycle, logging, health, and failure reporting already follow the same conventions.

What Kontiki is not

Kontiki does not aim for maximum infrastructure choice. It is intentionally Python-first, RabbitMQ-based, and convention-driven. It does not abstract every broker, become a language-neutral platform, replace orchestration, or reproduce a tracing, long-term metrics, or IAM product. Those can coexist outside the common model; they are not the default for everyday needs.

Runtime

• One model from dev to production: merged YAML config, cli.run, and the same entrypoint decorators in tests (kontiki.testing mocks on the bus) and in production.
• Design interactions as messages: RPC for request/reply; events for async work. On @on_event, delivery is explicit — default (one instance per message, competing consumers), broadcast=True (every instance), in_session=True (one pinned instance via a session).
• Route by event_type: the event name is the routing contract; deployment identity (kontiki.service_name, kontiki.peers) and environment-specific names live in config, not in code.
• Fleet registry: heartbeats, degraded state (degraded_on), exception tracking, live instance ids (list_instances / GET /instances/{service_name}), and orchestrator live probes (GET /live/{service_name}). The bus runs without a registry; operating the fleet coherently assumes one.
• Integrated operations: browse the fleet in KontikiTUI, alert from registry signals with kontiki-monitor.

For gotchas, controlled failures (rpc_error), and patterns beyond this overview, see docs/advanced-features.md. For a feature-by-feature reference, see docs/features.md.

Mental model (short)

Kontiki suite

Kontiki is not only this runtime. The suite shares the same process model, registry, and terminal UI:

When services register with the Kontiki registry, KontikiTUI gives a live picture of the fleet from the terminal:

Quickstart

Install Kontiki (via pip or Poetry):

pip install kontiki

Define a simple service. The service class wires entrypoints; a delegate holds business logic (recommended pattern — see docs/features.md):

from kontiki.delegate import ServiceDelegate
from kontiki.messaging import Messenger, on_event, rpc
from kontiki.runner import cli


class MyDelegate(ServiceDelegate):
    async def setup(self):
        pass  # optional: init from self.container.config

    def process(self, payload):
        return {"processed": payload}


class MyService:
    name = "compute-api"  # optional: overridden by kontiki.service_name in config
    delegate = MyDelegate()
    messenger = Messenger()

    @rpc
    async def compute(self, x):
        return self.delegate.process(x)

    @on_event("example.thing.happened")
    async def on_thing(self, payload):
        result = self.delegate.process(payload)
        await self.messenger.publish("example.thing.processed", result)


def run():
    cli.run(MyService, "Example Kontiki service.", version="0.1.0")

Expose it as a CLI command in pyproject.toml:

[tool.poetry.scripts]
my_service = "myapp.main:run"

Run your service:

my_service --config config.yaml

RPC plus a chained event — the shape most meshes grow from. In production, peers resolve from config (kontiki.peers), delivery modes are set on handlers, and the registry tracks the fleet. See examples/events/broadcast/, examples/events/session/, and examples/registry/.

Testing a service in isolation

kontiki.testing lets you exercise one service on the bus without running its peers. The usual form is a Gherkin feature: an executable spec of the service boundary.

The feature shows the timeline — config and initial state, incoming events or RPC, calls to peers and their controlled responses, published events, return values, state changes. That sequence stays in the .feature, not in Python fixtures.

From Boomerang's subscription-service: the service starts from its config, an RPC comes in, matching recipients come out.

Scenario: Return matching recipient for exact area and category
  Given the subscription service is running with the following configuration
    """
    kontiki:
      amqp:
        url: amqp://guest:guest@localhost/
      http:
        address: 127.0.0.1
        port: 8000
    logging:
      directory: logs
      handlers:
        file:
          class: logging.handlers.RotatingFileHandler
          level: INFO
          maxBytes: 10485760
          backupCount: 5
      root:
        handlers: [file]
        level: INFO
    app:
      subscriptions:
        wind-fr69:
          category: weather.wind
          event_type: "*"
          criteria:
            - key: area.zone
              operator: eq
              value: FR-69
          endpoints:
            - email.email_primary
    """
  When I call the RPC get_recipients_for_alert on the subscription service with the following arguments
    """
    {
      "alert": {
        "schema_version": "1.0",
        "alert_id": "wx_wind_fr69",
        "source": "test",
        "category": "weather.wind",
        "event_type": "hail",
        "severity": "moderate",
        "occurred_at": "2026-01-15T12:00:00Z",
        "title": "Wind warning",
        "body": "Strong winds expected in FR-69.",
        "areas": [
          {"type": "zone", "value": "FR-69"}
        ],
        "attributes": {}
      }
    }
    """
  Then the RPC response is
    """
    [
      {
        "channel": "email",
        "endpoint_key": "email_primary"
      }
    ]
    """

Mocks, controlled return values, and message capture live in kontiki.testing; Behave steps drive them. The feature is the behavioural source of truth. Steps execute it; they should not invent behaviour missing from it.

See docs/features.md (Testing) and tests/integration/.

Documentation

• Features: docs/features.md
• Advanced features (patterns & gotchas): docs/advanced-features.md
• Configuration reference: docs/configuration.md
• Example configuration: docs/kontiki-config.example.yaml
• Contributing guidelines: CONTRIBUTING.md
• License: LICENSE

Kontiki requires RabbitMQ ≥ 4.3 (for V2.0+ features like quorum queues). You do not declare exchanges or queues yourself — decorators and config declare the topology. To start a broker locally:

make run-amqp

Examples

Examples can be run via the Makefile (see targets such as run-rpc-service, run-rpc-example, run-rpc-instance-example, run-simple-events-service, run-task-service, etc.). Shared logging is examples/common.yaml: console StreamHandler, default Kontiki formatter (omit formatters in YAML).

Misc

Kontiki did not come out of a naming workshop but from the album Kontiki by the band Cotton Mather. If you enjoy vintage 4-track indie pop as much as microservices, you should check it out.