etcion 0.9.0

Architecture as code — build, query, validate, and analyze enterprise architecture models in Python

etcion

Architecture as code. Build, query, validate, and analyze enterprise architecture models in Python.

Why etcion?

Enterprise architecture models are rich data structures — typed elements, directed relationships, cross-layer dependencies, governance rules. But most EA tooling treats them as static diagrams locked inside proprietary formats.

etcion turns your architecture into a first-class Python data structure. Once it's code, you can query it, validate it against rules, test what-if scenarios, diff versions, and integrate it with the rest of your analytical toolkit — pandas, networkx, Jupyter notebooks, CI/CD pipelines, or anything else Python touches.

Built on the ArchiMate 3.2 metamodel. Compatible with Archi via the Open Group Exchange Format.

What you can do

Build models programmatically

from etcion import (
    BusinessProcess, ApplicationService, ApplicationComponent,
    Model, Serving, Assignment,
)

order_handling = BusinessProcess(name="Order Handling")
api = ApplicationService(name="Order API")
backend = ApplicationComponent(name="Order Service")

model = Model(concepts=[
    order_handling, api, backend,
    Serving(name="serves", source=api, target=order_handling),
    Assignment(name="runs", source=backend, target=api),
])

Query the model graph

model.elements_by_layer(Layer.BUSINESS)
model.elements_by_name("Order", regex=False)
model.connected_to(backend)
model.sources_of(order_handling)

Detect structural patterns

from etcion.patterns import Pattern, RequiredPatternRule

# Every BusinessService must be backed by an ApplicationService
service_backing = (
    Pattern()
    .node("biz", BusinessService)
    .node("app", ApplicationService)
    .edge("app", "biz", Serving)
)

# Find services missing their backing
gaps = service_backing.gaps(model, anchor="biz")

# Enforce as a validation rule
model.add_validation_rule(RequiredPatternRule(
    pattern=service_backing,
    anchor="biz",
    description="Every BusinessService must be served by an ApplicationService",
))

Detect anti-patterns

from etcion.patterns import AntiPatternRule

# Technology should not directly serve Business (must go through Application)
bad_pattern = (
    Pattern()
    .node("tech", TechnologyService)
    .node("biz", BusinessProcess)
    .edge("tech", "biz", Serving)
)

model.add_validation_rule(AntiPatternRule(
    pattern=bad_pattern,
    description="Technology must not directly serve Business layer",
))

Model what-if scenarios

from etcion import analyze_impact, chain_impacts

# What breaks if we decommission the legacy CRM?
impact = analyze_impact(model, remove=legacy_crm, max_depth=3)
for item in impact.affected:
    print(f"  depth={item.depth}  {item.concept.name}")
print(f"Broken relationships: {len(impact.broken_relationships)}")

# What happens if we consolidate three systems onto one platform?
impact = analyze_impact(model, merge=([sys_a, sys_b, sys_c], target_platform))
print(f"Permission violations: {len(impact.violations)}")

# Chain multiple changes and validate the result
i1 = analyze_impact(model, remove=old_system)
i2 = analyze_impact(i1.resulting_model, replace=(legacy_db, cloud_db))
errors = i2.resulting_model.validate()

Validate against the spec

errors = model.validate()           # Collect all errors
model.validate(strict=True)         # Raise on first error

from etcion import is_permitted, Serving, ApplicationService, BusinessProcess
is_permitted(Serving, ApplicationService, BusinessProcess)  # True

Exchange with Archi and other tools

from etcion.serialization.xml import write_model, read_model

write_model(model, "architecture.xml", model_name="My Architecture")
loaded = read_model("exported_from_archi.xml")

Compare model versions

from etcion import diff_models

diff = diff_models(baseline_model, proposed_model)
print(diff.summary())  # "ModelDiff: 3 added, 1 removed, 2 modified"

Installation

pip install etcion              # Core library
pip install etcion[xml]         # + XML serialization (lxml)
pip install etcion[graph]       # + Pattern matching & impact analysis (networkx)
pip install etcion[xml,graph]   # Both

Requires Python 3.12 or later.

ArchiMate Coverage

58 concrete element types across all 7 layers, 11 relationship types, Junction, and 28 predefined viewpoints.

Layer	Elements
Strategy	Resource, Capability, ValueStream, CourseOfAction
Business	BusinessActor, BusinessRole, BusinessCollaboration, BusinessInterface, BusinessProcess, BusinessFunction, BusinessInteraction, BusinessEvent, BusinessService, BusinessObject, Contract, Representation, Product
Application	ApplicationComponent, ApplicationCollaboration, ApplicationInterface, ApplicationFunction, ApplicationInteraction, ApplicationProcess, ApplicationEvent, ApplicationService, DataObject
Technology	Node, Device, SystemSoftware, TechnologyCollaboration, TechnologyInterface, Path, CommunicationNetwork, TechnologyFunction, TechnologyProcess, TechnologyInteraction, TechnologyEvent, TechnologyService, Artifact
Physical	Equipment, Facility, DistributionNetwork, Material
Motivation	Stakeholder, Driver, Assessment, Goal, Outcome, Principle, Requirement, Constraint, Meaning, Value
Implementation & Migration	WorkPackage, Deliverable, ImplementationEvent, Plateau, Gap

Archi Compatibility

etcion reads and writes the Open Group ArchiMate Exchange Format, verified against Archi.

Import into Archi: File > Import > Open Exchange XML Model Export from Archi: File > Export > Open Exchange XML Model

Diagram layouts, folder organization, and visual styles survive round-trip as opaque XML.

Extending

# Custom validation rules
from etcion.validation.rules import ValidationRule

class RequireDocumentation:
    def validate(self, model):
        from etcion.exceptions import ValidationError
        return [
            ValidationError(f"'{e.name}' has no documentation")
            for e in model.elements if not e.description
        ]

model.add_validation_rule(RequireDocumentation())

# Language customization via profiles
from etcion.metamodel.profiles import Profile

cloud_profile = Profile(
    name="Cloud",
    specializations={ApplicationComponent: ["Microservice", "Lambda", "Container"]},
)
model.apply_profile(cloud_profile)

Development

git clone https://github.com/korpodevs/etcion.git
cd etcion
python -m venv .venv
source .venv/bin/activate
pip install -e ".[dev]"
pytest                    # 2685 tests
ruff check src/ test/     # Lint
mypy src/                 # Type check
mkdocs serve              # Local docs

License

MIT