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Announcements

ADR-003: Architecture model adapter system

Status: Accepted
Date: 2026-02-27
Authors: Anders Hassis

Context

Section titled “Context”

Architecture models can be written in different formats. LikeC4 uses a custom DSL (.c4 files). Structurizr uses its own workspace format. Teams choose based on existing tooling, team preferences, or ecosystem compatibility.

Erode needs to load, query, and patch architecture models regardless of format. Hardcoding support for a single format would limit adoption.

Structurizr support was initially implemented with a custom recursive-descent DSL parser (~567 lines). This was replaced by wrapping the official Structurizr CLI for reliability and reduced maintenance burden.

Decision

Section titled “Decision”

Define an ArchitectureModelAdapter interface that covers all operations the pipeline needs: loading a model from a path, finding components by repository URL or ID, querying dependencies and dependents, checking if a dependency is declared, and listing relationships. Each adapter carries AdapterMetadata with format-specific display information and help text.

Two implementations exist: LikeC4Adapter and StructurizrAdapter. An AdapterFactory creates the correct one based on configuration.

Rationale

Section titled “Rationale”

The adapter pattern decouples the pipeline from model format details. Adding a new format means implementing the interface without changing pipeline code.

AdapterMetadata lets each adapter provide format-specific user-facing messages (like “no component found” help text) without the pipeline knowing format details.

Consequences

Section titled “Consequences”

Positive

Section titled “Positive”
  • New architecture model formats can be added by implementing the interface.
  • Pipeline code stays format-agnostic.
  • Each adapter owns its parsing, querying, and error handling logic.

Negative

Section titled “Negative”
  • The interface must cover the superset of all format capabilities. Format-specific features that do not fit the interface require workarounds or optional methods.
  • The checkVersion method is optional, creating inconsistency in version checking across adapters.
Section titled “Related commits”
  • 8691ba8 - chore(release): release 0.4.0 (#24)