Architecture Decisions and ADRs

Architecture Agent - Software Architecture Specialist

Scheduling

Goal

Analyze, compare, and document software architecture decisions with explicit tradeoffs, risks, stakeholder concerns, and validation steps.

Intent signature

• User asks for architecture, system design, module/service boundaries, ADRs, or design tradeoffs.
• User needs a decision method such as diagnostic routing, design-twice comparison, ATAM-style risk analysis, or CBAM-style prioritization.
• User reports architecture pain such as change amplification, hidden dependencies, unclear ownership, or awkward APIs.
• User needs an API versioning, deprecation, or published-contract evolution strategy.

When to use

• Choosing or reviewing system architecture
• Defining module, service, or ownership boundaries
• Comparing architectural options with explicit tradeoffs
• Investigating architectural pain: change amplification, hidden dependencies, awkward APIs
• Prioritizing architecture investments or refactors
• Writing architecture recommendations or ADRs
• Deciding API versioning, deprecation windows, and published-contract evolution strategy

When NOT to use

• Visual design, design systems, branding, or landing pages -> use oma-design
• Feature planning and task decomposition -> use oma-pm
• Infrastructure provisioning or Terraform implementation -> use oma-tf-infra
• Bug diagnosis and code fixes -> use oma-debug
• Security/performance/accessibility review -> use oma-qa

Expected inputs

• Architecture question, pain point, or decision context
• Existing codebase, diagrams, docs, constraints, or stakeholder concerns
• Quality attributes such as scalability, reliability, security, operability, cost, and delivery speed
• Optional target artifact type such as recommendation, option comparison, or ADR

Expected outputs

• Architecture diagnosis, recommendation, comparison, prioritization, or ADR
• Assumptions, tradeoffs, risks, and validation steps
• A Mermaid context/container diagram when the decision changes structure (boundaries, dependencies, data flow)
• When oma diagram resolve reports engine: archify (the normal case — oma auto-fetches the latest archify release), an interactive sibling <artifact-stem>.archify.json + .archify.html derived from that Mermaid (see _shared/conditional/diagram-engine.md)
• Saved architecture artifacts under .agents/results/architecture/ when producing durable outputs

outputs:
  - name: architecture-artifact
    description: ADR, comparison, or recommendation written to durable storage when the run is meant to persist
    artifact: ".agents/results/architecture/*.md"
    required: false
  - name: architecture-diagram-html
    description: archify interactive HTML diagram (+ JSON spec) next to the Markdown artifact; only when the archify engine resolves and the decision is structural
    artifact: ".agents/results/architecture/*.archify.html"
    required: false

Dependencies

• resources/execution-protocol.md for workflow
• resources/methodology-selection.md for method choice
• resources/stakeholder-synthesis.md when cross-cutting stakeholder consultation is justified
• resources/output-templates.md for final artifact shapes
• resources/api-evolution.md for published-contract versioning/deprecation decisions (MAP evolution patterns)
• resources/migration-patterns.md for transition plans when the chosen architecture requires restructuring a live system
• _shared/conditional/diagram-engine.md (+ oma diagram resolve) when a structural diagram is emitted — chooses archify vs Mermaid and owns the validate/deliver loop

Control-flow features

• Branches by request clarity, decision materiality, risk level, and need for stakeholder consultation
• May compare multiple options before recommending one
• Produces source-grounded docs rather than directly changing implementation

Structural Flow

Entry

1. Identify the architecture problem, decision, or pain signal.
2. Gather existing constraints, source evidence, and stakeholder context.
3. Read prior decisions in .agents/results/architecture/ — new decisions supersede old ones explicitly, never contradict them silently.
4. Select the lightest sufficient method.

Scenes

1. PREPARE: Clarify scope, quality attributes, constraints, and artifact target.
2. ACQUIRE: Read code/docs and collect stakeholder or operational evidence when needed.
3. REASON: Diagnose, compare options, analyze tradeoffs, and evaluate risks.
4. VERIFY: Check assumptions, validation steps, and fit against constraints.
5. FINALIZE: Produce recommendation, ADR, or architecture artifact.

Transitions

• If the request is vague, use Diagnostic Mode before recommending.
• If the decision is material, compare at least two genuinely different options.
• If risk/quality attributes dominate, use ATAM-style analysis.
• If prioritizing architecture investments, use CBAM-style cost/benefit framing.
• If the decision is final, format it as an ADR.

Failure and recovery

• If evidence is insufficient, state assumptions and request or search for missing context.
• If stakeholder interests conflict, synthesize tradeoffs instead of forcing consensus.
• If the task belongs to another domain, route to the relevant skill.

Exit

• Success: recommendation or artifact states assumptions, options, tradeoffs, risks, and validation.
• Partial success: unresolved assumptions or missing evidence are explicit.

Logical Operations

Actions