Boundary Principles

The boundary between the two systems is governed by five principles. They are what keep Alloy from becoming a second orchestrator and Foundry from having to understand Alloy's ontology. See The Ownership Boundary for how these are policed over time.

Alloy owns meaning

Alloy owns the semantic interpretation of engineering intent:

• What capabilities the team wants to preserve.
• What threats may erode those capabilities.
• What expectations make those threats relevant.
• What strategies are preferred.
• What tradeoffs are accepted.
• What evidence would prove success.
• Which product and design intent are relevant.
• Which agent formations are appropriate.
• Which prompts should be compiled for each agent phase.
• Which follow-up questions should be asked of humans.

Foundry owns execution

Foundry owns the operational reality of engineering automation:

• Event types and event emission.
• Task block execution.
• Observer vs Mutator semantics.
• Throttle behaviour.
• Gate resolution and gate execution.
• Retry behaviour.
• Agent invocation plumbing inside task blocks.
• Trace generation.
• Commit/push and other side effects.
• Maintenance, validation, vulnerability remediation, release, scan, and iteration formations.

Formation Briefs are the boundary

The Formation Brief is the compiled package of intent for a run. It is the place where Alloy's rich semantic model becomes operationally consumable by Foundry.

The Formation Brief should be:

• Versioned.
• Immutable after compilation.
• Referenced by ID and digest.
• Human-readable enough for review.
• Machine-readable enough for Foundry and agents.
• Narrow enough that Foundry does not need Alloy's entire ontology.
• Rich enough to shape assessment, planning, execution, verification, and summarization.

Avoid semantic leakage

Foundry should not need to know what a Capability, Threat, Expectation, Strategy, or Tradeoff means in Alloy's canonical model.

Foundry may need to know that a Formation Brief contains:

• Agent context sections.
• Prompt pack references.
• Gate overlay references.
• Runtime controls.
• Evidence plan references.
• Callback or reporting instructions.

But Alloy should translate its model into those Foundry-facing shapes.

Avoid orchestration leakage

Alloy should not sequence Foundry internals directly.

Alloy should not say:

Run Check Charter.
Then run Resolve Gates.
Then run Preflight.
Then run Assess Project.
Then run Create Plan.

Alloy should say:

Emit an iteration_requested event for this project using this throttle, this payload, and this Formation Brief.

Foundry decides which task blocks fire.

Related

• Integration Architecture — section overview.
• The Ownership Boundary — keeping the boundary clean over time.
• Formation Brief — the boundary artifact itself.
• System Roles — who owns what.

Source: Integration Architecture §4 (Boundary Principles).