Skip to content
Agent OS
AOS-ADR-0002 Accepted foundation decision

ADR-0002: Portable Layer Contracts

ADR-0002: Portable Layer Contracts: scope, decisions, requirements, evidence, risks, and traceability for the Agent OS programme.

Edit on GitHub →

ADR-0002: Portable Layer Contracts

This record freezes a high-cost architectural decision, its rationale, consequences, reversal conditions, and required evidence.

Table of Contents

Purpose and Scope

Area: Architecture Decision.

This record freezes a high-cost architectural decision, its rationale, consequences, reversal conditions, and required evidence.

This document owns the semantics implied by ADR-0002: Portable Layer Contracts. It does not assert that every described subsystem already exists. It defines the target model, constraints, evidence needed to trust an implementation, and the boundary with adjacent documents.

Normative Position

  1. Architect contract-ready board packages, firmware manifests, test hooks, provisioning, calibration, update ownership, security response, lifecycle, and certification evidence.
  2. Request documentation rights and engineering support explicitly; do not assume an NDA grants source, redistribution, or long-term maintenance rights.
  3. Keep product layers independent of one ODM BSP.

Operating Model

The operating model is contract-first and evidence-driven. A component declares its authority, resources, lifecycle, error model, cancellation and timeout behavior, observability, version, and compatibility promise. Backends are replaceable only when the same conformance suite passes and no forbidden platform type leaks into portable layers.

Implementation proceeds through a reference model or mock, deterministic QEMU evidence where relevant, documentation-first physical hardware, and quality-hardware evidence. Pixel 9 adapters remain quarantined according to ADR-0004.

Requirements

  • R01. Architect contract-ready board packages, firmware manifests, test hooks, provisioning, calibration, update ownership, security response, lifecycle, and certification evidence.
  • R02. Request documentation rights and engineering support explicitly; do not assume an NDA grants source, redistribution, or long-term maintenance rights.
  • R03. Keep product layers independent of one ODM BSP.
  • R04. Specify normal, partial, denied, timeout, cancellation, restart, upgrade, and permanent-failure behavior.
  • R05. Expose structured diagnostics without leaking secrets or vendor-specific implementation details.
  • R06. Link material unknowns to a claim and, when testable, an experiment with an owner and gate.
  • R07. Update affected documentation and task data when evidence changes the model.

Failure and Degradation

Degradation must be explicit rather than accidental. The system reports capability absence, reduced quality, unavailable provider, stale data, or unsafe condition through typed states. It must not silently fall back to broader authority, unrestricted legacy execution, unverified firmware, lossy data migration, or irreversible agent action.

Recovery defines what state is retained, reconstructed, re-enrolled, compensated, or intentionally discarded. Unsupported hardware or providers are rejected at binding time where possible.

Evidence and Acceptance

  • RFI/RFQ matrix and redlined agreement.
  • Reference BSP portability review.
  • Pilot manufacturing, provisioning and OTA rehearsal.
  • Evidence records target identity, hardware revision, firmware, source commit, toolchain, configuration, seed, timestamps, artifacts, expected result, actual result, and reviewer.
  • Acceptance requires the referenced tasks to meet their own criteria; prose completion is not implementation completion.

Implementation Obligations

No current task row references this document directly. Before implementation begins, create an owned task or explicitly mark the document as informational.

Risks and Open Questions

  • Minimum order quantities, NRE, certification, support discontinuity and opaque subcontractors can overwhelm the programme.
  • Vendor changes can break reproducibility and update rights.
  • Contract clauses can prevent community publication.
  • Open-question rule: an unanswered high-impact question becomes a claim/experiment record and cannot be hidden in meeting notes.
  • Stop rule: work stops or changes track when legal rights, recovery, debug access, safety, or the required evidence path is unavailable.

Related Documents

Planning Reference Anchors

No additional task-specific anchors are required in this baseline.