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Agent OS
AOS-ARCH-018 Normative foundation

Legacy Containment and Replacement

Legacy Containment and Replacement: scope, decisions, requirements, evidence, risks, and traceability for the Agent OS programme.

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Legacy Containment and Replacement

This specification defines a native Agent OS contract. Android, Linux, Fuchsia and other systems may inform the design, but do not become ambient native ABI dependencies.

Table of Contents

Purpose and Scope

Area: System Architecture.

This specification defines a native Agent OS contract. Android, Linux, Fuchsia and other systems may inform the design, but do not become ambient native ABI dependencies.

This document owns the semantics implied by Legacy Containment and Replacement. 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. Pixel 9 is an evidence and quality-ceiling track, not the platform architecture.
  2. Allowed Android/Linux uses are stock baselines, lawful observation, recovery, extraction, and temporary isolated bridges with end dates.
  3. Every legacy cell declares inputs, outputs, taint, license, security boundary, replacement owner, and final acceptable gate.

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. Pixel 9 is an evidence and quality-ceiling track, not the platform architecture.
  • R02. Allowed Android/Linux uses are stock baselines, lawful observation, recovery, extraction, and temporary isolated bridges with end dates.
  • R03. Every legacy cell declares inputs, outputs, taint, license, security boundary, replacement owner, and final acceptable gate.
  • 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

  • Dependency scan proving no Android/Linux types above adapters.
  • SKU-specific acquisition and recovery dossier.
  • Native replacement or explicit track termination at each gate.
  • 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

Task Obligation Priority Gate/Milestone Verification
AOS-DOCS-030 Define public, internal, restricted, and counsel evidence bundles P0 M0 Run the relevant document, schema, conformance, build, experiment, or hardware checks; independently review boundary compliance and acceptance criteria.
AOS-PLAT-101 Implement the legacy-contamination interface linter P1 M2 Run the relevant document, schema, conformance, build, experiment, or hardware checks; independently review boundary compliance and acceptance criteria.
AOS-SEC-110 Implement source-taint and restricted-evidence policy checks P0 M2 Run the relevant document, schema, conformance, build, experiment, or hardware checks; independently review boundary compliance and acceptance criteria.
AOS-LEGAL-022 Implement clean-room roles, repositories, and taint labels P0 M0 Run the relevant document, schema, conformance, build, experiment, or hardware checks; independently review boundary compliance and acceptance criteria.

Risks and Open Questions

  • A temporary bridge can become permanent through schedule pressure.
  • Factory images and firmware may restrict redistribution or reverse engineering.
  • Pixel SKUs, unlockability, firmware, and vendor interfaces vary.
  • 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

Audit

AOS-PLAT-101 — Implement the legacy-contamination interface linter

Taint

AOS-DOCS-030 — Define public, internal, restricted, and counsel evidence bundles; AOS-SEC-110 — Implement source-taint and restricted-evidence policy checks; AOS-LEGAL-022 — Implement clean-room roles, repositories, and taint labels