Accessibility, Localization, and Input

This specification defines a user-facing capability in terms of entities, actions, history, consent, recovery, accessibility, and provider contracts.

Purpose and Scope
Normative Position
Operating Model
Requirements
Failure and Degradation
Evidence and Acceptance
Implementation Obligations
Risks and Open Questions
Related Documents
Planning Reference Anchors

Purpose and Scope

Area: Product System.

This specification defines a user-facing capability in terms of entities, actions, history, consent, recovery, accessibility, and provider contracts.

This document owns the semantics implied by Accessibility, Localization, and Input. 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

Define the boundary, owner, inputs, outputs, failure modes, observability, security authority, lifecycle, and compatibility policy.
Keep implementation facts separate from desired outcomes and unverified assumptions.
Require a reproducible evidence bundle before downstream components depend on the result.

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. Define the boundary, owner, inputs, outputs, failure modes, observability, security authority, lifecycle, and compatibility policy.
R02. Keep implementation facts separate from desired outcomes and unverified assumptions.
R03. Require a reproducible evidence bundle before downstream components depend on the result.
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

Reviewed specification.
Linked tasks, claims, sources and experiments.
Conformance or acceptance evidence.
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-PLAT-035	Implement input service and semantic event contract	P1	M4	multi-device, hotplug, timestamp/order, focus isolation, secure-field and accessibility tests
AOS-PROD-053	Implement notification, structured clipboard, and share services	P1	M8	sensitive clipboard, spoofing, expiry, background access, multi-format coercion and accessibility tests
AOS-PROD-070	Implement accessibility semantics and assistive-service baseline	P0	M8	keyboard-only, switch-only, screen-reader and custom-view conformance with disabled/limited sensory scenarios
AOS-PROD-071	Implement localization and multimodal input framework	P1	M8	RTL, CJK/Indic/Thai, mixed scripts, expansion, plural/case, time zones and original-retention tests
AOS-COMM-070	Establish translation and accessibility contribution workflow	P2	M8	pilot two non-English locales and one assistive-technology contribution through release

Risks and Open Questions

Undefined ownership and failure semantics create hidden coupling.
Unverified source claims can become architecture accidentally.
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.

Planning Reference Anchors

Acceptance Requirements

AOS-COMM-070 — Establish translation and accessibility contribution workflow; AOS-COMM-070 — Establish translation and accessibility contribution workflow

Assistive Services

AOS-PROD-070 — Implement accessibility semantics and assistive-service baseline; AOS-PROD-070 — Implement accessibility semantics and assistive-service baseline

Clipboard And Selection

AOS-PROD-053 — Implement notification, structured clipboard, and share services

Input Modalities

AOS-PLAT-035 — Implement input service and semantic event contract; AOS-PROD-071 — Implement localization and multimodal input framework; AOS-PROD-071 — Implement localization and multimodal input framework

Localization

AOS-PROD-071 — Implement localization and multimodal input framework; AOS-PROD-071 — Implement localization and multimodal input framework; AOS-COMM-070 — Establish translation and accessibility contribution workflow; AOS-COMM-070 — Establish translation and accessibility contribution workflow

Semantic Tree