Crate a11y_kit 

a11y-kit — the accessibility semantics layer (ADR-0004 §2; the keystone nobody in the ecosystem funds).

A platform-free semantic node model — role, accessible name, states, relations — plus a tree audit that runs headlessly in CI. Every toolkit lowers into this; none of them ship the gate.

use a11y_kit::{A11yNode, A11yRole, A11yTree, NodeId, Relation, States};

let mut tree = A11yTree::new();
let root = tree.push(A11yNode::new(NodeId(0), A11yRole::Window, "Chisel Docs"));
let panel = tree.push(
    A11yNode::new(NodeId(1), A11yRole::Group, "Tool palette")
        .with_parent(root)
        .with_states(States { focused: true, ..States::default() }),
);
let save = tree.push(
    A11yNode::new(NodeId(2), A11yRole::Button, "Save document")
        .with_parent(panel)
        .with_relation(Relation::LabelledBy(panel)),
);
assert!(tree.audit().is_ok(), "a well-formed tree passes");

The rules the audit enforces

1. ids are unique;
2. parents/relations resolve;
3. no parent cycles;
4. every interactive role carries an accessible name;
5. at most one focused node, and it must live inside a Window subtree (a focusable node floating as its own root is invisible to the screen reader).

AccessKit

Conversion into AccessKit’s transport types lands behind the accesskit feature (Wave 2.1, first toolkit adapter). The audit layer stays dependency-free so any CI can run it — including this repo’s.

Structs

A11yNode

One semantic node.

A11yTree

An insertion-ordered tree of semantic nodes.

NodeId

A stable node identity within one tree.

States

Node state flags.

TreeAudit

What an audit measured.

Enums

A11yRole

The semantic roles the estate’s controls map onto. Deliberately a toolkit-neutral subset of the ARIA/accesskit role vocabulary — the lowering adapters pick the framework’s spelling.

AuditError

Why an accessibility tree failed its audit.

Relation

A relation between nodes (the edges a screen reader traverses).

TriState

Tri-state checkbox value.

Constants

VERSION

The crate’s version, for callers that report it.

Functions

is_interactive

True for roles a keyboard user must be able to reach and operate — roles whose accessible name the audit requires.