version: "1.0.2" name: mcbe-json-ui-basics description: Explain the fundamentals of Minecraft Bedrock JSON UI in practical addon terms. Use when Codex must teach or reason about what a resource pack is, how JSON UI files are loaded, what _ui_defs.json and screen files do, how screens differ from templates, how Bedrock layout works across device sizes, or when a task is beginner-oriented and needs a correct mental model before implementation.

MCBE JSON UI Basics

Use this skill when the task first needs the Bedrock mental model.

Evidence first, skill second

Research the real evidence before applying anything written in this skill, and say which step answered:

1. The target pack itself: its _ui_defs.json, manifests, the files the request names, and the current Content Log.
2. Pinned official vanilla evidence: references/official/bedrock-samples-ui at the revision in references/official/bedrock-samples-ui.lock.json, node tools/vanilla-name-check.mjs <name> for any control, #binding, $variable, button id, renderer or screen file, the full local mirror under references/upstreams/bedrock-samples when present, and docs/83-vanilla-ui-1.26.50-diff.md for names that moved or disappeared.
3. Registered upstream sources and their cards: node tools/design-library.mjs sources --source ID and node tools/design-library.mjs patterns --source ID for the official docs, Wiki snapshots, schemas and sample addons pinned in config/design-research-lock.json (commit-pinned raw URLs for every file), then the repository docs/.
4. Only when steps 1–3 do not answer: this skill's own references. Label such guidance "inferred from skill guidance", never "confirmed".

A name, offset, selector or rule found in steps 1–3 overrides this skill. Older third-party references and example packs stay valid pattern evidence; do not delete or rewrite them because a vanilla name moved. Without this repository checkout, follow the same order with the official samples and docs you can reach and report which steps were unavailable.

Contract

• Input: the user's current understanding and the concrete pack or screen question.
• Output: a Bedrock-specific explanation tied to actual RP files and a clear next specialist when implementation begins.
• Success: requirements, common patterns, and runtime-dependent behavior are not conflated.

If data/skill-tool-profiles.json exists, the mcbe-json-ui-basics entry may identify read-only lookup helpers. Explanation does not require a tool; do not invoke commands that are absent from the checkout.

Workflow

1. Read references/basics-map.md.
2. Explain Bedrock JSON UI in resource-pack terms, not generic web UI terms.
3. Prefer practical rules over fake certainty.
4. State clearly when a rule is a hard requirement, a common pattern, or only a convenient authoring habit.

Hard rules

• Do not claim Bedrock has one fixed screen size.
• Do not describe JSON UI files as isolated from the rest of the resource pack.
• Do not treat schema validation as proof that the UI will render correctly.
• If the user moves from basics into a concrete implementation, route to mcbe-json-ui-master or the narrower specialized skill.