Design → Contractor Handoff Checklist for Playables: 9 File Artifacts to Deliver a Build‑Ready Demo

Playables are more than screens — they are behaviors, timing, state transitions, and sometimes mocked APIs. A design file alone leaves too much interpretation: what happens when a user taps an item, what the failure modes are, or whether the demo should simulate latency. That ambiguity creates developer questions and expensive rework.

A compact, standardized artifact bundle converts design intent into developer inputs: concrete UI assets, explicit interaction rules, lightweight API stubs, telemetry events, and acceptance tests. Teams that treat handoff as a product artifact (not a loose folder of files) reduce cycles and improve fidelity.

Below are the nine contractor‑ready artifacts to bundle for every playable. Each artifact maps to a single question developers always ask (What does it look like? How should it behave? What data does it need?). Deliver these in a zip or a single handoff page in your design tool so nothing is scattered.

Keep each artifact concise: a single page interactive spec, a one‑file OpenAPI stub, a telemetry CSV, a small asset pack, and a handful of acceptance tests are all you need to make a demo buildable without interpretation.

Developer‑ready mockups: deliver a single page per screen with exportable assets, named layers, font weights, and color tokens. Put a one‑line summary at the top: purpose, primary interaction, and success state. Embed image/asset export settings in the Figma (or equivalent) file so developers don’t guess sizes or formats.

Interactive spec: write a short step list for every flow (e.g., “1. Open splash → 2. Tap CTA → animation 400ms ease‑out → network call → show success modal”). Include explicit timings, easing values, and exact copy for microcopy. If a motion or timing is essential, include a 1–3 second video or GIF and a numeric duration in milliseconds.

JSON‑LD feature card: a tiny JSON‑LD file (schema.org Product or CreativeWork as appropriate) documents the demo’s identity and key features for marketing/product teams and can live in your handoff root. This file is primarily metadata: slug, title, short description, and a canonical example of the demo’s key property (for instance, a featured interaction name). JSON‑LD is machine‑readable and prevents downstream teams from guessing naming.

OpenAPI stub: deliver a one‑file OpenAPI (OAS) definition with the endpoints your demo touches, example request/response bodies, and the expected status codes. Keep it minimal — the goal is to remove backend ambiguity, not to spec a whole platform. Host the mock responses or include them inline so contractors can run a local mock server immediately.

Acceptance tests: write 6–10 discrete pass/fail scenarios that define a build‑ready demo. Prefer simple Gherkin lines or numbered steps: Given / When / Then or Step 1/2/3. Tests should cover the happy path, two key edge cases, and one failure simulation (e.g., API 500). These become the QA checklist the contractor uses to mark the demo done.

Asset pack & delivery: attach compressed assets (SVGs, optimized PNG/JPEG, fonts or links to licensed fonts), include an index.md at the root describing where to find each artifact, and provide one prototype link plus the OpenAPI mock URL. Put your checklist at the top of the design file or the handoff page so the contractor can tick items off while building.