Developer‑Ready Demo Contracts: 5 Contract Templates & Acceptance Criteria to Get Contractors Shipping Playables in 2–4 Weeks

Turn a one‑page brief into an enforceable deliverable by embedding a short, task‑focused SOW attachment under your MSA. Keep this SOW to 1–3 deliverables: (A) Interactive playable demo hosted on contractor staging, (B) Minimal admin UI to flip feature flags, (C) Hand‑over package (code, runbook, mock server).

Include timeline, fixed fee per milestone, acceptance window (10 business days), and what counts as "silence = acceptance" only if you intend it. Tie payments to signed acceptance certificates and list the authorized approver(s) by name or role.

Write acceptance criteria as objective, observable checks a product manager or QA can perform without reading code. For a playable demo, each acceptance item should map to a user story and include: test steps, expected JSON response or UI state, and an allowed defect severity (P0/P1).

Add an acceptance window (e.g., 10 business days) and explicit remediation steps: if a P0 remains open after the remediation window, the client may withhold final payment until fixed or accept a discount formula stated in the SOW.

Provide contractors with a single, minimal API contract so they can build the front end and playables against deterministic responses. Deliver a small OpenAPI/Swagger fragment that contains endpoints, request examples, response JSON, and status codes—this is the single source of truth for both client UI and mock servers.

Include example payloads for happy and unhappy flows, authentication expectations (if any), rate limits for the demo environment, and a small mock server runbook (how to start, port, environment variables). That lets contractors ship a first playable without waiting for backend changes.

Require the contractor to deliver a runnable mock server (Node/Express, FastAPI, or JSON Server) with seed data and a one‑command start script. The SOW should state that the demo will be evaluated against that mock server on the contractor’s staging URL and that the mock must implement the exact API stub defined in the contract.

Include instructions for deterministic behavior (fixed UUIDs, seeded RNG) and a test harness (curl commands or a Postman collection) so your reviewers can re‑run acceptance checks locally.

Acceptance should include telemetry proof points: simple events that prove core flows were executed on staging (e.g., session_started, level_completed). Specify event names, required fields, and a small retention/visibility expectation (events appear in telemetry dashboard within X minutes).

Also require a short QA checklist and a 3rd‑party smoke test (automated Playwright or Cypress script) that runs the demo’s happy path and returns exit code 0. These artifacts make acceptance fast and unemotional: the data will show whether the demo actually works.