mock-data-contract

name	mock-data-contract
namespace	process
description	Use WHEN a prototype, frontend handoff, or backend integration needs realistic mock data TO create schema-tied mock contracts and scenario fixtures before frontend implementation. Triggers: 'mock data contract', 'prepare mocks', 'data-fed prototype', 'frontend before backend'.
allowed-tools	["Read","Grep","Glob","Bash","Write","Edit"]
phase	handoff
prerequisites	["prototype-or-spec-exists"]
emits-artifact	mock-data-contract
confidence-rubric	confidence-rubrics/agent-delivery.yaml
gate-on-exit	true
version	1
last-verified	"2026-05-07T00:00:00.000Z"

Mock Data Contract

Create a contract-backed mock data bundle for data-fed prototypes and frontend-before-backend work. The output makes mock data useful for design, frontend implementation, API design, and backend integration without pretending local JSON is the backend.

When to invoke

• The prototype interaction depth is data-fed.
• A screen spec includes loading, empty, error, permission, validation, partial, pagination, or large-list data states.
• Frontend work must start before backend endpoints are available.
• /supervibe-design reaches prototype or handoff with fake API responses.
• A stack developer receives a prototype handoff and needs to know how mocks map to the eventual backend.

Do not invoke for purely visual prototypes, static marketing pages with no API state, or production seed data.

Expert Operating Standard

Follow docs/references/skill-expert-operating-standard.md: start from source of truth, preserve retrieval evidence, apply scope safety, use real producers with runtime receipts for durable delegated outputs, verify before completion claims, and keep confidence below gate when evidence is partial.

Step 0 - Read source of truth

Before writing fixtures, read the relevant available files:

• .supervibe/artifacts/prototypes/<slug>/config.json
• .supervibe/artifacts/prototypes/<slug>/spec.md
• .supervibe/artifacts/prototypes/<slug>/content/copy.md
• .supervibe/artifacts/prototypes/<slug>/mocks/ if it already exists
• .supervibe/artifacts/prototypes/<slug>/.approval.json when handoff is requested
• API specs such as openapi.yaml, openapi.json, schema.graphql, *.proto, or asyncapi.yaml
• Data model artifacts such as migrations, ORM models, Prisma schema, SQL schema, or data-modeler output
• API designer output, ADRs, and project memory entries for contracts, error envelopes, pagination, auth, and PII rules

If no API/schema/data-model source exists, create a provisional contract with explicit backend questions. Do not mark it schema-backed.

Decision tree

Is interaction data-fed?
  no  -> stop; no mock-data contract needed.
  yes -> continue.

Does an API/schema contract exist?
  yes -> derive mock-contract.json schemaRefs from it.
  no  -> check data model / spec / API designer notes.

Only product/spec shape exists?
  -> create contractStatus="provisional" and list backendQuestions.

Does the spec name states?
  yes -> cover every named state in mock-scenarios.json.
  no  -> require baseline states: success, loading, slow, empty, error, permission, validation, partial, large-list where relevant.

Does any fixture include real PII, secrets, or production export data?
  yes -> replace with synthetic values before handoff.
  no  -> continue.

Is handoff being produced?
  yes -> copy mocks into handoff/mocks/ and add backend-integration.md.
  no  -> keep mocks under prototype root and record readiness state.

Procedure

1. Resolve <slug> and target prototype root.
2. Classify contractStatus: api-backed, schema-backed, data-model-backed, or provisional.
3. Create .supervibe/artifacts/prototypes/<slug>/mocks/ if absent.
4. Write .supervibe/artifacts/prototypes/<slug>/mocks/mock-contract.json from templates/mock-data/mock-contract.json.tpl.
5. Write .supervibe/artifacts/prototypes/<slug>/mocks/mock-scenarios.json from templates/mock-data/mock-scenarios.json.tpl.
6. Write one JSON fixture per scenario under .supervibe/artifacts/prototypes/<slug>/mocks/api-fixtures/.
7. Write .supervibe/artifacts/prototypes/<slug>/mocks/README.md with data ownership, PII policy, backend questions, and replacement steps.
8. When producing handoff, copy the same mock bundle into .supervibe/artifacts/prototypes/<slug>/handoff/mocks/ and write handoff/backend-integration.md from templates/mock-data/backend-integration.md.tpl.
9. Verify scenario coverage, schema refs, PII safety, and backend drift notes.
10. Score with supervibe:confidence-scoring.

Output contract

Returns:

=== Mock Data Contract ===
Slug:           <slug>
Contract:       .supervibe/artifacts/prototypes/<slug>/mocks/mock-contract.json
Scenarios:      .supervibe/artifacts/prototypes/<slug>/mocks/mock-scenarios.json
Fixtures:       .supervibe/artifacts/prototypes/<slug>/mocks/api-fixtures/
Handoff copy:   <pending | .supervibe/artifacts/prototypes/<slug>/handoff/mocks/>
Backend notes:  <pending | .supervibe/artifacts/prototypes/<slug>/handoff/backend-integration.md>
Status:         <api-backed | schema-backed | data-model-backed | provisional>

Confidence: <N>.<dd>/10
Override:   <true|false>
Rubric:     agent-delivery

Guard rails

• DO NOT write happy-path-only mock data for data-fed prototypes.
• DO NOT use real PII, access tokens, secrets, production exports, or customer-identifying strings in fixtures.
• DO NOT call provisional mocks backend-ready; list the missing owner decision and backend questions.
• DO NOT let mock shape diverge from API/schema/data model without a drift note.
• DO NOT hand off data-fed prototypes without mock-contract.json, mock-scenarios.json, api-fixtures/, and backend integration notes.
• ALWAYS preserve the distinction between UI state, API response shape, and backend persistence shape.

Verification

This skill's output is verified by:

• mock-contract.json includes contractStatus, owner, schemaRefs, endpoints, entities, piiPolicy, and driftRule
• mock-scenarios.json includes scenario ids for success and every applicable non-happy-path state
• api-fixtures/ includes one fixture file per scenario id
• Fixture values are synthetic and contain no secrets, tokens, or production export markers
• backend-integration.md exists in handoff for approved data-fed prototypes
• Downstream prototype or handoff summary names the mock contract status and unresolved backend questions

Related

• supervibe:_ops:mock-data-designer - specialist agent for producing this bundle
• supervibe:_ops:api-designer - API contract owner
• supervibe:_ops:data-modeler - data-model owner
• supervibe:prototype - data-fed prototype consumer
• supervibe:prototype-handoff - packages mock data for stack developers
• rules/mock-data-contract.md - rule-level gate for frontend-before-backend workflows