# JSON Schemas > Published JSON Schemas for the Toy format and every platform contract. Source: https://docs.tune.toys/developers/schemas/ - ApiError: Error envelope returned by every failing API response. `requestId` echoes the X-Request-Id response header. - ApiKeyScopes: Scopes granted to one developer API key. - ApiKey: Metadata of one developer API key. The secret is returned once at creation or rotation and never stored in plain text. - ApiUsage: Metered usage of one developer app in UTC hourly or daily windows. Counters are informational and may lag by up to 30 seconds. - ArtifactDescriptor: One registered build output of a product version. digest, size, inventory, targetProfile, format and arch never change; a correction is a new artifact. - PlatformCommon: Shared scalar formats referenced by the other platform contracts. - DeveloperApp: A developer app groups API keys, usage, webhooks and a tier. `tier` is the last observed effective tier, computed from the owner's feature:api.pro grant. - PlatformEnums: Closed platform enums. Generated TypeScript exports each as a type and an as-const array; this file is their single source. - LicenseCertificate: Offline license certificate payload (tunetoys.license-certificate/1), signed in a SignedEnvelope with the license key. Contains no device ID, email or handle. allowedMajor or until is absent for the all update policy. - ListingRevisionContent: Content of one product listing revision. The effective value of a field is overrides[field] ?? generated[field]. - SoundAnalysis: One engine run over a media version: its state, the facet summary the index reads and the full report. A newer engine version appends a row; the resolved view takes the newest ready one. - SoundItem: The mutable catalog entry of one upload: what people see and edit (title, artwork, tags, declared musical fields, visibility). Bytes and rights live on its versions. Server-owned counters and the resolved view are separate shapes here. - SoundRelation: A directional relation between two media items, created by either owner. Symmetric in the UI; a relation to an item the viewer cannot read is omitted. - SoundRendition: One derived artifact of a media version (peaks, preview, thumbnail, score page, piano roll, beats). Immutable; unique per version, kind, recipe, toolchain and profile. - SoundVersion: One immutable upload of a media item: bytes, digest, rights, what the probe found and the tags the file carried. Never edited after creation; releases pin versions. - MediaVocabulary: The closed vocabularies of the Sounds catalog as one document (served to editors and used as the zero-shot tag prompts). The long lists (`Instrument`, `Genre`, `Mood`) are defined here; the short ones reference enums.schema.json. Generated TypeScript exports each titled list as a type and an as-const array. - NotificationEvent: Input of the single notify helper. params holds ICU arguments (ids, counts, handles), never rendered strings or private content. - PlatformMatrix: Per-version platform matrix: one entry per target profile. included means an artifact exists, supported is a creator claim, tested requires evidence. - PostContent: Author-supplied content of a review, comment or reply. Server-owned fields (author, verified owner, root, depth, pins, state) are not part of it. Replies inherit subject and team scope from their root. - ProductPage: Visibility-filtered public product listing, documents, versions, offers and head metadata shared by HTML and React. - SignedEnvelope: Ed25519 envelope for update manifests and license certificates. The signature covers a purpose-specific domain prefix followed by the exact payload bytes; verifiers check it before parsing and never re-canonicalize. - SoundLandingPage: Validated sound facet landing content, filters, pagination metadata and related categories. - SoundSearchParams: Query of GET /v1/sounds and /v1/sounds/facets: every filter optional, bounded, and owned by the page URL. Facet counts answer for the same filter set. - StorefrontPage: Published or member-preview storefront sections, theme and public product cards. - StorefrontRevisionContent: Content of one publisher storefront revision: validated theme tokens and ordered typed sections. Storefronts are data, never code. - UpdateManifest: Signed update feed payload for one product and channel (tunetoys.update-manifest/1). Lists artifact digests, never URLs or tickets. Signed in a SignedEnvelope with the update_feed key. - Webhook: A pro-tier webhook endpoint. Deliveries are signed with TuneToys-Signature: t=,v1=.