Reference: @chainrender/client

Verify signatures against the shipped types. Code examples in these docs illustrate usage and intent. The authoritative signatures are the TypeScript types shipped with @chainrender/client — your editor's autocomplete and the package's .d.ts files are the source of truth. Where an example and the shipped type differ, the shipped type wins.

The SDK is the headless, framework-agnostic core for authoring, grading, and rendering ChainRender apps. Install:

npm install @chainrender/client viem

Exports

Core functions

• compose.* — build a component from the closed vocabulary (box, heading, text, button, image, chart, table, controls, …). Constrained by construction: you can't express outside the vocabulary.
• compileComponent(node) → { hash, hex, … } — the content-addressed artifact. The hash is the app identity.
• grade(node, opts?) → { letter, word, locks, envelope, deviations } — the trust grade, drift-locked with the chain. opts.pinnedDep (a raw-CIDv1 IPFS dependency, { protocol:"ipfs", cid }) grades B (Pinned), fail-closed to A if unverifiable; also read from a pinnedDep on the node. Helpers: isVerifiablePinnedDep, pinnedDependencyLevel, pinnedCid, RAW_CIDV1, type PinnedDep.
• vocabulary() — the machine-readable schema (node types, a11y and behaviour fields, enums, capabilities, resolver kinds), derived from the real constants, so tooling never hardcodes them. See The Vocabulary.
• checkNode(tree, opts?) → { ok, issues, nodeCount, depth } (0.10.0) — checks a tree against everything compile() reads and reports what it would silently drop (unknown fields, bad enum values, a11y on images, args on batch members) plus the node/depth/size limits. Each issue has a path, a code (unknown-field, ignored-field, authoring-field, required, type, enum, format, limit) and a message. { authoring: true } accepts the builder-only fields — argValues on slots and images, image.scene, a root pinnedDep, and _-prefixed design-time keys (0.10.1).
• nodeJsonSchema(opts?) (0.10.0) — the same rules as a strict JSON Schema (draft 2020-12), to hand to an AI tool or validator. Also exported: fieldsOf, NODE_TYPES, NODE_ENUMS, TYPE_FIELDS, A11Y_FIELDS, BEHAVIOR_FIELDS, AUTHORING_FIELDS, IGNORED_BY_COMPILE, IGNORED_NESTED, NODE_LIMITS. Every field is listed on Node Fields.
• kinds / RESOLVER_KINDS — every first-party resolver kind with its args, data edge and capability, plus the per-family encoders (for example kinds.ens.encodeNameArgs(address), kinds.ens.encodeV2Args(resolver, inner, isText)). A descriptor with argsEncoding: "packed" takes raw bytes, not abi.encode. The full list: All Resolver Kinds.

peerDependencies: viem (required); react + the Farcaster miniapp SDK (optional, for those subpaths).

App metadata

The app-metadata seam (see App Metadata) is exposed through the SDK so authoring tools can read and write an app's on-chain descriptive info:

• encodeAppMeta(obj) → compact JSON string for the scene binding's meta field. Strips empties, size-capped.
• decodeAppMeta(str) → AppMeta object; never throws, returns { v: 1 } on any malformed input.
• getAppTitle / getAppAuthor / getAppDescription / getAppKind / getAppIcon / getAppCategory / getAppGrade / getAppGradeWord / getAppTags — safe accessors, each takes (meta, fallback?) and never throws.
• gradeLocks(meta) → the lock string for a grade letter. hasAppMeta(meta) → whether any field beyond the version marker is set.
• APP_META_VERSION — the current metadata schema version (readers are forward-compatible: a v1 reader still reads a future field's neighbours).

All are re-exported from chainc/appmeta.ts, the single source of truth. Adding a field there makes it available everywhere in one edit.