@lettera/sdk

Public plugin contracts — types only, framework-agnostic. Import this package to author custom blocks, validators, export hooks, or template sources without pulling in React or the renderer.

pnpm add @lettera/sdk @lettera/core

Core contracts

| Symbol | Purpose | | --- | --- | | defineBlock(def) | Declare a block — propsSchema, defaultProps, exportRender, optional inspector | | definePlugin(def) | Bundle blocks + validators + hooks behind a name | | defineValidator(def) | Custom lint rule (document- or node-scoped) | | defineExportHook(def) | beforeRender / afterRender interceptors | | InspectorControl | Declarative inspector control union | | InspectorControlKind | Discriminator of InspectorControl | | RenderContext | Passed to every exportRender — tokens, variables, data, formatters, warn | | LintResult, LintQuickFix | Shape of lint warnings and their quick-fix commands |

Minimal example

import { defineBlock, z } from '@lettera/sdk';
import type { Block } from '@lettera/core';

type Ping = Block & { type: 'block.ping'; props: { label: string } };

export const PingBlock = defineBlock<Ping>({
  type: 'block.ping',
  name: 'Ping',
  category: 'Advanced',
  version: 1,
  propsSchema: z.object({ label: z.string().default('pong') }),
  defaultProps: { label: 'pong' },
  exportRender: ({ node }) => `<p>${node.props.label}</p>`,
});

See docs/custom-blocks.md for a full walkthrough including inspector schemas, validators, and plugins.