npx skills add ...
npx skills add vercel-labs/json-render --skill yaml
npx skills add vercel-labs/json-render --skill yaml
YAML wire format for json-render with streaming parser, prompt generation, and AI SDK transform. Use when working with @json-render/yaml, YAML-based spec streaming, yaml-spec/yaml-edit fences, or YAML prompt generation.
YAML wire format for @json-render/core. Progressive rendering and surgical edits via streaming YAML.
yaml-spec, yaml-edit, yaml-patch, diff)TransformStream that converts YAML fences into json-render patchesOptions:
system (string) — Custom system message intromode ("standalone" | "inline") — Output mode, default "standalone"customRules (string[]) — Additional rules appended to prompteditModes (EditMode[]) — Edit modes to document, default ["merge"]Use pipeYamlRender as a drop-in replacement for pipeJsonRender:
For multi-turn edits, pass the previous spec:
The transform recognizes four fence types:
yaml-spec — Full spec, parsed progressively line-by-lineyaml-edit — Partial YAML deep-merged with current spec (RFC 7396)yaml-patch — RFC 6902 JSON Patch linesdiff — Unified diff applied to serialized specMethods: push(chunk), flush(), getResult(), getPatches(), reset(initial?)
The YAML package uses the universal edit mode system from core:
For custom parsing, use the exported constants:
| Export | Description |
|---|---|
yamlPrompt | Generate YAML system prompt from catalog |
createYamlTransform | AI SDK TransformStream for YAML fences |
pipeYamlRender | Convenience pipe wrapper (replaces pipeJsonRender) |
createYamlStreamCompiler | Streaming YAML parser with patch emission |
YAML_SPEC_FENCE | Fence constant for yaml-spec |
YAML_EDIT_FENCE | Fence constant for yaml-edit |
YAML_PATCH_FENCE | Fence constant for yaml-patch |
DIFF_FENCE | Fence constant for diff |
FENCE_CLOSE | Fence close constant |
diffToPatches | Re-export: object diff to JSON Patch |
deepMergeSpec | Re-export: RFC 7396 deep merge |
import { pipeYamlRender } from "@json-render/yaml";
import { createUIMessageStream, createUIMessageStreamResponse } from "ai";
const stream = createUIMessageStream({
execute: async ({ writer }) => {
writer.merge(pipeYamlRender(result.toUIMessageStream()));
},
});
return createUIMessageStreamResponse({ stream });pipeYamlRender(result.toUIMessageStream(), {
previousSpec: currentSpec,
});import { createYamlStreamCompiler } from "@json-render/yaml";
const compiler = createYamlStreamCompiler<Spec>();
// Feed chunks as they arrive from any source
const { result, newPatches } = compiler.push("root: main\n");
compiler.push("elements:\n main:\n type: Card\n");
// Flush remaining data at end of stream
const { result: final } = compiler.flush();
// Reset for next stream (optionally with initial state)
compiler.reset({ root: "main", elements: {} });import { buildEditInstructions, buildEditUserPrompt } from "@json-render/core";
import type { EditMode } from "@json-render/core";
// Generate edit instructions for YAML format
const instructions = buildEditInstructions({ modes: ["merge", "patch"] }, "yaml");
// Build user prompt with current spec context
const userPrompt = buildEditUserPrompt({
prompt: "Change the title to Dashboard",
currentSpec: spec,
config: { modes: ["merge"] },
format: "yaml",
serializer: (s) => yamlStringify(s, { indent: 2 }).trimEnd(),
});import {
YAML_SPEC_FENCE, // "```yaml-spec"
YAML_EDIT_FENCE, // "```yaml-edit"
YAML_PATCH_FENCE, // "```yaml-patch"
DIFF_FENCE, // "```diff"
FENCE_CLOSE, // "```"
} from "@json-render/yaml";