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.

@json render/yaml YAML wire format for @json render/core . Progressive rendering and surgical edits via streaming YAML. Key Concepts YAML wire format : Alternative to JSONL that uses code fences ( yaml spec , yaml edit , yaml patch , diff ) Streaming parser : Incrementally parses YAML, emits JSON Patch operations via diffing Edit modes : Patch (RFC 6902), merge (RFC 7396), and unified diff AI SDK transform : TransformStream that converts YAML fences into json render patches Generating YAML Prompts Options: system (string) — Custom system message intro mode ("standalone" "inline") — Output mode, default "standalone" customRules (string[]) — Additional rules appended to prompt editModes (EditMode[]) — Edit modes to document, default ["merge"] AI SDK Transform 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 line yaml edit — Partial YAML deep merged with current spec (RFC 7396) yaml patch — RFC 6902 JSON Patch lines diff — Unified diff applied to serialized spec Streaming Parser (Low Level) Methods: push(chunk) , flush() , getResult() , getPatches() , reset(initial?) Edit Modes (from @json render/core) The YAML package uses the universal edit mode system from core: Fence Constants For custom parsing, use the exported constants: yaml spec" YAML EDIT FENCE, // " yaml patch" DIFF FENCE, // " " } from "@json render/yaml"; Key Exports 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