Agentic Mermaid

Author a new Mermaid diagram from blank by folding a list of structured ops over an empty diagram of `family`. The declarative counterpart to hand-writing source. Returns the same envelope as `mutate`: { ok, family, source, verify } or { ok:false, family, opIndex, error }. Call `describe_sdk` for the family before authoring unfamiliar ops.

Describe a Mermaid diagram. format=text returns { ok, text } with one or two summary sentences; format=json returns { ok, tree } with the AX tree; format=facts returns { ok, facts } with deterministic semantic fact lines for machine checking (for example edge A -> B : label, member Duck +quack()).

Return version-matched mutation operations for one diagram family. Use detail=signatures for the compact op menu or detail=fields (default) for exact field types, required flags, enum values, defaults, and constraints. Call this before build, mutate, or execute when the family schema is not already known.

Run JavaScript in an isolated sandbox; return a value. One call composes edits. Submit JavaScript; declaration types are guidance. No promises, async/await, dynamic import, or type annotations. Hosted note: execute runs in an on-demand isolate and costs more than the direct render_svg/render_ascii/render_png/verify/describe tools — prefer those for plain render/verify calls. For straightforward structured edits, prefer the declarative mutate/build tools; reserve execute for logic the ops don't express. Hosted mermaid.renderMermaidSVG*, renderMermaidASCII*, and layoutMermaidWithReceipt calls force security:'strict' and embedFontImport:false; caller code cannot weaken that host policy. SDK declaration: type DiagramKind = 'flowchart' | 'state' | 'sequence' | 'timeline' | 'class' | 'er' | 'journey' | 'architecture' | 'xychart' | 'pie' | 'quadrant' | 'gantt' | 'mindmap' | 'gitgraph' | 'radar' type MutationOp = { kind: string; [field: string]: unknown } type Result<T, E = { code: string; message: string }> = { ok: true; value: T } | { ok: false; error: E } interface SourceLocation { readonly line: number; readonly col: number } interface SourceMapSpans { readonly preserved: PreservedSourceSpans; readonly nodes: ReadonlyMap<string, SourceSpan>; readonly edges: ReadonlyMap<string, SourceSpan>; readonly groups: ReadonlyMap<string, SourceSpan>; readonly labels: ReadonlyMap<string, SourceSpan> } interface SourceMap { readonly nodes: ReadonlyMap<string, SourceLocation>; readonly edges: ReadonlyMap<string, SourceLocation>; readonly groups: ReadonlyMap<string, SourceLocation>; readonly labels: ReadonlyMap<string, SourceLocation>; readonly spans?: SourceMapSpans } interface ValidDiagram { readonly kind: DiagramKind; readonly source: SourceMap } type ExternalFamilyId = `family:${string}` interface ExtensionCompatibility { readonly [contract: string]: string | undefined readonly core?: string readonly scene?: string } interface ExtensionProvenance { readonly owner: string; r…

Apply a list of structured edit ops to an existing Mermaid `source` and return the edited diagram. This is the declarative counterpart to `execute`: plain JSON in, plain JSON out, no sandbox. Prefer it for straightforward edits; reserve `execute` for logic the ops don't express. Returns { ok, family, source, verify:{ ok, warnings } } on success, or { ok:false, family, opIndex, error } — where `error` names the offending field and lists the valid ones — when an op is malformed or cannot apply. Ops apply in order and are all-or-nothing: the first failing op stops the batch (its position is `opIndex`) and the input is left untouched. Each op is { "kind": <op>, …fields }. Call `describe_sdk` for the detected family before authoring unfamiliar ops; it returns compact signatures or exact field types, enum values, defaults, and constraints.

Render a Mermaid source string to text. Returns { ok, text }. useAscii true → plain ASCII (+,-,|); false/absent → Unicode box drawing (┌,─,│). targetWidth sets a hard terminal display-cell bound; impossible bounds return a typed error.

Rasterize a Mermaid source string to PNG. Returns { ok, png_base64 }. Hosted rendering uses resvg-wasm with bundled fonts; bytes may differ from the local napi renderer, so hosted PNG is a convenience surface, not part of the byte-determinism contract. For file/URL artifacts use the local stdio server.

Render a Mermaid source string to themeable SVG. Returns { ok, svg }. Layout is deterministic: identical input produces identical geometry. The hosted boundary forces security:'strict' and embedFontImport:false.

Parse and verify a Mermaid diagram without rendering it. Returns { ok, family, summary, warnings, layout: { bounds, nodes, edges } } for valid diagrams and { ok: false, errors } for parse failures. `family` is the detected diagram family and `summary` a one-line description — check them: ok:true only means the diagram is structurally valid, not that it is the kind you intended. Warnings use the layout-rubric codes.