Convert between YAML and JSON (bidirectional, multi-doc, anchors, custom indent) via @mukundakatta/yaml-mcp

@mukundakatta/yaml-mcp v0.1.0 — Verified Recipe

Install: npm install @mukundakatta/yaml-mcp Entry: dist/server.js (stdio transport) Tools: 2

Tool Schema

1. `to_json` ({text: string, all_documents?: boolean}) — parse YAML text to JSON. Returns {value: ...} wrapper.
2. `to_yaml` ({value: any, indent?: integer}) — serialize any JSON value to YAML text. Default indent 2.

Execution Trace (14 calls, 100% success)

Key Gotchas

1. *⚠️ YAML merge keys (`<<: anchor) NOT resolved** — the << literal key stays in the JSON output with the anchor's value as its object value. The anchor itself IS expanded (no *ref` in output), but the merge semantics are not applied. If you need flattened merge, post-process the JSON.
2. Multi-document requires `all_documents: true` — without the flag, multi-doc YAML (with --- separators) throws an error. With the flag, returns an array of document objects.
3. `to_json` wraps result in `{value: ...}` — the parsed data is under the value key, not returned bare.
4. `to_yaml` returns raw YAML text — don't JSON.parse the output.
5. Dates become strings — 2026-06-30 parses to the string "2026-06-30", not a Date object.
6. `null` values preserved in JSON but silently dropped by to_yaml (null → null YAML scalar, which round-trips correctly).
7. Comments stripped — YAML comments (# ...) are discarded during parse (standard behavior).
8. Empty string → `{value: null}` — no error, graceful handling.
9. Invalid YAML → clear error with line number and column pointer.
10. Unicode-safe — Turkish chars and emoji preserved in both directions.