MCP JSON Navigator

/** * Verbosity levels * 5 → raw * 4 small-expand → primitives kept; expand small lists/objects; otherwise fallback to level 2 * 3 size-summary → primitives kept; lists/objects show size + char count * 2 summary-count → primitives kept; lists → N items; objects → N keys * 1 type-map → key → type (string, number, boolean, list, object, null) * 0 root-only → keys */ export function simplify( value: any, verbosity: number, listDisplayLimit: number = 5, objectDisplayLimit: number = 6, charDisplayLimit: number = 200 ): any { if (verbosity === 5) return value; if (verbosity === 0) { if (Array.isArray(value)) return `[list: ${value.length} items]`; if (value && typeof value === "object") return Object.keys(value); return value; } // Value not an object if (value === null || typeof value !== "object") return value; // LIST at root (not inside an object key) if (Array.isArray(value)) { const length = value.length; const sizeChars = charSize(value); if (verbosity === 4) return "list"; if (verbosity === 3) return `[list: ${length} items]`; if (verbosity === 2) return `[list: ${length} items, ${sizeChars} chars]`; if (verbosity === 1) { if (length <= listDisplayLimit || sizeChars <= charDisplayLimit) { return value.map(v => simplify(v, 1, listDisplayLimit, objectDisplayLimit, charDisplayLimit)); } // fallback to level 2 summary return `[list: ${length} items, ${sizeChars} chars]`; } return value; } // OBJECT const keys = Object.keys(value); if (verbosity === 1) { // key → type return Object.fromEntries( keys.map(k => { const v = value[k]; if (v === null) return [k, "null"]; if (Array.isArray(v)) return [k, "list"]; return [k, typeof v]; }) ); } if (verbosity === 2) { return Object.fromEntries( keys.map(k => { const v = value[k]; if (v === null || typeof v !== "object") return [k, v]; if (Array.isArray(v)) return [k, `[list: ${v.length} items]`]; return [k, `[object: ${Object.keys(v).length} keys]`]; }) ); } if (verbosity === 3) { return Object.fromEntries( keys.map(k => { const v = value[k]; if (v === null || typeof v !== "object") return [k, v]; if (Array.isArray(v)) { return [k, `[list: ${v.length} items, ${charSize(v)} chars]`]; } return [k, `{object: ${Object.keys(v).length} keys, ${charSize(v)} chars}`]; }) ); } if (verbosity === 4) { const totalChars = charSize(value); if (keys.length <= objectDisplayLimit || totalChars <= charDisplayLimit) { // expand: recurse with v=1 for each key return Object.fromEntries( keys.map(k => [k, simplify(value[k], 1, listDisplayLimit, objectDisplayLimit, charDisplayLimit)]) ); } // fallback to level 3 per key return simplify(value, 3, listDisplayLimit, objectDisplayLimit, charDisplayLimit); } return value; } function charSize(value: any): number { try { return JSON.stringify(value)?.length ?? Number.MAX_VALUE; } catch { return Number.MAX_VALUE; } }