n8n-workflow-builder-mcp

import fs from 'fs/promises'; import path from 'path'; import os from 'os'; import Database from 'better-sqlite3'; import { getCurrentN8nVersion } from '../nodes/versioning'; /** * Environment helpers for nodes DB and cache settings. */ function getNodesDbPath(): string | null { const envPath = process.env.N8N_NODES_DB_PATH?.trim(); if (envPath && envPath.length > 0) { return path.resolve(envPath); } // Default under user cache dir const home = os.homedir(); if (!home) return null; const defaultDir = path.join(home, '.cache', 'n8n-nodes'); return path.join(defaultDir, 'catalog.sqlite'); } function getWorkflowNodesRootDir(): string { // Existing code expects workflow_nodes relative to compiled dist path // Keep compatibility by materializing into project root workflow_nodes return path.resolve(__dirname, '../../workflow_nodes'); } async function ensureDir(dir: string): Promise<void> { await fs.mkdir(dir, { recursive: true }).catch(() => { }); } function openDb(dbPath: string, readOnly = true): Database.Database { const db = new Database(dbPath, { readonly: readOnly, fileMustExist: true }); return db; } export interface NodesDbVersionRow { version: string; builtAt: number; numNodes: number; sha256?: string | null; } export interface NodesDbNodeRow { id: string; // filename without extension version: string; nodeType: string; baseName?: string | null; typeVersion?: string | number | null; // stored as JSON or number filename: string; // original filename, e.g., http_request.json raw: string; // raw JSON string } function readVersionMeta(db: Database.Database, version: string): NodesDbVersionRow | null { try { const row = db.prepare( 'SELECT version, builtAt, numNodes, sha256 FROM versions WHERE version = ?' ).get(version) as NodesDbVersionRow | undefined; return row || null; } catch { return null; } } function* iterateNodes(db: Database.Database, version: string): Generator<NodesDbNodeRow> { const stmt = db.prepare( 'SELECT id, version, nodeType, baseName, typeVersion, filename, raw FROM nodes WHERE version = ?' ); for (const row of stmt.iterate(version)) { yield row as NodesDbNodeRow; } } async function directoryExists(dir: string): Promise<boolean> { try { const st = await fs.stat(dir); return st.isDirectory(); } catch { return false; } } async function countJsonFiles(dir: string): Promise<number> { try { const files = await fs.readdir(dir); return files.filter(f => f.endsWith('.json')).length; } catch { return 0; } } export async function materializeVersionFromDb(version: string, opts?: { targetRootDir?: string; force?: boolean }): Promise<{ ok: boolean; reason?: string }> { const dbPath = getNodesDbPath(); if (!dbPath) return { ok: false, reason: 'No DB path resolved' }; const targetRoot = opts?.targetRootDir || getWorkflowNodesRootDir(); const targetDir = path.join(targetRoot, version); await ensureDir(targetDir); let db: Database.Database | null = null; try { db = openDb(dbPath, true); } catch (e: any) { return { ok: false, reason: `Open DB failed: ${e?.message || String(e)}` }; } try { const meta = readVersionMeta(db, version); if (!meta) { return { ok: false, reason: `Version ${version} not found in DB` }; } const existing = await countJsonFiles(targetDir); if (!opts?.force && existing >= (meta.numNodes || 0) && existing > 0) { // Assume already materialized return { ok: true }; } // Clean directory before writing (only JSON files) try { const files = await fs.readdir(targetDir); await Promise.all( files.filter(f => f.endsWith('.json')).map(f => fs.rm(path.join(targetDir, f)).catch(() => { })) ); } catch { } // Write nodes const writer = async (row: NodesDbNodeRow) => { const outFile = path.join(targetDir, row.filename || `${row.id}.json`); await fs.writeFile(outFile, row.raw, 'utf8'); }; for (const row of iterateNodes(db, version)) { await writer(row); } const after = await countJsonFiles(targetDir); if (after === 0) { return { ok: false, reason: 'No files written' }; } return { ok: true }; } finally { try { db?.close(); } catch { } } } function compareSemver(a: string, b: string): number { const normalize = (v: string) => v.replace(/^v/i, ''); const pa = normalize(a).split('.').map(n => parseInt(n, 10) || 0); const pb = normalize(b).split('.').map(n => parseInt(n, 10) || 0); const len = Math.max(pa.length, pb.length); for (let i = 0; i < len; i++) { const na = pa[i] ?? 0; const nb = pb[i] ?? 0; if (na !== nb) return na - nb; } return 0; } export function listDbVersions(): string[] { const dbPath = getNodesDbPath(); if (!dbPath) return []; let db: Database.Database | null = null; try { db = openDb(dbPath, true); const rows = db.prepare('SELECT version FROM versions').all() as Array<{ version: string }>; return rows.map(r => r.version); } catch { return []; } finally { try { db?.close(); } catch { } } } export async function materializeBestVersion(preferred?: string, opts?: { force?: boolean }): Promise<{ ok: boolean; version?: string; reason?: string }> { const versions = listDbVersions(); if (versions.length === 0) return { ok: false, reason: 'DB has no versions' }; let chosen: string | undefined; if (preferred && versions.includes(preferred)) { chosen = preferred; } else if (preferred) { // choose best <= preferred const sorted = versions.slice().sort((a, b) => compareSemver(b, a)); const pv = preferred; for (const v of sorted) { if (compareSemver(v, pv) <= 0) { chosen = v; break; } } if (!chosen) chosen = sorted[0]; } else { chosen = versions.slice().sort((a, b) => compareSemver(b, a))[0]; } const res = await materializeVersionFromDb(chosen!, { force: opts?.force }); if (!res.ok) return { ok: false, reason: res.reason }; return { ok: true, version: chosen }; } export async function materializeIfConfigured(): Promise<void> { // Always materialize from DB // Prefer env override, then current version if already set, then latest in DB const preferred = process.env.N8N_VERSION || getCurrentN8nVersion() || undefined; const out = await materializeBestVersion(preferred).catch((e: any) => ({ ok: false as const, reason: e?.message || String(e) })); if (!out.ok) { console.warn(`[WARN] Failed to materialize nodes from DB: ${out.reason || 'unknown error'}`); return; } const chosenVersion = (out as { ok: true; version?: string }).version; console.error(`[DEBUG] Materialized nodes for version ${chosenVersion || preferred || 'latest'} from DB into ${getWorkflowNodesRootDir()}`); }