n8n-nodes-datatable-cache

A Data Table Cache node for n8n: a read-through / write-back cache backed by an n8n data table, with hit/miss routing and TTL expiry.

📦 npm: n8n-nodes-datatable-cache

Requirements: an n8n version whose public API serves /api/v1/data-tables (older instances return 404), and executionOrder: v1 (the default on recent n8n).

What it does

Two inputs (Input, Update), two outputs (Cache Hit, Cache Miss), wired as a loop:

 Input  ─▶ ┌─ Data Table Cache ─┐ ─▶ Cache Hit  → use payload
 Update ─▶ └────────────────────┘ ─▶ Cache Miss → work ─┐
                ▲──────────────── Update ───────────────┘

• Input — look up by key. A fresh hit emits the cached payload on Cache Hit; a miss or expired hit emits the item on Cache Miss (with the stale row under _staleRow).
• Update — write processed items back; each is upserted and re-emitted on Cache Hit.

Wire it as a loop: Cache Miss → your work → the Update input; take Cache Hit onward.

➡️ Setup — one-time install: community node, data table, API key, credential (with screenshots). ➡️ Usage guide — per-workflow: importable example, node config, the cache loop, TTL, and evicting expired rows.

Install

Community node (n8n Settings → Community Nodes → Install): n8n-nodes-datatable-cache.

Setup (quick)

• Data table with columns cache_key, payload, last_modified (and optional last_access) — see Setup.
• Credential: the built-in n8n API credential — an API key (with dataTable* scopes) and a Base URL ending in /api/v1.

Parameters

| Parameter | Default | Notes | | -------------------- | --------------- | ---------------------------------------------------- | | Data Table | — | Pick from list or enter the table ID | | Key Column | cache_key | Column matched against the cache key | | Cache Key | — | Value to look up (Input) or store under (Update) | | Payload Column | payload | Holds the JSON-stringified payload | | Last Modified Column | last_modified | ISO timestamp of the last write | | Last Access Column | last_access | ISO timestamp of the last hit (optional; leave empty to skip) | | Max Age + Unit | 3600 s | A hit older than this becomes a miss | | Measure From | Last Modified | Whether TTL counts from last_modified or last_access |

Limitations

• Expiry: TTL only (filter-condition mode planned).
• Concurrency: last-write-wins — fine for a cache, not for transactional data.
• Malformed payload: degrades to { _raw: <value> } rather than throwing.
• Continue On Fail: errored items are emitted with an error field (lookup → Cache Miss, store → Cache Hit) instead of failing the run.

Development

npm install
npm run build   # tsc + copy assets to dist/
npm run lint

All data-table I/O is isolated in nodes/DataTableCache/stores/ behind the CacheStore interface; client.ts (dataTableRequest) is the single line to revisit on n8n API changes.

License

MIT