Gmail & Chat Currency Rates: Gemini + Frankfurter API n8n

Instant currency-rate replies from Gmail or chat—powered by Gemini + Frankfurter API (with smart caching)

This n8n workflow listens for exchange-rate questions in Gmail or an n8n chat trigger, extracts the currency pair, and replies with the latest reference rate using a Google Gemini AI agent calling the Frankfurter exchange-rate API. To reduce repeated model/API calls, it caches successful answers in n8n Data Tables with a configurable TTL.

What this workflow does

• Triggers on new messages: starts when a new Gmail email matches the exchange-rate search filter, or when an n8n chat message is received.
• Normalizes input: converts incoming email/chat content into a common format (session ID, user text, source channel, sender email) and processes requests one at a time.
• Builds a per-day cache key: extracts two ISO 4217 currency codes from the message and checks an n8n Data Table for a cached response for that pair/day.
• Uses cache when fresh: if a valid cached entry exists within the configured TTL, the workflow returns it directly—no new AI call.
• Fetches fresh rates with Gemini when needed: if there’s no fresh cache hit, the workflow runs a Google Gemini-powered agent that calls the Frankfurter API and generates a short plain-text (one to two sentences) reply.
• Caches results + logs metrics: stores valid rate answers back into the cache, then logs query details (source, currency pair, cache hit, latency) to a second Data Table.

Use cases

• Answering “What’s the EUR to USD rate today?” directly in your support inbox via Gmail.
• Providing quick currency-rate responses in an n8n chat interface for operators or customers.
• Reducing AI and API usage costs with per-day caching of successful responses.

Technical details

• Integrations/Nodes: Gmail (trigger + replies), Google Gemini (PaLM) API credentials, and n8n Data Tables for caching + logging.
• Core node types: if, set, code, no op, gmail, data table.
• Credentials required: Gmail OAuth2 and Google Gemini (PaLM) API credentials.