Promo seeker: Auto-find promo codes with SerpAPI, Gemini & Telegram

Promo Seeker automatically finds, verifies, and delivers active promo codes to users via Telegram or email using SerpAPI + Gemini (OpenRouter). Saves hours of manual searching and deduplicates results into an n8n Data Table for fast reuse. Why Use This Workflow? Time Savings: Reduces manual promo hunting from 2 hours to 5 minutes per query. Cost Reduction: Cuts reliance on paid scraping tools or manual services — potential savings of $50–$200/month. Error Prevention: Cross-references sources and enforces a 30‑day recency filter to reduce expired-code hits by 60% vs single-source checks. Scalability: Handles hundreds of queries per day with Data Table upserts and optional scheduling for continuous discovery. Ideal For - Marketing / Growth Managers: Quickly discover competitor or partner discounts to promote in campaigns. - Customer Support / Operations: Respond to user requests with verified promo codes via Telegram or email. - Affiliate / Content Teams: Aggregate and maintain a clean promo feed for newsletters or site widgets. How It Works 1. Trigger: Incoming request via Webhook, Telegram message, Google Form submission, or scheduled run. 2. Data Collection: The LangChain agent uses SerpAPI search results and Gemini (OpenRouter) to locate recent promo codes. 3. Processing: Filter for recency (last 30 days), extract code, value, terms, and expiry. 4. Intelligence Layer: Gemini 2.5 Pro (OpenRouter) + LangChain agent structure and verify results, outputting a standardized JSON. 5. Output & Delivery: If a code exists in the Data Table, notify the requester via Telegram and Gmail; otherwise, return results and upsert them into the Data Table. 6. Storage & Logging: Results stored/upserted in an n8n Data Table to prevent duplicates and enable fast lookups. Setup Guide Prerequisites | Requirement | Type | Purpose | |-------------|------|---------| | n8n instance | Essential | Execute the workflow — import JSON to your n8n instance | | SerpAPI account | Essential | Web search results for promo code discovery | | OpenRouter (Gemini) account | Essential | Language model (Gemini 2.5 Pro) for extraction and verification | | Telegram Bot (BotFather) | Essential | Receive queries and send promo notifications | | Gmail OAuth2 | Essential | Send rich email notifications | | n8n Data Tables | Essential | Store and deduplicate promo code records | Get your n8n instance here: n8n instance — import the JSON and begin configuration. (Repeat link for convenience) n8n instance Installation Steps 1. Import the JSON workflow into your n8n instance. 2. Configure credentials (use n8n's Credentials UI — do NOT paste keys into nodes): - SerpAPI: paste your SerpAPI API Key from your SerpAPI dashboard. - OpenRouter API: paste your OpenRouter API Key (for Gemini 2.5 Pro). - Telegram API: create bot via @BotFather, then add Bot Token to Telegram credentials. - Gmail OAuth2: use n8n's Gmail OAuth2 credential flow and authorize the account. 3. Update environment-specific values: - Webhook path: /v1/promo-seeker (configured in the Webhook node) or replace with your preferred path. - Data Table ID: point to your own Data Table - Form/webhook recipient fields (email/chatId mappings). 4. Customize settings: - Adjust the LangChain agent prompt (Promo Seeker Agent) for different recency windows or regional focus. - Change max results/limit on the Data Table node (default limit = 3). 5. Test execution: - Trigger via Telegram or a POST to the webhook with sample payload: - Confirm notifications arrive and Data Table rows are upserted. Technical Details Core Nodes | Node | Purpose | Key Configuration | |------|---------|-------------------| | SerpAPI | Fetch web search results | Provide credential; adjust search params in agent prompt | | Gemini 2.5Pro (OpenRouter) | Extract & verify promo details | Use OpenRouter credential; model google/gemini-2.5-pro | | Promo Seeker Agent (LangChain) | Orchestrates search + parsing | System prompt enforces 30‑day recency & result format | | Structured Output Parser | Validates agent output | JSON schema example for platform/code/value/terms/validUntil | | Data Table (Get row(s)) | Lookup existing promos | Filters by platform; limit = 3 | | If (Code Exist?) | Branching logic | Checks existence of platform field | | Data Table (Upsert row(s)) | Insert or update promo | Mapping from agent output to Data Table columns | | Telegram Trigger / Telegram | Receive queries & notify users | Webhook-based trigger; parsemode = HTML for messages | | Gmail | Send rich HTML emails | Uses Gmail OAuth2 credential | | Webhook / Form Trigger | Alternate inputs | Webhook path /v1/promo-seeker and Form trigger for manual submissions | Workflow Logic - On trigger, the Platform Set node normalizes the incoming query and receiver. - Get row(s) checks Data Table for existing promos. - If found: notify via Telegram and send Gmail (email template included). - If not found: the Promo Seeker Agent runs SerpAPI searches, parses structured output, then Upsert row(s) saves results and notifications are sent. - Structured Output Parser enforces correct JSON to avoid bad upserts. Customization Options Basic Adjustments - Recency window: change the agent prompt to 7/14/30 days. - Result limit: increase Data Table Get limit or change Upsert batch size. Advanced Enhancements - Add Slack or Microsoft Teams notifications (moderate complexity). - Add caching layer (Redis) to reduce repeated SerpAPI calls (advanced). - Parallelize searches across multiple search engines (higher API usage & complexity). Performance & Optimization | Metric | Expected Performance | Optimization Tips | |--------|----------------------|-------------------| | Execution time | 8–30s per new search (depends on SerpAPI + LM response) | Reduce SerpAPI page depth; cache recent results | | API calls | 3–10 SerpAPI calls per complex query | Batch queries; use higher-quality search params | | Error handling | Agent retries on malformed output | Use retry nodes and set onError strategy for downstream nodes | Troubleshooting | Problem | Cause | Solution | |---------|-------|----------| | No results returned | Query too vague or rate-limited API | Improve query specificity; check SerpAPI quota | | Gmail send fails | OAuth scope not granted or token expired | Reconnect Gmail OAuth2 credential in n8n | | Telegram webhook not firing | Incorrect bot token or webhook setup | Recreate Telegram credential and check bot permissions | | Duplicate rows | Upsert mapping mismatch | Ensure promoCode mapping in Upsert matches structured output | | Agent returns malformed JSON | LM prompt too permissive | Tighten the agent system prompt and validate with Structured Output Parser | --- Created by: khaisa Studio Category: Marketing Automation Tags: promo-codes, coupons, serpapi, telegram, gmail, openrouter, data-tables Need custom workflows or help adapting this template? 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