Zero‑Lag Amazon PPC: Inventory‑Aware Bidding with n8n + Supabase

The Problem

Manual Amazon PPC management bleeds margin. Human reaction time can’t keep pace with price swings, stock-outs, or sudden demand spikes. The typical spreadsheet workflow causes:

• Bidding that ignores inventory reality (paying for clicks on items about to stock out).
• Budget drift and dayparting guesswork that misses high-intent windows.
• Slow search-term harvesting and weak negative control, letting waste compound.
• Placement volatility (Top of Search vs. Product Pages) without guardrails.
• Fragmented data between Ads and Seller Central, so decisions arrive hours late—after the money’s gone.

The Engineering Solution

We wire a closed-loop PPC controller using only the PDV stack: n8n for orchestration, Supabase as the operational store, Amazon Ads API for campaigns/bids/budgets, and SP-API for inventory and price. Gemini assists with decision summaries and exception notes. Everything runs containerized on GCP (Cloud Run) where needed.

Blueprint

1. Data ingest (every 15 minutes)

• Amazon Ads API: Pull campaign, ad group, keyword/product-target metrics, budgets, placement performance, and search term reports.
• SP-API: Pull inventory levels and current buy box price/your price for mapped SKUs/ASINs.
• Persist to Supabase tables: metrics_hourly, inventory_snapshots, price_snapshots, entities (campaigns/ad groups/keywords/targets), and placements.

2. Target computation (n8n Code Nodes)

• Inventory-aware throttle: If days-of-cover < threshold, scale down bids Y% or pause low-ROAS entities first.
• Target CPC: target_cpc = target_acos × net_price × conv_rate. Use a 14‑day rolling conversion rate; fallback to account baseline if data sparse.
• Bid bounds: Apply min/max bid per entity from Supabase constraints to avoid runaway bids.
• Placement multipliers: Boost Top of Search when its CVR and ROAS beat baseline by a defined delta; dampen when underperforming.
• Search-term miner: Promote terms with orders ≥ N and ACoS ≤ target as exact/phrase. Add negatives for terms with spend ≥ S and 0 orders (or ACoS ≫ target).

3. Change writer (idempotent, rate-limit aware)

• Amazon Ads API: Update keyword/product-target bids, placement settings, negatives, and campaign/portfolio budgets. Use budget rules to pre-schedule spend for predictable peaks (e.g., payday weekends or promo windows).
• Supabase: Log decisions and before/after values with an idempotency key (entity_id + window_start) to prevent double-writes.

4. Safety rails and rollbacks

• Portfolio hard caps to prevent runaway days.
• Variance brake: If ACoS spikes > X% versus 7‑day trend, freeze increases and step down bids.
• Out-of-stock kill switch: If inventory hits 0 for a SKU, pause relevant product ads and high-overlap keywords.
• Dry‑run mode: Simulate changes to verify impact before live pushes.

5. Observability and handoff

• Supabase powers a Cloud Run dashboard: decisions, exceptions, and ROI deltas with drill-down to each change.
• Gemini produces human-readable rationales for changes ("Top of Search CVR +22% vs. baseline; multiplier set to +20% within cap").
• n8n sub-workflows isolate accounts/brands; retries and backoffs respect API limits; failures create review tasks in Supabase.

Implementation Notes (operator-first)

• Schedules: 15‑min control loop; 24‑hour rebalance for budgets and placement caps; hourly search-term mining.
• Concurrency: One queue per account in n8n; entity-level batching to minimize API calls.
• Mapping: SKU↔ASIN↔ad entity relations stored in Supabase to align Ads and SP-API data.
• Compliance: Deterministic rules with transparent logs; no black-box training on Amazon data.

The PDV Advantage

Amazon Ads Optimization by PDV is not “another dashboard.” It’s a deterministic PPC control system that converts chaotic inputs (inventory, price, demand surges) into profitable bids and budgets, in minutes—not days.

• Inventory-aware PPC: SP-API signals throttle waste before it happens.
• Budget utilization without overspend: Scheduled budget rules tied to real demand windows.
• Faster search-term flywheel: Automated harvesting/negatives with guardrails.
• Audit-ready: Every change is explainable, reversible, and stored in Supabase.
• Built for scale: n8n sub-workflows, Supabase SQL, Cloud Run containers—no vendor lock, no fragile scripts.

If you manage PPC with spreadsheets, you’re already late. Put your campaigns on rails.

Book a 30‑minute Build Audit to see your inventory-aware PPC loop live. We implement in 14 days using your Amazon Ads + SP‑API credentials.