Connecting Shopify, Amazon Ads, and Seller Central (SP-API): Permissions, Inventory & Billing Rules
Complete integration guide for connecting Shopify stores with Amazon Ads API v3 and Seller Central SP-API, covering permissions, inventory synchronization, and Shopify App Store billing compliance.
By Salfars Platform Team · Integrations & Partner APIs · Published
Summary & Direct Answer
Connecting an e-commerce brand to Amazon requires handling two distinct authorization systems: Amazon Advertising API v3 for Sponsored Products spend, and Seller Central Selling Partner API (SP-API) for inventory and order management. For Shopify merchants, billing and installation must strictly follow Shopify App Store requirements.
Methodology: This guide distinguishes advertising and seller authorizations. Confirm the required account roles and supported operations during setup; Amazon SP-API uses LWA access tokens and no longer requires AWS SigV4 signing.
Understanding Amazon's Dual-Grant Ecosystem
A common point of confusion for brand operators is assuming that an Amazon advertising connection provides access to product sales and inventory data. In Amazon's technical architecture, advertising campaigns and store operations belong to entirely separate API ecosystems with separate credentials and authorization flows.
The Amazon Advertising API v3 governs Sponsored Products, Sponsored Brands, and campaign keyword bids. In contrast, Amazon Selling Partner API (SP-API) manages inventory, FBA stock levels, orders, and merchant fulfillment.
Audit & Verification Checklist
- ✓ Amazon Advertising API: Governed by Login with Amazon (LWA) and advertiser profiles.
- ✓ Amazon SP-API: Requires separate seller authorization and an LWA access token; AWS IAM and SigV4 signing are no longer required.
- ✓ Cross-referencing advertising spend with inventory prevents promoting out-of-stock ASINs.
Amazon Ads API vs. Amazon SP-API Breakdown
Review the scope and capability boundaries between the two Amazon connection surfaces.
| Dimension | Amazon Ads API (v3) | Amazon SP-API (Selling Partner) | Orchestration Role in Salfars |
|---|---|---|---|
| Primary Function | Campaign creation, keyword bids, budget allocation | Orders, catalog items, FBA inventory, pricing | Synchronizes ad spend with inventory availability |
| Authentication | OAuth 2.0 via Login with Amazon (LWA) | Separate LWA authorization for seller access; AWS SigV4 is not required | Automated token refresh with secure token vault |
| Data Surfaced | Impressions, clicks, spend, attributed sales, ACOS | Units sold, reserved stock, buy box status, returns | Compare ad spend with seller data; margin requires complete cost inputs |
| Mutual Dependency | Can manage ads independently of seller status | Can manage inventory independently of advertising | Salfars unifies both into one conversational interface |
Shopify App Store Compliance: Rules 1.2.1 and 2.3.1
For brands running on Shopify, software integrations must comply with strict platform rules:
1. Rule 1.2.1 (Billing Source): Any merchant who installs Salfars through the Shopify App Store must be billed exclusively through the Shopify App Pricing API (Starter $19/mo, Growth $49/mo). External credit card forms or third-party checkouts are forbidden for Shopify-acquired merchants.
2. Rule 2.3.1 (Install Entrypoint): App installation must originate via the official Shopify App Store listing. Use the App Store installation path rather than a manual shop-domain form.
Shopify-installed users manage their billing directly within Shopify Admin. Return to Salfars after a plan change to synchronize the verified subscription state.
Prompt Playbook: Synchronizing Inventory and Amazon Spend
Prevent wasted ad spend on low-stock Amazon ASINs with this automated query:
Authoritative Documentation Sources
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