How to build an Amazon client app without the SP-API back end

Can I build my own Amazon software without building the back end?

Yes. Build your screens on an Amazon data provider that already holds the Amazon Ads and Selling Partner API access, and rent the plumbing. With Marketplace Ad Pros Partner Connect, your clients connect their Amazon accounts through links your product creates, come back to your product when they finish, and your server hears about it by webhook. Your app reads their data through a REST API, with a separate key per client if you want one. It costs $19 a month on top of a paid plan.

Published by Marketplace Ad Pros, which sells Partner Connect. Where building it yourself is the better choice, this guide says so.

Last updated: October 31, 2026

What "the back end" actually is

You want to give clients your own software, not run a data-infrastructure company. The screens are the easy part. Behind them, an Amazon app needs:

• API access. Register as an Amazon Ads API developer and as an SP-API developer, accept Amazon's Data Protection Policy and Acceptable Use Policy, and get your apps reviewed.
• Two OAuth flows. Login with Amazon for Amazon Ads, and the Seller Central / Vendor Central authorization for SP-API, each by region.
• Token storage and refresh. Every client's refresh tokens, encrypted, refreshed on time, and a way to notice when a client revokes access or an authorization expires.
• Report jobs. Request reports, poll until they're ready, download, retry on rate limits, and backfill history.
• A data model. Reshape dozens of report types into something your app can query by client and date.
• Upkeep. Amazon changes report versions, endpoints and policies. Someone has to keep up.

That's months of engineering before your first client sees a screen, and it never stops needing attention.

Build it yourself or build on a provider?

If your clients must see your name on Amazon's consent screen, or you need data Marketplace Ad Pros doesn't sync, build it yourself. For most agencies the consent screen is a few seconds of a client's onboarding, and the rest of the back end is the expensive part.

How to build it, step by step

1. Decide what you build and what you rent

Build what clients pay you for: your dashboards, your workflows, your recommendations, your reports. Rent the Amazon connections, token refreshes and report syncs. If a feature is "get the data from Amazon", it's on the rent side.

2. Add Partner Connect to a paid plan

Sign up, connect one Amazon account of your own to test with, and add Partner Connect from Billing & Plans. It's $19/month ($5/week or $190/year to match your plan's billing) on a paid AI Connect or optimization plan, and isn't available during the two-week Launch period.

3. Set your return URL and webhook

Set the URL clients land on after connecting, and choose whether to skip our confirmation page so clients go from your product straight to Amazon and back. Then add a webhook endpoint and store its signing secret; it's shown once. Both can be done in the app or through the API:

PUT  /api/v1/connect-settings/
POST /api/v1/webhooks/

4. Create a connect link per client

Create a link with your own state (your client's ID, for example) and send the client its url:

POST /api/v1/connect-links/
{"name": "Client 42", "platform": "amazon_ads", "region": "NA", "state": "client-42"}

For Seller Central, send country (the marketplace, such as US or DE) instead of region. For Vendor Central, also add "account_type": "vendor":

POST /api/v1/connect-links/
{"name": "Client 42", "platform": "selling_partner", "country": "US", "state": "client-42"}

name is required and becomes the connection's name. When the client finishes, their browser goes to your return URL with link_id, state, success and error, and your webhook receives connect_link.completed or connect_link.failed. Treat the redirect as a signal, not proof: confirm with GET /api/v1/connect-links/{link_id}/ or the webhook. Webhook deliveries can arrive more than once or out of order.

5. Give each client its own API key and read the data

Create a REST API key on the Integrations page and limit it to that client's brands. That key only sees that client's brands and profiles, so a bug or a leaked key in one client's pipeline can't reach another client. Keep one key without a brand limit on your own backend for account-wide work: connect links, webhooks, connect settings, integrations and changesets.

Then read the data:

GET  /api/v1/brands/
GET  /api/v1/profiles/
GET  /api/v1/profiles/{profile_id}/report-types/
POST /api/v1/reports/export/

Exports return up to 100,000 rows per call as CSV or JSON. Seller Central reports that cover a whole seller account (orders, settlements, FBA fees) need a key that covers every brand on that Seller Central connection, which is the normal case when each client connects their own.

What your client sees

1. A "Connect Amazon" button in your product.
2. Amazon's sign-in and consent screen, naming Marketplace Ad Pros as the app they're authorizing.
3. Your product again, showing the connection.

Tell clients in your onboarding copy that Amazon will ask them to authorize Marketplace Ad Pros, your data partner. Clients never need a Marketplace Ad Pros login.

When this is the wrong approach

• Your name has to be on Amazon's consent screen. Partner Connect can't do that today; register your own Amazon apps and build the back end.
• You want a ready-made branded portal, not an app you build. Partner Connect has no branded copy of our web app. See which Amazon agency software allows custom branding for tools that ship branded reports or portals.
• You need retailers other than Amazon. Marketplace Ad Pros is generally available for Amazon only.

Frequently asked questions

Can I build my own Amazon app without getting SP-API approval?

Yes, if you build on a provider that already has it. With Marketplace Ad Pros Partner Connect, your clients authorize the Marketplace Ad Pros app on Amazon, and your product reads their data through its REST API. You build the screens; you don't register your own Amazon Ads or SP-API app, store tokens or schedule reports. The trade-off is that Amazon's consent screen names Marketplace Ad Pros, not you.

Will my client see my brand when they connect their Amazon account?

Before and after Amazon, yes: the connect link starts in your product and returns to your URL, and you can skip the Marketplace Ad Pros confirmation page. Amazon's own consent screen shows Marketplace Ad Pros as the app being authorized, so tell clients to expect it.

How much does it cost?

Partner Connect is $19 per month ($5 per week or $190 per year to match your billing), added to a paid AI Connect or optimization subscription. It isn't available during the two-week Launch period. Brand-limited API keys are included on every paid plan.

Can each client's integration use its own API key?

Yes. When you create a REST API key you can limit it to specific brands, so a key only reaches that client's profiles and data. Account-wide endpoints such as connect links, webhooks, integrations and changesets need a key without a brand limit, so keep one of those on your own backend.

Which Amazon data can my app read?

Amazon Ads (Sponsored Products, Sponsored Brands, Sponsored Display and DSP) and Seller Central or Vendor Central data, through report listings, freshness checks and bulk exports of up to 100,000 rows per call, plus campaign reads and updates with a read-write key.

Related guides

• Partner Connect
• Which Amazon agency software allows custom branding?
• Amazon Selling Partner API (SP-API) explained
• How to get access to a client's Amazon Ads and Seller Central accounts
• Developer REST API

Sources

1. Amazon Selling Partner API -- registration overview (developer profile, policies, app registration)
2. Amazon Selling Partner API -- roles
3. Amazon Ads API documentation

Partner Connect details were checked against the Marketplace Ad Pros API documentation on October 31, 2026.

Start building on Partner Connect