API

Amazon Advertising

Connect to Advertising data. Application required.

Go Helix

Intentwise Analytics

Aggregates all your Amazon data across Amazon APIs into a much easier to work with format.

JS Cobalt

Access to JS Cobalt Data.

Keepa

Best historic data for products

KeywordTool

Estimate Search Volume

MerchantWords

Merchant Words data

Product Advertising

This API is not designed to be used by sellers. Requires an active Amazon affiliate account. Lot's of data if you qualify.

Rainforest

Well documented API that can replace scraping needs.

SP-API

Direct connection to seller data. Sales and inventory of a merchant. Application required.

Sconad

Estimate Search Volume

SellerApp

SellerApp Data

SmartScout

Access to SmartScout brand, category and market share data.