Amazon Ads launched the Inventory Management Unified APIs in open beta in March 2026, bringing programmatic access to deals, supplier proposals, and inventory groups under a single consolidated framework within Amazon Ads API v1. The release was documented in March 2026 in Amazon's Advanced Tools Center release notes, represents a structural shift for developers and programmatic buyers who previously had to navigate fragmented endpoints to manage the same objects. It is the latest in a series of API consolidation moves that Amazon has been executing across its advertising platform since late 2024.

The new Ads Inventory Management API operates under the common Amazon Ads data model. Rather than introducing an entirely new convention, the release slots into the same architectural pattern that Amazon has been applying across campaign management, reporting, and account registration - consolidating what were previously disparate endpoints into a smaller, more consistent set of operations. According to the release notes, the API is part of Amazon Ads API v1 and follows the common model.

Five endpoints at launch; more coming

Five API endpoints launched in open beta immediately. According to the release notes, these cover:

  • POST /adsApi/v1/create/inventoryGroup/dsp - creates an inventory group
  • POST /adsApi/v1/retrieve/inventoryGroup/dsp - retrieves inventory groups in bulk
  • POST /adsApi/v1/query/dealPlanningMetrics/dsp - retrieves directional average metrics for input deals
  • POST /adsApi/v1/query/dealAvails/dsp - retrieves deal avails details
  • POST /adsApi/v1/query/suppliertargetItem/dsp - adds targeting constraints to a proposed deal within a supplier ad product, restricted to Amazon owned and operated extensions

These five cover reading and structuring inventory. A considerably larger set is listed as upcoming, covering deal creation and updates, deal performance metrics, exchange listings, and advertiser access management. What is not yet live includes creating deals themselves via API, updating deals, querying deal performance, or listing exchanges programmatically.

According to the documentation, the forthcoming endpoints include POST /adsApi/v1/create/advertisingDeals/dsp, POST /adsApi/v1/update/advertisingDeals/dsp, and POST /adsApi/v1/query/dealPerformance/dsp. Exchange listing comes through GET /adsApi/v1/exchange/dsp. Advertiser access management - fetching, updating, and deleting advertiser access to a deal - is also listed as forthcoming, spread across GET, POST, and DELETE operations.

The gap between what launched and what is coming matters for developers planning integrations. The current set supports planning and structure; the creation and performance measurement of deals awaits the second wave of endpoints.

Supplier proposals: more complete for Amazon supply

The supplier proposal workflow is more complete at launch for Amazon owned and operated inventory. According to the release notes, a substantial set of proposal endpoints is already available, all restricted to Amazon owned and operated extensions. These include:

  • POST /adsApi/v1/create/supplierProposal/dsp - creates a proposal
  • POST /adsApi/v1/create/supplierProposedDealRevision/dsp - submits a proposal revision
  • POST /adsApi/v1/query/supplierProposal/dsp - retrieves a list of proposals for an advertiser
  • POST /adsApi/v1/query/supplierProposalHistoricalVersion/dsp - retrieves proposal history
  • POST /adsApi/v1/retrieve/supplierProposedDealHistoricalVersion/dsp - retrieves proposed deal history
  • POST /adsApi/v1/query/supplierProposedDeal/dsp - retrieves a supplier proposed deal
  • POST /adsApi/v1/update/supplierProposal/dsp - updates an existing supplier proposal
  • POST /adsApi/v1/update/supplierProposedDeal/dsp - updates an existing supplier proposed deal
  • POST /adsApi/v1/create/supplierProposedDealForecast/dsp - retrieves a forecast for the proposed deal, available without targeting

Additional supplier information endpoints cover supplier details, publisher, ad products, and ad product pricing - all restricted to Amazon owned and operated supply. This scope covers much of the proposal lifecycle for Amazon's own supply, while third-party exchange deal creation awaits the upcoming endpoints.

The proposal objects are relevant for buyers working with Amazon Publisher Direct (APD), Amazon Publisher Cloud (APC), Prime Video, and Twitch. These supply sources involve a negotiation step before a deal is activated. According to the documentation in the Betas section of the Advanced Tools Center, the process involves three steps: retrieving a profile ID corresponding to the advertiser account, creating and managing a proposal with APC or APD or Amazon owned and operated publishers, and then associating the resulting approved deal object with an ad group in Amazon DSP.

Deal management entities

The API covers 19 entity types. According to the documentation, these are: AdvertisingDeal, InventoryGroup, DealPlanningMetrics, DealPerformance, DealAvails, DealAdvertiserAccess, DealAdvertiserAccessEntry, Supplier, SupplierAdProduct, SupplierAdProductPrice, SupplierProposal, SupplierProposalHistoricalVersion, SupplierProposedDeal, SupplierProposedDealHistoricalVersion, SupplierProposedDealRevision, SupplierPublisher, SupplierTargetDefinition, SupplierTargetItem, and SupplierProposedDealForecast. Each entity maps to a distinct API specification accessible in the Advanced Tools Center.

The common model context

The Inventory Management API fits within the broader unification effort Amazon has been executing since the Campaign Management API launched in beta in May 2025. In December 2025, Amazon declared campaign management generally available for Sponsored Products, Sponsored Brands, and Amazon DSP worldwide, noting the company had reduced nearly 200 separate endpoint variations down to 16 in that domain. The unified campaign management launch and unified reporting system announced at unBoxed in November 2025 sit within the same infrastructure strategy.

Inventory management is a more specialized domain, primarily relevant to programmatic buyers operating Amazon DSP at scale and working directly with deals, private marketplaces, and supplier proposals. But the structural principle is identical: consolidate fragmented endpoints under a single, consistent API model. Dustin Wassner, Head of Technology at BTR Media, commented on LinkedIn that the update follows the same pattern established with the Sponsored Ads Unified Endpoints, describing DSP receiving the same treatment as a meaningful development. According to Alexander Brockhoff, Principal Product at Amazon Ads, the company is "working hard to make the new version of the API more consistent, to make it more maintainable."

Catch-Up Boost deprecated alongside the inventory release

The March 2026 release notes also documented the deprecation of Catch-Up Boost pacing in Amazon DSP, in both the UI and API. This legacy manual control allowed advertisers to increase delivery aggressiveness under "Even" pacing. According to the release notes, it was replaced by Dynamic Catchup in 2024. Dynamic Catchup runs automatically, adjusts daily based on under-delivery patterns, and requires no user input. Key stated benefits include running without manual setup, adjusting daily based on under-delivery patterns, improving smooth delivery and consistency across flights, and maximizing budget utilization without delivery volatility.

The UI removed the Catch-Up Boost field on March 23, 2026. API inputs for the field can still technically be sent but are ignored in ad delivery. The affected endpoints are POST /dsp/v1/adGroups and PATCH /dsp/v1/adGroups, where the Catch-Up Boost field is now marked as deprecated.

April 2026: cross-account reach and frequency

In April 2026, Amazon added cross-account reach and frequency measurement to the reporting API in open beta. According to the release notes, the feature allows advertisers to measure deduplicated reach and frequency across multiple Amazon Ads accounts with granularity options of daily, weekly, monthly, yearly, day-of-month, and custom time periods. Manager account and cross-manager account frequency group reporting were also added. Advertisers can measure total unique audience reach across Sponsored Ads (excluding Sponsored Products) and Amazon DSP investments in a single view for budget allocation. This builds on the custom cross-campaign reach and frequency capabilities that Amazon added in February 2026.

Context for programmatic buyers

The Inventory Management API matters most to agencies, trading desks, and technology platforms operating Amazon DSP at scale. Direct deal management - creating and managing private marketplace deals, negotiating with publishers through proposals, structuring inventory groups - has historically required manual work in the Amazon DSP console or custom API implementations that were less consistent than newer endpoint patterns.

The Amazon Ads Supply Desk launched in 2024 addressed part of this complexity through a consultative service that curates pre-made inventory packages. The Inventory Management API is a different solution - programmatic, self-service, and designed for integration rather than consultation. Together they represent two approaches to the same underlying challenge: deal activation in Amazon DSP involves significant operational overhead at scale.

The Amazon DSP forecasting API reached general availability in October 2025, providing programmatic access to campaign performance projections including spend, reach, CPC, CPA, and ROAS at the campaign flight level. The inventory management API's DealPlanningMetrics endpoint extends that logic to the deal level - before a deal is booked, advertisers can query directional average metrics for input deals, giving a sense of expected scale without committing to the deal first.

Amazon's programmatic supply landscape has also expanded considerably over the past year. Disney inventory became available on Amazon DSP in June 2025 through integration with Disney's Real-Time Ad Exchange, giving buyers access to Disney+, ESPN, and Hulu. Amazon DSP added Spotify's global audio and video inventory in October 2025 across nine initial markets. As that supply ecosystem grows, tools to manage deals programmatically become more operationally necessary for buyers working across multiple supply sources through a single DSP seat.

The MCP layer

Amazon opened its Ads MCP Server in open beta in February 2026, connecting AI platforms including Claude and ChatGPT to advertising workflows through natural language. The server was first launched in closed beta in November 2025. As inventory management endpoints mature and more deal management operations become available, those endpoints become accessible to AI agents through the MCP layer without requiring agents to construct endpoint-specific API requests.

Wassner's LinkedIn post drew an explicit connection between the unified API structure and AI agent potential, noting that a tool like Claude Cowork could be asked to pull all active deals across DSP accounts, cross-reference planning metrics against actual avails, and flag deals that are significantly under-delivering against forecast. That workflow would require the DealPlanningMetrics and DealAvails endpoints now live, alongside the DealPerformance endpoint still listed as upcoming.

Timeline

  • 2024: Dynamic Catchup introduced in Amazon DSP, replacing Catch-Up Boost as the default pacing mechanism
  • May 2025: Amazon Ads Campaign Management API launches in beta for Sponsored Products, Sponsored Brands, and Amazon DSP
  • October 2025: Amazon DSP forecasting API reaches general availability
  • October 2025: Amazon launches unified account for global campaign management
  • November 10-11, 2025: Amazon launches Campaign Manager and unified reporting at unBoxed
  • November 13, 2025: Amazon launches closed beta for Ads MCP Server
  • December 2025: Campaign Management API reaches general availability for Sponsored Products, Sponsored Brands, and Amazon DSP
  • February 2, 2026: Amazon opens Ads MCP Server in open beta at IAB Annual Leadership Meeting
  • February 2026: Custom cross-campaign reach and frequency measurement added to reporting API in open beta
  • March 23, 2026: Amazon DSP removes Catch-Up Boost field from UI
  • March 2026: Amazon Ads Inventory Management Unified APIs launch in open beta; Catch-Up Boost deprecated in ADSP API
  • April 2026: Cross-account reach and frequency measurement added to reporting API in open beta

Summary

Who: Amazon Ads, addressing developers, programmatic buyers, agencies, and technology platforms building on Amazon DSP through the Amazon Ads API.

What: The Inventory Management Unified APIs entered open beta under Amazon Ads API v1, consolidating programmatic access to deals, supplier proposals, and inventory groups. Five endpoints launched immediately; a larger set covering deal creation, deal performance, exchange listings, and advertiser access management is listed as upcoming. The March release also deprecated Catch-Up Boost in the ADSP API, where the field is now marked deprecated in POST /dsp/v1/adGroups and PATCH /dsp/v1/adGroups.

When: March 2026, as documented in the Amazon Ads Advanced Tools Center release notes. The Catch-Up Boost UI field was removed on March 23, 2026.

Where: Available through the Amazon Ads API to Amazon DSP advertisers and developers. The supplier proposals workflow for Amazon owned and operated supply - including Prime Video and Twitch - is more fully featured at launch than the third-party exchange deal creation workflow, which remains in the upcoming endpoints list.

Why: The unified API structure reduces integration complexity for developers managing deals, proposals, and inventory groups programmatically, following the same common model pattern Amazon has applied across campaign management and reporting. As Amazon's DSP supply ecosystem expands with Disney, Spotify, Netflix, and other premium publishers, programmatic deal management at scale becomes more operationally relevant for buyers working with multiple supply sources through a single platform.

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