AdCP — Release Notes

High-level summaries of major AdCP releases with migration guidance. For detailed technical changelogs, see CHANGELOG.md.

Version 3.0.0-rc.3

Status: Release Candidate | AdCP 3.0 overview

What’s New

Trusted Match Protocol (TMP) — Real-time execution layer for AdCP. 9 schemas, 12 documentation pages, provider discovery on products, typed artifacts for content resolution, and lightweight context matching. Deprecates AXE.
Order Lifecycle Management — confirmed_at on order creation, cancellation at media buy and package level with canceled_by attribution, per-package creative_deadline, valid_actions for state-aware agents, revision for optimistic concurrency, and include_history for revision audit trails. 7 new error codes.
Governance Simplification — Remove binding field from check_governance (inferred from discriminating fields), remove mode from sync_plans (governance agent configuration, not protocol), remove escalated status (handled via async task lifecycle). Three terminal statuses: approved, denied, conditions.
Seller-Assigned IDs — Remove buyer_ref, buyer_campaign_ref, and campaign_ref. Seller-assigned media_buy_id and package_id are canonical. idempotency_key on all mutating requests. Opaque governance_context string replaces structured schema.
Proposal Lifecycle — Draft/committed proposal status, finalization via refine action, insertion order signing, and expiry enforcement on create_media_buy. Guaranteed products start as draft with indicative pricing.
Audience Bias Governance — Structured audience data for fairness validation. New schemas for audience selectors, constraints, policy categories, and restricted attributes (GDPR Article 9). 10 policy category definitions, 8 restricted attribute definitions, 13 seed policies across US, EU, and platform regulations.
Streaming and Audio Delivery Metrics — completed_views (renamed from video_completions), reach, reach_unit, and frequency in aggregated totals. Audio/podcast-native metrics. reach_unit co-occurrence constraint on delivery-metrics.json.
Availability Forecasts — budget now optional on ForecastPoint for total available inventory. New availability forecast range unit. Guaranteed products include availability forecasts with estimated cost.
Advertiser Industry Taxonomy — Two-level dot-notation categories on brand manifest and create_media_buy. Restricted categories (gambling, cannabis, dating) require explicit declaration.
Content Standards Detail — content_standards_detail on get_adcp_capabilities for pre-buy visibility into local evaluation and artifact delivery capabilities. sampling removed from get_media_buy_artifacts (configured at creation time).
Event Source Health — Optional health on event sources (status, match rate, event volume, issues) and measurement_readiness on products for buyer event setup evaluation.
Collection/Installment Extensions — special and limited_series fields, installment deadlines with deadline policies, print-capable creative formats with physical units, DPI, bleed, and color space.
Scoped adagents.json Authorization — Delegation types, placement governance, signing keys, country and time-window constraints on authorized_agents.

Breaking Changes

Change	rc.2	rc.3
Buyer references	`buyer_ref`, `buyer_campaign_ref`, `campaign_ref` on requests	Removed — seller-assigned `media_buy_id` and `package_id` are canonical
Idempotency	`buyer_ref` as implicit dedup key	Explicit `idempotency_key` on all mutating requests
Governance context	Structured `governance-context.json` schema	Opaque `governance_context` string
`check_governance` binding	`binding` field on request	Removed — inferred from discriminating fields
`sync_plans` mode	`mode` field (audit/advisory/enforce)	Removed — governance agent configuration
`check_governance` status	`escalated` as possible status	Removed — use async task lifecycle
`get_media_buy_artifacts`	`sampling` parameter on request	Removed — sampling configured at media buy creation
FormatCategory	`format-category.json` enum, `type` on Format	Removed — use `assets` array or `asset_types` filter
Shows/episodes	`show`, `episode`, `show_id`, `episode_id`	Renamed to `collection`, `installment`, `collection_id`, `installment_id`

Migration Notes For rc.2 Adopters

Buyer references — Remove buyer_ref and campaign_ref from request payloads. Use idempotency_key for safe retries instead.
Governance — Remove binding from check_governance calls, mode from sync_plans, and stop handling escalated status. Use async task polling for human review workflows.
Artifacts — Remove sampling from get_media_buy_artifacts requests. Configure sampling at create_media_buy time.
Format filtering — Replace format_types filters with asset_types on list_creative_formats or channels on get_products.
Collections — Rename show/episode references to collection/installment throughout.

Version 3.0.0-rc.2

Status: Release Candidate | AdCP 3.0 overview

What’s New

Brand Protocol Rights Lifecycle — get_rights, acquire_rights, update_rights tasks for brand licensing. Generation credentials, creative approval webhooks, revocation notifications, and usage reporting. Authenticated webhooks (HMAC-SHA256), actionable vs final rejection convention, DDEX PIE mapping for music licensing, and sandbox tooling for scenario testing.
Visual Guidelines on Brand Manifest — Structured visual_guidelines field on brand.json: photography, graphic style, shapes, iconography, composition, motion, logo placement, colorways, type scale, asset libraries, and restrictions. Enables generative creative systems to produce on-brand assets.
Collections and Installments — Content dimension for products representing persistent programs (podcasts, TV series, YouTube channels). collections on products references collections declared in an adagents.json by domain and collection ID — collection creators can serve as canonical sources regardless of distribution. collection_targeting_allowed controls whether buyers can select a subset or get the bundle. Distribution identifiers for cross-seller matching, installment lifecycle states, break-based ad inventory, talent linking, collection relationships, international content ratings.
Sponsored Intelligence Channel — sponsored_intelligence added to the media channel taxonomy for AI platform advertising (AI assistants, AI search, generative AI experiences).
Property Governance Integration — Optional property_list parameter on get_products for filtering products by governance-evaluated property lists. property_list_applied response field confirms filtering.
Campaign Governance and Policy Registry — sync_plans, check_governance, report_plan_outcome, and get_plan_audit_logs for plan-level governance. Adds audit/advisory/enforce modes, delegated budget authority, seller-side governance checks, portfolio governance, registry-backed shared policies, and governance_context for canonical plan extraction.
Account Model Simplification — Removed account_resolution capability. require_operator_auth now determines both auth model and account reference style.
Creative Workflow Upgrades — build_creative now supports inline preview via include_preview, multi-format output via target_format_ids, quality tiers for draft vs production output, catalog-driven item_limit, and library retrieval using creative_id plus optional macro substitution and trafficking context. preview_creative also adds quality control parameters.
Creative Library Protocol Unification — list_creatives and sync_creatives now live in the Creative Protocol. Creative agents can advertise supports_generation, supports_transformation, and has_creative_library so buyers can route generation, transformation, and library retrieval intentionally.
Disclosure Persistence — Regulatory disclosure requirements can now specify persistence (continuous, initial, flexible) in addition to position and duration, with matching capability declarations on formats.
Product Discovery and Planning Ergonomics — Product discovery adds exclusivity and preferred_delivery_types; products may omit delivery_measurement; packages and proposals support per-package start_time / end_time; and get_products now supports time_budget with incomplete response reporting.
Accounts and Sandbox Refinements — sync_accounts adds payment_terms, sandbox capability moves to the account capability block, and sandbox now participates in the account natural key for implicit account flows.
Governance Agent Sync — sync_governance task for syncing governance agent endpoints to specific accounts. Supports both explicit accounts (account_id) and implicit accounts (brand + operator) via account references. Replace semantics per call. Governance sync is now a dedicated tool — removed from sync_accounts and list_accounts.

Breaking Changes

Change	rc.1	rc.2
Account resolution	`account_resolution` capability	Removed — `require_operator_auth` determines account model
Creative library operations	`list_creatives` and `sync_creatives` documented under Media Buy	Creative library tasks now live in the Creative Protocol
Sandbox capability	`media_buy.features.sandbox`	`account.sandbox`
DOOH flat rate parameters	`flat_rate.parameters` without discriminator	`flat_rate.parameters.type: "dooh"` required when parameters are present
delete_content_standards	Documented task	Removed — archive standards via `update_content_standards` instead
get_property_features	Standalone task	Removed — use property list filters and `get_adcp_capabilities` for feature discovery
Governance agent sync	`governance_agents` on `sync_accounts` request and `list_accounts` request	Moved to dedicated `sync_governance` task

Migration Notes For rc.1 Adopters

Creative task routing — If you adopted 3.0.0-rc.1, update any assumptions that creative library operations are Media Buy tasks. list_creatives and sync_creatives are Creative Protocol operations in rc.2, even when a sales agent implements them on the same endpoint.
Capability discovery — Replace reads of account_resolution with require_operator_auth, and read sandbox support from account.sandbox instead of media_buy.features.sandbox.
Creative request/response handling — build_creative can now return inline previews, multiple manifests, or a library-resolved manifest. Clients that assumed only single-format manifest-in / manifest-out behavior should update their response handling.
DOOH validation — Existing v3 DOOH flat_rate integrations must add type: "dooh" inside parameters when those parameters are provided.

Other Updates

Certification program — Three-tier certification (Basics, Practitioner, Specialist) taught by Addie through interactive chat, with vibe coding build projects for non-technical participants.
Documentation — Illustrated protocol walkthroughs, buy-side guides, FAQ expansion, schema-compliant examples, and collapsed sidebar navigation.

Version 3.0.0-rc.1

Status: Release Candidate | AdCP 3.0 overview

What’s New

Keyword Targeting — keyword_targets and negative_keywords on the targeting overlay for search and retail media. Per-keyword bid prices with broad, phrase, and exact match types. Incremental management via keyword_targets_add and keyword_targets_remove on package updates. by_keyword breakdown in delivery reporting.
Optimization Goals Redesign — optimization_goal (singular) replaced by optimization_goals (array). Discriminated union on kind: metric for seller-native delivery metrics or event for conversion tracking. Priority ordering for multi-goal packages. New metric types: engagements, follows, saves, profile_visits. View duration configuration for video completion goals.
Reach Optimization — reach as a metric optimization goal with reach_unit (individuals, households, devices, accounts, cookies, custom) and optional target_frequency band (min/max/window). Products declare supported_reach_units when reach is in their supported metrics.
Expanded Frequency Cap — frequency_cap now supports max_impressions + per + window in addition to the existing suppress_minutes.
Signal Pricing Models — Discriminated union with three pricing models: cpm, percent_of_media (with optional max_cpm), and flat_fee. Structured pricing_options array replaces the legacy pricing object on signals. pricing_option_id on activate_signal. idempotency_key on report_usage for preventing double-billing.
Dimension Breakdowns — Opt-in reporting dimensions on get_media_buy_delivery: by_geo, by_device_type, by_device_platform, by_audience, by_placement — each with truncation flags. New reporting_dimensions request parameter with per-dimension limit and sort_by controls. Capability declaration at seller level (get_adcp_capabilities → media_buy.reporting) and product level (reporting_capabilities).
Device Type Targeting — New device_type field (form factor: desktop, mobile, tablet, ctv, dooh, unknown) distinct from existing device_platform (OS). With device_type_exclude for negative targeting. Declared in get_adcp_capabilities targeting capabilities.
Deliver-to Flattening — The nested deliver_to object in get_signals request replaced with two top-level fields: destinations and countries. Simplifies queries where the caller is querying a platform’s own signal agent.
Metric Optimization Capabilities — Products declare metric_optimization block with supported_metrics, supported_view_durations, and supported_targets. max_optimization_goals on products. Conversion tracking declares supported_targets. multi_source_event_dedup flag in get_adcp_capabilities.
Swiss & Austrian Postal Codes — ch_plz and at_plz added to the postal-system enum, with corresponding updates to get_adcp_capabilities.
Brand Identity Unification — brand-manifest.json deleted. Task schemas now reference brands by { domain, brand_id } (BrandRef) instead of passing inline manifests. Brand data is resolved from brand.json or the registry at execution time.
Delivery Forecasts on Products — estimated_exposures replaced with structured forecast field using the DeliveryForecast type. Products now return time periods, metric ranges, and methodology context during discovery.
Proposal Refinement via Buying Mode — proposal_id removed from get_products request. Refinement now uses buying_mode: "refine" with a typed refine array (see item 21). Session continuity (context_id in MCP, contextId in A2A) carries conversation history across calls. Proposal execution via create_media_buy with proposal_id is unchanged.
First-Class Catalogs — sync_catalogs task with 13 catalog types (structural and industry-vertical). Formats declare catalog_requirements. Catalogs include conversion_events and content_id_type for attribution alignment.
New Tasks — get_media_buys for operational campaign monitoring, get_creative_features for creative governance, sync_audiences for CRM-based audience management.
Buying Mode — buying_mode on get_products with three modes: brief (natural language discovery), wholesale (full catalog), and refine (typed change-requests on previous results). Now required on all get_products calls.
Sandbox Mode — sandbox protocol parameter on all tasks for testing without side effects.
Creative Brief Type — CreativeBrief type on build_creative request for structured creative direction.
Campaign Reference — campaign_ref field for cross-operation campaign grouping across multiple media buys.
Geo Proximity Targeting — geo_proximity targeting overlay for point-based proximity targeting. Three methods: travel_time isochrones (e.g., “within 2hr drive of Düsseldorf”), radius (e.g., “within 30km of Heathrow”), and pre-computed geometry (buyer provides a GeoJSON polygon). Structured capability declaration in get_adcp_capabilities with per-method and transport mode support.
Typed Refinement with Seller Acknowledgment — refine redesigned from nested object to typed change-request array with scope discriminator (request, product, proposal). Field renames: product_id/proposal_id → id, notes → ask. Seller responses include refinement_applied — a positionally-matched array with per-ask status (applied, partial, unable) and notes.
AI Provenance and Disclosure — provenance object on creative manifests, assets, and artifacts for AI content transparency. IPTC-aligned digital_source_type enum (9 values), ai_tool metadata, human_oversight levels, C2PA soft references via manifest_url, regulatory disclosure with per-jurisdiction requirements (EU AI Act, California SB 942), and third-party verification results. provenance_required on creative policy for seller enforcement.
Creative Compliance — compliance object on creative briefs with required_disclosures (structured items with text, position, jurisdictions, regulation, minimum duration) and prohibited_claims. New disclosure-position enum with 8 standard positions. Formats declare supported_disclosure_positions. supports_compliance capability flag replaces supports_brief.
Manifest Unification — Creative manifest model unified to format_id + assets. Briefs and catalogs become proper asset types (brief, catalog) within the assets map. All asset reference lists across creative-manifest, creative-asset, and list-creatives-response aligned to 14 asset types with consistent anyOf validation.
Structured Error Recovery — recovery field on errors with three classifications: transient (retry after delay), correctable (fix request and resend), terminal (requires human action). 18 standard error codes (INVALID_REQUEST, RATE_LIMITED, POLICY_VIOLATION, PRODUCT_UNAVAILABLE, etc.) with recovery mappings in the new error-code enum.
Agent Ergonomics — fields parameter on get_products for response projection (24 projectable fields). include_package_daily_breakdown opt-in on delivery reporting. Request-side attribution_window for cross-platform normalization. Buy-level start_time/end_time on get_media_buys. supported_pricing_models on seller capabilities. Audience metadata: description, audience_type (crm, suppression, lookalike_seed), tags, and total_uploaded_count for match rate calculation.
Signal Deactivation — action field on activate_signal with activate (default) and deactivate values for compliance-driven signal removal.
Signal Metadata — categories (valid values for categorical signals) and range (min/max for numeric signals) on signal entries in get_signals responses.
Media Buy Rejection — rejected status added to media-buy-status enum with rejection_reason on the MediaBuy object.
Idempotency — idempotency_key on update_media_buy and sync_creatives for at-most-once execution. idempotency_key added to create_media_buy for at-most-once creation.

Breaking Changes

Change	beta.3	rc.1
Brand identity	Inline `brand_manifest` object	`brand` (BrandRef: `{ domain, brand_id }`) — resolved at execution time
Product exposure estimates	`estimated_exposures` (integer)	`forecast` (DeliveryForecast object)
Proposal refinement	`proposal_id` on `get_products` request	Removed — use `buying_mode: "refine"` with typed `refine` array
Optimization goals	`optimization_goal` (singular object)	`optimization_goals` (array of discriminated union)
AudienceMember identity	`external_id` in uid-type enum	`external_id` is required top-level field, removed from enum
Signals deliver_to	Nested `deliver_to` object	Top-level `destinations` and `countries`
Signals pricing	`pricing: { cpm }`	Structured `pricing_options[]` array
report_usage	`kind` and `operator_id` fields	Both removed
Refinement model	`refine` object with `overall`/`products`/`proposals`	`refine` array of typed change-requests with `scope` discriminator
Creative assignments	`{ creative_id: package_id[] }` map	Typed array with `creative_id`, `package_id`, `weight`, `placement_ids`
Signals account	String `account_id`	`account` (AccountReference object)
Signals deployments	`deployments` field	`destinations` (renamed)
Package catalogs	`catalog` (single object)	`catalogs` (array)
buying_mode	Not present	Required — three modes: `brief`, `wholesale`, `refine`
Creative brief delivery	Top-level `creative_brief` on `build_creative`	`brief` asset type in manifest `assets` map
Creative capability	`supports_brief`	`supports_compliance`

Other Changes

audience-source enum for breakdown-level audience attribution
device-type enum (desktop, mobile, tablet, ctv, dooh, unknown) for form factor targeting and breakdown reporting
sort-metric enum for controlling breakdown sort order
geo-breakdown-support schema for declaring per-geography breakdown capabilities
Keyword targeting capability flags in get_adcp_capabilities
reporting object in get_adcp_capabilities for declaring dimension breakdown support
geo_proximity capability object in get_adcp_capabilities for declaring supported proximity methods and transport modes
error-code enum with 18 standard error codes and recovery classifications
disclosure-position enum (8 standard positions for regulatory disclosures)
digital-source-type enum (9 IPTC-aligned values for AI content classification)
provenance core object for AI content transparency across creative schemas
consent-basis enum extracted from sync_audiences (consent, legitimate_interest, contract, legal_obligation)
date-range and datetime-range core types replacing inline period objects
Property list filters relaxed: countries_all and channels_any no longer required
Signal categories and range metadata on get_signals responses
rejected media buy status with rejection_reason
idempotency_key on update_media_buy and sync_creatives
Removed not:{} patterns from 7 response schemas for Python codegen compatibility

Version 3.0.0-beta.3

Status: Beta | AdCP 3.0 overview

What’s New

Delivery Forecasting - Predict campaign performance before committing budget. New DeliveryForecast type with budget curves, forecast methods (estimate, modeled, guaranteed), daypart targeting windows, and GRP demographic notation. Forecasts attach to product allocations and proposals, enabling budget curve analysis across spend levels.
Brand Protocol - Brand discovery and identity resolution via brand.json. Four manifest variants (authoritative redirect, house redirect, brand agent, house portfolio) with builder tools, registry, and admin UI. Brands declare authorized_operators to control which agents can represent them.
Account Management - sync_accounts task lets agents declare brand portfolios to sellers with upsert semantics. Account capabilities in get_adcp_capabilities describe billing requirements and operator authorization. Two billing models (operator, agent) with account lifecycle (active, pending_approval, payment_required, suspended, closed). account_id is optional on create_media_buy — single-account agents can omit it.
Commerce Media - Catalog-driven product discovery (catalog on get_products), catalog-driven packages, per-catalog-item delivery reporting (by_catalog_item), store catchment targeting, and catalog_types on products. Cross-retailer GTIN matching via catalog selectors. Commerce attribution metrics (roas, new_to_brand_rate) in delivery response. See the Commerce Media Guide and Catalogs.
Creative Delivery Reporting - Per-creative metrics breakdown within by_package in delivery responses. New get_creative_delivery task on creative agents for variant-level delivery data with manifests. Three variant tiers: standard (1:1), asset group optimization, and generative creative. Format-level reported_metrics declare which metrics each format can provide.
CPA & TIME Pricing Models - Two new pricing models. CPA (Cost Per Acquisition) for outcome-based campaigns — covers CPO, CPL, CPI use cases differentiated by event_type. TIME for sponsorship-based advertising where price scales with duration (hour, day, week, month) with optional min/max constraints.
Conversion Tracking - New events protocol with sync_event_sources and log_event tasks for attribution and measurement.
Signal Catalog - Data providers become first-class members with signal definitions, categories, targeting schemas, and value types. New schemas for signal discovery and integration into products.
Cursor-Based Pagination - All list operations (list_creatives, tasks_list, list_property_lists, get_property_list, get_media_buy_artifacts) standardized on cursor-based pagination with shared pagination-request.json and pagination-response.json schemas.
Accessibility in Creative Formats - Two-layer accessibility model. Format-level wcag_level (A/AA/AAA) and requires_accessible_assets flag. Asset-level metadata for inspectable assets (alt text, captions, transcripts) and self-declared properties for opaque assets (keyboard navigable, motion control). Buyers can filter by wcag_level in list_creative_formats.
Targeting Restrictions & Geo Exclusion - Functional restriction overlays for age (with verification methods), device platform (Sec-CH-UA-Platform values), and language localization. Geographic exclusion fields (geo_countries_exclude, geo_regions_exclude, geo_metros_exclude, geo_postal_areas_exclude) enable RCT holdout groups and regulatory exclusions.
Typed Asset Requirements - Discriminated union schemas for all 12 asset types (image, video, audio, text, markdown, HTML, CSS, JavaScript, VAST, DAAST, URL, webhook) using asset_type as discriminator.
Universal Macros - universal-macro.json enum defining all 54 standard ad-serving macros, including 6 new additions: GPP_SID, IP_ADDRESS, STATION_ID, COLLECTION_NAME, INSTALLMENT_ID, AUDIO_DURATION.
Brand Manifest Improvements - Structured tone object with voice, attributes, dos, donts fields. Logo objects gain orientation, background, variant, usage fields.

Breaking Changes

Change	beta.2	beta.3
Pagination	`limit`/`offset`	Cursor-based `pagination` object
Brand manifest tone	`string \| object`	Object only with structured fields

Other Changes

optimization_goals on package requests — buyers can specify conversion and metric optimization goals when creating or updating media buys
Attribution window metadata on delivery response: click_window_days, view_window_days, and attribution model (last_touch, first_touch, linear, time_decay, data_driven)
Channel fields on property and product schemas: supported_channels and channels referencing Media Channel Taxonomy enum
account_id added to get_media_buy_delivery and get_media_buy_artifacts requests
date_range_support in reporting capabilities
minItems: 1 on request-side arrays for stricter validation
FormatCategory enum and type field removed from Format objects (use assets array instead)
format_id optional in preview_creative (falls back to creative_manifest.format_id)
selection_mode on repeatable asset groups to distinguish sequential (carousel) from optimize (asset pool) behavior
Session ID fallback recommendation for MCP agent context_id

Version 3.0.0-beta.2

Status: Beta | Full Changelog | AdCP 3.0 overview Building on beta.1, this release adds account-level billing, property targeting controls, CTV technical specs, and agent-driven UI rendering for Sponsored Intelligence.

What’s New

Accounts & Agents - AdCP now distinguishes Brand (whose products are advertised), Account (who gets billed), and Agent (who places the buy). New account_id field on media buys, product queries, and creative operations enables multi-account billing with rate cards and credit limits.
Property Targeting - Products can declare property_targeting_allowed to let buyers target a subset of publisher properties. When enabled, buyers pass a property_list in their targeting overlay and the package runs on the intersection.
A2UI for Sponsored Intelligence - Sponsored Intelligence sessions now support agent-driven UI rendering via MCP Apps, enabling rich interactive experiences within AI assistants.
CTV & Streaming Constraints - Video formats gain technical constraint fields for frame rate, HDR, GOP structure, and moov atom position. Audio formats add codec, sampling rate, channel layout, and loudness normalization (LUFS/true peak) fields.
Creative Protocol Discovery - get_adcp_capabilities now includes "creative" in supported_protocols, letting agents discover creative services at runtime.

Schema Changes

New account.json, list-accounts-request.json, list-accounts-response.json schemas
account_id added to create-media-buy-request, get-products-request, sync-creatives-request, and their responses
Shared price-guidance.json schema extracted to fix duplicate type generation across pricing options
property_targeting_allowed and property_list fields added to product and targeting overlay schemas
Video/audio asset schemas extended with CTV technical constraint fields

Removed

Removed	Replacement
`list_property_features` task	`get_adcp_capabilities`
`list_authorized_properties` task	`get_adcp_capabilities` portfolio section
`adcp-extension.json` schema	`get_adcp_capabilities` task
`assets_required` format field	`assets` array with `required` boolean
`preview_image` format field	`format_card` object

Version 3.0.0-beta.1

Status: Beta | Full Changelog | AdCP 3.0 overview

This is a beta release. While the API is stable for testing, breaking changes may occur before the final 3.0.0 release. We encourage early adopters to test and provide feedback.

What’s New

Version 3.0.0 is a major release that expands AdCP beyond media buying into governance, brand suitability, and conversational commerce. See the AdCP 3.0 overview for detailed upgrade instructions. 🎯 Key Themes:

Media Channel Taxonomy - Complete overhaul from 9 format-oriented channels to 19 planning-oriented channels that reflect how buyers allocate budgets. See Media Channel Taxonomy.
Governance Protocol - New protocol domain for property lists, content standards, and brand suitability evaluation with collaborative calibration workflows.
Sponsored Intelligence Protocol - Conversational brand experiences in AI assistants. Defines how hosts invoke brand agent endpoints for rich engagement without breaking conversational flow. See Sponsored Intelligence.
Protocol-Level Capability Discovery - get_adcp_capabilities task replaces agent card extensions, providing runtime discovery of capabilities, supported protocols, and geo targeting systems.
Creative Assignment Weighting - Replace simple creative ID arrays with weighted assignments supporting traffic allocation and placement targeting.
Global Geo Targeting - Structured geographic targeting with named systems (Nielsen DMA, UK ITL, Eurostat NUTS2, etc.) for international markets.

Breaking Changes Summary

Change	v2.x	v3.x
Channels	9 values	19 planning-oriented values
Creative assignment	`creative_ids: [...]`	`creative_assignments: [{...}]`
Metro targeting	`geo_metros: ["501"]`	`geo_metros: [{ system, code }]`
Postal targeting	`geo_postal_codes`	`geo_postal_areas` with system
Asset discovery	`assets_required: [...]`	`assets: [{ asset_id, required }]`

See AdCP 3.0 overview for detailed before/after examples and migration steps.

New Protocol Domains

Governance Protocol

Brand suitability and inventory curation:

Property Lists - create_property_list, get_property_list, update_property_list, delete_property_list, list_property_lists
Content Standards - create_content_standards, get_content_standards, update_content_standards, calibrate_content, validate_content_delivery
Product Filtering - Pass property lists to get_products for compliant inventory discovery

New Features

get_adcp_capabilities task - Runtime capability discovery replacing agent card extensions
Unified asset discovery - assets array with required boolean for full asset visibility
Property list filtering - Pass governance lists to get_products for brand-safe inventory

Removed in v3

Removed	Replacement
`adcp-extension.json` agent card	`get_adcp_capabilities` task
`list_authorized_properties` task	`get_adcp_capabilities` portfolio section
`assets_required` in formats	`assets` array with `required` boolean
`preview_image` in formats	`format_card` object
`creative_ids` in packages	`creative_assignments` array
`geo_postal_codes`	`geo_postal_areas`
`fixed_rate` in pricing	`fixed_price`
`price_guidance.floor`	`floor_price` (top-level)

Quick Migration Checklist

Update channel enum values (taxonomy guide)
Replace creative_ids with creative_assignments
Add system specification to metro/postal targeting
Implement get_adcp_capabilities task
Update format parsing to use assets array

View AdCP 3.0 overview →

Version 2.5.0

Released: November 2025 | Full Changelog

What’s New

Version 2.5.0 is a developer experience and API refinement release that significantly improves type safety, schema infrastructure, and creative workflow performance. This release prepares AdCP for production-scale integrations with better TypeScript/Python code generation, stricter validation semantics, and flexible schema versioning. 🎯 Key Themes:

Type Safety & Code Generation - Comprehensive discriminator fields throughout the protocol enable excellent TypeScript/Python type inference and eliminate ambiguous union types.
Batch Creative Previews - Generate previews for up to 50 creatives in a single API call with optional direct HTML embedding, reducing preview generation time by 5-10x.
Schema Infrastructure - Build-time schema versioning with semantic paths (/schemas/2.5.0/, /schemas/v2/, /schemas/v2.5/) enables version pinning and automatic minor version tracking.
API Consistency - Atomic response semantics (success XOR error) and standardized webhook payloads eliminate ambiguity and improve reliability.
Signal Protocol Refinement - Activation keys returned per deployment with permission-based access, enabling proper multi-platform signal activation.
Template Formats - Dynamic creative sizing with accepts_parameters enables formats that accept runtime dimensions, durations, and other parameters.
Enhanced Product Discovery - Structured filters with date ranges, budget constraints, country targeting, and channel filtering improve product search precision.

Key Enhancements

Type Safety & Code Generation

Discriminator fields added to all discriminated union types (destinations, pricing, property selectors, preview requests/responses)
Atomic response semantics - All task responses now use strict success XOR error patterns with oneOf discriminators
Explicit type declarations on all const fields for proper TypeScript literal type generation
31 new enum schemas extracted from inline definitions for better reusability

Schema Infrastructure

Build-time versioning - Schemas now support semantic version paths (/schemas/2.5.0/), major version aliases (/schemas/v2/), and minor version aliases (/schemas/v2.5/)
Consistent media buy responses - Both create_media_buy and update_media_buy now return full Package objects
Standardized webhook payload - Protocol envelope at top-level with task data under result field

Product Discovery

Structured filters - Extracted filter objects into separate schemas (product-filters.json, creative-filters.json, signal-filters.json)
Enhanced filtering - Date ranges (start_date, end_date), budget ranges with currency, country targeting, and channel filtering
Full enum support - Filters now accept complete enum values without artificial restrictions

Signal Protocol

Activation keys - activate_signal now returns deployment-specific activation keys (segment IDs, key-value pairs) based on authenticated permissions
Consistent terminology - Standardized on “deployments” throughout signal requests and responses

Creative Protocol

Batch preview support - Preview multiple creatives in one request (preview_creative supports 1-50 items)
Direct HTML embedding - Responses can include raw HTML for iframe-free rendering
Simplified brand manifest - Single required field (name) eliminates duplicate type generation
Template formats - accepts_parameters field enables dynamic formats (e.g., display_[width]x[height], video_[duration]s)
Inline creative updates - sync_creatives task provides upsert semantics for updating creatives in existing campaigns

Documentation & Testing

Testable documentation - All code examples can be validated against live schemas
Client library prominence - NPM badges and installation instructions in intro
Fixed 389 broken links across 50 documentation files

Migration Guide

Discriminator Fields (Breaking)

Many schemas now require explicit discriminator fields. Update your code to include these fields: Signal Destinations:

// Before
{
  "platform_id": "ttd"
}

// After
{
  "type": "platform",
  "platform_id": "ttd"
}

Property Selectors:

// Before
{
  "publisher_domain": "dailyplanet.com",
  "property_ids": ["cnn_ctv_app"]
}

// After
{
  "publisher_domain": "dailyplanet.com",
  "selection_type": "by_id",
  "property_ids": ["cnn_ctv_app"]
}

Pricing Options:

// Before
{
  "pricing_model": "cpm",
  "rate": 12.50
}

// After (fixed pricing uses fixed_price field)
{
  "pricing_model": "cpm",
  "fixed_price": 12.50
}

Webhook Payload Structure (Breaking)

Webhook payloads now use protocol envelope at top-level: Before:

{
  "task_id": "task_123",
  "status": "completed",
  "media_buy_id": "mb_456",
  "packages": [...]
}

After:

{
  "task_id": "task_123",
  "task_type": "create_media_buy",
  "status": "completed",
  "timestamp": "2025-11-21T10:30:00Z",
  "result": {
    "media_buy_id": "mb_456",
    "packages": [...]
  }
}

Signal Activation Response (Breaking)

activate_signal response changed from single key to deployments array: Before:

{
  "activation_key": "segment_123"
}

After:

{
  "deployments": [
    {
      "destination": {"type": "platform", "platform_id": "ttd"},
      "activation_key": "segment_123",
      "status": "active"
    }
  ]
}

Template Formats

Formats can now accept parameters for dynamic sizing: Template Format Definition:

{
  "format_id": {"agent_url": "https://creative.adcontextprotocol.org", "id": "display_static"},
  "accepts_parameters": ["dimensions"],
  "renders": [{
    "role": "primary",
    "parameters_from_format_id": true
  }]
}

The parameters_from_format_id: true flag indicates dimensions come from the format_id at usage time. Usage (parameterized format_id):

{
  "format_id": {
    "agent_url": "https://creative.adcontextprotocol.org",
    "id": "display_static",
    "width": 300,
    "height": 250
  }
}

This creates a specific 300x250 variant of the display_static template.

Enhanced Product Filtering

New structured filters in get_products:

{
  "filters": {
    "start_date": "2026-01-01",
    "end_date": "2026-03-31",
    "budget_range": {
      "min": 10000,
      "max": 50000,
      "currency": "USD"
    },
    "countries": ["US", "CA"],
    "channels": ["display", "ctv"]
  }
}

Schema Versioning

New version paths available:

/schemas/2.5.0/ - Exact version (recommended for production)
/schemas/v2.5/ - Latest 2.5.x patch (auto-updates for patch releases)
/schemas/v2/ - Latest 2.x release (auto-updates for minor/patch)
/schemas/latest/ - Backward compat alias (same as v2)

Breaking Changes

Discriminator fields required in destinations, property selectors, pricing options, and preview requests
Webhook payload structure - Task data moved under result field; domain no longer required
Signal activation response - Changed from activation_key string to deployments array
Removed legacy creative fields - media_url, click_url, duration removed from list_creatives response

Non-Breaking Additions

Application context object (optional) in all task requests
product_card and format_card fields (optional) for visual UI support
Batch preview mode in preview_creative (backward compatible)
Package pricing fields in delivery reporting (already documented, now schema-enforced)
Minor version symlinks (/schemas/v2.5/)

Version 2.3.0

Released: October 2025 | Full Changelog

What’s New

Publisher-Owned Property Definitions - Properties are now owned by publishers and referenced by agents, following the IAB Tech Lab sellers.json model. This eliminates duplication and creates a single source of truth for property information. Placement Targeting - Products can now define multiple placements (e.g., homepage banner, article sidebar), and buyers can assign different creatives to each placement within a product purchase. Simplified Budgets - Budget is now only specified at the package level, enabling mixed-currency campaigns and eliminating redundant aggregation at the media buy level.

Migration Guide

Publisher-Owned Properties

Before:

{
  "properties": [{
    "publisher_domain": "dailyplanet.com",
    "property_name": "CNN CTV App",
    "property_tags": ["ctv", "premium"]
  }]
}

After:

{
  "publisher_properties": [
    {
      "publisher_domain": "dailyplanet.com",
      "property_tags": ["ctv"]
    }
  ]
}

Buyers now fetch property definitions from https://dailyplanet.com/.well-known/adagents.json.

Remove Media Buy Budget

Before:

{
  "budget": 50000,
  "packages": [...]
}

After:

{
  "packages": [
    {"package_id": "p1", "budget": 30000},
    {"package_id": "p2", "budget": 20000}
  ]
}

Budget is specified per package only.

Breaking Changes

properties field in products → publisher_properties
list_authorized_properties returns publisher_domains array
Removed budget from create_media_buy/update_media_buy requests

Version 2.2.0

Released: October 2025 | Full Changelog

What’s New

Build Creative Alignment - The build_creative task now follows a clear “manifest-in → manifest-out” transformation model with consistent parameter naming.

Migration Guide

Before:

{
  "source_manifest": {...},
  "promoted_offerings": [...]
}

After:

{
  "creative_manifest": {
    "format_id": {...},
    "assets": {
      "promoted_offerings": [...]
    }
  }
}

Breaking Changes

build_creative parameter renamed: source_manifest → creative_manifest
Removed promoted_offerings as top-level parameter (now in manifest assets)

Version 2.1.0

Released: January 2025 | Full Changelog

What’s New

Simplified Asset Schema - Separated asset payload schemas from format requirement schemas, eliminating redundancy. Asset types are now determined by format specifications rather than declared in manifests.

Migration Guide

Before:

{
  "assets": {
    "banner_image": {
      "asset_type": "image",
      "url": "https://cdn.example.com/banner.jpg",
      "width": 300,
      "height": 250
    }
  }
}

After:

{
  "assets": {
    "banner_image": {
      "url": "https://cdn.example.com/banner.jpg",
      "width": 300,
      "height": 250
    }
  }
}

Breaking Changes

Removed asset_type field from creative manifest payloads
Schema paths changed: /creative/asset-types/*.json → /core/assets/*-asset.json
Constraint fields moved from asset payloads to format specifications

Version 2.0.0

Released: October 2025 | Full Changelog

What’s New

First production release of the Advertising Context Protocol with:

8 Media Buy Tasks - Complete workflow from product discovery to delivery reporting
3 Creative Tasks - AI-powered creative generation and management
2 Signals Tasks - First-party data integration
Standard Formats - Industry-standard display, video, and native formats
Multi-Protocol Support - Works with MCP and A2A

Core Features

Natural language product discovery with brief-based targeting
Asynchronous task management with human-in-the-loop approvals
JSON Schema validation for all requests and responses
Publisher-owned property definitions via .well-known/adagents.json
Comprehensive format specifications with asset requirements

Versioning Policy

AdCP follows Semantic Versioning 2.0.0:

PATCH (x.x.N) - Bug fixes, documentation, clarifications
MINOR (x.N.0) - New features, backward-compatible additions
MAJOR (N.0.0) - Breaking changes

Deprecation Process

Breaking changes follow a 6-month deprecation cycle:

Deprecation Notice - Feature marked deprecated in minor release
Transition Period - Minimum 6 months support with warnings
Migration Guide - Detailed upgrade path provided
Breaking Change - Removed in next major version

Additional Resources

Technical Changelog - CHANGELOG.md
GitHub Releases - Release Archive
Community - Slack
Issues - GitHub Issues
Support - support@adcontextprotocol.org

Documentation

​Version 3.0.0-rc.3

​What’s New

​Breaking Changes

​Migration Notes For rc.2 Adopters

​Version 3.0.0-rc.2

​What’s New

​Breaking Changes

​Migration Notes For rc.1 Adopters

​Other Updates

​Version 3.0.0-rc.1

​What’s New

​Breaking Changes

​Other Changes

​Version 3.0.0-beta.3

​What’s New

​Breaking Changes

​Other Changes

​Version 3.0.0-beta.2

​What’s New

​Schema Changes

​Removed

​Version 3.0.0-beta.1

​What’s New

​Breaking Changes Summary

​New Protocol Domains

​Governance Protocol

​Sponsored Intelligence Protocol

​New Features

​Removed in v3

​Quick Migration Checklist

​Version 2.5.0

​What’s New

​Key Enhancements

​Type Safety & Code Generation

​Schema Infrastructure

​Product Discovery

​Signal Protocol

​Creative Protocol

​Documentation & Testing

​Migration Guide

​Discriminator Fields (Breaking)

​Webhook Payload Structure (Breaking)

​Signal Activation Response (Breaking)

​Template Formats

​Enhanced Product Filtering

​Schema Versioning

​Breaking Changes

​Non-Breaking Additions

​Version 2.3.0

​What’s New

​Migration Guide

​Publisher-Owned Properties

​Remove Media Buy Budget

​Breaking Changes

​Version 2.2.0

​What’s New

​Migration Guide

​Breaking Changes

​Version 2.1.0

​What’s New

​Migration Guide

​Breaking Changes

​Version 2.0.0

​What’s New

​Core Features

​Versioning Policy

​Deprecation Process

​Additional Resources

Version 3.0.0-rc.3

What’s New

Breaking Changes

Migration Notes For rc.2 Adopters

Version 3.0.0-rc.2

What’s New

Breaking Changes

Migration Notes For rc.1 Adopters

Other Updates

Version 3.0.0-rc.1

What’s New

Breaking Changes

Other Changes

Version 3.0.0-beta.3

What’s New

Breaking Changes

Other Changes

Version 3.0.0-beta.2

What’s New

Schema Changes

Removed

Version 3.0.0-beta.1

What’s New

Breaking Changes Summary

New Protocol Domains

Governance Protocol

Sponsored Intelligence Protocol

New Features

Removed in v3

Quick Migration Checklist

Version 2.5.0

What’s New

Key Enhancements

Type Safety & Code Generation

Schema Infrastructure

Product Discovery

Signal Protocol

Creative Protocol

Documentation & Testing

Migration Guide

Discriminator Fields (Breaking)

Webhook Payload Structure (Breaking)

Signal Activation Response (Breaking)

Template Formats

Enhanced Product Filtering

Schema Versioning

Breaking Changes

Non-Breaking Additions

Version 2.3.0

What’s New

Migration Guide

Publisher-Owned Properties

Remove Media Buy Budget

Breaking Changes

Version 2.2.0

What’s New

Migration Guide

Breaking Changes

Version 2.1.0

What’s New

Migration Guide

Breaking Changes

Version 2.0.0

What’s New

Core Features

Versioning Policy

Deprecation Process

Additional Resources