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Prerelease upgrade notes

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rc.3 → 3.0

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Breaking for rc.3 adopters

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Media buy status migration

1. Status filters — Replace pending_activation with both pending_creatives and pending_start in status_filter arrays on get_media_buys and get_media_buy_delivery.
2. Status comparisons — Any if (status === 'pending_activation') needs to branch on which condition you’re checking. If you want “not yet serving,” check for both pending_creatives and pending_start. If you want “ready but waiting for flight date,” check only pending_start.
3. State machine transitions — rejected is now valid from both pending_creatives and pending_start (previously only from pending_activation). pending_creatives → pending_start happens when creatives are assigned via sync_creatives.
4. Legacy alias — pending continues to be accepted as an alias for pending_start in delivery response status filters.

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Capabilities model simplification

{
  "features": {
    "content_standards": true,
    "audience_targeting": true
  },
  "trusted_match": {
    "supported": true,
    "uid_types": ["email_sha256"]
  }
}

{
  "content_standards": { ... },
  "audience_targeting": { ... },
  "trusted_match": {
    "uid_types": ["email_sha256"]
  }
}

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preview_creative schema flattening

{
  "creative_manifest": { "format_id": { ... }, "assets": { ... } }
}

{
  "request_type": "single",
  "creative_manifest": { "format_id": { ... }, "assets": { ... } }
}

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Governance lifecycle migration

{
  "media_buy_id": "mb_456",
  "planned_delivery": { ... }
}

{
  "governance_context": "campaign_2024_q4_nova",
  "purchase_type": "media_buy",
  "planned_delivery": { ... }
}

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context and ext fields

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Additive changes in 3.0

• RFC 9421 request signing profile (optional in 3.0, mandatory under AdCP Verified) — Ed25519 HTTP Message Signatures with canonicalized covered-component list. Published test vectors at static/compliance/source/test-vectors/request-signing/. sf-binary encoding and URL canonicalization pinned for bit-identical canonical inputs. 15-step verification checklist with keyid cap-before-crypto.
• Webhook signing unified on RFC 9421 — Baseline-required for sellers emitting webhooks. Sellers publish a signing JWK in their JWKS at jwks_uri; new signers use adcp_use: "request-signing" for webhook delivery, while deprecated webhook-signing keys remain accepted during the compatibility window. Use a distinct kid if you want webhook-only key material. 14-step webhook verifier checklist in the Security guide. HMAC-SHA256 remains a legacy fallback through 3.x (the entire authentication object is removed in 4.0).
• Property-list webhook signing defined — Property-list change deliveries use RFC 9421 Signature, Signature-Input, and Content-Digest headers. The published 3.1 schema required a body-level signature without defining an algorithm, signed bytes, or key discovery; 3.2 senders set that deprecated field to the compatibility marker rfc9421, while receivers accept any string from an older 3.x sender and ignore it for authentication. Keeping the marker required and unconstrained avoids a 3.x schema break; it is removed in 4.0. Collection-list webhook schema and behavior remain unchanged pending separately versioned work.
• Required idempotency_key on every webhook payload — Sender-generated UUID v4 across all five webhook payload schemas. Replaces fragile (task_id, status, timestamp) dedup. revocation-notification.notification_id renamed to idempotency_key for protocol-wide consistency.
• check_governance on every spend-commit — Governance invocation is required at commit, not just at plan approval. Closes the loophole where partial spends could skip governance.
• Experimental status mechanism — status: experimental marker for fields and tasks in production use but not yet under full stability guarantees. custom pricing-model escape hatch on signals.
• submitted branch on create_media_buy — Seller has accepted the payload for processing but has not yet confirmed the order. Distinct from pending_creatives and pending_start.
• Time semantics + activate_signal idempotency — Unifies time-field semantics across the protocol. activate_signal added to the required-idempotency table.
• Known limitations + privacy-considerations reference pages — New /docs/reference/known-limitations and /docs/reference/privacy-considerations. Platform-agnostic lint prevents vendor-specific language from creeping into the spec.
• Signed JWS governance_context — Governance decisions are now cryptographically verifiable. Sellers resolve the governance agent’s JWKS via sync_governance and verify sub / aud / phase / exp before honoring the decision.
• Universal security storyboard — Every agent runs /compliance/{version}/universal/security.yaml (unauth rejection, API key, OAuth/RFC 9728, audience binding). Agents declaring signing also run the signed_requests harness.
• Cross-instance state persistence — Architecture spec requires persistent state (tasks, media buys, plans, signed artifacts, idempotency keys) across horizontally-scaled instances.
• Security implementation guide — New docs/building/by-layer/L1/security.mdx documents threat model, three-principal model (brand / operator / agent), and verification paths. Retires ambiguous “principal” terminology.
• GDPR Art 22 / EU AI Act Annex III as schema invariants — New registry policy eu_ai_act_annex_iii. requires_human_review on policies and categories. Schema-level enforcement of human_review_required: true for regulated verticals.
• Operating an Agent guide — New doc for publishers without engineering teams — three paths: partner, self-host, build.
• Release cadence policy — Named cadence: patch monthly, minor quarterly, major annual if needed. v2 EOL August 1, 2026.
• CHARTER.md — Formal governance charter published.
• Collection lists — Program-level brand safety using distribution identifiers (IMDb, Gracenote, EIDR) for cross-publisher matching. New targeting overlay fields (collection_list, collection_list_exclude). New genre taxonomy enum.
• Broadcast TV support — Ad-ID identifiers, broadcast spot formats (:15, :30, :60), Agency Estimate Number, measurement windows (Live, C3, C7), delivery data completeness (is_final, measurement_window).
• Offline reporting delivery — reporting_delivery_methods on capabilities, reporting_bucket on accounts, supports_offline_delivery on product reporting_capabilities. Avro and ORC added as file format options.
• TMPX exposure tracking — Country-partitioned identity and macro connectivity for the Trusted Match Protocol execution layer.
• TMP provider registration — provider-registration.json schema, GET /health endpoint, dual discovery models (static config and dynamic API), per-provider latency budget semantics.
• TMP multi-identity Identity Match — identity-match-request replaces single user_token + uid_type with an identities array (minItems 1, maxItems 3). Router filters per provider and re-signs with RFC 8785 JCS canonicalization; cache key adds consent_hash. Adds rampid_derived to the uid-type enum. Breaking relative to prior pre-release TMP drafts only; TMP remains pre-release in 3.0 and stabilizes in 3.1.0.
• GOVERNANCE_DENIED error — New correctable error code for governance-rejected operations.
• context/ext fields — Optional context and ext on all request/response schemas across governance, collection, property, SI, and content-standards protocols.
• Compliance testing capability — Agents include a compliance_testing: { scenarios: [...] } block in get_adcp_capabilities declaring which comply_test_controller scenarios they support. The block’s presence is the signal — compliance testing is NOT a supported_protocols value. Storyboard runners use the block to determine whether deterministic testing steps can be validated.
• Specialisms + compliance catalog — Storyboards ship in the protocol at /compliance/{version}/ (universal + protocols + specialisms + test-kits). New specialisms field on get_adcp_capabilities with 19 values across 6 protocols. Per-version protocol tarball at /protocol/{version}.tgz. See the Compliance Catalog.
• Structured measurement terms — measurement_terms on products and media buys for billing vendor, IVT threshold, and viewability floor negotiation. cancellation_policy on guaranteed products. viewability-standard enum. TERMS_REJECTED error code.
• Unified vendor pricing — pricing_options[] on list_creatives, build_creative, get_creative_features, and property-list. Shared vendor-pricing-option.json schema.
• Per-request version declaration — adcp_major_version on all v3 request schemas. VERSION_UNSUPPORTED error code. Multi-version sellers supporting v2 clients must detect v2 payloads by structural cues, not by this field (v2 schemas do not have it).
• Broadcast forecast schema — measurement_source, packages, and guaranteed_impressions on DeliveryForecast. New forecast-range-unit and forecastable-metric enums.
• Broadcast station identifiers — station_id and facility_id identifier types. linear_tv property type.
• Brand schema extensions — Generic agents array on brand.json. Visual tokens (border_radius, elevation, spacing, extended color roles). Structured font definitions.
• Per-item error schema — sync_creatives, sync_catalogs, and sync_event_sources response errors now use error.json ref.
• Property relationship field — relationship on brand.json property definitions (owned, direct, delegated, ad_network) for bilateral verification with adagents.json delegation types.
• sales agent type restored — sales restored to brand-agent-type enum. Sales agents (SSPs, publishers) are distinct from buying agents (DSPs, buyer platforms).
• Required tasks reference — New reference page consolidating required, conditional, and optional tasks across all AdCP protocols by agent role.
• Storyboard validation fixes — 20+ validation bugs fixed across 11 storyboard files: corrected field paths (creatives[0].action, media_buy_deliveries, renders[0].preview_url), added missing value: to field_value checks, added value property to storyboard validation schema.

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rc.1 → rc.2

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Potentially breaking for rc.1 adopters

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Additive changes in rc.2

• Creative generation and preview — build_creative adds include_preview, preview_inputs, preview_quality, preview_output_format, quality, item_limit, and multi-format target_format_ids. Buyers can now preview inline, choose draft vs production generation, and request multiple output formats in one call.
• Creative library retrieval — build_creative also supports library retrieval using creative_id, optional concept_id, media_buy_id, package_id, and macro_values, so ad servers and creative platforms can resolve stored creatives into delivery-ready manifests.
• Creative capability discovery — Creative agents can declare supports_generation, supports_transformation, and has_creative_library. list_creatives now uses library-oriented fields like include_snapshot, has_served, and items.
• Product discovery and planning — get_products adds exclusivity, preferred_delivery_types, and time_budget, with incomplete in the response. Products may omit delivery_measurement, and packages can now carry per-package start_time / end_time.
• Compliance and governance — Creative disclosures add persistence semantics, and campaign governance introduces sync_plans, check_governance, report_plan_outcome, and get_plan_audit_logs.
• Accounts and sandbox ergonomics — sync_accounts adds payment_terms, and sandbox now participates in the natural account key for buyer-declared account references.

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Need help?

• Community: Slack — best for quick questions from other implementers
• Issues: GitHub Issues — for bugs, spec questions, or migration edge cases
• Full v2 → v3 migration: Migration guide