Optionalcontext_Transport-managed conversation identifier. On A2A, this maps to the native Message/Task contextId used to associate messages with a conversation; it is not carried inside the AdCP DataPart. On MCP, a request-body context_id, where admitted by the selected request schema, is a compatibility-only field: servers MUST ignore it, callers MUST NOT rely on it for continuity, and it MUST NOT select session state, identity, account, authorization, task continuation, or idempotency scope. MCP continuity, if provided, comes from the transport session. Distinct from context (per-request opaque echo, see below) and from task_id (AdCP operation tracking).
OptionalcontextOptionaltask_Unique identifier for tracking asynchronous operations. Present when a task requires extended processing time. Used to query task status and retrieve results when complete.
OptionalmessageHuman-readable summary of the task result. Provides natural language explanation of what happened, suitable for display to end users or for AI agent comprehension. Generated by the protocol layer based on the task response.
OptionaltimestampISO 8601 timestamp when the response was generated. Useful for debugging, logging, cache validation, and tracking async operation progress.
OptionalreplayedSet to true when this response was returned from the idempotency cache rather than from a fresh execution. Set to false (or omitted) when the request was executed fresh. Buyers use this to distinguish cached replays from new executions — matters for billing reconciliation, audit logs, state-machine routing (cached state-tracking fields are historical snapshots, not current state — re-read via the resource's read endpoint), and any downstream system that assumes exactly-once event semantics. replayed appears only when the request actually resolved through the idempotency cache. Pure reads may ignore an optional idempotency_key; when a seller voluntarily caches keyed reads, those responses use the same replay indicator and full cache contract.
Optionaladcp_Optionalpush_Optionalgovernance_Opaque authorization context issued only by an approved check_governance decision. Buyers attach it to governed requests across protocol roles (media buys, rights acquisitions, signal activations, creative services); receiving services persist it and forward it on subsequent execution and lifecycle checks. The context is the authoritative plan binding at service boundaries, so a service MUST NOT require a separate plan_id.
Governance agents MUST emit a compact JWS per the AdCP JWS profile. Verifiers validate standard authorization claims such as signature, issuer, audience, expiry, and replay protection, but intermediaries MUST NOT interpret embedded governance state for business logic. A conditions or denied verdict never carries an authorization context.
This is the primary correlation key for audit and reporting across the governance lifecycle.
OptionalpayloadConceptual grouping for the task-specific response data defined by individual task response schemas (e.g., get-products-response.json, create-media-buy-response.json). payload is a documentary construct — it is NOT a required wire field, and its on-the-wire shape depends on transport (see Transport serialization below). Task response schemas declare body fields without wrapping them in a payload object; the wire representation places those body fields per transport convention. On MCP the body fields appear as siblings of envelope fields at the root of the tool response; on A2A they appear inside task.artifacts[0].parts[].DataPart; on REST they appear at the root of the JSON body.
Optionaladcp_Release-precision AdCP version (VERSION.RELEASE, e.g. "3.0", "3.1", "3.1-beta"). On a request: the buyer's release pin — the seller validates against its supported_versions and returns VERSION_UNSUPPORTED on cross-major mismatch, or downshifts to the highest supported release within the same major. On a response: the release the seller actually served — clients SHOULD validate the response against that release's schema, not against their pin. Patches are not negotiated; surface them as build_version on capabilities for operational visibility. When omitted, falls back to adcp_major_version (deprecated) or server default. Buyers SHOULD emit both adcp_version and adcp_major_version through 3.x to remain compatible with sellers that only read the legacy field. NORMALIZATION: SDKs that read full-semver values from bundle metadata (e.g. ComplianceIndex.published_version = "3.1.0-beta.1") MUST normalize to release-precision ("3.1-beta.1") before emitting on the wire — meta-field values are NOT valid wire values.
Optionaladcp_DEPRECATED in favor of adcp_version (release-precision string). Servers MUST continue to honor this field through 3.x. Removed in 4.0. Original semantics: the AdCP major version the buyer's payloads conform to. Sellers validate against their supported major_versions and return VERSION_UNSUPPORTED if unsupported. When omitted, the seller assumes its highest supported version.
Optionalaccount_Account identifier. Present when the response spans or is scoped to a specific account.
Optionalmedia_Publisher's media buy identifier. Present when the request was scoped to a single media buy.
ISO 4217 currency code for monetary values in this response (e.g., 'USD', 'EUR')
Date range for the report.
Creative delivery data with variant breakdowns
Creative identifier
Optionalmedia_buy_id?: stringPublisher's media buy identifier for this creative. Present when the request spanned multiple media buys, so the buyer can correlate each creative to its media buy.
Optionalformat_id?: LegacyFormatReferenceStructuredObjectOptionalformat_kind?: CanonicalFormatKindOptionalformat_option_ref?: FormatOptionReferenceOptionaltotals?: DeliveryMetricsOptionalvariant_count?: numberTotal number of agent-unique variant_id rows for this creative. When max_variants was specified in the request, this may exceed the number of items in the variants array.
Variant-level delivery breakdown. Each agent-unique variant_id identifies one immutable served execution and each row includes metrics from exactly one source revision and, for localized delivery, exactly one locale variant. A distinct revision, locale, or rendered manifest receives a distinct variant_id; metrics MUST NOT cross those boundaries. For standard creatives, contains one row per source revision and locale represented in the reporting period. For asset group optimization, one per combination, source revision, and locale. For generative creative, one per generated execution, source revision, and locale. Empty when a creative has no variants yet.
OptionalpaginationPagination information. Present when the request included pagination parameters. Note: get_creative_delivery uses page-based pagination (limit/offset) for historical reasons, distinct from the cursor-based PaginationResponse used by list_* tools. Field naming aligned with PaginationResponse.total_count in 3.1; the legacy total field is retained as a deprecated alias until 4.0. Sellers MUST populate both fields identically; buyers SHOULD prefer total_count (the canonical name) and ignore total if both are present.
Maximum number of creatives requested
Number of creatives skipped
Whether more creatives are available beyond this page
Optionaltotal_count?: numberTotal number of creatives matching the request filters. Canonical field name (matches PaginationResponse.total_count). Sellers SHOULD populate this and the deprecated total field identically until 4.0; buyers SHOULD prefer this field.
Optionaltotal?: numberOptionalerrorsTask-specific errors and warnings
Optionalext
Response payload for get_creative_delivery task. Returns creative delivery data with variant-level breakdowns including manifests and metrics.