Interface LegacyListCreativesResponse

Session/conversation identifier for tracking related operations across multiple task invocations. Managed by the protocol layer to maintain conversational context. Distinct from context (per-request opaque echo, see below).

Unique identifier for tracking asynchronous operations. Present when a task requires extended processing time. Used to query task status and retrieve results when complete.

Human-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.

ISO 8601 timestamp when the response was generated. Useful for debugging, logging, cache validation, and tracking async operation progress.

Set 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. From 3.1 onward, replayed MAY appear on responses to any request that resolved via the idempotency cache, including read tools — universal idempotency_key (see security.mdx §Idempotency) means the cache holds read responses too.

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.

Conceptual 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.

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.

Summary of the query that was executed

Array of creative assets matching the query

Breakdown of creatives by canonical format kind. Keys SHOULD be format_kind values; an implementation may append a stable option suffix when separate product or publisher options must be distinguished.

Breakdown of creatives by status

Task-specific errors (e.g., invalid filters, account not found)

When true, this response contains simulated data from sandbox mode.