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    KVM

    Key-Value Map

    programmatic

    Structured key-value payload passed inside OpenRTB 2.6+ extension fields (ext.kvm) to transmit arbitrary signals between SSP, DSP, and bidder — including AdCP context payloads and agentic intent hints.

    What is a KVM?

    A Key-Value Map (KVM) is a structured key → value payload carried inside the ext field of an OpenRTB 2.6+ bid request, as defined by the IAB Tech Lab OpenRTB specification. It lets publishers, SSPs, and bidders exchange arbitrary signals that aren't part of the core OpenRTB spec — without requiring a new spec revision for every signal type.

    KVMs are the carrier mechanism for next-generation programmatic signals: AdCP context payloads, agentic intent hints, vector-based audience scores, and contextual brand-safety flags all travel as KVMs.

    Where KVMs live in the bid request

    KVMs can attach at multiple levels of the OpenRTB object graph:

    {
  "imp": [{
    "ext": {
      "kvm": {
        "adcp_context": "agentic-research",
        "intent_score": 0.87,
        "garm_floor": "low"
      }
    }
  }],
  "site": {
    "ext": {
      "kvm": {
        "page_topic_vec": "v1:0.42,0.18,...",
        "ucp_session": "abc123"
      }
    }
  }
}

    See the OpenRTB 2.6 specification (§3.2 — Object Model) for the formal definition of the ext extension fields used above.

    • imp[].ext.kvm — per-impression signals (creative-level)
    • site.ext.kvm / app.ext.kvm — page or app context
    • user.ext.kvm — audience or session signals (consent-gated)
    • bidrequest.ext.kvm — exchange-level metadata

    Role in agentic RTB

    In agentic ad pipelines, KVMs are how the DSP tells downstream bidders why this impression matters. An AdCP context payload — describing the user's research intent, content vector, and brand-safety class — is serialized into a KVM and passed in imp.ext.kvm. The bidder's LLM-driven model then decodes the KVM and adjusts its bid strategy in real time.

    This is the mechanical foundation of AdCOM-style structured ad commerce: a flexible signal-carrier that doesn't require ratifying a new IAB spec for every new use case.

    Why it matters

    • Spec-flexible: new signals ship without OpenRTB revisions
    • Vendor-neutral: any SSP/DSP that respects the ext convention can read KVMs
    • Composable: multiple signals coexist in a single kvm object
    • Forward-compatible: agentic, contextual, and identity signals all share the same carrier

    Caveats

    KVMs are powerful but unstandardized — imp.ext.kvm.intent_score from one SSP may mean something different from another SSP's. Successful KVM use depends on bilateral schema agreements between sellers and buyers, often documented in deal-specific SSP↔DSP integration guides. The AdCP initiative (adcontextprotocol.org) is one effort to standardize the most common KVM payloads.

    Related reading