MessageHeader Profile

Canonical	../StructureDefinition/nexus-emr-core-messageheader
Status	draft (experimental) · 1.26.0
Base	MessageHeader (constraint)
Source	FSH · JSON

Nexus EMR profile for MessageHeader -- the routing envelope on an eReferral message bundle, consumed by the gateway's operation-routing middleware. Infrastructure rather than clinical content: no effective date, and R4 gives it no identifier element. First pass: the event vocabulary is not settled.

TypedFhir API / Pydantic schema

The typed accessor surface MessageHeader exposes for MessageHeader — generated from this IG's compiled profile; each typed accessor has a validating raw-FHIR twin (xRaw) where marked. The three ports are parity-enforced.

The AI-facing shape: from typed_fhir.facade.generated.schemas import MessageHeaderSchema — model_json_schema() is a structured-output / tool definition; instantiating validates an extraction. Generated source.

class MessageHeaderSchema(BaseModel):
    """AI-facing shape of the MessageHeader profile: the facade's typed accessor
    surface (curated + salient fields) as a pydantic model. `model_json_schema()` is a
    structured-output / tool schema; instantiating validates an extraction."""

    model_config = ConfigDict(extra="forbid")

    destination: dict | None = Field(
        None,
        description=(
            "The intended receiver(s). The destination application which the message is intended "
            "for. Note: There SHOULD be at least one destination, but in some circumstances, the "
            "source system is unaware of any particular destination system. "
            "MessageHeader.destination — 0..*"
        ),
    )
    sender: Reference | None = Field(
        None,
        description=(
            "The organization or person responsible for the message content. Identifies the "
            "sending system to allow the use of a trust relationship. Note: Distinct from "
            "`source`, which is the technical sending system. `sender` is who is accountable for "
            "the content -- for inbound partner traffic this is usually an Organization. "
            "MessageHeader.sender — 0..1"
        ),
    )
    source: dict | None = Field(
        None,
        description=(
            "The system that sent the message. The source application from which this message "
            "originated. MessageHeader.source — 1..1"
        ),
    )
    responsible: Reference | None = Field(
        None,
        description=(
            "The party accountable for the message. The person or organization that accepts "
            "overall responsibility for the contents of the message. The implication is that the "
            "message event happened under the policies of the responsible party. Note: Usually "
            "only for the request but can be used in a response. MessageHeader.responsible — 0..1"
        ),
    )
    reason: Concept | None = Field(
        None,
        description=(
            "Cause of event. Coded indication of the cause for the event - indicates a reason for "
            "the occurrence of the event that is a focus of this message. MessageHeader.reason — "
            "0..1"
        ),
    )
    response: dict | None = Field(
        None,
        description=(
            "Present when this message is a response to an earlier one. Information about the "
            "message that this message is a response to. Only present if this message is a "
            "response. MessageHeader.response — 0..1"
        ),
    )
    focus: Reference | None = Field(
        None,
        description=(
            "The resource(s) this message concerns. The actual data of the message - a reference "
            "to the root/focus class of the event. Note: Points at the other entries in the "
            "message bundle -- typically a ServiceRequest or Task for an eReferral, plus the "
            "Patient. These are intra-bundle references and resolve within the bundle, NOT "
            "against the server, which is the usual reason a naive resolver reports them missing. "
            "MessageHeader.focus — 0..*"
        ),
    )