Projo FHIR Documentation - Local Development build (v0.1.0) built by the FHIR (HL7® FHIR® Standard) Build Tools. See the Directory of published versions

Extensions

Extensions

Projo defines extensions under two namespaces:

Namespace	Used for
https://projo.evoleen.com/fhir/StructureDefinition/	Projo-owned orchestration extensions (hardcoded)
https://firearrow.io/fhir/StructureDefinition/	Transport-shared extensions (configurable via EXTENSION_BASE_URL; default firearrow.io)

The firearrow.io namespace is reserved by the Fire Arrow FHIR server. Projo writes into it at runtime because the orchestrator and sidecar share the same FHIR server and must agree on transport-layer URLs; the base is overridable for test environments that run against a different Fire Arrow deployment.

This page is the catalog. Each extension also has a dedicated artifact page linked from the Artifacts menu of this IG.

Active extensions

Task extensions

URL	Value type	Description
https://projo.evoleen.com/fhir/StructureDefinition/delivery-time	valueDateTime	Stamps the actual delivery instant of the outbound communication referenced by the Task. This is the only active Task extension; all other Task state lives on Task.businessStatus and Task.output.

Patient extensions (orchestrator-owned, ADR 0012)

URL	Value type	Description
https://projo.evoleen.com/fhir/StructureDefinition/last-used-messaging-channel	valueCode	The messaging channel the patient last used to send an inbound (a communication-medium code). Stamped at Patient creation and updated on channel change. Read by buildOutboundCR to default the next outbound CR's medium (precedence: override > last-used > default).
https://projo.evoleen.com/fhir/StructureDefinition/opted-out	valueDateTime	Timestamp marking that the patient opted out via a STOP command. Read by the opt-out guards to suppress plan application / re-engagement.

CommunicationRequest extensions (orchestrator-owned, projo namespace)

URL	Value type	Description
https://projo.evoleen.com/fhir/StructureDefinition/web-answer-token	valueString	SHA-256 hash of the bearer token used to access the web answer channel. Set by the orchestrator when a CommunicationRequest is routed to the web channel (ADR 0011). The plaintext token is never stored.
https://projo.evoleen.com/fhir/StructureDefinition/next-reminder-timestamp	valueDateTime	Orchestrator-owned reminder schedule. The orchestrator writes the next planned reminder time; the sidecar reads it and fires the reminder when due.

CommunicationRequest extensions (transport-shared, firearrow namespace)

URL	Value type	Description
https://firearrow.io/fhir/StructureDefinition/last-inbound-message-timestamp	valueDateTime	Sidecar transport stamp. Updated by the sidecar on every inbound message addressed to the CommunicationRequest's conversation.
https://firearrow.io/fhir/StructureDefinition/web-answer-link	valueUrl	Web answer hosting URL. Populated when a CommunicationRequest is answered via the web channel.
https://firearrow.io/fhir/StructureDefinition/inbound-sender-bsuid	valueString	Reverse CommunicationRequest: sender BSUID (WhatsApp business-scoped user id).
https://firearrow.io/fhir/StructureDefinition/inbound-sender-profile-name	valueString	Reverse CommunicationRequest: sender profile name as reported by WhatsApp.
https://firearrow.io/fhir/StructureDefinition/inbound-business-phone	valueString	Reverse CommunicationRequest: receiving business phone number (E.164).
https://firearrow.io/fhir/StructureDefinition/inbound-business-phone-id	valueString	Reverse CommunicationRequest: receiving Meta Phone Number ID.
https://firearrow.io/fhir/StructureDefinition/inbound-message-timestamp	valueDateTime	Reverse CommunicationRequest: original inbound event time.
https://firearrow.io/fhir/StructureDefinition/identity-resolution-reason	valueCode	Reverse CommunicationRequest: reason code from the identity-resolution-reason code system.
https://firearrow.io/fhir/StructureDefinition/waba-account-id (on CommunicationRequest)	valueString	Reverse CommunicationRequest: WABA account ID that received the inbound message.

Organization extensions

URL	Namespace	Value type	Description
https://projo.evoleen.com/fhir/StructureDefinition/plan-slot	projo	Complex (repeating)	Two fields: kind (code, from plan-slot-kind code system) + planDefinition (canonical). Declares which PlanDefinition the organization is enrolled in for a given slot. ADR 0002 (plan slots), ADR 0007 (multi-slot).
https://projo.evoleen.com/fhir/StructureDefinition/default-plan	projo	valueCanonical	Legacy / read-fallback. The pre-ADR-0007 single-slot default plan. Retained for read-back of older organizations; new writes use plan-slot.
https://projo.evoleen.com/fhir/StructureDefinition/preferred-language	projo	valueString	Organization's preferred patient-facing language, ISO 639-1 code.
https://firearrow.io/fhir/StructureDefinition/wa-phone-number-id	firearrow	valueString	Cached Meta Phone Number ID for outbound messaging. Refreshed by the sidecar.
https://firearrow.io/fhir/StructureDefinition/waba-account-id	firearrow	valueString	WABA account ID for the organization. Multi-WABA support (issue #238).
https://firearrow.io/fhir/StructureDefinition/waba-template-invitation	firearrow	valueString	Per-organization WhatsApp template name override for invitations.
https://firearrow.io/fhir/StructureDefinition/waba-template-reminder	firearrow	valueString	Per-organization WhatsApp template name override for reminders.
https://firearrow.io/fhir/StructureDefinition/waba-template-web-invitation	firearrow	valueString	Per-organization WhatsApp template name override for web-channel invitations.
https://firearrow.io/fhir/StructureDefinition/waba-template-web-reminder	firearrow	valueString	Per-organization WhatsApp template name override for web-channel reminders.

Questionnaire extensions

URL	Value type	Description
https://projo.evoleen.com/fhir/StructureDefinition/extraction-writeback	Complex	Declares how extracted resources are written back to the subject. Two fields: target (code, from extraction-writeback-target code system: subject) + mode (code, from extraction-writeback-mode code system: fill-if-empty). ADR 0010.

Retired extensions

The following extensions are no longer written by current code but may still be present on older resources. They are documented for historical context and for migration tooling that must read them.

Retired Task extensions

URL	Value type	Description
https://firearrow.io/fhir/StructureDefinition/wa-conversation-status	valueCode	WhatsApp conversation window status. Replaced by Task.businessStatus.
https://firearrow.io/fhir/StructureDefinition/wa-current-link-id	valueString	Current web answer link id. Replaced by the web channel extensions.
https://firearrow.io/fhir/StructureDefinition/wa-last-outbound-message-id	valueString	Last outbound WhatsApp message id (wamid). Superseded by Communication linkage.
https://firearrow.io/fhir/StructureDefinition/wa-last-inbound-message-id	valueString	Last inbound WhatsApp message id (wamid). Superseded by Communication linkage.
https://firearrow.io/fhir/StructureDefinition/wa-last-activity-timestamp	valueDateTime	Last WhatsApp activity timestamp. Replaced by last-inbound-message-timestamp on the CommunicationRequest.
https://firearrow.io/fhir/StructureDefinition/wa-last-reminder-timestamp	valueDateTime	Last reminder sent timestamp. Replaced by next-reminder-timestamp on the CommunicationRequest.
https://firearrow.io/fhir/StructureDefinition/wa-attempt-count	valueInteger	Outbound delivery attempt counter. Replaced by Task retry logic.
https://firearrow.io/fhir/StructureDefinition/wa-error-code	valueString	Last WhatsApp API error code. Replaced by Task.status = failed + Task.statusReason.
https://firearrow.io/fhir/StructureDefinition/wa-error-detail	valueString	Last WhatsApp API error detail. Replaced by Task.status = failed + Task.statusReason.

Retired Patient extensions

URL	Value type	Description
https://firearrow.io/fhir/StructureDefinition/wa-last-user-message-ts	valueDateTime	Last inbound message timestamp from the patient. Replaced by the sidecar stamping last-inbound-message-timestamp on the CommunicationRequest.
https://firearrow.io/fhir/StructureDefinition/wa-last-sender-phone-number-id	valueString	Last sender's Meta Phone Number ID. Replaced by inbound-business-phone-id on the reverse CommunicationRequest.