How do I create a patient, prescription, and order in one API call?

Blend’s composite endpoint creates a patient, a prescriber, an electronic prescription, and an order in a single request. Post any combination of the four top-level objects — patient, prescriber, electronic_prescription, order — and each one follows the same required fields as its individual endpoint. Patients and prescribers can be referenced instead of created, so a returning patient doesn’t need their profile re-sent. The whole request is atomic. If any single entity fails validation, the entire request fails and nothing is created.

A new patient, new prescription, and order in one request

curl -X POST https://api.byblend.com/api/v1/prescriptions/electronic_prescriptions/composite \
  -H "Authorization: Bearer {access_token}" \
  -H "Content-Type: application/json" \
  -d '{
    "patient": {
      "first_name": "Willard",
      "last_name": "Donnelly",
      "email": "wdonnelly@example.com",
      "phone": "6417383445",
      "date_of_birth": "1990-01-01",
      "external_id": "clinic-pt-4471",
      "address": {
        "address_1": "140 Lindgren Street",
        "city": "Boston",
        "state": "MA",
        "zip_code": "02108"
      }
    },
    "prescriber": {
      "npi": "1234567890"
    },
    "electronic_prescription": {
      "medication": {
        "product_code": "HC-RAPA31",
        "drug_name": "Rapamycin",
        "quantity": 30,
        "units": "C48480",
        "days_supply": 30,
        "refills": 4,
        "sig": "Take one capsule by mouth once weekly",
        "written_at": "2026-08-20T00:00:00"
      }
    },
    "order": {
      "products": {
        "prescription": [
          { "product_code": "HC-RAPA31", "quantity": 1 }
        ]
      }
    }
  }'

The response returns { id, created } for each entity plus a summary reporting entities_created and entities_referenced — so you can tell at a glance whether the patient was newly created or matched to an existing record.

Referencing instead of creating

For a returning patient, drop the full profile and pass a reference:

"patient": { "external_id": "clinic-pt-4471" }

Prescribers can be referenced by id or npi. See how Blend matches entities for the full matching rules.

All-or-nothing. A malformed address on the patient means the prescription and order are not created either. Validate each object against its individual endpoint’s requirements before combining them.

Order merging still applies. If the patient already has an open order, the order in your composite request merges into it. Pass force_new=true as a querystring argument to prevent that — see Order Merging.

When to use it

Reach for composite when your system already holds everything at once — a checkout flow, an intake form, an EMR pushing a completed visit. Use the individual endpoints when entities arrive at different times, which is the more common pattern for businesses whose prescriptions come through Surescripts.

Composite creation

POST /prescriptions/electronic_prescriptions/composite

Create an order

POST /orders

Create a patient

POST /patients

Create an electronic prescription

POST /prescriptions/electronic_prescriptions

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How do I create a patient, prescription, and order in one API call?

A new patient, new prescription, and order in one request

Referencing instead of creating

When to use it

Composite creation

Create an order

Create a patient

Create an electronic prescription

​A new patient, new prescription, and order in one request

​Referencing instead of creating

​When to use it

Composite creation

Create an order

Create a patient

Create an electronic prescription

A new patient, new prescription, and order in one request

Referencing instead of creating

When to use it