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Your first write: an Observation and a Condition

Step 2 of the developer path: write a LOINC-coded Observation and an ICD-10 Condition to a sandbox patient with an author and an Idempotency-Key, in curl, Python and JavaScript, then check the timeline, FHIR and provenance.

Step 2 of 5. You can read the sandbox (see Your first API call); now write two of the most common things a health app stores: a measurement (an Observation, coded with LOINC) and a diagnosis already made by a clinician (a Condition, coded with ICD-10). Every write records who the author is and can be retried safely.

In short:

Before you start

You need a sandbox key with the write scope (the key from Get a sandbox key has read and write) and the id of a sandbox patient:

export ANPHEROS_KEY=sk_test_your_key_here
export PID=$(curl -s https://platform.anpheros.com/v1/patients -H "Authorization: Bearer $ANPHEROS_KEY" \
  | python3 -c "import sys, json; print(json.load(sys.stdin)['data'][0]['id'])")
echo $PID

1. Write an Observation

A fasting glucose of 112 mg/dL, measured by a device:

curl -X POST "https://platform.anpheros.com/v1/patients/$PID/observations" \
     -H "Authorization: Bearer $ANPHEROS_KEY" -H 'content-type: application/json' \
     -H "Idempotency-Key: $(uuidgen)" -d '{
  "code": "2339-0", "display": "Glucose", "category": "laboratory",
  "value": 112, "unit": "mg/dL", "effective_at": "2026-09-19T08:10:00Z",
  "author_type": "device"
}'

The answer is the stored observation, with its id, its fhir reference (Observation/…) and updated_at.

• category is the FHIR observation category: laboratory for lab results, vital-signs for blood pressure, heart rate, weight and the like.
• author_type says who wrote it: patient, practitioner, device, import or ai. If you leave it out the platform records import, never patient by assumption. A write by ai carries the HL7 AI asserted label.
• Idempotency-Key: send the same request with the same key again (after a timeout, for example) and you get the same answer without a second observation.

2. Write a Condition

A type 2 diabetes diagnosis, active since March 2021, entered by a clinician:

curl -X POST "https://platform.anpheros.com/v1/patients/$PID/conditions" \
     -H "Authorization: Bearer $ANPHEROS_KEY" -H 'content-type: application/json' \
     -H "Idempotency-Key: $(uuidgen)" -d '{
  "code": "E11.9", "display": "Type 2 diabetes mellitus without complications",
  "clinical_status": "active", "onset": "2021-03-01", "author_type": "practitioner"
}'

{"id":"…","patient":"…","code":"E11.9","system":"http://hl7.org/fhir/sid/icd-10","display":"Type 2 diabetes mellitus without complications","clinical_status":"active","onset":"2021-03-01","abatement":null,"note":null,"updated_at":"…","fhir":"Condition/…"}

• system defaults to ICD-10 (http://hl7.org/fhir/sid/icd-10); only code is required.
• clinical_status is one of active, recurrence, relapse, inactive, remission, resolved. onset and abatement are dates (YYYY-MM-DD).
• Store a diagnosis that a clinician made. An app that suggests diagnoses itself may be a medical device under EU and US rules; Anpheros stores what you send and does not diagnose.

3. The same writes in Python and JavaScript

import os, uuid, requests

BASE = "https://platform.anpheros.com"
H = {"Authorization": f"Bearer {os.environ['ANPHEROS_KEY']}"}
pid = requests.get(f"{BASE}/v1/patients", headers=H).json()["data"][0]["id"]

obs = requests.post(f"{BASE}/v1/patients/{pid}/observations",
                    headers={**H, "Idempotency-Key": str(uuid.uuid4())},
                    json={"code": "2339-0", "display": "Glucose", "category": "laboratory", "value": 112,
                          "unit": "mg/dL", "effective_at": "2026-09-19T08:10:00Z", "author_type": "device"})
cond = requests.post(f"{BASE}/v1/patients/{pid}/conditions",
                     headers={**H, "Idempotency-Key": str(uuid.uuid4())},
                     json={"code": "E11.9", "clinical_status": "active", "onset": "2021-03-01",
                           "author_type": "practitioner"})
print(obs.status_code, obs.json()["fhir"], cond.status_code, cond.json()["fhir"])

const BASE = 'https://platform.anpheros.com';
const H = { Authorization: `Bearer ${process.env.ANPHEROS_KEY}`, 'content-type': 'application/json' };
const { data } = await (await fetch(`${BASE}/v1/patients`, { headers: H })).json();
const post = (path, body) => fetch(`${BASE}${path}`, {
  method: 'POST', headers: { ...H, 'Idempotency-Key': crypto.randomUUID() }, body: JSON.stringify(body),
}).then(r => r.json());
const obs = await post(`/v1/patients/${data[0].id}/observations`, { code: '2339-0', display: 'Glucose',
  category: 'laboratory', value: 112, unit: 'mg/dL', effective_at: '2026-09-19T08:10:00Z', author_type: 'device' });
const cond = await post(`/v1/patients/${data[0].id}/conditions`, { code: 'E11.9', clinical_status: 'active',
  onset: '2021-03-01', author_type: 'practitioner' });
console.log(obs.fhir, cond.fhir);

The SDKs add the Idempotency-Key for you: anpheros.observations.create(...) in TypeScript and Dart. See SDKs.

4. Check what you wrote

# the record, newest first
curl "https://platform.anpheros.com/v1/patients/$PID/timeline" -H "Authorization: Bearer $ANPHEROS_KEY"
# the same Condition as strict FHIR R4
curl "https://platform.anpheros.com/fhir/R4/Condition?patient=$PID&code=http://hl7.org/fhir/sid/icd-10|E11.9" \
     -H "Authorization: Bearer $ANPHEROS_KEY"
# who wrote it, and when
curl "https://platform.anpheros.com/v1/patients/$PID/provenance/Observation/<observation id>" \
     -H "Authorization: Bearer $ANPHEROS_KEY"

Nothing is overwritten silently: an update creates a new version, and the history stays at /fhir/R4/{Type}/{id}/_history.

Common errors

Next step

Step 3: when a real person uses your app, they sign in and approve access themselves: Create an OAuth app and the consent screen.

Frequently asked questions

Do I have to use LOINC and ICD-10?

They are the defaults: LOINC for observations and ICD-10 for conditions. Codes from other systems can be sent with their system; see FHIR code systems.

Can I write with FHIR instead of /v1?

Yes. POST /fhir/R4/Observation and POST /fhir/R4/Condition take FHIR R4 resources and store them in the same record, with the same ids.

What happens if I send the same write twice?

With the same Idempotency-Key, the second request returns the first answer and nothing is duplicated. Without one, you get two resources.

Read https://developers.anpheros.com/guides/first-write.md and help me write my first Observation and Condition to a sandbox patient. Use the Anpheros sandbox (base URL https://platform.anpheros.com) with my API key from the ANPHEROS_KEY environment variable, never written in the code. Give me complete, runnable code, the response I should expect, and how to fix the errors in https://developers.anpheros.com/guides/troubleshooting.md if a call fails.

Try it free in the sandbox · first FHIR call in 5 minutesFree · 30 synthetic patients · no cardYour first API call in 2 minutes →