This document is intended as a detailed reference for the precise behavior of the drchrono API. If this is your first time using the API, start with our tutorial. If you are upgrading from a previous version, take a look at the changelog section.

Authorization

Initial authorization

There are three main steps in the OAuth 2.0 authentication workflow:

1. Redirect the provider to the authorization page.
2. The provider authorizes your application and is redirected back to your web application.
3. Your application exchanges the authorization_code that came with the redirect for an access_token and refresh_token.

Step 1: Redirect to drchrono

The first step is redirecting your user to drchrono, typically with a button labeled "Connect to drchrono" or "Login with drchrono". This is just a link that takes your user to the following URL:

https://drchrono.com/o/authorize/?redirect_uri=REDIRECT_URI_ENCODED&response_type=code&client_id=CLIENT_ID_ENCODED&scope=SCOPES_ENCODED

• REDIRECT_URI_ENCODED is the URL-encoded version of the redirect URI (as registered for your application and used in later steps).
• CLIENT_ID_ENCODED is the URL-encoded version of your application's client ID.
• SCOPES_ENCODED is a URL-encoded version of a space-separated list of scopes, which can be found in each endpoint or omitted to default to all scopes.

The scope parameter consists of an optional, space-separated list of scopes your application is requesting. If omitted, all scopes will be requested.

Scopes are of the form BASE_SCOPE:[read|write] where BASE_SCOPE is any of user, calendar, patients, patients:summary, billing, clinical and labs. You should request only the scopes you need. For instance, an application which sends "Happy Birthday!" emails to a doctor's patients on their birthdays would use the scope parameter "patients:summary:read", while one that allows patients to schedule appointments online would need at least "patients:summary:read patients:summary:write calendar:read calendar:write clinical:read clinical:write".

Step 2: Provider authorization

After logging in (if necessary), the provider will be presented with a screen with your application's name and the list of permissions you requested (via the scope parameter).

When they click the "Authorize" button, they will be redirected to your redirect URI with a code query parameter appended, which contains an authorization code to be used in step 3. If they click the "Cancel" button, they will be redirected to your redirect URI with error=access_denied instead.

Note: This authorization code expires extremely quickly, so you must perform step 3 immediately, ideally before rendering the resulting page for the end user.

Step 3: Token exchange

The code obtained from step 2 is usable exactly once to obtain an access token and refresh token. Here is an example token exchange in Python:

import datetime, pytz, requests

if 'error' in get_params:
    raise ValueError('Error authorizing application: %s' % get_params[error])

response = requests.post('https://drchrono.com/o/token/', data={
    'code': get_params['code'],
    'grant_type': 'authorization_code',
    'redirect_uri': 'http://mytestapp.com/redirect_uri',
    'client_id': 'abcdefg12345',
    'client_secret': 'abcdefg12345',
})
response.raise_for_status()
data = response.json()

# Save these in your database associated with the user
access_token = data['access_token']
refresh_token = data['refresh_token']
expires_timestamp = datetime.datetime.now(pytz.utc) + datetime.timedelta(seconds=data['expires_in'])

You now have all you need to make API requests authenticated as that provider. When using this access token, you'll only be able to access the data that the user has access to and that you have been granted permissions for.

Refreshing an access token

Access tokens only last 48 hours (given in seconds in the 'expires_in' key in the token exchange step above), so they occasionally need to be refreshed. It would be inconvenient to ask the user to re-authorize every time, so instead you can use the refresh token like the original authorization to obtain a new access token. Replace the code parameter with refresh_token, change the value grant_type from authorization_code to refresh_token, and omit the redirect_uri parameter.

Example in Python:

...
response = requests.post('https://drchrono.com/o/token/', data={
    'refresh_token': get_refresh_token(),
    'grant_type': 'refresh_token',
    'client_id': 'abcdefg12345',
    'client_secret': 'abcdefg12345',
})
...

Webhooks

In order to use drchrono API webhooks, you first need to have an API application on file (even if it is in Test Model). Each API webhook is associated with one API application, go to here to set up both API applications and webhooks!

Once you registered an API application, you will see webhook section in each saved API applications. Create a webhook and register some events there and save all the changes, then you are good to go!

Webhooks setup

All fields under webhooks section are required.

Callback URL Callback URl is used to receive all hooks when subscribed events are triggered. This should be an URL under your control.

Secret token Secret token is used to verify webhooks, this is very important, please set something with high entropy. Also we will talk more about this later.

Events

Events is used to register events you want to receiver notification when they happen. Currently we support following events.

Event name | Event description ---------- | ----------------- APPOINTMENT_CREATE | We will deliver a hook any time an appointment is created APPOINTMENT_MODIFY | We will deliver a hook any time an appointment is modified PATIENT_CREATE | We will deliver a hook any time a patient is created PATIENT_MODIFY | We will deliver a hook any time a patient is modified PATIENT_PROBLEM_CREATE | We will deliver a hook any time a patient problem is created PATIENT_PROBLEM_MODIFY | We will deliver a hook any time a patient problem is modified PATIENT_ALLERGY_CREATE | We will deliver a hook any time a patient allergy is created PATIENT_ALLERGY_MODIFY | We will deliver a hook any time a patient allergy is modified PATIENT_MEDICATION_CREATE | We will deliver a hook any time a patient medication is created PATIENT_MEDICATION_MODIFY | We will deliver a hook any time a patient medication is modified CLINICAL_NOTE_LOCK | We will deliver a hook any time a clinical note is locked CLINICAL_NOTE_UNLOCK | We will deliver a hook any time a clinical note is unlocked TASK_CREATE | We will deliver a hook any time a task is created TASK_MODIFY | We will deliver a hook any time a task is modified and any time creation, modification and deletion of task notes, associated task item TASK_DELETE | We will deliver a hook any time a task is deleted

Webhooks verification

In order to make sure the callback URL in webhook is under your control, we added a verification step before we send any hooks out to you.

Verification can be done by clicking "Verify webhook" button in webhooks setup page. After you click the button, we will send a GET request to the callback URL, along with a parameter called msg.

Please use your webhook's secret token as hash key and SHA-256 as digest constructor, hash the msg value with HMAC algorithm. And we expect a 200 JSON response, in JSON response body, there should be a key called secret_token existing, and its value should be equal to the hashed msg. Otherwise, verification will fail.

Here is an example webhook verification in Python:

import hashlib, hmac

def webhook_verify(request):
    secret_token = hmac.new(WEBHOOK_SECRET_TOKEN, request.GET['msg'], hashlib.sha256).hexdigest()
    return json_response({
        'secret_token': secret_token
    })

Webhooks header and body

Header

Key | Value --- | ----- X-drchrono-event | Event that triggered this hook, could be any one event above or PING X-drchrono-signature | Secret token associated with this webhook X-drchrono-delivery | ID of this delivery

Body

Key | Value --- | ----- receiver | This will be an JSON representation of the webhook object | This will be an JSON representation of the object related to the triggered event, this would share same serializer as drchrono API

Webhooks ping and deliveries

Webhooks ping and deliveries will be sent as POST requests.

PING:

You can always ping your webhook to check things, by clicking the "Ping webhook" button in webhook setup page. And a hook with header X-drchrono-event: PING would be sent to the callback URL.

Deliveries:

You can check recent deliveries by clicking the "deliveries" link in webhook setup page. And you can resend a hook by clicking "redeliver" button after select a specific delivery.

Webhooks delivery mechanism

We will delivery a hook the moment a subscribed event is triggered. We will not record any response header or body you send back after you receive the hook. However we only consider the response status code. We will consider any 2xx responses as successfully delivered. Any other responses, like 302 would be considered failing. And we will try to redeliver unsuccessfully delivered hooks 3 times, first redeliver happens at 1 hour after the initial event, second receliver happens 3 hours after the initial event, and the third redeliver happens 7 hours after the initial event. After these redeliveries, if the delivery is still unsuccessful, you have to redeliver it by hand.

Webhooks security

You may want to secure your webhooks to only consider requests send out from drchrono. And this is where secret_token is needed in request header. Try to set the secret_token to something with high entropy, a good example could be taking the output of ruby -rsecurerandom -e 'puts SecureRandom.hex(20)'. After this, you might want to verify all request headers you received on your server with this token.

iframe integration

Some API apps provide additional functionality for interacting with patient data not offered by drchrono, and can benefit by being incorporated into drchrono's patient information page via iframe. We have created a simple API to make this possible.

To make an existing API application accessible via an iframe on the patient page, you need to update either "Patient iframe" or "Clinical note iframe" section in API management page, to make the iframe to appear on (either the patient page or the clinical note page), with the URL that the iframe will use for each page, and the height it should have. The application will be reviewed before it is approved to ensure that it is functional and secure.

Register a Doctor

iframe applications will appear as choices on the left-hand menu of the patient page for doctors registered with your application. To register a doctor with your application, make a POST request to the /api/iframe_integration endpoint using the access token for the corresponding doctor. This endpoint does not expect any payload.

To disable your iframe application for a doctor, make a DELETE request to the same endpoint.

Populating the iframe

There are two places where the iframe can be displayed, either within the patient detail page or the clinical note page, shown below respectively:

When requesting approval for your iframe app, you must specify a URL for one or both of these pages which will serve as the base URL for your IFrame contents. When a doctor views your iframe, the source URL will have various query parameters appended to it, for example for the patient page the src parameter of the IFrame will be:

<iframe_url>?doctor_id=<doctor_id>&patient_id=<patient_id>&practice_id=<practice_id>&iat=<iat>&jwt=<jwt>

The jwt parameter is crucial if your application transfers any sort of PHI and does not implement its own login system. It encapsulates the other parameters in a JSON web token (JWT) and signs them using SHA-256 HMAC with your client_secret as the key. This verifies that the iframe is being loaded within one of drchrono's pages by an authorized user. In production, you should validate the JWT using an approved library (which are listed on the official site), and only use the parameters extracted from the JWT. Using Python and Django, this might look like:

import jwt

CLIENT_SECRET = <client_secret>
MAX_TIME_DRIFT_SECONDS = 60

def validate_parameters(request):
    token = request.GET['jwt']

    return jwt.decode(token, CLIENT_SECRET, algorithms=['HS256'], leeway=MAX_TIME_DRIFT_SECONDS)

Modern browsers' same-origin policy means that data cannot be passed between your application and drchrono's page through the iframe. Therefore, interaction must happen through the API, using information provided in JWT.

Versions and deprecation

Stability Policy

Changes to this API version will be limited to adding endpoints, or adding fields to existing endpoints, or adding optional query parameters. Any new fields which are not read-only will be optional.

Deprecation Policy

The drchrono API is versioned. Versions can be in the following states:

• Active: This is our latest and greatest version of the API. It is actively supported by our API team and is improved upon with new features, bug fixes and optimizations that do not break backwards compatibility.

• Deprecated: A deprecated API version is considered second best--having been surpassed by our active API version. An API version remains in this state for one year, after which time it falls to the not supported state. A deprecated API version is passively supported; while it won't be removed until becoming unsupported, it may not receive new features but will likely be subject to security updates and performance improvements.

• Unsupported: An API version in the not supported state may be deactivated at any time. An application using an unsupported API version should migrate to an active API version.

Version Map

| Version Name | Previous Name | Start Date | Deprecation Date | |--------------|---------------|------------|------------------| | v2 | v2015_08 | 08/2015 | TBA | | v3 | v2016_06 | 06/2016 | | | v4 | N/A | 09/2018 | |

If you are looking for documentation for an older version

• V4(Hunt Valley) (old V4 documentation)
• V3(Sunnyvale)
• V2(Mountain View)

Changelog

Here's changelog for different versions

• V4 Changelog
• V3 changelog