Cerner Adapter

A Source Custom node that polls a Cerner FHIR endpoint on an interval and pushes every matching resource downstream as JSON.

Part of the Linkiir Adapters package — see requesting the package.

What it does

On each interval the node discovers Cerner's token endpoint from the published SMART configuration, obtains an access token for the scopes you requested, runs your FHIR search, and pushes one message per resource returned. The token is cached and reused until it nears expiry.

Cerner FHIR endpoint  →  Cerner Adapter  →  your next node

Before you start

The client ID.
An RSA keypair, with the public half published as a JWKS.
The Key ID (kid) identifying which key in that JWKS Cerner should verify against.
The base URL of the Cerner FHIR endpoint for your tenant.

If you do not already have a keypair, generate one:

openssl genrsa -out cerner_private.pem 2048
openssl rsa -in cerner_private.pem -pubout -out cerner_public.pem

File	What to do with it
`cerner_public.pem`	Publish it as part of a JWKS on the CernerCentral System Account
`cerner_private.pem`	Put it on the machine running the Linkiir Runtime, readable only by the account the Runtime runs as

The node stores the key's path, not its contents, so the key never enters the project or an export.

Set it up

Open the Cerner FHIR Adapter node in the Workflow Builder and click Edit.

Fill in the connection fields:

Field	Value
Base URL	The Cerner FHIR root for your tenant
Client ID	The client ID from the System Account
Private Key Path	Absolute path to `cerner_private.pem`
Key ID	The `kid` of the matching public key in your JWKS
Scopes	The scopes your integration needs, space-separated

Say what to fetch with Resource Type and Search Query.
Set Live Mode off, then Save.
Connect a downstream node and start the workflow. Authentication still runs, so this first pass proves the client ID, key, and kid line up.
Turn Live Mode on. The log reports how many resources were pushed.

Configuration reference

Field	Type	Default	Purpose
Interval	number	`60000`	Milliseconds between polls
Base URL	string	(empty)	Root of the Cerner FHIR endpoint. A trailing slash is added if missing
Client ID	string	(empty)	OAuth client identifier from the CernerCentral System Account
Private Key Path	file path	(empty)	PEM RSA private key used to sign the token request
Key ID	string	(empty)	The `kid` identifying which public key in your JWKS Cerner verifies against
Scopes	string	`system/Patient.read`	SMART on FHIR scopes requested on the token exchange
Resource Type	string	`Patient`	FHIR resource type to search each poll
Search Query	string	(example)	Search parameters as a URL query string
Live Mode	bool	`true`	Off simulates the FHIR calls. Authentication is always live
Verify TLS	bool	`true`	Verify Cerner's TLS certificate. Turn off only for a local test proxy

Verify it worked

With Live Mode off, the node starts clean and logs that no request was sent.
With Live Mode on, the log reports a count of pushed resources and the downstream node receives that many messages.
Each message is a single FHIR resource as JSON.

If it didn't work

Symptom in the log	Cause	Fix
`CONFIG_ERROR` naming a field	That field is empty, or a file path cannot be read	Fill the field; check the Runtime account can read the key
`AUTH_FAILED` mentioning the assertion or signature	The Key ID does not match the published JWKS, or the private key is not the pair of the published public key	Re-check the `kid`, and republish the JWKS if needed
`AUTH_FAILED` mentioning scopes	The System Account is not approved for a requested scope	Reduce Scopes to what the account is granted
`HTTP_401` after a successful token	The token does not carry the scope the search needs	Add the scope, then restart the node
`HTTP_404`	Wrong Base URL for the tenant, or a misspelled Resource Type	Correct the URL or resource type
`Live Mode is off` and nothing is pushed	Working as configured	Turn Live Mode on
No error, but nothing pushed	The search matched nothing	Widen the Search Query

What it does​

Before you start​

Set it up​

Configuration reference​

Verify it worked​

If it didn't work​

Next​