Medplum JS Client Library

The Medplum JS Client Library is a pure TypeScript library for calling a FHIR server from the browser.

Key Features

- FHIR validation and operations
- FHIR client to create, read, update, delete, patch, and search
- WebSockets for realtime communication
- Evaluation of FhirPath
- No external dependencies

Installation

Add as a dependency:

``bash
npm install @medplum/core
`

Basic Usage

Create a new MedplumClient:

`ts
import { MedplumClient } from '@medplum/core';

const medplum = new MedplumClient();
`

Create a MedplumClient with additional configuration options:

`ts
import { MedplumClient } from '@medplum/core';

const medplum = new MedplumClient({
baseUrl: 'https://www.example.com/fhir/R4/',
clientId: 'MY_CLIENT_ID',
});
`

Authenticate with client credentials

`ts
const medplum = new MedplumClient();
await medplum.startClientLogin(MY_CLIENT_ID, MY_CLIENT_SECRET);
`

Authenticating with Medplum

If you are using Medplum as your FHIR server, you can use a direct sign-in API to authenticate email and password.

Before you begin

1. Create a project in the Medplum App
2. Enable Email/Password

After that, you can use the startLogin() method:

`ts
const loginResult = await medplum.startLogin({ email, password, remember });
const profile = await medplum.processCode(loginResult.code);
console.log(profile);
`

Authenticating with OAuth

Authenticate with a FHIR server via OAuth2 redirect:

`ts
medplum.signInWithRedirect().then((user) => console.log(user));
`

Search

Search for any resource using a FHIR search string:

`ts
search(
resourceType: K,
query?: URLSearchParams | string,
options: RequestInit = {}
): ReadablePromise>>
`

Example:

`ts
const bundle = await medplum.search('Patient', 'given=eve');
bundle.entry.forEach((entry) => console.log(entry.resource));
`

Create

Create resource:

`ts
createResource(resource: T): Promise
`

Example:

`ts
medplum.createResource({
resourceType: 'Observation',
subject: {
reference: 'Patient/123',
},
valueQuantity: {
// ...
},
// ...
});
`

Read a resource

Read a resource by ID:

`ts
readResource(resourceType: string, id: string): Promise
`

Example:

`ts
const patient = await medplum.readResource('Patient', '123');
`

Read resource history

Read resource history:

`ts
readHistory(resourceType: string, id: string): Promise>
`

Example:

`ts
const historyBundle = await medplum.readHistory('Patient', '123');
`

Read resource version

Read a specific version:

`ts
readVersion(resourceType: string, id: string, vid: string): Promise
`

Example:

`ts
const version = await medplum.readVersion('Patient', '123', '456');
`

Update a resource

Update a resource:

`ts
updateResource(resource: T): Promise
`

Example:

`ts
const result = await medplum.updateResource({
resourceType: 'Patient',
id: '123',
name: [
{
family: 'Smith',
given: ['John'],
},
],
});
console.log(result.meta.versionId);
`

Delete a resource

Delete a resource:

`ts
deleteResource(resourceType: string, id: string): Promise
`

Example:

`ts
await medplum.deleteResource('Patient', '123');
`

Patch a resource

Patch a resource:

`ts
patchResource(resourceType: string, id: string, operations: Operation[]): Promise
`

Example:

`ts
const result = await medplum.patchResource('Patient', '123', [
{ op: 'replace', path: '/name/0/family', value: 'Smith' },
]);
console.log(result.meta.versionId);
`

GraphQL

Execute a GraphQL query:

`ts
graphql(query: string, options?: RequestInit): Promise
`

Example:

`ts
const result = await graphql(
{
PatientList(name: "Alice") {
name {
given
family
}
}
}
);
``

About Medplum

Medplum is a healthcare platform that helps you quickly develop high-quality compliant applications. Medplum includes a FHIR server, React component library, and developer app.

License

Apache 2.0. Copyright © Medplum 2025