Class Client

FHIR REST client. Provides typed methods for all FHIR interactions.

Example

import { Client } from 'fhir-kit-client';

const client = new Client({ baseUrl: 'https://r4.smarthealthit.org' });
const patient = await client.read({ resourceType: 'Patient', id: '123' });

Index

Constructors

constructor

new Client(config?: ClientConfig): Client
Parameters
- config: ClientConfig = ...
  Client configuration. baseUrl is required.
Returns Client
Throws
If baseUrl is blank or not a string.
- Defined in src/client.ts:148

Properties

`Readonly`httpClient

httpClient: HttpClient

Underlying HTTP client — exposed for advanced use cases.

`Readonly`pagination

pagination: Pagination

Pagination helper.

Accessors

baseUrl

get baseUrl(): string
FHIR server base URL.

Returns string
- Defined in src/client.ts:174
set baseUrl(url: string): void
Parameters
- url: string
Returns void
- Defined in src/client.ts:178

bearerToken

set bearerToken(token: string): void
Set the OAuth2 bearer token used for Authorization headers.
Parameters
- token: string
Returns void
- Defined in src/client.ts:192

customHeaders

get customHeaders(): Record<string, string>
Custom headers sent with every request.

Returns Record<string, string>
- Defined in src/client.ts:183
set customHeaders(headers: Record<string, string>): void
Parameters
- headers: Record<string, string>
Returns void
- Defined in src/client.ts:187

Methods

batch

batch(__namedParameters: BundleParams): Promise<FhirResource>
Submit a batch Bundle (FHIR batch interaction).

The body.type field must be 'batch'. Each entry is processed independently; partial failures are reported per-entry in the response.
Parameters
- __namedParameters: BundleParams
Returns Promise<FhirResource>
The batch response Bundle.
- Defined in src/client.ts:426

capabilityStatement

capabilityStatement(options?: RequestOptions): Promise<FhirResource>
Fetch the server's CapabilityStatement.
Parameters
- Optionaloptions: RequestOptions
  Per-request options.
Returns Promise<FhirResource>
The CapabilityStatement resource.
- Defined in src/client.ts:290

compartmentSearch

compartmentSearch(
__namedParameters: CompartmentSearchParams,
): Promise<FhirResource>
Search within a FHIR compartment.
Parameters
- __namedParameters: CompartmentSearchParams
Returns Promise<FhirResource>
A search result Bundle.
- Defined in src/client.ts:563

create

create(__namedParameters: CreateParams): Promise<FhirResource>
Create a new resource (FHIR create interaction).
Parameters
- __namedParameters: CreateParams
Returns Promise<FhirResource>
The created resource (with server-assigned id).

Throws
If resourceType is invalid or the server returns an error.
- Defined in src/client.ts:353

delete

delete(__namedParameters: DeleteParams): Promise<FhirResource>
Delete a resource by type and id (FHIR delete interaction).
Parameters
- __namedParameters: DeleteParams
Returns Promise<FhirResource>
The server's response (often an OperationOutcome).

Throws
If resourceType is invalid or the server returns an error.
- Defined in src/client.ts:367

history

history(__namedParameters?: HistoryParams): Promise<FhirResource>
Retrieve history. Dispatches to instance-, type-, or system-level history based on the parameters provided.
Parameters
- __namedParameters: HistoryParams = {}
Returns Promise<FhirResource>
A history Bundle.
- Defined in src/client.ts:608

nextPage(__namedParameters: PaginationParams): Promise<FhirResource> | undefined
Return the next page of a Bundle search result.
Parameters
- __namedParameters: PaginationParams
Returns Promise<FhirResource> | undefined
The next page Bundle, or undefined if there is no next page.
- Defined in src/client.ts:481

operation

operation(__namedParameters: OperationParams): Promise<FhirResource>
Invoke a FHIR operation ($name) at the system, type, or instance level.
Parameters
- __namedParameters: OperationParams
Returns Promise<FhirResource>
The operation output resource.
- Defined in src/client.ts:455

patch

patch(__namedParameters: PatchParams): Promise<FhirResource>
Patch a resource using JSON Patch (RFC 6902) (FHIR patch interaction).

Sends Content-Type: application/json-patch+json.
Parameters
- __namedParameters: PatchParams
Returns Promise<FhirResource>
The patched resource.

Throws
If resourceType is invalid or the server returns an error.
- Defined in src/client.ts:410

prevPage(__namedParameters: PaginationParams): Promise<FhirResource> | undefined
Return the previous page of a Bundle search result.
Parameters
- __namedParameters: PaginationParams
Returns Promise<FhirResource> | undefined
The previous page Bundle, or undefined if there is no previous page.
- Defined in src/client.ts:492

read

read(__namedParameters: ReadParams): Promise<FhirResource>
Read a resource by type and id (FHIR read interaction).
Parameters
- __namedParameters: ReadParams
Returns Promise<FhirResource>
The requested resource.

Throws
If resourceType is invalid or the server returns an error.
- Defined in src/client.ts:324

request

request(
requestUrl: string,
__namedParameters?: RawRequestParams,
): Promise<FhirResource>
Execute a raw request against the FHIR server. Useful for endpoints not covered by higher-level methods.
Parameters
- requestUrl: string
  Path or absolute URL to request.
- __namedParameters: RawRequestParams = {}
Returns Promise<FhirResource>
The parsed FHIR response.
Example
```
client.request('Patient/123')
client.request('Patient/123', { method: 'DELETE' })
client.request('Patient', { method: 'POST', body: newPatient })
```
- Defined in src/client.ts:311

resolve

resolve(
    __namedParameters: {
        context?: FhirResource;
        options?: RequestOptions;
        reference: string;
    },
): Promise<FhirResource>
Resolve a FHIR reference to a resource.
- Absolute URL (http://...): fetches directly or creates a new client for a foreign base URL.
- Relative URL (Patient/123): fetches from this client's baseUrl.
- Contained reference (#id): resolved from context.contained[].
- Bundle-scoped reference: resolved from context.entry[].fullUrl.
Parameters
- __namedParameters: { context?: FhirResource; options?: RequestOptions; reference: string }
Returns Promise<FhirResource>
The resolved FHIR resource.
- Defined in src/client.ts:209

resourceHistory

resourceHistory(
    __namedParameters: {
        id: string;
        options?: RequestOptions;
        resourceType: string;
    },
): Promise<FhirResource>
Instance-level history for a specific resource.
Parameters
- __namedParameters: { id: string; options?: RequestOptions; resourceType: string }
Returns Promise<FhirResource>
A history Bundle.
- Defined in src/client.ts:626

resourceSearch

resourceSearch(__namedParameters: ResourceSearchParams): Promise<FhirResource>
Search within a specific resource type (FHIR type-level search).
Parameters
- __namedParameters: ResourceSearchParams
Returns Promise<FhirResource>
A search result Bundle.
- Defined in src/client.ts:536

search

search(__namedParameters?: SearchCallParams): Promise<FhirResource>
Search for resources. Dispatches to the appropriate search variant based on parameters:
- compartment + resourceType → compartment search
- resourceType only → type-level search
- searchParams only → system-wide search
Parameters
- __namedParameters: SearchCallParams = {}
Returns Promise<FhirResource>
A search result Bundle.

Throws
If resourceType is invalid or insufficient parameters are provided.
- Defined in src/client.ts:510

smartAuthMetadata

smartAuthMetadata(
__namedParameters?: { options?: RequestOptions },
): Promise<SmartAuthMetadata>
Fetch SMART OAuth 2.0 authorization metadata from the server.

Races three sources simultaneously and resolves with the first successful response: .well-known/smart-configuration, metadata (CapabilityStatement), and .well-known/openid-configuration. Rejects only if all three fail.
Parameters
- __namedParameters: { options?: RequestOptions } = {}
Returns Promise<SmartAuthMetadata>
SMART auth metadata containing authorizeUrl, tokenUrl, etc.
- Defined in src/client.ts:231

systemHistory

systemHistory(
__namedParameters?: { options?: RequestOptions },
): Promise<FhirResource>
System-level history across all resource types.
Parameters
- __namedParameters: { options?: RequestOptions } = {}
Returns Promise<FhirResource>
A history Bundle.
- Defined in src/client.ts:657

systemSearch

systemSearch(__namedParameters?: SystemSearchParams): Promise<FhirResource>
System-wide search across all resource types.
Parameters
- __namedParameters: SystemSearchParams = {}
Returns Promise<FhirResource>
A search result Bundle.
- Defined in src/client.ts:549

transaction

transaction(__namedParameters: BundleParams): Promise<FhirResource>
Submit a transaction Bundle (FHIR transaction interaction).

The body.type field must be 'transaction'. All entries succeed or fail together (atomic).
Parameters
- __namedParameters: BundleParams
Returns Promise<FhirResource>
The transaction response Bundle.
- Defined in src/client.ts:440

typeHistory

typeHistory(
__namedParameters: { options?: RequestOptions; resourceType: string },
): Promise<FhirResource>
Type-level history for all instances of a resource type.
Parameters
- __namedParameters: { options?: RequestOptions; resourceType: string }
Returns Promise<FhirResource>
A history Bundle.
- Defined in src/client.ts:646

update

update(__namedParameters: UpdateParams): Promise<FhirResource>
Update a resource (FHIR update interaction).

Supports conditional update via searchParams (sets the If-Match criteria). Provide either id or searchParams, not both.
Parameters
- __namedParameters: UpdateParams
Returns Promise<FhirResource>
The updated resource.

Throws
If resourceType is invalid, both or neither of id/searchParams are provided, or the server returns an error.
- Defined in src/client.ts:387

vread

vread(__namedParameters: VreadParams): Promise<FhirResource>
Read a specific version of a resource (FHIR vread interaction).
Parameters
- __namedParameters: VreadParams
Returns Promise<FhirResource>
The specified version of the resource.

Throws
If resourceType is invalid or the server returns an error.
- Defined in src/client.ts:339

`Static`httpFor

httpFor(
requestResponse: FhirResource,
): { request: Request | undefined; response: Response | undefined }
Return the raw Request and Response objects attached to a FHIR response value by the HTTP layer.
Parameters
- requestResponse: FhirResource
  A FHIR resource returned by any client method.
Returns { request: Request | undefined; response: Response | undefined }
{ request, response } — either may be undefined for synthetic responses.
- Defined in src/client.ts:166

Class Client

Example

Index

Constructors

Properties

Accessors

Methods

Constructors

constructor

Parameters

Returns Client

Throws

Properties

ReadonlyhttpClient

Readonlypagination

Accessors

baseUrl

Returns string

Parameters

Returns void

bearerToken

Parameters

Returns void

customHeaders

Returns Record<string, string>

Parameters

Returns void

Methods

batch

Parameters

Returns Promise<FhirResource>

capabilityStatement

Parameters

Returns Promise<FhirResource>

compartmentSearch

Parameters

Returns Promise<FhirResource>

create

Parameters

Returns Promise<FhirResource>

Throws

delete

Parameters

Returns Promise<FhirResource>

Throws

history

Parameters

Returns Promise<FhirResource>

nextPage

Parameters

Returns Promise<FhirResource> | undefined

operation

Parameters

Returns Promise<FhirResource>

patch

Parameters

Returns Promise<FhirResource>

Throws

prevPage

Parameters

Returns Promise<FhirResource> | undefined

read

Parameters

Returns Promise<FhirResource>

Throws

request

Parameters

Returns Promise<FhirResource>

Example

resolve

Parameters

Returns Promise<FhirResource>

resourceHistory

Parameters

Returns Promise<FhirResource>

resourceSearch

Parameters

Returns Promise<FhirResource>

search

Parameters

`Readonly`httpClient

`Readonly`pagination

`Static`httpFor