# @aehrc/sdc-populate > Performs the $populate operation from the HL7 FHIR SDC (Structured Data Capture) specification: http://hl7.org/fhir/uv/sdc Latest version **4.7.2** (published 2026-09-10) · Apache-2.0 license · 0 weekly downloads ## Install ```sh npm install @aehrc/sdc-populate pnpm add @aehrc/sdc-populate yarn add @aehrc/sdc-populate bun add @aehrc/sdc-populate ``` ## Health **Score 75/100 (B)** — status: active. Positive: has types; esm support; no vulnerabilities; has provenance; recently updated; high maintenance score; high quality score. Warnings: low downloads. ## Facts | | | |---|---| | Version | 4.7.2 | | Published | 2026-09-10 | | First published | 2023-09-01 | | Weekly downloads | 0 | | License | Apache-2.0 | | TypeScript types | bundled | | Module format | ESM + CommonJS | | Dependencies | 5 | | Unpacked size | 812.5 KB | | Known vulnerabilities | 0 | | Install scripts | no | | Provenance | attested (GitHub Actions) | | GitHub stars | 61 | | Maintainers | clinnygee, janadh, maryammehdiza, johngrimes, leoniedickson | ## Links - npm: https://www.npmjs.com/package/@aehrc/sdc-populate - Repository: https://github.com/aehrc/smart-forms - Homepage: https://github.com/aehrc/smart-forms#readme - Issues: https://github.com/aehrc/smart-forms/issues - npm.io page: https://npm.io/package/@aehrc/sdc-populate ## Dependencies (5) - [dayjs](https://npm.io/package/dayjs.md) ^1.11.21 - [fhirpath](https://npm.io/package/fhirpath.md) ^4.10.1 - [js-base64](https://npm.io/package/js-base64.md) ^3.7.8 - [fhirclient](https://npm.io/package/fhirclient.md) ^2.6.3 - [fhir-sdc-helpers](https://npm.io/package/fhir-sdc-helpers.md) ^0.1.0 ## Recent versions - 4.7.2 (latest) — 2026-09-10 - 4.0.0-beta.2 (beta) — 2025-04-09 - 4.7.1 — 2026-07-03 - 4.7.0 — 2026-03-25 - 4.6.3 — 2026-03-11 - 4.6.2 — 2025-08-07 - 4.6.1 — 2025-08-07 - 4.6.0 — 2025-07-24 - 4.5.0 — 2025-07-14 - 4.4.0 — 2025-07-10 - 4.3.1 — 2025-06-18 - 4.3.0 — 2025-06-02 - 4.2.0 — 2025-06-02 - 4.1.0 — 2025-05-22 - 4.0.1 — 2025-04-10 - … 38 more at https://npm.io/package/@aehrc/sdc-populate/versions ## README # SDC-Populate A Typescript reference implementation of the [$populate](http://hl7.org/fhir/uv/sdc/OperationDefinition-Questionnaire-populate.html) operation from the [HL7 FHIR Structured Data Capture Specification](http://hl7.org/fhir/uv/sdc/ImplementationGuide/hl7.fhir.uv.sdc) designed for [Form Population](http://hl7.org/fhir/uv/sdc/populate.html). Check out the [API Reference](https://smartforms.csiro.au/docs/api/sdc-populate) for technical specifications. ## Usage There are two ways to use this package: 1. Using it in a web app 2. Using it in a backend service e.g. ExpressJS ### Using it in a web app It is recommended to use `populateQuestionnaire()`, which performs an in-app population. This means that the app is not sending data to an external server, but rather using the library to populate the questionnaire in the app itself. ```ts const { populateSuccess, populateResult } = await populateQuestionnaire({ questionnaire: yourQuestionnaireResource, fetchResourceCallback: yourFetchResourceCallbackFunction, fetchResourceRequestConfig: yourFetchResourceRequestConfig, patient: yourPatient, }); // Pre-population is successful if (populateSuccess && populateResult !== null) { const questionnaireResponse = populateResult.populatedResponse; // Do things with the pre-populated questionnaireResponse... } ``` You will also need to define your own `fetchResourceCallback` function and `fetchResourceRequestConfig`. This function is responsible for fetching resources from your FHIR server. It should return a promise that resolves to the resource you want to fetch. ```ts import { FetchResourceRequestConfig, FetchResourceCallback } from '@aehrc/sdc-populate'; const ABSOLUTE_URL_REGEX = /^(https?|ftp):\/\/[^\s/$.?#].[^\s]*$/; export const yourFetchResourceRequestConfig: FetchResourceRequestConfig = { sourceServerUrl: 'https://proxy.smartforms.io/fhir', authToken: string | null }; export const yourFetchResourceCallbackFunction: FetchResourceCallback = async ( query: string, requestConfig: FetchResourceRequestConfig ) => { let { sourceServerUrl } = requestConfig; const { authToken } = requestConfig; const headers: Record = { Accept: 'application/json;charset=utf-8' }; if (authToken) { headers['Authorization'] = `Bearer ${authToken}`; } if (!sourceServerUrl.endsWith('/')) { sourceServerUrl += '/'; } const requestUrl = ABSOLUTE_URL_REGEX.test(query) ? query : `${sourceServerUrl}${query}`; const response = await fetch(requestUrl, { headers }); if (!response.ok) { throw new Error(`HTTP error when performing ${requestUrl}. Status: ${response.status}`); } return response.json(); }; ``` Available parameters for `populateQuestionnaire()`: | Parameter | Description | |-------------------------------|--------------------------------------------------------------------------------------------------| | `questionnaire` | Questionnaire to populate | | `fetchResourceCallback` | A callback function to fetch resources from your FHIR server | | `fetchResourceRequestConfig` | Any request configuration to be passed to the fetchResourceCallback (e.g., headers, auth, etc.) | | `patient` | Patient resource as patient in context | | `user` | Practitioner resource as user in context (optional) | | `encounter` | Encounter resource as encounter in context (optional) | | `fetchTerminologyCallback` | A callback function to fetch terminology resources (optional) | | `fetchTerminologyRequestConfig` | Any request configuration to be passed to the fetchTerminologyCallback (e.g., headers, auth, etc.) (optional) | ### Using it in a backend service Using this library in a backend service requires more pre-configuration. Due to how the [$populate](https://hl7.org/fhir/uv/sdc/OperationDefinition-Questionnaire-populate.html) works, you will need to provide a bunch of input parameters to the `populate()` function. There is a sample implementation of how to use the `populate()` function in https://github.com/aehrc/smart-forms/blob/main/services/populate-express/src/index.ts. ### Local development notes It's recommended to run this library within a web app or a service if you're doing local development. This library compiles to both CommonJS and ES Modules, so there is no problems in using it across web frameworks and Node-based backends. To compile the code, use `npm run compile`. To watch for changes, use `npm run watch`. Note: Do not use `tsc` or `tsc -w` as it will only compile to ES Modules, which means it will not work with CommonJS-based implementations. --- _Source: https://npm.io/package/@aehrc/sdc-populate · Machine-readable twin of the npm.io package page. 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