---
title: "Configure the client"
description: "Set API version, organization, headers, and platform request attribution."
---

> Documentation Index
> Fetch the complete documentation index at: https://docs-staging.affinityrx.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Configure the client

Configure transport defaults once. Pass practice context and attribution in request options.

```typescript
import { Affinity } from "@affinity-health/sdk";

const affinity = new Affinity(process.env.AFFINITY_API_KEY!, {
  timeout: 60_000,
  maxNetworkRetries: 0,
});
```

| Option              | Default                      | Purpose                                                 |
| ------------------- | ---------------------------- | ------------------------------------------------------- |
| `timeout`           | `60_000`                     | Milliseconds per request attempt, including body reads. |
| `maxNetworkRetries` | `0`                          | Additional attempts, from zero to ten.                  |
| `apiVersion`        | `2026-09-28`                 | Dated API contract.                                     |
| `baseUrl`           | `https://api.affinityrx.com` | API endpoint.                                           |
| `fetch`             | `globalThis.fetch`           | Custom Fetch implementation.                            |

## Select a practice

Practice API keys identify their practice automatically. Platforms can scope a client once:

```typescript
const practice = affinity.forPractice(practiceId);
const patient = await practice.patients.get(patientId);
```

`forPractice()` returns a new client without changing the original. A conflicting practice ID is rejected.
For one request, pass `practiceId` in the last argument:

```typescript
await affinity.patients.update(patientId, { email: "alex@example.com" }, { practiceId });
```

## Attribute an action

Pass `actorId` and `actorType` when recording a person or worker in your platform.
Attribution does not grant signing authority or identify the prescription's prescriber.

```typescript
await practice.patients.update(
  patientId,
  { email: "alex@example.com" },
  { actorId: session.user.id, actorType: "user" },
);
```

Signing still requires the clinician's approval, attestation, and exact reviewed order revision.

## Retries and cancellation

Retries default to zero. When enabled, reads and keyed writes retry connection failures, timeouts,
and HTTP 429, 500, 502, 503, and 504 responses. Generated keys remain unchanged within one call.
Persist explicit keys for consequential actions so a retry from another process uses the same key.
Retry delays honor `Retry-After` and are capped at 30 seconds.

```typescript
const patient = await practice.patients.get(patientId, {
  signal: AbortSignal.timeout(10_000),
});
```

An aborted signal also cancels retry waits.

Source: https://docs-staging.affinityrx.com/guides/reference/sdks/typescript-configuration/index.mdx