# Letters

Letters written or received on behalf of a Patient.

## Create up to 100 Letters in one request

`POST /v1/letter_batches`

Each item accepts a public HTTPS `file_url` or Base64-encoded `file_base64`. Carebit creates all Letters together. If any item fails validation, no Letters are created.

**Required API scopes:** `letters.create`

## Parameters

- `Idempotency-Key` (header, `string`) (required) - Client-generated idempotency key. Required for every POST/PATCH write. Replay of the same key with the same body returns the stored response with an `Idempotency-Replayed: true` header. Same key + different body returns `422 idempotency_key_reused`. A duplicate that arrives while the first request is still in flight returns `409 idempotency_conflict` with `Retry-After: 1`.

## Request body (`application/json`)

- `object`
  - `items` (`array`) - The letters to create. Items are processed in their submitted order.
    - `items` (`object`)
      - `automatically_create_resource_permission_for_patient` (`boolean`) - Whether Carebit should automatically share the letter with the patient after processing.
      - `booking_id` (`string | null`) - format: `uuid`; The identifier of the booking associated with the letter, or null when it is not linked to a booking.
      - `clinician_id` (`string | null`) - format: `uuid`; The identifier of the clinician associated with the letter, or null when none is assigned.
      - `description` (`string | null`) - A description of the Letter.
      - `file_base64` (`string`) - format: `byte`; The letter bytes encoded as Base64. Provide this with `filename` instead of `file_url`. The decoded file can be at most 7 MB.
      - `file_url` (`string`) - format: `uri`; The public HTTPS URL that Carebit can fetch.
      - `filename` (`string | null`) - The filename to use for the letter. Required with `file_base64`; defaults to the remote file's filename for URL sources.
      - `notify_patient_of_resource_permission` (`boolean`) - Whether Carebit should notify the patient when the letter is shared with them.
      - `patient_id` (`string`) - format: `uuid`; The identifier of the patient that the letter belongs to.
      - `status` (`string`) - enum: `awaiting_receipt`, `awaiting_review`, `awaiting_sending`, `complete`, `draft`, `reviewed`; The workflow status to assign to the letter.
      - `title` (`string`) - The display title of the letter.

### Example

```json
{
  "items": [
    {
      "automatically_create_resource_permission_for_patient": true,
      "file_url": "https://storage.example.invalid/letters/referral.pdf",
      "notify_patient_of_resource_permission": true,
      "patient_id": "00000000-0000-4000-8000-000000000004",
      "status": "complete",
      "title": "Referral letter"
    }
  ]
}
```

## Response `202`

The batch was accepted. Poll it for each file's import status.

- `object`
  - `completed_count` (`integer`) - The number of items that finished processing successfully.
  - `created_at` (`string`) - format: `date-time`; An ISO 8601 timestamp in UTC, with a `Z` suffix. For example, `2026-07-01T09:00:00Z`.
  - `failed_count` (`integer`) - The number of items that finished processing with an error.
  - `id` (`string`) - format: `uuid`; The resource's unique identifier, formatted as an RFC 4122 version 4 UUID.
  - `items` (`array`) - The import items in their original request order.
    - `items` (`object`)
      - `created_resource` (`string | null`) - format: `uri`; The URL of the resource created for a succeeded item. Null unless `status` is `succeeded`.
      - `created_resource_id` (`string | null`) - format: `uuid`; The identifier of the resource created for a succeeded item. Null unless `status` is `succeeded`.
      - `created_resource_type` (`string | null`) - enum: `null`, `Attachment`, `Letter`, `Note`, `TestResult`; The type of resource created for a succeeded item. Null unless `status` is `succeeded`.
      - `error` (`any`) - The failure details for this item. Null unless the item has failed.
      - `id` (`string`) - format: `uuid`; The resource's unique identifier, formatted as an RFC 4122 version 4 UUID.
      - `object` (`any`) - Always `remote_file_import_batch_item`.
      - `position` (`integer`) - The zero-based position of the item in the submitted batch.
      - `status` (`string`) - enum: `failed`, `pending`, `processing`, `succeeded`; The current download, validation, and malware-scanning status of the item.
  - `links` (`object`) - URLs to related resources.
    - `self` (`string`) - format: `uri`; The full URL of a related resource.
  - `object` (`any`) - Discriminator value emitted at `object`.
  - `resource_type` (`string`) - enum: `letter`, `note`, `test_result`; The type of resource created by every item in the batch.
  - `status` (`string`) - enum: `completed`, `pending`, `processing`; The current download, validation, and malware-scanning status of the batch.
  - `total_count` (`integer`) - The total number of items submitted in the batch.
  - `updated_at` (`string`) - format: `date-time`; An ISO 8601 timestamp in UTC, with a `Z` suffix. For example, `2026-07-01T09:00:00Z`.

### Example

```json
{
  "id": "ebc38802-f219-4c7b-8136-8e963a0c69e0",
  "object": "remote_file_import_batch",
  "completed_count": 0,
  "created_at": "2026-01-01T09:00:00Z",
  "failed_count": 0,
  "items": [
    {
      "id": "57bed2bf-e2e1-463b-8a96-643e3817a8b8",
      "object": "remote_file_import_batch_item",
      "created_resource": "https://api.carebit.co/v1/letters/c3d4e5f6-0718-49ab-acde-f01234567890",
      "created_resource_id": "7e09a8e3-e3c1-4dee-863b-85d56e4329da",
      "created_resource_type": null,
      "error": null,
      "position": 0,
      "status": "failed"
    }
  ],
  "links": {
    "self": "https://api.carebit.co/v1/remote_file_import_batches/ebc38802-f219-4c7b-8136-8e963a0c69e0"
  },
  "resource_type": "letter",
  "status": "completed",
  "total_count": 1,
  "updated_at": "2026-01-01T09:00:00Z"
}
```

## Response `400`

The `Idempotency-Key` header is missing (`idempotency_key_required`) or exceeds 255 characters (`idempotency_key_too_long`).

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `401`

The access token is missing, invalid, expired, or revoked.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `403`

The access token lacks the required scope, or the project is disabled.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `404`

Error response.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `409`

A concurrent request holds the idempotency lease (`idempotency_conflict`). Retry after the delay indicated by `Retry-After`.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `422`

The `Idempotency-Key` was previously used with a different request body (`idempotency_key_reused`), or the request body failed validation.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `429`

Too many requests. Retry after the delay indicated by `Retry-After`.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Code samples

```bash
curl -X POST "https://api.carebit.co/v1/letter_batches" \
  -H "Authorization: Bearer $CAREBIT_ACCESS_TOKEN" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{
  "items": [
    {
      "automatically_create_resource_permission_for_patient": true,
      "file_url": "https://storage.example.invalid/letters/referral.pdf",
      "notify_patient_of_resource_permission": true,
      "patient_id": "00000000-0000-4000-8000-000000000004",
      "status": "complete",
      "title": "Referral letter"
    }
  ]
}'
```

```javascript
const response = await fetch("https://api.carebit.co/v1/letter_batches", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.CAREBIT_ACCESS_TOKEN}`,
    "Content-Type": "application/json",
    "Idempotency-Key": crypto.randomUUID(),
  },
  body: JSON.stringify({
  "items": [
    {
      "automatically_create_resource_permission_for_patient": true,
      "file_url": "https://storage.example.invalid/letters/referral.pdf",
      "notify_patient_of_resource_permission": true,
      "patient_id": "00000000-0000-4000-8000-000000000004",
      "status": "complete",
      "title": "Referral letter"
    }
  ]
}),
});

if (!response.ok) {
  throw new Error(`Carebit API error: ${response.status}`);
}

const data = await response.json();
```

```python
import os
import requests
import uuid

response = requests.post(
    "https://api.carebit.co/v1/letter_batches",
    headers={
        "Authorization": f"Bearer {os.environ['CAREBIT_ACCESS_TOKEN']}",
        "Idempotency-Key": str(uuid.uuid4()),
    },
    json={
        "items": [
            {
                "automatically_create_resource_permission_for_patient": True,
                "file_url": "https://storage.example.invalid/letters/referral.pdf",
                "notify_patient_of_resource_permission": True,
                "patient_id": "00000000-0000-4000-8000-000000000004",
                "status": "complete",
                "title": "Referral letter"
            }
        ]
    }
)
response.raise_for_status()
data = response.json()
```

```ruby
require "httparty"
require "json"
require "securerandom"

response = HTTParty.post(
  "https://api.carebit.co/v1/letter_batches",
  headers: {
    "Authorization" => "Bearer #{ENV.fetch("CAREBIT_ACCESS_TOKEN")}",
    "Idempotency-Key" => SecureRandom.uuid,
    "Content-Type" => "application/json"
  },
  body: {
    "items" => [
      {
        "automatically_create_resource_permission_for_patient" => true,
        "file_url" => "https://storage.example.invalid/letters/referral.pdf",
        "notify_patient_of_resource_permission" => true,
        "patient_id" => "00000000-0000-4000-8000-000000000004",
        "status" => "complete",
        "title" => "Referral letter"
      }
    ]
  }.to_json
)
raise "Carebit API error: #{response.code}" unless response.success?
data = response.parsed_response
```

```php
<?php

$client = new GuzzleHttp\Client();

$response = $client->post("https://api.carebit.co/v1/letter_batches", [
    "headers" => [
      "Authorization" => "Bearer " . getenv("CAREBIT_ACCESS_TOKEN"),
      "Idempotency-Key" => bin2hex(random_bytes(16)),
    ],
    "json" => [
      "items" => [
        [
          "automatically_create_resource_permission_for_patient" => true,
          "file_url" => "https://storage.example.invalid/letters/referral.pdf",
          "notify_patient_of_resource_permission" => true,
          "patient_id" => "00000000-0000-4000-8000-000000000004",
          "status" => "complete",
          "title" => "Referral letter"
        ]
      ]
    ]
]);
$data = json_decode((string) $response->getBody(), true, flags: JSON_THROW_ON_ERROR);
```


## List Letters

`GET /v1/letters`

**Required API scopes:** `letters.read`

## Parameters

- `patient_id` (query, `string`)
- `booking_id` (query, `string`)
- `status` (query, `string`)
- `created_since` (query, `string`)
- `limit` (query, `integer`) - The maximum number of items to return. Defaults to `25`; the maximum is `100`.
- `starting_after` (query, `string`) - Return items after this resource ID. You cannot use this with `cursor`.
- `cursor` (query, `string`) - The `next_cursor` value from the previous page. You cannot use this with `starting_after`.

## Response `200`

Paginated list of `Letter` objects.

- `any`

### Example

```json
{
  "object": "list",
  "data": [
    {
      "id": "c3d4e5f6-0718-49ab-acde-f01234567890",
      "object": "letter",
      "automatically_create_resource_permission_for_patient": true,
      "created_at": "2026-01-01T09:00:00Z",
      "download_url": "https://files.example.invalid/document.pdf?signature=test",
      "filename": "referral-letter.pdf",
      "links": {
        "booking": "https://api.carebit.co/v1/bookings/92a3b4c5-d6e7-4f01-8234-56789abcdef0",
        "clinician": "https://api.carebit.co/v1/clinicians/2b3c4d5e-6f70-489a-9bcd-ef0123456789",
        "patient": "https://api.carebit.co/v1/patients/1a2b3c4d-5e6f-4789-8abc-def012345678",
        "remote_file_import_batch": "https://api.carebit.co/v1/remote_file_import_batches/ebc38802-f219-4c7b-8136-8e963a0c69e0"
      },
      "notify_patient_of_resource_permission": true,
      "remote_file_import_batch_id": "ebc38802-f219-4c7b-8136-8e963a0c69e0",
      "sent_at": "2026-01-01T09:00:00Z",
      "status": "awaiting_proofreading",
      "title": "Dr",
      "updated_at": "2026-01-01T09:00:00Z"
    }
  ],
  "has_more": false,
  "next_cursor": "eyJzdGFydF90aW1lIjoiMjAyNi0wMS0wMVQwOTowMDowMFoifQ",
  "url": "/v1/letters"
}
```

## Response `400`

A filter or pagination parameter is invalid.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `401`

The access token is missing, invalid, expired, or revoked.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `403`

The access token lacks the required scope, or the project is disabled.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `429`

Too many requests. Retry after the delay indicated by `Retry-After`.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Code samples

```bash
curl -X GET "https://api.carebit.co/v1/letters" \
  -H "Authorization: Bearer $CAREBIT_ACCESS_TOKEN"
```

```javascript
const response = await fetch("https://api.carebit.co/v1/letters", {
  method: "GET",
  headers: {
    Authorization: `Bearer ${process.env.CAREBIT_ACCESS_TOKEN}`,
  },
});

if (!response.ok) {
  throw new Error(`Carebit API error: ${response.status}`);
}

const data = await response.json();
```

```python
import os
import requests

response = requests.get(
    "https://api.carebit.co/v1/letters",
    headers={
        "Authorization": f"Bearer {os.environ['CAREBIT_ACCESS_TOKEN']}",
    }
)
response.raise_for_status()
data = response.json()
```

```ruby
require "httparty"

response = HTTParty.get(
  "https://api.carebit.co/v1/letters",
  headers: {
    "Authorization" => "Bearer #{ENV.fetch("CAREBIT_ACCESS_TOKEN")}"
  }
)
raise "Carebit API error: #{response.code}" unless response.success?
data = response.parsed_response
```

```php
<?php

$client = new GuzzleHttp\Client();

$response = $client->get("https://api.carebit.co/v1/letters", [
    "headers" => [
      "Authorization" => "Bearer " . getenv("CAREBIT_ACCESS_TOKEN"),
    ]
]);
$data = json_decode((string) $response->getBody(), true, flags: JSON_THROW_ON_ERROR);
```


## Create a Letter with a file

`POST /v1/letters`

Creates the Letter immediately, then imports its file in the background. Provide the file as a public HTTPS `file_url` or Base64-encoded `file_base64`. Poll `/v1/remote_file_import_batches/:remote_file_import_batch_id` for the import status.

**Required API scopes:** `letters.create`

## Parameters

- `Idempotency-Key` (header, `string`) (required) - Client-generated idempotency key. Required for every POST/PATCH write. Replay of the same key with the same body returns the stored response with an `Idempotency-Replayed: true` header. Same key + different body returns `422 idempotency_key_reused`. A duplicate that arrives while the first request is still in flight returns `409 idempotency_conflict` with `Retry-After: 1`.

## Request body (`application/json`)

- `object`
  - `automatically_create_resource_permission_for_patient` (`boolean`) - Whether Carebit should automatically share the letter with the patient after processing.
  - `booking_id` (`string | null`) - format: `uuid`; The identifier of the booking associated with the letter, or null when it is not linked to a booking.
  - `clinician_id` (`string | null`) - format: `uuid`; The identifier of the clinician associated with the letter, or null when none is assigned.
  - `description` (`string | null`) - A description of the Letter.
  - `file_base64` (`string`) - format: `byte`; The letter bytes encoded as Base64. Provide this with `filename` instead of `file_url`. The decoded file can be at most 7 MB.
  - `file_url` (`string`) - format: `uri`; The public HTTPS URL that Carebit can fetch.
  - `filename` (`string | null`) - The filename to use for the letter. Required with `file_base64`; defaults to the remote file's filename for URL sources.
  - `notify_patient_of_resource_permission` (`boolean`) - Whether Carebit should notify the patient when the letter is shared with them.
  - `patient_id` (`string`) - format: `uuid`; The identifier of the patient that the letter belongs to.
  - `status` (`string`) - enum: `awaiting_receipt`, `awaiting_review`, `awaiting_sending`, `complete`, `draft`, `reviewed`; The workflow status to assign to the letter.
  - `title` (`string`) - The display title of the letter.

### Example

```json
{
  "automatically_create_resource_permission_for_patient": true,
  "file_url": "https://storage.example.invalid/letters/referral.pdf",
  "filename": "referral.pdf",
  "notify_patient_of_resource_permission": true,
  "patient_id": "00000000-0000-4000-8000-000000000004",
  "status": "complete",
  "title": "Referral letter"
}
```

## Response `201`

The requested `Letter`.

- `object`
  - `automatically_create_resource_permission_for_patient` (`boolean`) - Whether Carebit automatically shares the letter with the patient after processing.
  - `created_at` (`string`) - format: `date-time`; An ISO 8601 timestamp in UTC, with a `Z` suffix. For example, `2026-07-01T09:00:00Z`.
  - `download_url` (`string | null`) - format: `uri`; The short-lived signed download URL for the Letter. Null until the uploaded file passes malware scanning.
  - `filename` (`string | null`) - The original filename of the letter document.
  - `id` (`string`) - format: `uuid`; The resource's unique identifier, formatted as an RFC 4122 version 4 UUID.
  - `links` (`object`) - URLs to related resources.
    - `booking` (`string | null`) - format: `uri`; The full URL of a related resource.
    - `clinician` (`string | null`) - format: `uri`; The full URL of a related resource.
    - `patient` (`string | null`) - format: `uri`; The full URL of a related resource.
    - `remote_file_import_batch` (`string`) - format: `uri`; The full URL of a related resource.
  - `notify_patient_of_resource_permission` (`boolean | null`) - Whether Carebit notifies the patient when the letter is shared with them.
  - `object` (`any`) - Discriminator value emitted at `object`.
  - `remote_file_import_batch_id` (`string`) - format: `uuid`; The identifier of the remote file import batch created for the uploaded file. Set on the create response. Poll `/v1/remote_file_import_batches/:id` for processing status.
  - `sent_at` (`string | null`) - format: `date-time`; An ISO 8601 timestamp in UTC, with a `Z` suffix. For example, `2026-07-01T09:00:00Z`.
  - `status` (`string | null`) - enum: `awaiting_proofreading`, `awaiting_receipt`, `awaiting_review`, `awaiting_sending`, `awaiting_typing`, `complete`, `draft`, `reviewed`, `null`; The Letter's workflow status. Null while the Letter is being created.
  - `title` (`string | null`) - The display title of the letter.
  - `updated_at` (`string`) - format: `date-time`; An ISO 8601 timestamp in UTC, with a `Z` suffix. For example, `2026-07-01T09:00:00Z`.

### Example

```json
{
  "id": "c3d4e5f6-0718-49ab-acde-f01234567890",
  "object": "letter",
  "automatically_create_resource_permission_for_patient": true,
  "created_at": "2026-01-01T09:00:00Z",
  "download_url": "https://files.example.invalid/document.pdf?signature=test",
  "filename": "referral-letter.pdf",
  "links": {
    "booking": "https://api.carebit.co/v1/bookings/92a3b4c5-d6e7-4f01-8234-56789abcdef0",
    "clinician": "https://api.carebit.co/v1/clinicians/2b3c4d5e-6f70-489a-9bcd-ef0123456789",
    "patient": "https://api.carebit.co/v1/patients/1a2b3c4d-5e6f-4789-8abc-def012345678",
    "remote_file_import_batch": "https://api.carebit.co/v1/remote_file_import_batches/ebc38802-f219-4c7b-8136-8e963a0c69e0"
  },
  "notify_patient_of_resource_permission": true,
  "remote_file_import_batch_id": "ebc38802-f219-4c7b-8136-8e963a0c69e0",
  "sent_at": "2026-01-01T09:00:00Z",
  "status": "awaiting_proofreading",
  "title": "Dr",
  "updated_at": "2026-01-01T09:00:00Z"
}
```

## Response `400`

The `Idempotency-Key` header is missing (`idempotency_key_required`) or exceeds 255 characters (`idempotency_key_too_long`).

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `401`

The access token is missing, invalid, expired, or revoked.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `403`

The access token lacks the required scope, or the project is disabled.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `404`

Error response.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `409`

A concurrent request holds the idempotency lease (`idempotency_conflict`). Retry after the delay indicated by `Retry-After`.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `422`

The `Idempotency-Key` was previously used with a different request body (`idempotency_key_reused`), or the request body failed validation.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `429`

Too many requests. Retry after the delay indicated by `Retry-After`.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Code samples

```bash
curl -X POST "https://api.carebit.co/v1/letters" \
  -H "Authorization: Bearer $CAREBIT_ACCESS_TOKEN" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{
  "automatically_create_resource_permission_for_patient": true,
  "file_url": "https://storage.example.invalid/letters/referral.pdf",
  "filename": "referral.pdf",
  "notify_patient_of_resource_permission": true,
  "patient_id": "00000000-0000-4000-8000-000000000004",
  "status": "complete",
  "title": "Referral letter"
}'
```

```javascript
const response = await fetch("https://api.carebit.co/v1/letters", {
  method: "POST",
  headers: {
    Authorization: `Bearer ${process.env.CAREBIT_ACCESS_TOKEN}`,
    "Content-Type": "application/json",
    "Idempotency-Key": crypto.randomUUID(),
  },
  body: JSON.stringify({
  "automatically_create_resource_permission_for_patient": true,
  "file_url": "https://storage.example.invalid/letters/referral.pdf",
  "filename": "referral.pdf",
  "notify_patient_of_resource_permission": true,
  "patient_id": "00000000-0000-4000-8000-000000000004",
  "status": "complete",
  "title": "Referral letter"
}),
});

if (!response.ok) {
  throw new Error(`Carebit API error: ${response.status}`);
}

const data = await response.json();
```

```python
import os
import requests
import uuid

response = requests.post(
    "https://api.carebit.co/v1/letters",
    headers={
        "Authorization": f"Bearer {os.environ['CAREBIT_ACCESS_TOKEN']}",
        "Idempotency-Key": str(uuid.uuid4()),
    },
    json={
        "automatically_create_resource_permission_for_patient": True,
        "file_url": "https://storage.example.invalid/letters/referral.pdf",
        "filename": "referral.pdf",
        "notify_patient_of_resource_permission": True,
        "patient_id": "00000000-0000-4000-8000-000000000004",
        "status": "complete",
        "title": "Referral letter"
    }
)
response.raise_for_status()
data = response.json()
```

```ruby
require "httparty"
require "json"
require "securerandom"

response = HTTParty.post(
  "https://api.carebit.co/v1/letters",
  headers: {
    "Authorization" => "Bearer #{ENV.fetch("CAREBIT_ACCESS_TOKEN")}",
    "Idempotency-Key" => SecureRandom.uuid,
    "Content-Type" => "application/json"
  },
  body: {
    "automatically_create_resource_permission_for_patient" => true,
    "file_url" => "https://storage.example.invalid/letters/referral.pdf",
    "filename" => "referral.pdf",
    "notify_patient_of_resource_permission" => true,
    "patient_id" => "00000000-0000-4000-8000-000000000004",
    "status" => "complete",
    "title" => "Referral letter"
  }.to_json
)
raise "Carebit API error: #{response.code}" unless response.success?
data = response.parsed_response
```

```php
<?php

$client = new GuzzleHttp\Client();

$response = $client->post("https://api.carebit.co/v1/letters", [
    "headers" => [
      "Authorization" => "Bearer " . getenv("CAREBIT_ACCESS_TOKEN"),
      "Idempotency-Key" => bin2hex(random_bytes(16)),
    ],
    "json" => [
      "automatically_create_resource_permission_for_patient" => true,
      "file_url" => "https://storage.example.invalid/letters/referral.pdf",
      "filename" => "referral.pdf",
      "notify_patient_of_resource_permission" => true,
      "patient_id" => "00000000-0000-4000-8000-000000000004",
      "status" => "complete",
      "title" => "Referral letter"
    ]
]);
$data = json_decode((string) $response->getBody(), true, flags: JSON_THROW_ON_ERROR);
```


## Get a Letter

`GET /v1/letters/:id`

**Required API scopes:** `letters.read`

## Parameters

- `id` (path, `string`) (required)

## Response `200`

The requested `Letter`.

- `object`
  - `automatically_create_resource_permission_for_patient` (`boolean`) - Whether Carebit automatically shares the letter with the patient after processing.
  - `created_at` (`string`) - format: `date-time`; An ISO 8601 timestamp in UTC, with a `Z` suffix. For example, `2026-07-01T09:00:00Z`.
  - `download_url` (`string | null`) - format: `uri`; The short-lived signed download URL for the Letter. Null until the uploaded file passes malware scanning.
  - `filename` (`string | null`) - The original filename of the letter document.
  - `id` (`string`) - format: `uuid`; The resource's unique identifier, formatted as an RFC 4122 version 4 UUID.
  - `links` (`object`) - URLs to related resources.
    - `booking` (`string | null`) - format: `uri`; The full URL of a related resource.
    - `clinician` (`string | null`) - format: `uri`; The full URL of a related resource.
    - `patient` (`string | null`) - format: `uri`; The full URL of a related resource.
    - `remote_file_import_batch` (`string`) - format: `uri`; The full URL of a related resource.
  - `notify_patient_of_resource_permission` (`boolean | null`) - Whether Carebit notifies the patient when the letter is shared with them.
  - `object` (`any`) - Discriminator value emitted at `object`.
  - `remote_file_import_batch_id` (`string`) - format: `uuid`; The identifier of the remote file import batch created for the uploaded file. Set on the create response. Poll `/v1/remote_file_import_batches/:id` for processing status.
  - `sent_at` (`string | null`) - format: `date-time`; An ISO 8601 timestamp in UTC, with a `Z` suffix. For example, `2026-07-01T09:00:00Z`.
  - `status` (`string | null`) - enum: `awaiting_proofreading`, `awaiting_receipt`, `awaiting_review`, `awaiting_sending`, `awaiting_typing`, `complete`, `draft`, `reviewed`, `null`; The Letter's workflow status. Null while the Letter is being created.
  - `title` (`string | null`) - The display title of the letter.
  - `updated_at` (`string`) - format: `date-time`; An ISO 8601 timestamp in UTC, with a `Z` suffix. For example, `2026-07-01T09:00:00Z`.

### Example

```json
{
  "id": "c3d4e5f6-0718-49ab-acde-f01234567890",
  "object": "letter",
  "automatically_create_resource_permission_for_patient": true,
  "created_at": "2026-01-01T09:00:00Z",
  "download_url": "https://files.example.invalid/document.pdf?signature=test",
  "filename": "referral-letter.pdf",
  "links": {
    "booking": "https://api.carebit.co/v1/bookings/92a3b4c5-d6e7-4f01-8234-56789abcdef0",
    "clinician": "https://api.carebit.co/v1/clinicians/2b3c4d5e-6f70-489a-9bcd-ef0123456789",
    "patient": "https://api.carebit.co/v1/patients/1a2b3c4d-5e6f-4789-8abc-def012345678",
    "remote_file_import_batch": "https://api.carebit.co/v1/remote_file_import_batches/ebc38802-f219-4c7b-8136-8e963a0c69e0"
  },
  "notify_patient_of_resource_permission": true,
  "remote_file_import_batch_id": "ebc38802-f219-4c7b-8136-8e963a0c69e0",
  "sent_at": "2026-01-01T09:00:00Z",
  "status": "awaiting_proofreading",
  "title": "Dr",
  "updated_at": "2026-01-01T09:00:00Z"
}
```

## Response `401`

The access token is missing, invalid, expired, or revoked.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `403`

The access token lacks the required scope, or the project is disabled.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `404`

Error response.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Response `429`

Too many requests. Retry after the delay indicated by `Retry-After`.

- `object`
  - `error` (`object`) - The structured details that describe why the request failed.
    - `code` (`string`) - The machine-readable error code.
    - `errors` (`array | null`) - Additional errors from a failed validation.
      - `items` (`object`)
        - `code` (`string`) - The machine-readable code for this validation error.
        - `message` (`string`) - A message that explains this validation error.
        - `param` (`string | null`) - The name of the parameter that caused this validation error, when known.
    - `message` (`string`) - A message that explains the error and how to resolve it.
    - `param` (`string | null`) - The name of the parameter that caused the error, when known.
    - `type` (`string`) - enum: `authentication_error`, `permission_error`, `invalid_request_error`, `rate_limit_error`, `api_error`; The high-level category of the error.

### Example

```json
{
  "error": {
    "code": "resource_missing",
    "errors": [
      {
        "code": "resource_missing",
        "message": "The requested resource was not found.",
        "param": "patient_id"
      }
    ],
    "message": "The requested resource was not found.",
    "param": "patient_id",
    "type": "authentication_error"
  }
}
```

## Code samples

```bash
curl -X GET "https://api.carebit.co/v1/letters/8f14e45f-ea7d-4b6f-9c2a-1d3e5f7a9b0c" \
  -H "Authorization: Bearer $CAREBIT_ACCESS_TOKEN"
```

```javascript
const response = await fetch("https://api.carebit.co/v1/letters/8f14e45f-ea7d-4b6f-9c2a-1d3e5f7a9b0c", {
  method: "GET",
  headers: {
    Authorization: `Bearer ${process.env.CAREBIT_ACCESS_TOKEN}`,
  },
});

if (!response.ok) {
  throw new Error(`Carebit API error: ${response.status}`);
}

const data = await response.json();
```

```python
import os
import requests

response = requests.get(
    "https://api.carebit.co/v1/letters/8f14e45f-ea7d-4b6f-9c2a-1d3e5f7a9b0c",
    headers={
        "Authorization": f"Bearer {os.environ['CAREBIT_ACCESS_TOKEN']}",
    }
)
response.raise_for_status()
data = response.json()
```

```ruby
require "httparty"

response = HTTParty.get(
  "https://api.carebit.co/v1/letters/8f14e45f-ea7d-4b6f-9c2a-1d3e5f7a9b0c",
  headers: {
    "Authorization" => "Bearer #{ENV.fetch("CAREBIT_ACCESS_TOKEN")}"
  }
)
raise "Carebit API error: #{response.code}" unless response.success?
data = response.parsed_response
```

```php
<?php

$client = new GuzzleHttp\Client();

$response = $client->get("https://api.carebit.co/v1/letters/8f14e45f-ea7d-4b6f-9c2a-1d3e5f7a9b0c", [
    "headers" => [
      "Authorization" => "Bearer " . getenv("CAREBIT_ACCESS_TOKEN"),
    ]
]);
$data = json_decode((string) $response->getBody(), true, flags: JSON_THROW_ON_ERROR);
```