# Update pref

URL: https://docs.hanzo.ai/docs/openapi/pref/patch-pref

> Merges a JSON object key-wise into the signed-in caller's OWN preference document and answers with the whole document after the merge, so a surface saves `theme` without having to send back the `density` another surface owns.

`PATCH /v1/pref`

> [Pref →](https://docs.hanzo.ai/docs/openapi/pref) · [All API references →](https://docs.hanzo.ai/docs/openapi) · [Get started →](https://docs.hanzo.ai/docs/guides)

|               |                                        |
| ------------- | -------------------------------------- |
| **Address**   | `https://api.hanzo.ai/v1/pref`         |
| **Method**    | `PATCH`                                |
| **Operation** | `patch_pref`                           |
| **Auth**      | `Authorization: Bearer $HANZO_API_KEY` |

Merges a JSON object key-wise into the signed-in caller's OWN preference document and answers with the whole document after the merge, so a surface saves `theme` without having to send back the `density` another surface owns. The merge is SHALLOW and the key space is open: an unnamed key is left untouched, a named key is replaced whole, and a key sent with a `null` value is DELETED. The subject is the `<owner>/<name>` identity built from the validated credential and is the mandatory predicate on the write, so there is no path to another user's preferences — not for an org admin, not for a platform SuperAdmin. Fails closed: no validated principal is 403; an empty body or a literal `null` is 400; and a patch or a resulting document over 16 KiB or 128 keys is 413.

## Request

The document declares no body for `PATCH /v1/pref`. The handler is typed in cloud but its shape is not yet emitted, so the fields are not listed here — ask MCP's `describe` for `patch_pref`, which answers from the running route.

## Response

The document declares no response body for this operation. It answers `200` on success and the platform error shape on failure — see [Errors](https://docs.hanzo.ai/docs/errors).

## Examples

**CLI**

```bash
hanzo pref patch
```

**SDK**

**.ts**

```ts
import { Configuration, PrefApi } from 'hanzoai';

const api = new PrefApi(new Configuration({ accessToken: process.env.HANZO_API_KEY }));
const { data } = await api.patchPref();
```

**.py**

```python
from hanzoai.cloud import ApiClient, Configuration
from hanzoai.cloud.api import PrefApi

client = ApiClient(Configuration(access_token=os.environ["HANZO_API_KEY"]))
result = PrefApi(client).patch_pref()
```

**.go**

```go
cfg := hanzoai.NewConfiguration()
cfg.AddDefaultHeader("Authorization", "Bearer "+os.Getenv("HANZO_API_KEY"))
client := hanzoai.NewAPIClient(cfg)

resp, _, err := client.PrefAPI.PatchPref(context.Background()).Execute()
if err != nil {
	return err
}
```

**.rs**

```rust
use hanzo_client::apis::{configuration::Configuration, pref_api};

let mut cfg = Configuration::new();
cfg.bearer_access_token = std::env::var("HANZO_API_KEY").ok();

let result = pref_api::patch_pref(&cfg, Default::default()).await?;
```

**.java**

```java
import ai.hanzo.cloud.ApiClient;
import ai.hanzo.cloud.api.PrefApi;

ApiClient client = new ApiClient();
client.setBearerToken(System.getenv("HANZO_API_KEY"));

var result = new PrefApi(client).patchPref();
```

**HTTP**

```bash
curl -X PATCH https://api.hanzo.ai/v1/pref \
  -H "Authorization: Bearer $HANZO_API_KEY"
```

**MCP**

MCP reaches **pref** through the `pref` tool, which names its 1 operations with its own verbs — this one among them, under a name only MCP declares. `describe` explains any of them:

```bash
curl -X POST https://api.hanzo.ai/v1/mcp \
  -H "Content-Type: application/json" \
  -d '{
       "jsonrpc": "2.0",
       "id": 1,
       "method": "tools/call",
       "params": {
         "name": "describe",
         "arguments": {
           "op": "list_prefs"
         }
       }
     }'
```

---

[Pref API](https://docs.hanzo.ai/docs/openapi/pref) · [All Hanzo APIs](https://docs.hanzo.ai/docs/openapi) · [Interactive reference](https://docs.hanzo.ai/docs/openapi/reference)