# Create items

URL: https://docs.hanzo.ai/docs/openapi/eval/post-eval-datasets-by-name-items

> Writes one graded example — its input, its expected output, free-form metadata and a status — into the dataset named in the path, and answers 201 with it.

`POST /v1/eval/datasets/{name}/items`

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

|               |                                                      |
| ------------- | ---------------------------------------------------- |
| **Address**   | `https://api.hanzo.ai/v1/eval/datasets/{name}/items` |
| **Method**    | `POST`                                               |
| **Operation** | `post_eval_datasets_by_name_items`                   |
| **Auth**      | `Authorization: Bearer $HANZO_API_KEY`               |

Writes one graded example — its input, its expected output,
free-form metadata and a status — into the dataset named in the path, and
answers 201 with it.

That dataset MUST already exist for this org: an unknown one is 404, never a
silent create. Requires a validated principal; 401 without one.

## Request

7 fields, body `application/json` (required).

| Field            | In   | Type   | Required | Description                                                                                                                        |
| ---------------- | ---- | ------ | -------- | ---------------------------------------------------------------------------------------------------------------------------------- |
| `name`           | path | string | yes      |                                                                                                                                    |
| `expectedOutput` | body | any    | —        | Expected is the answer a correct model produces, which the judge grades against, stored as raw JSON exactly as sent, up to 64 KiB. |
| `id`             | body | string | —        | ID makes the write idempotent — re-posting the same id replaces that example in place.                                             |
| `input`          | body | any    | —        | Input is what the model under test will be given, stored as raw JSON exactly as sent, up to 64 KiB.                                |
| `metadata`       | body | object | —        | Metadata is a free-form object stored with the example.                                                                            |
| `metadata.*`     | body | any    | —        |                                                                                                                                    |
| `status`         | body | string | —        | Status is ACTIVE (the default) or ARCHIVED.                                                                                        |

## Response

| Status    | Body            | Meaning |
| --------- | --------------- | ------- |
| `201`     | eval.itemView   | created |
| `default` | problem-details | refused |

`201` body — 9 fields.

| Field            | In   | Type   | Always | Description                                                                      |
| ---------------- | ---- | ------ | ------ | -------------------------------------------------------------------------------- |
| `createdAt`      | body | string | —      | CreatedAt is when the example was first written.                                 |
| `datasetName`    | body | string | —      | Dataset is the set this example belongs to.                                      |
| `expectedOutput` | body | any    | —      | Expected is the answer a correct model produces, which the judge grades against. |
| `id`             | body | string | —      | ID is the example's handle, unique within the caller's org.                      |
| `input`          | body | any    | —      | Input is what the model under test is given, as it was written.                  |
| `metadata`       | body | object | —      | Metadata is the free-form object stored with the example.                        |
| `metadata.*`     | body | any    | —      |                                                                                  |
| `status`         | body | string | —      | Status is ACTIVE or ARCHIVED.                                                    |
| `updatedAt`      | body | string | —      | UpdatedAt is when it last changed.                                               |

Failure carries the platform error shape — see [Errors](https://docs.hanzo.ai/docs/errors).

## Examples

**CLI**

```bash
hanzo eval datasets items create <name>
```

**SDK**

**.ts**

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

const api = new EvalApi(new Configuration({ accessToken: process.env.HANZO_API_KEY }));
const { data } = await api.postEvalDatasetsByNameItems({ name: 'name', expectedOutput: "<expectedOutput>", id: "<id>" });
```

**.py**

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

client = ApiClient(Configuration(access_token=os.environ["HANZO_API_KEY"]))
result = EvalApi(client).post_eval_datasets_by_name_items(name='name', expected_output="<expectedOutput>", id="<id>")
```

**.go**

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

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

**.rs**

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

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

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

**.java**

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

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

var result = new EvalApi(client).postEvalDatasetsByNameItems();
```

**HTTP**

```bash
curl -X POST https://api.hanzo.ai/v1/eval/datasets/<name>/items \
  -H "Authorization: Bearer $HANZO_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
       "expectedOutput": "<expectedOutput>",
       "id": "<id>"
     }'
```

**MCP**

MCP reaches **eval** through the `eval` tool, which names its 16 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_eval_datasets"
         }
       }
     }'
```

---

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