# Create evaluators

URL: https://docs.hanzo.ai/docs/openapi/eval/post-eval-evaluators

> Saves a reusable judge for the caller's org — the judge model and the written criteria it grades against — and answers 201 with it.

`POST /v1/eval/evaluators`

> [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/evaluators` |
| **Method**    | `POST`                                    |
| **Operation** | `post_eval_evaluators`                    |
| **Auth**      | `Authorization: Bearer $HANZO_API_KEY`    |

Saves a reusable judge for the caller's org — the judge model
and the written criteria it grades against — and answers 201 with it.

Like a dataset, the NAME is the key: re-posting a name edits that judge rather
than adding a second one. Requires a validated principal; 401 without one.

## Request

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

| Field       | In   | Type   | Required | Description                                                                           |
| ----------- | ---- | ------ | -------- | ------------------------------------------------------------------------------------- |
| `criteria`  | body | string | —        | Criteria is the written standard the judge applies; over 64 KiB is refused.           |
| `model`     | body | string | —        | Model is the model that will do the grading.                                          |
| `name`      | body | string | yes      | Name is the judge's org-unique handle, matching ^\[A-Za-z0-9]\[A-Za-z0-9.\_-]{0,63}$. |
| `scoreName` | body | string | —        | ScoreName is the name the resulting scores are filed under.                           |

## Response

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

`201` body — 6 fields.

| Field       | In   | Type   | Always | Description                                                 |
| ----------- | ---- | ------ | ------ | ----------------------------------------------------------- |
| `createdAt` | body | string | —      | CreatedAt is when the judge was first defined.              |
| `criteria`  | body | string | —      | Criteria is the written standard the judge applies.         |
| `model`     | body | string | —      | Model is the model that does the grading.                   |
| `name`      | body | string | —      | Name is the judge's org-unique handle.                      |
| `scoreName` | body | string | —      | ScoreName is the name the resulting scores are filed under. |
| `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 evaluators create --name <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.postEvalEvaluators({ name: "<name>" });
```

**.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_evaluators(name="<name>")
```

**.go**

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

resp, _, err := client.EvalAPI.PostEvalEvaluators(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_evaluators(&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).postEvalEvaluators();
```

**HTTP**

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

**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)