---
title: Update an Agent Analytics evaluator
description: Updates an evaluator addressed by its stable identifier. Absent fields are unchanged. Each update creates a new inactive version; the response id is that new…
product: general
lang: en
last_updated: 2026-10-21
token_estimate: 1782
---
# Update an Agent Analytics evaluator

> For AI agents: a documentation index is available at [/docs/llms.txt](/docs/llms.txt). Append `.md` to any page URL for markdown, or send `Accept: text/markdown`.

## Update an Agent Analytics evaluator

**PATCH** `/v1/projects/{project_id}/agent-analytics/evaluators/{evaluator_stable_id}`

Full URL: `https://developer-api.amplitude.com/v1/projects/{project_id}/agent-analytics/evaluators/{evaluator_stable_id}`

**Servers:**
- Production (US): `https://developer-api.amplitude.com/v1/projects/{project_id}/agent-analytics/evaluators/{evaluator_stable_id}`
- Production (EU): `https://developer-api.eu.amplitude.com/v1/projects/{project_id}/agent-analytics/evaluators/{evaluator_stable_id}`

Update an Agent Analytics evaluator

Updates an evaluator addressed by its stable identifier. Absent fields are
unchanged. Each update creates a new inactive version; the response `id` is
that new version, and `stable_id` is unchanged.

Updating does not activate. An evaluator already active in the UI keeps
serving its current active version until the new one is promoted there.

## Authorizations

| Name | Type | Required | Default | Description |
| --- | --- | --- | --- | --- |
| Authorization | string | Yes | — | http |

## Path parameters

| Name | Type | Required | Default | Description |
| --- | --- | --- | --- | --- |
| project_id (path) | string | Yes | 12345 | Amplitude project identifier, backed by the canonical app ID. Constraints: pattern: ^[0-9]+$ |
| evaluator_stable_id (path) | string | Yes | — | Evaluator identifier that survives updates. Prefer this over a version identifier, which changes each time the evaluator is updated. |

## Header parameters

| Name | Type | Required | Default | Description |
| --- | --- | --- | --- | --- |
| Idempotency-Key (header) | string | Yes | — | Unique idempotency key used to safely retry write operations. Constraints: min length: 8, max length: 255 |

## Body (application/json)

| Name | Type | Required | Default | Description |
| --- | --- | --- | --- | --- |
| topic | string | No | — | Constraints: min length: 1, max length: 255 |
| description | string | No | — | Constraints: min length: 1 |
| tags | object[] | No | — | Replaces the full tag set when present. |
| tags.id | string | Yes | — | — |
| tags.label | string | Yes | — | Value stored on a result for this tag, such as `RESP_DATA_RESPONSE_MISMATCH`. |
| tags.description | string | Yes | — | — |
| suite_id | string | No | — | Constraints: nullable |

## Response (application/json)

**200** — New inactive evaluator version.

| Name | Type | Required | Default | Description |
| --- | --- | --- | --- | --- |
| data | object | Yes | — | — |
| data.id | string | Yes | — | Identifier for this evaluator version. Changes when the evaluator is updated. |
| data.object | string | Yes | — | — |
| data.project_id | string | Yes | — | — |
| data.stable_id | string | Yes | — | Identifier that survives updates. Use this to address an evaluator across versions. |
| data.topic | string | Yes | — | Human-readable evaluator name. Called `topic` to match the field already returned by the Agent Analytics read surface. Constraints: min length: 1 |
| data.output_type | string | Yes | — | Allowed values: binary, categorical, score |
| data.description | string | Yes | — | Evaluator prompt or rubric. |
| data.suite_id | string | No | — | Constraints: nullable |
| data.suite_name | string | No | — | Constraints: nullable |
| data.tags | object[] | Yes | — | Permitted output values. Required for `binary` and `categorical` evaluators; constrains what a result may record. |
| data.tags.id | string | Yes | — | — |
| data.tags.label | string | Yes | — | Value stored on a result for this tag, such as `RESP_DATA_RESPONSE_MISMATCH`. |
| data.tags.description | string | Yes | — | — |
| data.is_active | boolean | Yes | — | Read-only. Evaluators created or updated through this API are inactive. Activation is a separate permission and is not exposed here. |

```json
{
  "data": {
    "id": "string",
    "object": "agent_analytics_evaluator",
    "project_id": "string",
    "stable_id": "string",
    "topic": "string",
    "output_type": "binary",
    "description": "string",
    "suite_id": "string",
    "suite_name": "string",
    "tags": [
      {
        "id": "string",
        "label": "string",
        "description": "string"
      }
    ],
    "is_active": true
  }
}
```

**400**

**401**

**403**

**404**

**422**

**429**

**502**

## Code samples

### cURL

```bash
curl -X PATCH "https://developer-api.amplitude.com/v1/projects/12345/agent-analytics/evaluators/{evaluator_stable_id}" \
  -H "Content-Type: application/json" \
  -H "Authorization: YOUR_API_KEY"
```

### Python

```python
import requests

response = requests.patch(
    "https://developer-api.amplitude.com/v1/projects/12345/agent-analytics/evaluators/{evaluator_stable_id}",
    headers={
        "Content-Type": "application/json",
        "Authorization": "YOUR_API_KEY"
    }
)
data = response.json()
```

### JavaScript

```javascript
const response = await fetch("https://developer-api.amplitude.com/v1/projects/12345/agent-analytics/evaluators/{evaluator_stable_id}", {
  method: "PATCH",
  headers: {
    "Content-Type": "application/json",
    "Authorization": "YOUR_API_KEY"
  }
});
const data = await response.json();
```

### PHP

```php
<?php
$ch = curl_init("https://developer-api.amplitude.com/v1/projects/12345/agent-analytics/evaluators/{evaluator_stable_id}");
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "PATCH");
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    "Content-Type: application/json",
    "Authorization: YOUR_API_KEY"
]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$response = curl_exec($ch);
curl_close($ch);
```

### Go

```go
package main

import (
  "bytes"
  "net/http"
)

func main() {
req, _ := http.NewRequest("PATCH", "https://developer-api.amplitude.com/v1/projects/12345/agent-analytics/evaluators/{evaluator_stable_id}", nil)
req.Header.Set("Content-Type", "application/json")
req.Header.Set("Authorization", "YOUR_API_KEY")
  client := &http.Client{}
  resp, _ := client.Do(req)
  defer resp.Body.Close()
}
```

### Java

```java
HttpClient client = HttpClient.newHttpClient();
HttpRequest request = HttpRequest.newBuilder()
      .uri(URI.create("https://developer-api.amplitude.com/v1/projects/12345/agent-analytics/evaluators/{evaluator_stable_id}"))
      .method("PATCH", HttpRequest.BodyPublishers.noBody())
.header("Content-Type", "application/json")
      .header("Authorization", "YOUR_API_KEY")
      .build();
HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
```

### Ruby

```ruby
require "net/http"
require "json"

uri = URI("https://developer-api.amplitude.com/v1/projects/12345/agent-analytics/evaluators/{evaluator_stable_id}")
request = Net::HTTP::Patch.new(uri)
request["Content-Type"] = "application/json"
request["Authorization"] = "YOUR_API_KEY"
response = Net::HTTP.start(uri.hostname, uri.port, use_ssl: uri.scheme == "https") do |http|
  http.request(request)
end
```