> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://humanloop.com/docs/v4/api/datasets/create-datapoint/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://humanloop.com/_mcp/server.

# Create Datapoint

POST https://api.humanloop.com/v4/datasets/{dataset_id}/datapoints
Content-Type: application/json

Create a new datapoint for a dataset.

Here in the v4 API, this has the following behaviour:
* Retrieve the current latest version of the dataset.
* Construct a new version of the dataset with the new testcases added.
* Store that latest version as a committed version with an autogenerated commit
  message and return the new datapoints

Reference: https://humanloop.com/docs/v4/api/datasets/create-datapoint

## Authentication

- `X-API-KEY` header (required) — API Key authentication via header

## Request

### Path parameters

- `dataset_id` (string, required) — String ID of dataset. Starts with `evts_`.

### Body (application/json)

This endpoint expects a Request.

- `Request`

## Response

### 201

Successful Response

- `list of DatapointResponse`

## Errors

### 422 Datasets Create Datapoint Request Unprocessable Entity Error

Validation Error

- `detail` (list of ValidationError, optional)

## Types

### CreateDatapointsByLogsRequest

- `log_ids` (list of string, required) — The IDs of the logs to create datapoints from.

### CreateDatapointRequest

- `inputs` (map from string to string, optional) — The inputs to the prompt template for this datapoint.
- `messages` (list of ChatMessageWithToolCall, optional) — The chat messages for this datapoint.
- `target` (map from string to CreateDatapointRequestTargetValue, optional) — Object with criteria necessary to evaluate this datapoint.

### DatapointResponse

- `id` (string, required)
- `dataset_id` (string, optional)
- `inputs` (map from string to string, optional)
- `messages` (list of ChatMessageWithToolCall, optional)
- `target` (map from string to DatapointResponseTargetValue, optional)

### ValidationError

- `loc` (list of ValidationErrorLocItem, required)
- `msg` (string, required)
- `type` (string, required)

### ChatMessageWithToolCall

- `role` (enum, required) — Role of the message author.
  - Allowed values: `user`, `assistant`, `system`, `tool`, `developer`
- `content` (Content, optional) — The content of the message.
- `name` (string, optional) — Optional name of the message author.
- `tool_call_id` (string, optional) — Tool call that this message is responding to.
- `tool_calls` (list of ToolCall, optional) — A list of tool calls requested by the assistant.
- `thinking` (list of ChatMessageWithToolCallThinkingItem, optional) — Model's chain-of-thought for providing the response. Present on assistant messages if model supports it.
- `tool_call` (FunctionTool, optional, deprecated) — NB: Deprecated in favour of tool_calls. A tool call requested by the assistant.

### CreateDatapointRequestTargetValue

### DatapointResponseTargetValue

### ValidationErrorLocItem

### Content

The content of the message.

### ToolCall

A tool call to be made.

- `id` (string, required)
- `type` ("function", required) — The type of tool to call.
- `function` (FunctionTool, required) — A function tool to be called by the model where user owns runtime.

### ChatMessageWithToolCallThinkingItem

- `type`: `thinking`
  - `signature` (string, required) — Cryptographic signature that verifies the thinking block was generated by Anthropic.
  - `thinking` (string, required) — Model's chain-of-thought for providing the response.
- `type`: `redacted_thinking`
  - `data` (string, required) — Thinking block Anthropic redacted for safety reasons. User is expected to pass the block back to Anthropic

### FunctionTool

A function tool to be called by the model where user owns runtime.

- `name` (string, required)
- `arguments` (string, optional)

## Examples

**Request**

```json
{
  "log_ids": [
    "log_ids"
  ]
}
```

**Response**

```json
[
  {
    "id": "id",
    "dataset_id": "dataset_id",
    "inputs": {
      "key": "value"
    },
    "messages": [
      {
        "role": "user"
      }
    ],
    "target": {
      "key": "value"
    }
  }
]
```

**SDK Code**

```python
import requests

url = "https://api.humanloop.com/v4/datasets/dataset_id/datapoints"

payload = { "log_ids": ["log_ids"] }
headers = {
    "X-API-KEY": "<apiKey>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.json())
```

```javascript
const url = 'https://api.humanloop.com/v4/datasets/dataset_id/datapoints';
const options = {
  method: 'POST',
  headers: {'X-API-KEY': '<apiKey>', 'Content-Type': 'application/json'},
  body: '{"log_ids":["log_ids"]}'
};

try {
  const response = await fetch(url, options);
  const data = await response.json();
  console.log(data);
} catch (error) {
  console.error(error);
}
```

```go
package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.humanloop.com/v4/datasets/dataset_id/datapoints"

	payload := strings.NewReader("{\n  \"log_ids\": [\n    \"log_ids\"\n  ]\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("X-API-KEY", "<apiKey>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(res)
	fmt.Println(string(body))

}
```

```ruby
require 'uri'
require 'net/http'

url = URI("https://api.humanloop.com/v4/datasets/dataset_id/datapoints")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["X-API-KEY"] = '<apiKey>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"log_ids\": [\n    \"log_ids\"\n  ]\n}"

response = http.request(request)
puts response.read_body
```

```java
import com.mashape.unirest.http.HttpResponse;
import com.mashape.unirest.http.Unirest;

HttpResponse<String> response = Unirest.post("https://api.humanloop.com/v4/datasets/dataset_id/datapoints")
  .header("X-API-KEY", "<apiKey>")
  .header("Content-Type", "application/json")
  .body("{\n  \"log_ids\": [\n    \"log_ids\"\n  ]\n}")
  .asString();
```

```php
<?php
require_once('vendor/autoload.php');

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api.humanloop.com/v4/datasets/dataset_id/datapoints', [
  'body' => '{
  "log_ids": [
    "log_ids"
  ]
}',
  'headers' => [
    'Content-Type' => 'application/json',
    'X-API-KEY' => '<apiKey>',
  ],
]);

echo $response->getBody();
```

```csharp
using RestSharp;

var client = new RestClient("https://api.humanloop.com/v4/datasets/dataset_id/datapoints");
var request = new RestRequest(Method.POST);
request.AddHeader("X-API-KEY", "<apiKey>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"log_ids\": [\n    \"log_ids\"\n  ]\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = [
  "X-API-KEY": "<apiKey>",
  "Content-Type": "application/json"
]
let parameters = ["log_ids": ["log_ids"]] as [String : Any]

let postData = JSONSerialization.data(withJSONObject: parameters, options: [])

let request = NSMutableURLRequest(url: NSURL(string: "https://api.humanloop.com/v4/datasets/dataset_id/datapoints")! as URL,
                                        cachePolicy: .useProtocolCachePolicy,
                                    timeoutInterval: 10.0)
request.httpMethod = "POST"
request.allHTTPHeaderFields = headers
request.httpBody = postData as Data

let session = URLSession.shared
let dataTask = session.dataTask(with: request as URLRequest, completionHandler: { (data, response, error) -> Void in
  if (error != nil) {
    print(error as Any)
  } else {
    let httpResponse = response as? HTTPURLResponse
    print(httpResponse)
  }
})

dataTask.resume()
```