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# Create decision

POST https://api-gateway.merge.dev/v1/decisions
Content-Type: application/json

Ask a decision model typed questions about some state and get one typed answer per question.

Reference: https://docs.merge.dev/merge-gateway/api-overview/decisions/create

## Authentication

- `Authorization` header (bearer token, required) — Your production key sent as a bearer token.

## Request

### Body (application/json)

This endpoint expects a DecisionRequestSchema.

- `model` (string, required) — Decision model ID, for example `typesafe/jev-1.13`.
- `state` (DecisionRequestSchemaState, required) — Content to evaluate, as text or structured data.
- `questions` (map from string to DecisionQuestionSchema, required) — Questions to answer, keyed by names you choose.
- `vendor` (string, optional, nullable) — Pin the vendor that runs this request.
- `customer` (string, optional, nullable) — Customer ID (UUID) to scope this request to, applying that customer's routing policy, provider keys, budget, and usage attribution.

## Response

### 200

Successful Response

- `model` (string, required) — Concrete model version that answered.
- `vendor` (string, required) — Vendor that served the request.
- `answers` (map from string to any, required) — One typed answer per question, keyed by your question names.
- `usage` (DecisionUsage, required) — Token usage for a decision request.
- `object` ("decision", optional, default: decision)

## Errors

### 422 Unprocessable Entity Error

Validation Error

- `detail` (list of ValidationError, optional)

## Types

### DecisionRequestSchemaState

Content to evaluate, as text or structured data.

### DecisionQuestionSchema

One typed question.

- `type` (enum, required) — Answer type: `noul` (yes or no), `choice`, or `score`.
  - Allowed values: `noul`, `choice`, `score`
- `instructions` (string, required) — What the question asks.
- `criteria` (DecisionQuestionSchemaCriteria, optional, nullable) — Answer space: required for `choice` (option to description map) and `score` (at least two ordered levels), optional for `noul`.

### DecisionUsage

Token usage for a decision request.

- `input_tokens` (integer, required)
- `output_tokens` (integer, required)
- `total_tokens` (integer, required)
- `cost` (double, optional, nullable) — Cost of the request in USD.

### ValidationError

Single field-level validation error. `loc` is the JSON path to the offending field, `msg` is a human-readable explanation, and `type` is a stable machine-readable error code.

- `loc` (list of ValidationErrorLocItems, required)
- `msg` (string, required)
- `type` (string, required)
- `input` (any, optional)
- `ctx` (ValidationErrorCtx, optional)

### DecisionQuestionSchemaCriteria

Answer space: required for `choice` (option to description map) and `score` (at least two ordered levels), optional for `noul`.

### ValidationErrorLocItems

### ValidationErrorCtx

## Examples

**Request**

```json
{
  "model": "string"
}
```

**Response**

```json
{
  "model": "string",
  "vendor": "string",
  "answers": {},
  "usage": {
    "input_tokens": 1,
    "output_tokens": 1,
    "total_tokens": 1,
    "cost": 1.1
  },
  "object": "decision"
}
```

**SDK Code**

```python
import requests

url = "https://api-gateway.merge.dev/v1/decisions"

payload = { "model": "string" }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.json())
```

```javascript
const url = 'https://api-gateway.merge.dev/v1/decisions';
const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: '{"model":"string"}'
};

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-gateway.merge.dev/v1/decisions"

	payload := strings.NewReader("{\n  \"model\": \"string\"\n}")

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

	req.Header.Add("Authorization", "Bearer <token>")
	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-gateway.merge.dev/v1/decisions")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"model\": \"string\"\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-gateway.merge.dev/v1/decisions")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"model\": \"string\"\n}")
  .asString();
```

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

$client = new \GuzzleHttp\Client();

$response = $client->request('POST', 'https://api-gateway.merge.dev/v1/decisions', [
  'body' => '{
  "model": "string"
}',
  'headers' => [
    'Authorization' => 'Bearer <token>',
    'Content-Type' => 'application/json',
  ],
]);

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

```csharp
using RestSharp;

var client = new RestClient("https://api-gateway.merge.dev/v1/decisions");
var request = new RestRequest(Method.POST);
request.AddHeader("Authorization", "Bearer <token>");
request.AddHeader("Content-Type", "application/json");
request.AddParameter("application/json", "{\n  \"model\": \"string\"\n}", ParameterType.RequestBody);
IRestResponse response = client.Execute(request);
```

```swift
import Foundation

let headers = [
  "Authorization": "Bearer <token>",
  "Content-Type": "application/json"
]
let parameters = ["model": "string"] as [String : Any]

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

let request = NSMutableURLRequest(url: NSURL(string: "https://api-gateway.merge.dev/v1/decisions")! 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()
```