> ## Documentation Index
> Fetch the complete documentation index at: https://cantonfoundation-generated-reference-full-stack-preview.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# POST /v2/interactive-submission/preferred-packages

> Compute the preferred packages for the vetting requirements in the request. A preferred package is the highest-versioned package for a provided package-name that is vetted by all the participants hosting the provided parties.

<div class="x2mdx-ref-page x2mdx-ref-page--operation x2mdx-ref-page--manual-api" />

<div class="x2mdx-ref-hero">
  <p class="x2mdx-ref-summary">Compute the preferred packages for the vetting requirements in the request. A preferred package is the highest-versioned package for a provided package-name that is vetted by all the participants hosting the provided parties.</p>

  <div class="x2mdx-ref-badges">
    <span class="x2mdx-ref-badge x2mdx-ref-badge--protocol">OpenAPI</span>

    <a class="x2mdx-ref-badge x2mdx-ref-badge--changed" href="#history-updated-3-5">Updated 3.5</a>
  </div>
</div>

<RequestExample>
  ```bash cURL theme={"theme":{"light":"github-light","dark":"github-dark"}}
  curl --request POST \
    --url 'http://localhost:7575/v2/interactive-submission/preferred-packages' \
    --header 'Authorization: Bearer $TOKEN' \
    --header 'Content-Type: application/json' \
    --data '{
    "packageVettingRequirements": [
      {
        "parties": [
          "<string>"
        ],
        "packageName": "<string>"
      }
    ],
    "synchronizerId": "<string>",
    "vettingValidAt": "<string>"
  }'
  ```

  ```python Python theme={"theme":{"light":"github-light","dark":"github-dark"}}
  import json
  import requests

  url = "http://localhost:7575/v2/interactive-submission/preferred-packages"
  headers = {'Authorization': 'Bearer <token>', 'Content-Type': 'application/json'}
  payload = json.loads(r'''{
    "packageVettingRequirements": [
      {
        "parties": [
          "<string>"
        ],
        "packageName": "<string>"
      }
    ],
    "synchronizerId": "<string>",
    "vettingValidAt": "<string>"
  }''')
  response = requests.request(
      "POST", url, headers=headers, json=payload
  )

  print(response.text)
  ```

  ```javascript JavaScript theme={"theme":{"light":"github-light","dark":"github-dark"}}
  const response = await fetch('http://localhost:7575/v2/interactive-submission/preferred-packages', {
    method: 'POST',
    headers: {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
  },
    body: JSON.stringify({
    "packageVettingRequirements": [
      {
        "parties": [
          "<string>"
        ],
        "packageName": "<string>"
      }
    ],
    "synchronizerId": "<string>",
    "vettingValidAt": "<string>"
  }),
  });

  console.log(await response.text());
  ```

  ```php PHP theme={"theme":{"light":"github-light","dark":"github-dark"}}
  <?php
  $curl = curl_init();

  curl_setopt_array($curl, [
      CURLOPT_URL => 'http://localhost:7575/v2/interactive-submission/preferred-packages',
      CURLOPT_RETURNTRANSFER => true,
      CURLOPT_CUSTOMREQUEST => 'POST',
      CURLOPT_POSTFIELDS => <<<'JSON'
  {
    "packageVettingRequirements": [
      {
        "parties": [
          "<string>"
        ],
        "packageName": "<string>"
      }
    ],
    "synchronizerId": "<string>",
    "vettingValidAt": "<string>"
  }
  JSON,
      CURLOPT_HTTPHEADER => [
          "Authorization: Bearer <token>",
          "Content-Type: application/json"
      ],
  ]);

  $response = curl_exec($curl);
  echo $response;
  ```

  ```go Go theme={"theme":{"light":"github-light","dark":"github-dark"}}
  package main

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

  func main() {
    req, _ := http.NewRequest("POST", "http://localhost:7575/v2/interactive-submission/preferred-packages", bytes.NewBufferString(`{
    "packageVettingRequirements": [
      {
        "parties": [
          "<string>"
        ],
        "packageName": "<string>"
      }
    ],
    "synchronizerId": "<string>",
    "vettingValidAt": "<string>"
  }`))
    req.Header.Set("Authorization", "Bearer <token>")
    req.Header.Set("Content-Type", "application/json")
    response, _ := http.DefaultClient.Do(req)
    defer response.Body.Close()
    body, _ := io.ReadAll(response.Body)
    fmt.Println(string(body))
  }
  ```

  ```java Java theme={"theme":{"light":"github-light","dark":"github-dark"}}
  import java.net.URI;
  import java.net.http.HttpClient;
  import java.net.http.HttpRequest;
  import java.net.http.HttpResponse;

  var request = HttpRequest.newBuilder()
      .uri(URI.create("http://localhost:7575/v2/interactive-submission/preferred-packages"))
      .header("Authorization", "Bearer <token>")
      .header("Content-Type", "application/json")
      .method("POST", HttpRequest.BodyPublishers.ofString("""
  {
    "packageVettingRequirements": [
      {
        "parties": [
          "<string>"
        ],
        "packageName": "<string>"
      }
    ],
    "synchronizerId": "<string>",
    "vettingValidAt": "<string>"
  }
  """))
      .build();
  var response = HttpClient.newHttpClient().send(
      request, HttpResponse.BodyHandlers.ofString());
  System.out.println(response.body());
  ```

  ```ruby Ruby theme={"theme":{"light":"github-light","dark":"github-dark"}}
  require 'net/http'
  require 'uri'

  uri = URI('http://localhost:7575/v2/interactive-submission/preferred-packages')
  request = Net::HTTP::Post.new(uri)
  request['Authorization'] = 'Bearer <token>'
  request['Content-Type'] = 'application/json'
  request.body = <<~JSON
  {
    "packageVettingRequirements": [
      {
        "parties": [
          "<string>"
        ],
        "packageName": "<string>"
      }
    ],
    "synchronizerId": "<string>",
    "vettingValidAt": "<string>"
  }
  JSON
  response = Net::HTTP.start(uri.hostname, uri.port) do |http|
    http.request(request)
  end
  puts response.body
  ```
</RequestExample>

<ResponseExample>
  ```json 200 theme={"theme":{"light":"github-light","dark":"github-dark"}}
  {
    "packageReferences": [
      {
        "packageId": "<string>",
        "packageName": "<string>",
        "packageVersion": "<string>"
      }
    ],
    "synchronizerId": "<string>"
  }
  ```

  ```text 400 theme={"theme":{"light":"github-light","dark":"github-dark"}}
  <string>
  ```

  ```json default theme={"theme":{"light":"github-light","dark":"github-dark"}}
  {
    "code": "<string>",
    "cause": "<string>",
    "correlationId": "<string>",
    "traceId": "<string>",
    "context": {},
    "resources": [
      [
        "<string>"
      ]
    ],
    "errorCategory": 123,
    "grpcCodeValue": 123,
    "retryInfo": "<string>",
    "definiteAnswer": false
  }
  ```
</ResponseExample>

## Authorizations

### httpAuth

<ParamField header="Authorization" type="string" required>
  HTTP bearer authentication. Send the token as `Authorization: Bearer &lt;token&gt;`. Ledger API standard JWT token
</ParamField>

### apiKeyAuth

<ParamField header="Sec-WebSocket-Protocol" type="string" required>
  API key authentication in the header. Ledger API standard JWT token (websocket)
</ParamField>

## Body

<div class="x2mdx-ref-badges">
  <span class="x2mdx-ref-badge x2mdx-ref-badge--neutral">application/json</span>
</div>

<ParamField body="packageVettingRequirements" type="object[]" required>
  OpenAPI type: <code>PackageVettingRequirement\[]</code>.

  The package-name vetting requirements for which the preferred packages should be resolved. Generally it is enough to provide the requirements for the intended command's root package-names. Additional package-name requirements can be provided when additional Daml transaction informees need to use package dependencies of the command's root packages. Required: must be non-empty

  <Expandable title="child attributes">
    <ParamField body="parties" type="string[]" required>
      The parties whose participants' vetting state should be considered when resolving the preferred package. Required: must be non-empty
    </ParamField>

    <ParamField body="packageName" type="string" required>
      The package-name for which the preferred package should be resolved. Required
    </ParamField>
  </Expandable>
</ParamField>

<ParamField body="synchronizerId" type="string">
  The synchronizer whose vetting state should be used for resolving this query. If not specified, the vetting states of all synchronizers to which the participant is connected are used. Optional
</ParamField>

<ParamField body="vettingValidAt" type="string">
  The timestamp at which the package vetting validity should be computed on the latest topology snapshot as seen by the participant. If not provided, the participant's current clock time is used. Optional
</ParamField>

## Responses

### 200

<div class="x2mdx-ref-badges">
  <span class="x2mdx-ref-badge x2mdx-ref-badge--neutral">application/json</span>
</div>

<ResponseField name="packageReferences" type="PackageReference[]" required>
  The package references of the preferred packages. Must contain one package reference for each requested package-name. If you build command submissions whose content depends on the returned preferred packages, then we recommend submitting the preferred package-ids in the `package_id_selection_preference` of the command submission to avoid race conditions with concurrent changes of the on-ledger package vetting state. Required: must be non-empty

  <Expandable title="child attributes">
    <ResponseField name="packageId" type="string" required>
      Required
    </ResponseField>

    <ResponseField name="packageName" type="string" required>
      Required
    </ResponseField>

    <ResponseField name="packageVersion" type="string" required>
      Required
    </ResponseField>
  </Expandable>
</ResponseField>

<ResponseField name="synchronizerId" type="string" required>
  The synchronizer for which the package preferences are computed. If the synchronizer\_id was specified in the request, then it matches the request synchronizer\_id. Required
</ResponseField>

### 400

Invalid value, Invalid value for: body

<div class="x2mdx-ref-badges">
  <span class="x2mdx-ref-badge x2mdx-ref-badge--neutral">text/plain</span>
</div>

<ResponseField name="value" type="string" required />

### default

<div class="x2mdx-ref-badges">
  <span class="x2mdx-ref-badge x2mdx-ref-badge--neutral">application/json</span>
</div>

<ResponseField name="code" type="string" required />

<ResponseField name="cause" type="string" required />

<ResponseField name="correlationId" type="string" />

<ResponseField name="traceId" type="string" />

<ResponseField name="context" type="Map_String" required />

<ResponseField name="resources" type="Tuple2_String_String[]" />

<ResponseField name="errorCategory" type="integer (int32)" required />

<ResponseField name="grpcCodeValue" type="integer (int32)" />

<ResponseField name="retryInfo" type="string" />

<ResponseField name="definiteAnswer" type="boolean" />

## History

<div class="x2mdx-ref-history" aria-label="Reference history">
  <div class="x2mdx-ref-history-event x2mdx-ref-history-event--changed" id="history-updated-3-5">
    <div class="x2mdx-ref-history-event-head">
      <span class="x2mdx-ref-history-event-label">Updated</span>
      <code class="x2mdx-ref-history-event-version">3.5</code>
    </div>

    <p class="x2mdx-ref-history-event-detail">The POST /v2/interactive-submission/preferred-packages operation changed in this snapshot.</p>
  </div>
</div>