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

# Lookup an update by its offset

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

<div class="x2mdx-ref-hero">
  <p class="x2mdx-ref-eyebrow">JSON Ledger API</p>

  <h1 class="x2mdx-ref-title">Lookup an update by its offset</h1>

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

    <span class="x2mdx-ref-badge x2mdx-ref-badge--added">Since 3.4</span>

    <span class="x2mdx-ref-badge x2mdx-ref-badge--changed">Changed 3.5</span>
  </div>
</div>

Lookup an update by its offset. If there is no update with this offset, or all the events are filtered, an UPDATE\_NOT\_FOUND error will be raised.

## Protocol Details

<dl class="x2mdx-ref-meta-grid">
  <div class="x2mdx-ref-meta-item">
    <dt>Operation ID</dt>
    <dd>postV2UpdatesUpdate-by-offset</dd>
  </div>

  <div class="x2mdx-ref-meta-item">
    <dt>Authentication</dt>
    <dd>Bearer token</dd>
  </div>

  <div class="x2mdx-ref-meta-item">
    <dt>Published</dt>
    <dd>3.5</dd>
  </div>
</dl>

## Inputs

### Request body

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

<ParamField body="offset" type="number" required>
  OpenAPI type: `integer (int64)`.

  The offset of the update being looked up. Must be a valid absolute offset (positive integer). Required
</ParamField>

<ParamField body="updateFormat" type="object" required>
  OpenAPI type: `UpdateFormat`.

  A format specifying what updates to include and how to render them.
</ParamField>

## Outputs

### 200

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

<ResponseField name="update" type="Update">
  *
</ResponseField>

### 400

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

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

### 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>

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

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

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

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

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

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

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

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

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

## History

<div class="x2mdx-ref-history" aria-label="Reference history">
  <div class="x2mdx-ref-history-event x2mdx-ref-history-event--changed">
    <div class="x2mdx-ref-history-event-head">
      <span class="x2mdx-ref-history-event-label">Changed</span>
      <code class="x2mdx-ref-history-event-version">3.5</code>
    </div>

    <p class="x2mdx-ref-history-event-detail">The POST /v2/updates/update-by-offset operation changed in this snapshot.</p>
  </div>

  <div class="x2mdx-ref-history-event x2mdx-ref-history-event--introduced">
    <div class="x2mdx-ref-history-event-head">
      <span class="x2mdx-ref-history-event-label">Introduced</span>
      <code class="x2mdx-ref-history-event-version">3.4</code>
    </div>
  </div>
</div>

<RequestExample>
  ```bash Request theme={null}
  curl --request POST \
    --url 'http://localhost:7575/v2/updates/update-by-offset' \
    --header 'Authorization: Bearer $TOKEN' \
    --header 'Content-Type: application/json' \
    --data '{"offset":0,"updateFormat":{"includeTransactions":{},"includeReassignments":{},"includeTopologyEvents":{}}}'
  ```
</RequestExample>

<ResponseExample>
  ```json 200 response theme={null}
  {
    "update": {}
  }
  ```

  ```json default response theme={null}
  {
    "code": "string",
    "cause": "string",
    "correlationId": "string",
    "traceId": "string",
    "context": {},
    "resources": [
      [
        "string"
      ]
    ],
    "errorCategory": 0,
    "grpcCodeValue": 0,
    "retryInfo": "string",
    "definiteAnswer": false
  }
  ```
</ResponseExample>