# Diff a version of a attribute definition

`GET /v1/attributes/{id}/versions/{version}/diff`

- Authentication: required (Bearer token)
- Required scope: `api.attributes.view`

What changed between this version and another: a field-by-field list of what changed.

The direction is always FROM the addressed version TO the other side,
so a diff against `current` reads as "what has happened since".

## Path parameters

- `id` (string, required) — The attribute's UUID or its name.
- `version` (integer, required) — The version number, as returned by the versions collection. Version numbers are the handle on every kind here, including the kinds whose dashboard routes address a version by row id.

## Query parameters

- `against` (string, optional) — `current` (the default) diffs against the live definition; a number diffs against that version of the same definition.

## Example request

```bash
curl 'https://api.sendops.dev/v1/attributes/string/versions/0/diff' \
  -H "Authorization: Bearer $SENDOPS_API_KEY"
```

## Responses

### 200 — The diff

Content type: `application/json`

```json
{
  "kind": "string",
  "from": 0,
  "to": 0,
  "against_current": true,
  "unified": "string",
  "source_withheld": "string",
  "fields": [
    {
      "field": "string",
      "from": "string",
      "to": "string"
    }
  ],
  "truncated": true,
  "identical": true
}
```

### 401 — Missing, malformed, or unknown API key

Content type: `application/problem+json`

```json
{
  "type": "https://example.com",
  "title": "string",
  "status": 0,
  "detail": "string",
  "code": "invalid_key",
  "request_id": "string",
  "retry_after": 0,
  "retention_days": 0,
  "scope": "string",
  "resource": "string",
  "errors": [
    {
      "field": "string",
      "reason": "string"
    }
  ],
  "attribute_id": "00000000-0000-0000-0000-000000000000",
  "content_hash": "string",
  "differs": [
    "string"
  ]
}
```

### 403 — Key lacks the required scope or plan limit violated

Content type: `application/problem+json`

```json
{
  "type": "https://example.com",
  "title": "string",
  "status": 0,
  "detail": "string",
  "code": "invalid_key",
  "request_id": "string",
  "retry_after": 0,
  "retention_days": 0,
  "scope": "string",
  "resource": "string",
  "errors": [
    {
      "field": "string",
      "reason": "string"
    }
  ],
  "attribute_id": "00000000-0000-0000-0000-000000000000",
  "content_hash": "string",
  "differs": [
    "string"
  ]
}
```

### 404 — Resource not found

Content type: `application/problem+json`

```json
{
  "type": "https://example.com",
  "title": "string",
  "status": 0,
  "detail": "string",
  "code": "invalid_key",
  "request_id": "string",
  "retry_after": 0,
  "retention_days": 0,
  "scope": "string",
  "resource": "string",
  "errors": [
    {
      "field": "string",
      "reason": "string"
    }
  ],
  "attribute_id": "00000000-0000-0000-0000-000000000000",
  "content_hash": "string",
  "differs": [
    "string"
  ]
}
```

### 429 — Per-org rate limit exceeded

Content type: `application/problem+json`

```json
{
  "type": "https://example.com",
  "title": "string",
  "status": 0,
  "detail": "string",
  "code": "invalid_key",
  "request_id": "string",
  "retry_after": 0,
  "retention_days": 0,
  "scope": "string",
  "resource": "string",
  "errors": [
    {
      "field": "string",
      "reason": "string"
    }
  ],
  "attribute_id": "00000000-0000-0000-0000-000000000000",
  "content_hash": "string",
  "differs": [
    "string"
  ]
}
```

### 500 — Unexpected server-side failure. The `code` is `internal_error`. The
`request_id` field can be quoted to SendOps support to investigate.

Content type: `application/problem+json`

```json
{
  "type": "https://example.com",
  "title": "string",
  "status": 0,
  "detail": "string",
  "code": "invalid_key",
  "request_id": "string",
  "retry_after": 0,
  "retention_days": 0,
  "scope": "string",
  "resource": "string",
  "errors": [
    {
      "field": "string",
      "reason": "string"
    }
  ],
  "attribute_id": "00000000-0000-0000-0000-000000000000",
  "content_hash": "string",
  "differs": [
    "string"
  ]
}
```