> For the complete documentation index, see [llms.txt](https://sevenval.gitbook.io/flat/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sevenval.gitbook.io/flat/develop/cookbook/upstream-response.md).

# Processing Upstream Responses

Let's take a look at how responses from upstream systems provided by [`request`](/flat/develop/reference/actions/request.md)/[`requests`](/flat/develop/reference/actions/requests.md) or [`proxy-request`](/flat/develop/reference/actions/proxy-request.md) actions can be processed further.

The [`body` function](/flat/develop/reference/functions/body.md) provides you with the raw body of an HTTP response. For further processing, it may be necessary to parse the body using functions like [`json-parse`](/flat/develop/reference/functions/json-parse.md) or [`xml-parse`](/flat/develop/reference/functions/xml-parse.md):

```markup
<flow>
  <requests>{
    "xml":  { "url": "…" } },
    "json": { "url": "…" } }
  }
  </requests>

  <eval out="$upstream-json">json-parse(body('json'))</eval>
  <eval out="$upstream-xml">xml-parse(body('xml'))</eval>

  <if test="$upstream-json/success">…</if>
  …
</flow>
```

The [`$upstream` variable](/flat/develop/reference/variables.md) gives additional information about upstream responses like the HTTP status and the headers. The following recursive [sub-flow](/flat/develop/reference/actions/sub-flow.md) demonstrates a general way how to follow a redirect:

request.xml:

```markup
<flow>
  <request>{"id": "my-request", "url": {{ $url }}}</request>

  <if test="$upstream/my-request/status = 302">
    <eval out="$url">$upstream/my-request/headers/location</eval>
    <sub-flow src="request.xml"/>
  </if>
</flow>
```

To just pass the upstream response downstream you can use the [`pass-body` action](/flat/develop/reference/actions/pass-body.md):

```markup
<flow>
  <request>{"url": "http://example.com"}</request>
  <pass-body/>
</flow>
```