---
title: "Understanding Response Time Headers in the Unified API"
img: https://unified.to/images/logo.svg
date: 2026-07-13T00:00:00.000Z
tag: Guides
description: "Every response from the Unified API includes custom HTTP headers that break down exactly where time was spent during your request. This gives you visibility..."
url: "https://docs.unified.to/guides/understanding_response_time_headers_in_the_unified_api"
---

# Understanding Response Time Headers in the Unified API
------
_July 13, 2026_

Every response from the Unified API includes custom HTTP headers that break down exactly where time was spent during your request. This gives you visibility into whether latency is coming from the third-party integration or from Unified's processing layer.


### The Headers


**`X-Response-Time`** — The total end-to-end time for your request, measured from when the Unified API received it to when the response was sent back.


**`X-EndApi-Response-Time`** — The time spent waiting on the third-party API (e.g., Salesforce, Slack, HubSpot). This is the network round-trip to the downstream service plus its processing time.


**`X-Unified-Response-Time`** — The time spent inside Unified's own code — authentication, data mapping, validation, and response formatting. Calculated as the total time minus the end API time.


### When They Appear


`X-Response-Time` is included on every response. The two breakdown headers (`X-Unified-Response-Time` and `X-EndApi-Response-Time`) only appear when your request involved a call to a third-party API. Requests that are handled entirely by Unified (such as validation errors or metadata lookups) will only include `X-Response-Time`.


### Example


```plain text
HTTP/1.1 200 OK
X-Response-Time: 340ms
X-Unified-Response-Time: 12ms
X-EndApi-Response-Time: 328ms
```


In this example, the third-party API took 328ms to respond, while Unified added just 12ms of overhead for auth, field mapping, and validation.


### How to Use This

- **Debugging slow requests** — If `X-EndApi-Response-Time` is high, the bottleneck is the third-party provider, not Unified. You may want to check the provider's status page or consider caching on your end.
- **Monitoring** — Log these headers alongside your own application metrics to build a complete picture of your API call latency.
- **Support** — When reaching out about performance concerns, include these header values to help pinpoint the issue faster.