---
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://unified.to/blog/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](/technology) 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.