---
title: "Passthrough API"
url: "https://docs.unified.to/passthrough/overview"
description: "API reference for Passthrough API. Launch multiple pre-built Passthrough integrations today with zero maintenance — all through a single API."
generated_at: "2026-06-26T21:08:50.520Z"
---
# Passthrough API

The Passthrough API allows you to access SaaS endpoints through your existing connections, even if those endpoints aren't explicitly supported in our unified models. Think of it as a way to "pass through" your API requests directly to the third-party platform while still leveraging Unified.to's connection management and authentication handling.

For examples of the Passthrough API in action, see: [How to use the Passthrough API](https://docs.unified.to/guides/how%5Fto%5Fuse%5Fthe%5Fpassthrough%5Fapi)

## [How it works](#how-it-works)

When you make a Passthrough API request:

1. You send your request to Unified.to's Passthrough endpoint, specifying:
  * The connection ID for the integration you want to access
  * The platform-specific API path you want to call
  * Any HTTP method, headers, query parameters, or body data needed
2. Unified.to handles:
  * Authentication with the platform using your stored connection credentials
  * Routing your request to the correct platform API endpoint
3. The SaaS application processes your request and sends back a response
4. Unified.to forwards the response back to you without modification

### [Path construction](#path-construction)

The path you provide should be relative to the platform's base API URL. For example:

* If the full endpoint URL is `https://api.vendor.com/v2/users`
* You would specify `v2/users` as the path

You can find the base URL for each integration under the **Feature Support > Passthrough** tab on [app.unified.to/integrations](https://app.unified.to/integrations) (click through to the integration to see it).

### [Headers, parameters, and payloads](#headers-parameters-and-payloads)

* You can send any platform-specific headers your request needs, such as `Content-Type`
* For write operations, you can include a payload in the request
* Query parameters can be included in the path or as separate parameters
* All headers from the response are passed back to you
* There is only one reserved URL parameter, and that is `__domain`. Use it to override the default API URL for that integration.

### [Response handling](#response-handling)

Unlike Unified.to's standard endpoints which return normalized data, Passthrough API responses contain raw data. This means:

* Response formats will vary between platforms
* You'll need to handle platform-specific data structures
* Error formats will be platform-specific

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