> AI agents: this is one page from PostHog's docs. Full index of Markdown docs for LLMs: https://posthog.com/llms.txt

# Linking Semrush as a source

Canonical URL: https://posthog.com/docs/data-pipelines/sources/semrush

> **Cloud region:** This page uses US Cloud hosts. For an EU Cloud project, use `https://eu.posthog.com` instead of `https://us.posthog.com` or `https://app.posthog.com` (app host for links).

## On this page

- [Prerequisites](#prerequisites)
- [Adding a data source](#adding-a-data-source)
- [API units](#api-units)
- [Sync modes](#sync-modes)
- [Configuration](#configuration)
- [Supported tables](#supported-tables)
- [Troubleshooting](#troubleshooting)

![](https://res.cloudinary.com/dmukukwp6/image/upload/texture_tan_9608fcca70)

![](https://res.cloudinary.com/dmukukwp6/image/upload/texture_tan_dark_a92b0e022d)

Let AI connect your sources for you

Skip the manual setup — run this in your project and the wizard auto-detects your databases and APIs and connects them to PostHog.

`npx @posthog/wizard warehouse`

![PostHog Wizard hedgehog](https://res.cloudinary.com/dmukukwp6/image/upload/wizard_3f8bb7a240.png)

![](https://res.cloudinary.com/dmukukwp6/image/upload/wizard_3f8bb7a240.png)Let AI connect your sources for you

The Semrush connector syncs Site Audit data from your Semrush projects into the PostHog data warehouse, so you can analyze SEO health alongside your product data.

## Prerequisites

You need:

-   A Semrush account with an **SEO Business subscription**
-   A **project with Site Audit enabled**
-   A **v3 API key** from your Semrush profile
-   Sufficient **API units** (100 units per table request, plus 100 units for connection validation)

## Adding a data source

1.  In PostHog, go to the [Sources tab](https://app.posthog.com/data-management/sources) of the data pipeline section.
2.  Click **\+ New source** and click **Link** next to this source.
3.  Enter your credentials (see [Configuration](#configuration) below) and click **Next**.
4.  Select the tables you want to sync, choose a sync method and frequency, then click **Import**.

Once the syncs are complete, you can start querying this data in PostHog.

When linking Semrush, you'll need:

-   **API key (v3)** – find it under [API keys](https://www.semrush.com/accounts/api-keys/active) in your Semrush profile.
-   **Project ID** – the numeric project ID from your Semrush project URL. For example, if your project URL is `https://www.semrush.com/projects/123456/site-audit/`, the project ID is `123456`.

## API units

Semrush syncs consume your account's API units:

-   **100 units** per table request during syncing
-   **100 units** for connection validation
-   Retries (up to 3 attempts) can consume additional units

## Sync modes

Each table can be synced in one of several modes, depending on what the source supports:

-   **Webhook** (when available) – the source pushes changes to PostHog in real time. Fastest freshness, lowest ongoing cost, and the only mode that reliably captures updates and deletes.
-   **Incremental** – only new or updated rows are synced on each run, using a cursor field (such as an `updated_at` timestamp). Cheaper than a full refresh, but deletes aren't captured.
-   **Append only** – new rows are appended using a cursor field; existing rows are never updated. Ideal for immutable, append-only tables like event logs.
-   **Full refresh** – the whole table is reloaded on every sync. Use it when a table has no reliable cursor or when you need deletions reflected.

See [sync methods](https://posthog.com/docs/data-pipelines/sources.md#sync-methods) for a full explanation of how each mode works and how to choose between them.

All Semrush tables use full refresh syncing. The Semrush API doesn't expose pagination or server-side time filters, so each sync re-downloads all data.

## Configuration

| Option | Type | Required |
| --- | --- | --- |
| `API key (v3)` | password | Yes |
| `Project ID` | text | Yes |

## Supported tables

| Table | Description | Sync method | Incremental field | Primary key |
| --- | --- | --- | --- | --- |
| `site_audit` | Summary of the latest Site Audit for the configured Semrush project. | Full refresh | — | — |
| `site_audit_snapshots` | Completed audit IDs and completion dates for the configured Semrush project. | Full refresh | — | — |
| `site_audit_issue_descriptions` | Issue descriptions for Site Audit reports. | Full refresh | — | — |

## Troubleshooting

### Authentication failed

If you see "Semrush authentication failed," your API key is invalid or expired. Verify your v3 API key under [API keys](https://www.semrush.com/accounts/api-keys/active) in your Semrush profile.

### API access disabled

If you see "Semrush API access is disabled," check that:

-   Your Semrush account has an active SEO Business subscription
-   You have access to the configured project

### API units exhausted

If you see "Semrush API units or request limits are exhausted," you need to add more API units to your Semrush account or wait for your limits to reset. Contact Semrush support for help.

### Project not found

If you see "Semrush could not find this project," verify:

-   The project ID is correct (numeric only, from your project URL)
-   You have access to the project
-   Site Audit is enabled for the project

If your sync is failing or data looks wrong, see the [Data warehouse troubleshooting guide](https://posthog.com/docs/data-warehouse/troubleshooting.md). If that doesn't help, [contact support](https://us.posthog.com/#panel=support%3Asupport%3Adata_warehouse%3A%3Atrue) – we're happy to help.