Connect Semrush: API key, data types and unit cap
Connect your own Semrush API key as a data source; learn which data types it serves, how many API units each action uses and how to set a monthly unit cap.
Open this screen in the panelIf you have a Semrush subscription, SEOAsist can use its data as a data source. SEOAsist tracks rankings, finds the content gap, applies fixes and reports the results with that data. The connection is optional and runs on your own API key: every call uses API units from your Semrush account.
Connecting alone changes nothing. In the Data sources table on the Data tab of Integrations you choose which data types Semrush answers. A paid source is never used unless you pick it.
Which data types does it serve?
| Data type | Semrush report | Quality |
|---|---|---|
| Rank tracking | Domain Organic Search Keywords (domain_organic) | Approximate: positions from the Semrush database, not a live SERP check |
| Volume / CPC / KD | Batch Keyword Overview (phrase_these), Keyword Difficulty (phrase_kdi) when KD is missing | Full |
| Keyword ideas | Related Keywords (phrase_related), Broad Match (phrase_fullsearch) for long-tail | Full |
| Competitors and content gap | Competitors in Organic Search (domain_organic_organic), the domain_organic list of both domains | Full |
| Backlinks | Backlinks Overview, Backlinks, Referring Domains | Full (no spam score, so no toxic flag) |
The local map grid does not work with Semrush; it needs DataForSEO.
Prerequisites
- A Semrush account with API access (Business plan or purchased API units).
- The admin role in SEOAsist.
- The site's location must map to a Semrush database (Türkiye, Azerbaijan, Germany, the US, the UK…). Unsupported locations show a “location is not supported” message.
Getting the API key
- Sign in to semrush.com.
- Open Subscription info → API units.
- Copy the API key shown there.
Connecting it to SEOAsist
- Open the Semrush card on the Data tab of Integrations.
- Paste the key and press Connect.
- Before saving, SEOAsist sends Semrush a free balance query. On success you see “Semrush connected. Units left: …”.
- In the Data sources table on the same tab, pick Semrush (your account) for the data types you want.
The key is stored encrypted and is never sent to the browser in clear text; the card only shows a masked form. Test connection shows the remaining API units and uses none.
How many units does each action use?
Semrush bills per returned line. The values below are upper-bound estimates based on Semrush's official unit table.
| Action | Report | At most |
|---|---|---|
| Keyword research (Ideas) | phrase_related, 40 per line | 100 lines → 4,000 |
| Keyword research (Long-tail) | phrase_fullsearch, 20 per line | 100 lines → 2,000 |
| Fill volume / CPC / KD | phrase_these 10 per keyword (+ phrase_kdi 50 per keyword when KD is missing) | 300 keywords |
| Rank check | domain_organic, 10 per line | 1 pull per day, 1,000 lines → 10,000 |
| Find competitors | domain_organic_organic, 40 per line | 15 lines → 600 |
| Competitor sync | domain_organic, 10 per line | 500 per competitor + 1,000 of your own |
| Backlink sync | Overview 40 + backlinks 40 per line | 200 links → 8,040 |
| Backlink opportunities | backlinks_refdomains, 40 per line | 100 lines per competitor, up to 5 competitors |
Automatic jobs use units too: the daily rank pull for tracked keywords and the weekly backlink sync. A monthly cap covers them as well.
Monthly unit cap
Type a number in Monthly unit cap on the Semrush card and press Save. Before every call, SEOAsist adds this month's estimated usage and the call's estimated cost; if the cap would be exceeded, the call is not sent and you get a notification. The card summary shows “~… / … units this month”. Leave the field empty for no cap.
The estimate is calculated from Semrush's unit table; the exact usage is on semrush.com → API units.
Errors
| Message | Meaning | What to do |
|---|---|---|
| API key was rejected | Wrong or revoked key (ERROR 120) | Copy the key again and reconnect |
| API units ran out | Balance is zero or the total limit was hit (ERROR 132 / 134) | Top up units on semrush.com |
| No API access | Plan or report type disabled (ERROR 130 / 133 / 135) | Check your Semrush plan |
| Rate limit exceeded | Too many requests | SEOAsist waits and retries; if it persists, try again in a few minutes |
| Monthly unit cap reached | The cap you set | Raise the cap or wait for the new month |
On a key, balance or access error the related pages show a “Semrush is not working” banner and the owner is notified once a day. A chosen source that fails is never silently replaced by a free one: data stays stale until the problem is fixed, so charts never mix series.
FAQ
Why are rankings “Approximate”?
Positions come from the Semrush database. Semrush refreshes it on its own schedule and only for keywords it knows; a tracked keyword missing from it shows as not ranking. For a daily live SERP check, choose DataForSEO for rankings.
How do I remove the connection?
Open the card, press Remove and confirm. Data types set to Semrush go back to the default source; the Semrush series is kept but not continued.
Does SEOAsist charge for Semrush?
No. Units are taken directly from your Semrush account, separate from your SEOAsist plan. See Costs.
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