Connect Ahrefs: API v3 key, data types and unit cap
Connect your own Ahrefs API v3 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 an Ahrefs 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 v3 key: every call uses API units from your Ahrefs account.
Connecting alone changes nothing. In the Data sources table on the Data tab of Integrations you choose which data types Ahrefs answers. A paid source is never used unless you pick it.
Which data types does it serve?
| Data type | Ahrefs API v3 endpoint | Quality |
|---|---|---|
| Rank tracking | Site Explorer → organic-keywords (best position and URL) | Approximate: positions from the Ahrefs database, not a live SERP check |
| Volume / CPC / KD | Keywords Explorer → overview | Full |
| Keyword ideas | Keywords Explorer → related-terms, matching-terms for long-tail | Full |
| Competitors and content gap | Site Explorer → organic-competitors, the organic-keywords list of both domains | Full |
| Backlinks | Site Explorer → backlinks-stats, domain-rating, all-backlinks (one link per domain, including links lost in the last 90 days), refdomains | Full (Ahrefs' spam flag is shown as toxic) |
The local map grid does not work with Ahrefs; it needs DataForSEO. Domain Rating (0–100) appears in the rank column of the backlink views.
Prerequisites
- An Ahrefs account with API v3 access (Enterprise plan or the API add-on).
- The admin role in SEOAsist.
Getting the API key
- Sign in to app.ahrefs.com.
- Open Account settings → API keys (only workspace owners and admins can create keys).
- Create a key and copy it.
Connecting it to SEOAsist
- Open the Ahrefs card on the Data tab of Integrations.
- Paste the key and press Connect.
- Before saving, SEOAsist calls Ahrefs' free
limits-and-usageendpoint. On success you see “Ahrefs connected. Units left: …”. - In the Data sources table on the same tab, pick Ahrefs (your account) for the data types you want.
The key is stored encrypted and is never sent to the browser in clear text. Test connection shows the remaining units and uses none.
How many units does each action use?
Ahrefs charges at least 50 units per paid request; the cost per row is the sum of the selected fields (most fields 1 unit, volume / KD / intent / traffic 10 units). The values below are upper-bound estimates.
| Action | Endpoint | At most |
|---|---|---|
| Keyword research (Ideas / Long-tail) | related-terms / matching-terms, 32 per row | 100 rows → 3,200 |
| Fill volume / CPC / KD | overview, 32 per keyword | 300 keywords → 9,600 |
| Rank check | organic-keywords, 3 per row | 1 pull per day, 1,000 rows → 3,000 |
| Find competitors | organic-competitors, 13 per row | 15 rows → 195 |
| Competitor sync | organic-keywords, 27 per row | 500 per competitor + 1,000 of your own |
| Backlink sync | backlinks-stats 50 + domain-rating 50 + all-backlinks 10 per row | 500 links → 5,100 |
| Backlink opportunities | refdomains, 5 per row | 300 rows per competitor, up to 5 competitors |
Competitor sync is the most expensive action with Ahrefs. Try it with one competitor first and set a monthly cap.
Monthly unit cap
Type a number in Monthly unit cap on the Ahrefs 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. Leave the field empty for no cap. The exact usage is on app.ahrefs.com → API keys.
Errors
| Message | Meaning | What to do |
|---|---|---|
| API key was rejected | HTTP 401: wrong, expired or deleted key | Create a new key and reconnect |
| API units ran out | The unit limit was reached | Add units in Ahrefs or wait for the reset date |
| No API access | HTTP 403: the plan does not cover this endpoint | Check your Ahrefs plan |
| Rate limit exceeded | HTTP 429 (60 requests per minute by default) | SEOAsist waits and retries |
| Monthly unit cap reached | The cap you set | Raise the cap or wait for the new month |
On a key, unit or access error the related pages show an “Ahrefs 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.
FAQ
Why are rankings “Approximate”?
Positions come from the Ahrefs database; Ahrefs refreshes them on its own schedule and only for keywords it knows. 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 Ahrefs go back to the default source; the Ahrefs series is kept but not continued.
Does SEOAsist charge for Ahrefs?
No. Units are taken directly from your Ahrefs account. See Costs.
Related articles
- Data sources: the free layer, Bing Webmaster and optional DataForSEOWhere rankings, search volume, keyword ideas, competitor topics and backlinks come from, what the free sources can and can't do, how to add a Bing Webmaster key and how to choose DataForSEO per data type.
- Connect Semrush: API key, data types and unit capConnect 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.
- Connect DataForSEO: API credentials, costs and balanceConnect your DataForSEO account to SEOAsist and learn which modules it powers, how many calls each action uses and where to keep an eye on your balance.
- Costs: AI allowance, your own keys and DataForSEOCommon questions about what's included in your plan, what you pay through your own accounts and how monthly quotas are counted.
- Backlinks: tabs, Sync now and the weekly syncLearn what each tab on the Backlinks page shows, what Sync now does in the background, and which notification you get when a sync fails.