The Smartlead API lets you manage campaigns, leads and email accounts from your own code or tools. Every request is authenticated with an API key that you create in Settings.
API access is available on the Pro plan and higher. On Base and Popular plans, API Key Management is hidden.
You need to be the account owner, or a team member with admin access.
Click your avatar, then go to Settings → API Key Management.
Open Admin API Keys.
Copy an active key with the copy icon. If you have no key yet, click + Create Admin Key, enter a Key Name and click Create.
Treat the key like a password. Don't post it in chat, tickets or screenshots.
All endpoints use the base URL https://server.smartlead.ai/api/v1. Add your key to every request as the api_key query parameter:
GET https://server.smartlead.ai/api/v1/campaigns/?api_key=<your-api-key>The key must be sent in the URL. A key sent in a request header is not accepted.
Every endpoint, with its parameters and example responses, is listed in the Full API Documentation.
Admin keys share one rate limit. All admin keys on your account draw from one per-minute limit, 200 requests per minute by default. Creating more keys doesn't add capacity. Contact support if you need a higher limit.
Each client API key has its own limit, 60 requests per minute by default.
A few heavy endpoints also have their own limit of 10 calls per 60 seconds.
Going over a limit returns HTTP 429. Wait briefly and retry with a back-off.
You can add up to 1,000 leads per add-leads call, with up to 200 custom fields per lead.
You can create up to 25 admin API keys per account.
"API key is required." The key was sent in a header, or the path isn't under /api/v1/. Send it as ?api_key= on a /api/v1/ URL.
"API Key access denied". Your plan doesn't include API access. The account owner can upgrade in Settings → Subscription.
You can't see API Key Management. Your plan is below Pro, or you're a team member without admin access. The owner can make you an admin in Settings → Team Members.
HTTP 429. You've hit a rate limit. Space your calls out and check which tools share your admin keys.
Still stuck? Contact support from the chat in your Smartlead dashboard.