SmartLead
Connect SmartLead to build and run cold email campaigns, manage leads and sending accounts, answer replies, and track results.
You paste one SmartLead API key into PopMCP. An admin key reaches the whole account and every client sub-account; a client key reaches only the client it is assigned to.
- Setup time
- 3 min
- Auth
- API credentials
- API base URL
- https://server.smartlead.ai/api/v1
- Rate limits
- Per API key: 60 requests a minute and 1,000 an hour on SmartLead's Standard tier, 120 a minute and 3,000 an hour on Pro, custom on Enterprise, with short bursts of 10 or 20 a second. All admin keys share the account's limit. Lead statistics, all-leads activities and domain-wise health allow 10 requests per 60 seconds each.
Before you begin
- A SmartLead account at app.smartlead.ai. SmartLead's pricing table lists API & Webhooks as a per-plan feature, so if you cannot create a key, check that your plan includes it.
- Access to Settings from your profile menu, where API Key Management lives
- A decision on reach: the admin key covers every client, a client key covers one client. A PopMCP workspace holds one SmartLead connection.
- Smart Delivery, Smart Prospect or Smart Senders enabled on your SmartLead account if you want those tools. The same key reaches them.
Get your credentials
Open API Key Management
Sign in at app.smartlead.ai, open your profile menu and choose Settings, then API Key Management. The Admin API Keys section lists the keys that reach the whole account.
API Key Management
Admin keys reach the whole account. Client keys reach one client sub-account.
| Name | Status | Created |
|---|---|---|
| Primary keyOriginal admin key | Active | Jan 8, 2026 |
| Clay enrichmentAdmin key | Active | Jun 2, 2026 |
An account can hold up to 25 admin keys. They all share the account's one rate limit, and the primary key can be reset but not revoked.
Create a key for PopMCP
In Admin API Keys, click + Create API Key, enter a descriptive name such as PopMCP and click Create. To limit PopMCP to one client instead, create a client key and assign it to that client.
API Key Management
Admin keys reach the whole account. Client keys reach one client sub-account.
A client key is linked to exactly one client, and each client can have one key.
Copy the key before you leave the page
Click the copy icon next to the new key right away. SmartLead hides the full value once you leave the page, so a lost key has to be reset or replaced.
API Key Management
Admin keys reach the whole account. Client keys reach one client sub-account.
Reset Key issues a new value and invalidates the old one immediately. Revoked keys move to the Revoked Keys tab and cannot be reactivated.
Paste the key into PopMCP
In PopMCP, paste the key into API key and click Connect SmartLead. PopMCP checks it by listing one sending account, so no campaign or lead is touched.
Connect in PopMCP
Open your workspace, choose SmartLead in the marketplace, and fill in the connect dialog:
| Field | What to enter |
|---|---|
| API keysecret | In SmartLead (app.smartlead.ai) open Settings → API Keys, then copy your key (or generate one). Stored encrypted and used server-side only. A client sub-account key also works and limits the MCP to that client.Encrypted with AES-256-GCM on save and never shown again. |
PopMCP verifies the credential against SmartLead immediately. On success the connection flips to Verified and its MCP tools are provisioned.
Verify it worked
PopMCP shows SmartLead as Verified, labelled SmartLead (user <id>) once the account has at least one sending mailbox (or just SmartLead on an empty account). Asking the AI to list your campaigns returns your real campaign names and statuses.
Troubleshooting
SmartLead rejected this API key
Why: SmartLead answered 401 `Invalid API Key`: the key was copied incompletely, or it was reset or revoked after you copied it.
Fix: Copy the key again from Settings, API Key Management, or create a new one, and reconnect. PopMCP also accepts a pasted request URL containing api_key= and extracts the key.
The connection stopped working right after someone reset a key
Why: Reset Key generates a new value and invalidates the old one immediately, including the copy stored in PopMCP.
Fix: Reconnect SmartLead in PopMCP with the new value. Give PopMCP its own named key so other teams' resets do not break it.
Only one client's campaigns and mailboxes appear
Why: You pasted a client key, which is limited to the client it is assigned to.
Fix: Reconnect with an admin key from the Admin API Keys section if the connection should reach every client.
Smart Delivery, Smart Prospect or Smart Senders tools return 401 or 403
Why: The add-on is not enabled on your SmartLead account. The key itself is fine.
Fix: Enable the add-on in SmartLead, or ask the AI to stick to the core campaign, lead and inbox tools.
A tool fails even though SmartLead answered HTTP 200
Why: Some SmartLead endpoints, Smart Prospect especially, report failure as HTTP 200 with success: false. PopMCP turns that into an error carrying SmartLead's message.
Fix: Read the message in the error, for example missing credits or an invalid filter, fix the cause and retry.
429 or `You have exceeded the 10 requests in 60 sec limit for this endpoint!`
Why: The key hit its per-minute limit, which every admin key shares, or one of the endpoints capped at 10 requests per 60 seconds (lead statistics, all-leads activities, domain-wise health).
Fix: Wait 60 seconds and retry with fewer calls. For analytics, ask for one date range instead of many small ones.
There is no API Key Management page, only an API section
Why: SmartLead has renamed this area over time: older docs say Settings, API Keys or Settings, API.
Fix: Open your profile menu, choose Settings and look for the API key area under whichever name your account shows. If none exists, check that your plan includes API & Webhooks.
Reference
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