Smartlead API Reference

Authentication

All requests use query parameter auth: ?api_key={SMARTLEAD_API_KEY}

Environment variable: $SMARTLEAD_API_KEY

Base URL: https://server.smartlead.ai/api/v1

Rate Limiting

• Standard plan: 2,000 req/min (33 req/sec)
• Higher plans: 3,000 req/min (50 req/sec)
• Retry on 429 and 5xx with exponential backoff
• For bulk operations, use p-limit or PQueue with 8-15 concurrency

CLI Quick Reference

The smartlead CLI (@smartlead/cli) wraps all API endpoints. Use it for quick lookups:

# Campaigns
smartlead campaigns list
smartlead campaigns get <id>
smartlead campaigns create --name "Campaign Name"

# Leads
smartlead leads list --campaign-id <id>
smartlead leads add --campaign-id <id> --file leads.csv

# Email accounts
smartlead email-accounts list
smartlead email-accounts get <id>

# Analytics
smartlead analytics campaign <id>
smartlead analytics overall

# Master inbox
smartlead inbox replies

API Endpoints

Campaigns

GET  /campaigns/{id}                    — Fetch campaign by ID
POST /campaigns/create                  — Create new campaign
POST /campaigns/{id}/status             — Update status (START, PAUSED, STOP)
     Body: { "status": "START" }

Campaign Email Accounts

GET    /campaigns/{id}/email-accounts   — List accounts assigned to campaign
POST   /campaigns/{id}/email-accounts   — Add accounts to campaign
       Body: { "email_account_ids": [1, 2, 3] }
DELETE /campaigns/{id}/email-accounts   — Remove accounts from campaign

Campaign Sequences

GET  /campaigns/{id}/sequences          — Fetch sequences
POST /campaigns/{id}/sequences          — Save/update sequences
     Body: { "sequences": [{ "seq_number": 1, "seq_delay_details": { "delay_in_days": 0 }, "subject": "...", "email_body": "..." }] }

A/B/C Variants — use seq_variants array inside each sequence:

{
  "sequences": [{
    "seq_number": 1,
    "seq_delay_details": { "delay_in_days": 0 },
    "seq_variants": [
      { "variant_label": "A", "subject": "Subject A", "email_body": "<div>Body A</div>" },
      { "variant_label": "B", "subject": "Subject B", "email_body": "<div>Body B</div>" },
      { "variant_label": "C", "subject": "Subject C", "email_body": "<div>Body C</div>" }
    ]
  }]
}

Note: Do NOT include distribution field — SmartLead splits evenly automatically.

Email body order: content → PS unsub line → %signature% (signature always last)

Campaign Settings & Schedule

POST /campaigns/{id}/settings           — Update settings
     Body: { "track_settings": [...], "stop_lead_settings": "..." }

POST /campaigns/{id}/schedule           — Update schedule
     Body: { "timezone": "US/Eastern", "days_of_the_week": [1,2,3,4,5], "start_hour": "08:00", "end_hour": "17:00", "min_time_btw_emails": 8, "max_new_leads_per_day": 30 }

Leads

GET  /leads/?api_key={key}&email={email}
     — Lookup lead by email address

POST /campaigns/{id}/leads
     — Add leads to campaign (batch up to 100)
     Body: { "lead_list": [{ "email": "...", "first_name": "...", "last_name": "...", "company_name": "...", "custom_fields": { "field1": "value1" } }] }

Analytics

GET /analytics/day-wise-overall-stats
    ?api_key={key}&start_date=YYYY-MM-DD&end_date=YYYY-MM-DD
    — Day-by-day metrics (sent, opened, clicked, replied, bounced)

GET /analytics/day-wise-positive-reply-stats
    ?api_key={key}&start_date=YYYY-MM-DD&end_date=YYYY-MM-DD
    — Day-by-day positive reply counts

GET /analytics/overall-stats-v2
    ?api_key={key}&start_date=YYYY-MM-DD&end_date=YYYY-MM-DD
    — Overall campaign metrics for date range

GET /analytics/campaign/list
    ?api_key={key}
    — List all campaigns with summary stats

GET /campaigns/{id}/analytics
    ?api_key={key}
    — Analytics for specific campaign

GET /campaigns/{id}/analytics-by-date
    ?api_key={key}&start_date=YYYY-MM-DD&end_date=YYYY-MM-DD
    — Campaign analytics for specific date range (sent_count, reply_count)

Email Accounts (Global)

GET  /email-accounts
     ?api_key={key}&offset=0&limit=100
     — List all email accounts (paginated)

GET  /email-accounts/{id}
     ?api_key={key}
     — Get specific email account

POST /email-accounts/save
     — Create/update email account (SMTP details, warmup, etc.)

Master Inbox

POST /master-inbox/inbox-replies
     Body: { "api_key": "...", "offset": 0, "limit": 50, "message_type": "RECEIVED" }
     — Fetch inbox replies with filtering and pagination

Sub-Client / Custom API Key Pattern

• Normal sub-clients: Pass ?api_key={MAIN_KEY}&client_id={CLIENT_ID} on all requests
• Custom API key clients: Use the client's own API key directly, no client_id param

TypeScript Pattern

const SMARTLEAD_API = "https://server.smartlead.ai/api/v1";
const API_KEY = process.env.SMARTLEAD_API_KEY;

// GET example
const res = await fetch(`${SMARTLEAD_API}/campaigns/${campaignId}?api_key=${API_KEY}`);
const campaign = await res.json();

// POST example (add leads)
const res = await fetch(`${SMARTLEAD_API}/campaigns/${campaignId}/leads?api_key=${API_KEY}`, {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({ lead_list: leads.slice(0, 100) }),
});

Performance tip: cache the email-accounts list

If you hit /email-accounts more than a few times per script, paginate once at the start and keep the result in memory. Smartlead's pagination returns 100 per page — for accounts with thousands of inboxes, a full walk takes 30+ seconds.

For persistent caching across scripts, write the list to a local JSON file and refresh on a timer (e.g. every hour). The /smartlead-inbox-manager skill has scripts that implement this pattern.

What to do next

This is a reference skill — no direct next step. Used by all skills that interact with Smartlead (/smartlead-inbox-manager, /smartlead-campaign-upload-public, /email-deliverability-audit, /positive-reply-scoring, /deliverability-incident-response, etc.).

Return to the skill that sent you here.

Related skills

• Every skill that touches Smartlead uses this reference.