Overview

• Real email. campaigns.activate starts sending to the campaign’s leads and emails.reply sends a reply straight away. Neither is ever retried automatically; only read operations are.
• Lifetime contact limit. Every lead uploaded counts toward the plan’s lifetime contact limit (1,000 on Growth), including re-uploads and the same person in a second campaign. leads.create and leads.addBulk default skip_if_in_workspace to true for that reason. Re-adding or moving a lead who already replied restarts their sequence at step 1.
• Stopping a lead. A lead’s status is read-only. To stop follow-ups (for example after they answered on LinkedIn), call leads.updateInterestStatus, which completes the lead in its campaign.
• Replies without webhooks. Webhooks need the Hypergrowth plan or higher. On a plan without them, poll emails.list with email_type: 'received' for replies; it allows 20 requests a minute.
• Credits. emailVerification.verify spends Instantly email-verification credits and is never retried. leadLabels.testAiReplyLabel is limited to 500 calls per 30 days per workspace.
• Secrets. apiKeys.create returns the new key once; apiKeys.list and apiKeys.delete redact it, as webhook results redact header values.
• Not covered yet: Instantly’s AI agents (sales, inbox manager, lead finder, deliverability), SuperSearch enrichment, company lists, done-for-you account orders and the Google/Microsoft OAuth account connection.
• Time zones. Campaign schedules take Instantly’s own time zone list plus 63 common IANA zones it lacks (America/New_York, Europe/London, UTC and more), each sent as the listed zone with the same offsets and DST rules: America/New_York goes out as America/Detroit. The plugin re-checks each pair against the runtime’s time zone data and refuses an alias that no longer matches. Zones with no exact match are rejected, including Pacific time (Instantly’s America/Dawson stays at UTC-7 all year) and Canadian zones, several of which moved to permanent time in 2026.

• 165 typed API operations
• 4 synced entities (accounts, campaigns, emails, leads) for fast .search() / .list()
• 19 incoming webhook event types

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Setup

npm install corsair @corsair-dev/instantly

yarn add corsair @corsair-dev/instantly

pnpm install corsair @corsair-dev/instantly

bun add corsair @corsair-dev/instantly

import Database from 'better-sqlite3';
import { createCorsair } from 'corsair';
import { instantly } from '@corsair-dev/instantly';

export const corsair = createCorsair({
	plugins: [
		instantly(),
	],
	database: new Database('corsair.db'),
	kek: process.env.CORSAIR_KEK!,
	hub: {
		projectApiKey: process.env.CORSAIR_API_KEY!,
		signingSecret: process.env.CORSAIR_SIGNING_SECRET!,
	},
});

instantly()

const { connectUrl } = await corsair.manage.connect.createLink({
	plugin: 'instantly',
	tenantId: 'acme',
});
// redirect the user's browser to connectUrl

​

Example API calls

const tenant = corsair.withTenant('acme');
await tenant.instantly.api.emails.list({ is_unread: true, min_timestamp_created: '2026-10-28T00:00:00Z', limit: 20 });

const tenant = corsair.withTenant('acme');
await tenant.instantly.api.leads.addBulk({
	campaign_id: '01a181d1-c62c-745b-b842-870ce5b29862',
	leads: [{
		email: 'jordan@acme-logistics.com',
		first_name: 'Jordan',
		company_name: 'Acme Logistics',
		custom_variables: { pain_point: 'slow onboarding' },
	}],
});

​

Query synced data

const tenant = corsair.withTenant('acme');
const rows = await tenant.instantly.db.leads.search({
	data: { company_name: 'Acme Logistics' },
	limit: 10,
});

​

Webhooks

instantly({
    webhookHooks: {
        emails: {
            replyReceived: {
                after: async (ctx, result) => {
                    console.log('Reply from', result.data?.lead_email, result.data?.reply_text_snippet);
                }
            },
        },
    },
})

​

What’s next