Kit (ConvertKit)

Kit (formerly ConvertKit) is a creator email marketing platform with a REST API for managing subscribers, tags, sequences, forms, broadcasts, and automation rules.

• Website: https://kit.com
• API Docs: https://developers.kit.com
• Status: https://status.kit.com
• Pricing: https://kit.com/pricing
• Changelog: https://developers.kit.com/changelog
• GitHub Org: https://github.com/convertkit
• LinkedIn: https://www.linkedin.com/company/kit.com
• X: https://x.com/kit

API

The Kit API v4 is a REST API with a base URL of https://api.kit.com/v4. It supports both API key authentication and OAuth 2.0.

Authentication

• API Key: Pass via X-Kit-Api-Key header. Rate limit: 120 requests per 60-second rolling window.
• OAuth 2.0: Authorization Code Grant (with PKCE for SPAs/mobile). Rate limit: 600 requests per 60-second rolling window.

Resources

• Subscribers
• Tags
• Sequences
• Forms
• Broadcasts
• Automation rules
• Custom fields
• Purchases (e-commerce, OAuth only)

Plans

See plans/convertkit-plans-pricing.yml for full pricing details.

Plan	Monthly Price	Subscribers
Newsletter	Free	Up to 10,000
Creator	From $39/mo	From 1,000 (scales)
Pro	From $79/mo	From 1,000 (scales)

All plans include API access.