Middesk

Middesk is a business identity and verification platform providing API-first infrastructure for KYB (Know Your Business) compliance, EIN/TIN validation, business registration verification, UBO and officer research, sanctions screening, and ongoing business monitoring. Used by fintechs, lenders, banks, and marketplaces to automate customer onboarding and compliance workflows.

Website: https://www.middesk.com Developer Docs: https://docs.middesk.com API Reference: https://docs.middesk.com/reference Status: https://status.middesk.com Blog: https://www.middesk.com/blog GitHub: https://github.com/middesk LinkedIn: https://www.linkedin.com/company/middesk X: https://x.com/middeskhq

API

Middesk exposes a REST API with JSON responses over HTTPS. Two environments are available:

• Production: https://api.middesk.com/v1/
• Sandbox: https://api-sandbox.middesk.com/v1/

Authentication uses HTTP Basic Auth or Bearer token with API keys (prefixed mk_live for production, mk_test for sandbox). Keys are managed in the Middesk Dashboard under Settings > Developer > Credentials.

Key Products

• Business verification (KYB) — Secretary of State registration, EIN/TIN validation, address verification
• Owner and officer verification
• Sanctions and OFAC screening
• Adverse media and PEP screening
• Web presence and industry analysis
• Ongoing business monitoring with webhook notifications
• Lien search and management
• Entity management for payroll tax registration
• Business autocomplete and smart populate (prefill)
• Agentic compliance workflows

Repository Contents

• apis.yml — APIs.json 0.19 provider profile
• plans/middesk-plans-pricing.yml — Pricing plans and tiers
• rate-limits/middesk-rate-limits.yml — Rate limiting and authentication details
• finops/middesk-finops.yml — FinOps guidance and cost optimization strategies