Let's Encrypt Let's Encrypt Challenge API Validation challenges (HTTP-01, DNS-01, TLS-ALPN-01) Documentation GitHub OpenAPI Documentation 📖 Documentation https://letsencrypt.org/docs/ Specifications ⚙ OpenAPI https://raw.githubusercontent.com/api-evangelist/lets-encrypt/refs/heads/main/openapi/lets-encrypt-challenge-api-openapi.yml