openapi: 3.0.3 info: title: Let's Encrypt ACME Account Challenge API description: The ACME (Automatic Certificate Management Environment) protocol API used by Let's Encrypt to automate the issuance, renewal, and revocation of TLS certificates. Implements RFC 8555. version: '1.0' contact: name: Let's Encrypt url: https://letsencrypt.org/docs/ license: name: Mozilla Public License 2.0 url: https://www.mozilla.org/en-US/MPL/2.0/ servers: - url: https://acme-v02.api.letsencrypt.org description: Production ACME endpoint - url: https://acme-staging-v02.api.letsencrypt.org description: Staging ACME endpoint tags: - name: Challenge description: Validation challenges (HTTP-01, DNS-01, TLS-ALPN-01) paths: /acme/chall/{challengeId}: post: tags: - Challenge summary: Respond to a challenge operationId: respondChallenge parameters: - name: challengeId in: path required: true schema: type: string requestBody: required: true content: application/jose+json: schema: $ref: '#/components/schemas/JWS' responses: '200': description: Challenge response accepted components: schemas: JWS: type: object description: Flattened JSON Web Signature object per RFC 7515 properties: protected: type: string payload: type: string signature: type: string