Let's Encrypt

Let's Encrypt Challenge API

Validation challenges (HTTP-01, DNS-01, TLS-ALPN-01)

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

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OpenAPI Specification

lets-encrypt-challenge-api-openapi.yml Raw ↑ 
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