openapi: 3.1.0
info:
  title: ACME (RFC 8555) Protocol Account Directory API
  description: The Automatic Certificate Management Environment (ACME) protocol, defined in IETF RFC 8555, automates the interactions between Certificate Authorities and clients for issuing, renewing, and revoking X.509 certificates. ACME requests are JSON Web Signature (JWS) payloads carried over HTTPS. Server URLs are advertised by each ACME directory; this spec uses generic /acme/* paths.
  version: 1.0.0
  contact:
    name: IETF Datatracker
    url: https://datatracker.ietf.org/doc/html/rfc8555
  license:
    name: IETF Trust
    url: https://trustee.ietf.org/license-info
servers:
- url: https://acme-v02.api.letsencrypt.org
  description: Let's Encrypt production ACME directory (reference implementation)
- url: https://acme-staging-v02.api.letsencrypt.org
  description: Let's Encrypt staging ACME directory
tags:
- name: Directory
  description: Server discovery and nonce retrieval.
paths:
  /directory:
    get:
      operationId: getDirectory
      summary: Retrieve ACME directory
      description: Returns URLs for the supported resources of this ACME server.
      tags:
      - Directory
      responses:
        '200':
          description: Directory of ACME endpoints
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/GenericResponse'
  /acme/new-nonce:
    head:
      operationId: newNonce
      summary: Retrieve a new nonce
      description: Retrieve a fresh anti-replay nonce in the Replay-Nonce header.
      tags:
      - Directory
      responses:
        '200':
          description: Nonce returned in Replay-Nonce header
          headers:
            Replay-Nonce:
              schema:
                type: string
components:
  schemas:
    GenericResponse:
      type: object
      additionalProperties: true
x-generated-from: https://datatracker.ietf.org/doc/html/rfc8555
x-generated-by: claude-crawl-2026-05-08