openapi: 3.2.0
info:
  title: AAAA Nexus Shield API
  version: 0.5.1
  description: Formally verified AI safety APIs for autonomous agents. Supports REST, MCP, A2A (Google protocol), and x402 micropayment protocol.
  contact:
    email: atomadic69@gmail.com
    url: https://github.com/atomadictech/aaaa-nexus
servers:
- url: https://atomadic.tech
  description: Production
security: []
tags:
- name: Shield
  description: 'AAAA Shield: post-quantum key exchange, session management, key rotation'
paths:
  /v1/shield/session:
    post:
      operationId: shieldSession
      summary: Initialize Shield session
      description: Initialize an AAAA Shield session for post-quantum secure communication.
      tags:
      - Shield
      security:
      - ApiKeyAuth: []
      - X402PaymentProof: []
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
              - agent_id
              properties:
                agent_id:
                  type: string
                algorithm:
                  type: string
                  example: kyber-1024
      responses:
        '200':
          description: Shield session initialized
          content:
            application/json:
              schema:
                type: object
                properties:
                  session_id:
                    type: string
                  public_key:
                    type: string
                  algorithm:
                    type: string
                  created_at:
                    type: string
                    format: date-time
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '402':
          $ref: '#/components/responses/PaymentRequired'
  /v1/shield/post-quantum:
    post:
      operationId: shieldPostQuantum
      summary: Post-quantum key exchange
      description: Perform a post-quantum key exchange using Kyber or similar lattice-based algorithms.
      tags:
      - Shield
      security:
      - ApiKeyAuth: []
      - X402PaymentProof: []
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
              - session_id
              - public_key
              properties:
                session_id:
                  type: string
                public_key:
                  type: string
      responses:
        '200':
          description: Key exchange result
          content:
            application/json:
              schema:
                type: object
                properties:
                  session_id:
                    type: string
                  shared_secret_hash:
                    type: string
                  algorithm:
                    type: string
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '402':
          $ref: '#/components/responses/PaymentRequired'
  /v1/shield/verify:
    post:
      operationId: shieldVerify
      summary: Verify Shield session
      description: Verify the integrity of an AAAA Shield session.
      tags:
      - Shield
      security:
      - ApiKeyAuth: []
      - X402PaymentProof: []
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
              - session_id
              properties:
                session_id:
                  type: string
      responses:
        '200':
          description: Shield verification result
          content:
            application/json:
              schema:
                type: object
                properties:
                  session_id:
                    type: string
                  valid:
                    type: boolean
                  timestamp:
                    type: string
                    format: date-time
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '402':
          $ref: '#/components/responses/PaymentRequired'
  /v1/shield/rotate:
    post:
      operationId: shieldRotate
      summary: Rotate Shield keys
      description: Rotate the cryptographic keys for an AAAA Shield session.
      tags:
      - Shield
      security:
      - ApiKeyAuth: []
      - X402PaymentProof: []
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
              - session_id
              properties:
                session_id:
                  type: string
      responses:
        '200':
          description: Keys rotated
          content:
            application/json:
              schema:
                type: object
                properties:
                  session_id:
                    type: string
                  new_public_key:
                    type: string
                  rotated_at:
                    type: string
                    format: date-time
        '400':
          $ref: '#/components/responses/BadRequest'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '402':
          $ref: '#/components/responses/PaymentRequired'
  /v1/shield/status:
    get:
      operationId: getShieldStatus
      summary: Shield status
      description: Get the status of an AAAA Shield session.
      tags:
      - Shield
      parameters:
      - name: session_id
        in: query
        required: true
        schema:
          type: string
        description: Shield session ID
      security:
      - ApiKeyAuth: []
      - X402PaymentProof: []
      responses:
        '200':
          description: Shield status
          content:
            application/json:
              schema:
                type: object
                properties:
                  session_id:
                    type: string
                  status:
                    type: string
                    enum:
                    - active
                    - expired
                    - revoked
                  algorithm:
                    type: string
                  created_at:
                    type: string
                    format: date-time
                  last_rotated:
                    type: string
                    format: date-time
        '401':
          $ref: '#/components/responses/Unauthorized'
        '402':
          $ref: '#/components/responses/PaymentRequired'
components:
  responses:
    PaymentRequired:
      description: 'Payment required. Use x402 protocol: send USDC on Base L2, Polygon, or Solana to the treasury address provided in the response, then retry with the X-Payment-Proof header.'
      content:
        application/json:
          schema:
            type: object
            properties:
              error:
                type: string
                example: Payment required
              amount:
                type: string
                example: '0.002'
              currency:
                type: string
                example: USDC
              treasury:
                type: string
                description: Destination wallet address
              chains:
                type: array
                items:
                  type: string
                example:
                - base
                - polygon
                - solana
    BadRequest:
      description: Invalid request body or missing required fields.
      content:
        application/json:
          schema:
            type: object
            properties:
              error:
                type: string
    Unauthorized:
      description: Missing or invalid API key.
      content:
        application/json:
          schema:
            type: object
            properties:
              error:
                type: string
                example: Unauthorized
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: X-API-Key
      description: API key obtained from https://atomadic.tech/pay
    X402PaymentProof:
      type: apiKey
      in: header
      name: X-Payment-Proof
      description: Base64-encoded USDC payment proof for x402 autonomous payment flow (Base L2, Polygon, or Solana)
    AdminTokenAuth:
      type: apiKey
      in: header
      name: X-Admin-Token
      description: Admin token for privileged operations