openapi.yaml

openapi: 3.1.0
info:
  title: SolarProof API
  version: 1.0.0
  description: |
    End-to-end cryptographic proof of renewable energy — from physical meter to on-chain certificate.

    All responses are JSON. Timestamps are ISO 8601 strings unless noted.
  license:
    name: Apache 2.0
    url: https://www.apache.org/licenses/LICENSE-2.0

servers:
  - url: https://solarproof.vercel.app
    description: Production

security: []

paths:
  /api/readings:
    post:
      operationId: submitReading
      summary: Submit a signed meter reading
      description: |
        Verifies the Ed25519 signature, anchors the reading hash on Stellar,
        and mints energy certificates (1 token = 1 kWh).
      security: []
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ReadingRequest'
            example:
              meter_id: a1b2c3d4-e5f6-7890-abcd-ef1234567890
              kwh: 12.5
              timestamp: 1745366400
              signature_hex: "4b3e9f0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000f09a"
      responses:
        '201':
          description: Reading accepted, anchored, and certificates minted
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ReadingResponse'
        '400':
          description: Validation failed
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ValidationError'
        '401':
          description: Ed25519 signature invalid
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
              example:
                error: Invalid meter signature
        '404':
          description: Meter not registered or inactive
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
              example:
                error: Meter not found or inactive
        '409':
          description: Reading already anchored
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '500':
          description: Anchor or mint failed
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ReadingError'

  /api/verify:
    get:
      operationId: verifyCertificate
      summary: Retrieve chain of custody for a certificate
      description: |
        Public endpoint — no authentication required.
        Accepts a certificate UUID, reading hash (64-char hex), or mint transaction hash.
        Results are cached for 60 seconds.
      security: []
      parameters:
        - name: id
          in: query
          required: true
          description: Certificate UUID, reading hash (64-char hex), or mint transaction hash
          schema:
            type: string
          example: a1b2c3d4-e5f6-7890-abcd-ef1234567890
      responses:
        '200':
          description: Certificate found — full chain of custody returned
          headers:
            Cache-Control:
              schema:
                type: string
              example: public, max-age=60, stale-while-revalidate=30
            X-Cache:
              schema:
                type: string
                enum: [HIT, MISS]
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ChainOfCustody'
        '400':
          description: Missing or invalid id parameter
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ValidationError'
        '404':
          description: No certificate matches the given id
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
              example:
                error: Certificate not found

  /api/certificates/{id}/retire:
    post:
      operationId: retireCertificate
      summary: Retire a certificate
      description: |
        Permanently retires a certificate by calling the energy_token contract retire function.
        A retired certificate cannot be used again.
      security: []
      parameters:
        - name: id
          in: path
          required: true
          description: Certificate UUID
          schema:
            type: string
            format: uuid
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/RetireRequest'
      responses:
        '200':
          description: Certificate retired successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/RetireResponse'
        '400':
          description: Validation failed
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ValidationError'
        '404':
          description: Certificate not found
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
        '409':
          description: Certificate already retired
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
              example:
                error: Certificate already retired
        '500':
          description: Retire transaction failed
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'

  /api/health:
    get:
      operationId: healthCheck
      summary: Liveness check
      description: Returns 200 when the service is running. Used by uptime monitoring.
      security: []
      responses:
        '200':
          description: Service is healthy
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/HealthResponse'
              example:
                status: ok
                ts: 1745366400000
        '503':
          description: Service unavailable
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'

components:
  schemas:
    ReadingRequest:
      type: object
      required: [meter_id, kwh, timestamp, signature_hex]
      properties:
        meter_id:
          type: string
          format: uuid
          description: Registered meter identifier
        kwh:
          type: number
          exclusiveMinimum: 0
          description: Energy generated in kilowatt-hours
        timestamp:
          type: integer
          description: Unix timestamp in seconds (integer)
        signature_hex:
          type: string
          minLength: 128
          maxLength: 128
          description: Ed25519 signature of the canonical reading hash, hex-encoded (64 bytes)

    ReadingResponse:
      type: object
      required: [reading_id, anchor_tx_hash, mint_tx_hash]
      properties:
        reading_id:
          type: string
          format: uuid
        anchor_tx_hash:
          type: string
          description: Stellar transaction hash for the on-chain anchor
        mint_tx_hash:
          type: string
          description: Stellar transaction hash for the certificate mint

    ReadingError:
      type: object
      required: [error, reading_id]
      properties:
        error:
          type: string
        reading_id:
          type: string
          format: uuid
        anchor_tx_hash:
          type: string
          description: Present if anchoring succeeded but minting failed

    ChainOfCustody:
      type: object
      required: [certificate, on_chain]
      properties:
        certificate:
          type: object
          required: [id, kwh, issued_at, retired]
          properties:
            id:
              type: string
              format: uuid
            kwh:
              type: number
            issued_at:
              type: string
              format: date-time
            retired:
              type: boolean
            retired_at:
              type: ['string', 'null']
              format: date-time
            retired_by:
              type: ['string', 'null']
              description: Stellar wallet address that retired the certificate
        on_chain:
          type: object
          required: [anchor_tx, anchor_explorer, mint_tx, mint_explorer]
          properties:
            anchor_tx:
              type: string
            anchor_explorer:
              type: string
              format: uri
            mint_tx:
              type: string
            mint_explorer:
              type: string
              format: uri
        meter_proof:
          oneOf:
            - type: 'null'
            - type: object
              required: [meter_id, reading_hash, signature_hex, kwh, timestamp, verified]
              properties:
                meter_id:
                  type: string
                  format: uuid
                reading_hash:
                  type: string
                  description: Hex-encoded SHA-256 hash of the canonical reading
                signature_hex:
                  type: string
                  description: Ed25519 signature hex (128 chars)
                kwh:
                  type: number
                timestamp:
                  type: string
                  format: date-time
                verified:
                  type: boolean

    RetireRequest:
      type: object
      required: [wallet_address]
      properties:
        wallet_address:
          type: string
          description: Stellar wallet address of the certificate holder

    RetireResponse:
      type: object
      required: [id, retired, retired_at, retired_by, retire_tx_hash]
      properties:
        id:
          type: string
          format: uuid
        retired:
          type: boolean
        retired_at:
          type: string
          format: date-time
        retired_by:
          type: string
        retire_tx_hash:
          type: string

    HealthResponse:
      type: object
      required: [status, ts]
      properties:
        status:
          type: string
          enum: [ok]
        ts:
          type: integer
          description: Current Unix timestamp in milliseconds

    Error:
      type: object
      required: [error]
      properties:
        error:
          type: string

    ValidationError:
      type: object
      required: [error]
      properties:
        error:
          oneOf:
            - type: string
            - type: object
              properties:
                fieldErrors:
                  type: object
                  additionalProperties:
                    type: array
                    items:
                      type: string
                formErrors:
                  type: array
                  items:
                    type: string