openapi: 3.0.1
info:
  title: LLM Guard Output API
  description: Self-hostable REST API for LLM Guard, Protect AI's open-source (Apache 2.0) security toolkit for LLM interactions. The llm-guard-api service wraps the llm-guard Python library in a FastAPI application and exposes scanners that detect, redact, and sanitize prompts and outputs for prompt injection, PII, toxicity, secrets, banned topics, and more. Scanners are configured per deployment via scanners.yml. This specification documents the real self-hosted API surface; Protect AI's commercial products (Guardian, Recon, Layer) do not publish a public REST API and are not modeled here.
  termsOfService: https://protectai.com/terms
  contact:
    name: Protect AI / LLM Guard
    url: https://llm-guard.com/
  license:
    name: Apache 2.0
    url: https://www.apache.org/licenses/LICENSE-2.0
  version: '1.0'
servers:
- url: http://localhost:8000
  description: Default local llm-guard-api deployment (FastAPI/Uvicorn).
security:
- bearerAuth: []
- {}
tags:
- name: Output
paths:
  /analyze/output:
    post:
      operationId: analyzeOutput
      tags:
      - Output
      summary: Analyze and sanitize an output.
      description: Runs the configured output scanners over the LLM response (with the originating prompt for context) and returns the sanitized output, an overall validity flag, and per-scanner risk scores.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/AnalyzeOutputRequest'
      responses:
        '200':
          description: Output analyzed.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AnalyzeOutputResponse'
        '400':
          description: Invalid request.
        '403':
          description: Authentication failed.
  /scan/output:
    post:
      operationId: scanOutput
      tags:
      - Output
      summary: Scan an output.
      description: Runs the configured output scanners over the LLM response (with the originating prompt for context) and returns the validity flag and per-scanner risk scores without returning a modified output.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ScanOutputRequest'
      responses:
        '200':
          description: Output scanned.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ScanOutputResponse'
        '400':
          description: Invalid request.
        '403':
          description: Authentication failed.
components:
  schemas:
    ScanOutputResponse:
      type: object
      properties:
        is_valid:
          type: boolean
        scanners:
          type: object
          additionalProperties:
            type: number
            format: float
    AnalyzeOutputResponse:
      type: object
      properties:
        sanitized_output:
          type: string
        is_valid:
          type: boolean
        scanners:
          type: object
          additionalProperties:
            type: number
            format: float
    ScanOutputRequest:
      type: object
      required:
      - prompt
      - output
      properties:
        prompt:
          type: string
        output:
          type: string
        scanners_suppress:
          type: array
          items:
            type: string
    AnalyzeOutputRequest:
      type: object
      required:
      - prompt
      - output
      properties:
        prompt:
          type: string
          description: The originating prompt, used by output scanners for context.
        output:
          type: string
          description: The LLM response to analyze and sanitize.
        scanners_suppress:
          type: array
          items:
            type: string
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: Optional bearer token authentication, enabled per deployment via the llm-guard-api configuration. Deployments may also run without auth.