openapi: 3.0.1
info:
  title: LLM Guard Output Prompt 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specification documents the real self-hosted API surface; Protect AI's commercial products (Guardian, Recon, Layer) do not publish a public REST API and are not modeled here.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: Prompt
paths:
  /analyze/prompt:
    post:
      operationId: analyzePrompt
      tags:
      - Prompt
      summary: Analyze and sanitize a prompt.
      description: Runs the configured input scanners over the supplied prompt and returns the sanitized prompt, an overall validity flag, and per-scanner risk scores. Scanners that redact or anonymize content (for example PII anonymization) apply their changes to the returned sanitized_prompt.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/AnalyzePromptRequest'
      responses:
        '200':
          description: Prompt analyzed.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AnalyzePromptResponse'
        '400':
          description: Invalid request.
        '403':
          description: Authentication failed.
  /scan/prompt:
    post:
      operationId: scanPrompt
      tags:
      - Prompt
      summary: Scan a prompt.
      description: Runs the configured input scanners over the supplied prompt and returns the validity flag and per-scanner risk scores without returning a modified prompt. Use /analyze/prompt when sanitized text is required.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ScanPromptRequest'
      responses:
        '200':
          description: Prompt scanned.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ScanPromptResponse'
        '400':
          description: Invalid request.
        '403':
          description: Authentication failed.
components:
  schemas:
    ScanPromptResponse:
      type: object
      properties:
        is_valid:
          type: boolean
        scanners:
          type: object
          additionalProperties:
            type: number
            format: float
    AnalyzePromptResponse:
      type: object
      properties:
        sanitized_prompt:
          type: string
          description: The prompt after applicable scanners have redacted or anonymized content.
        is_valid:
          type: boolean
          description: True when the prompt passed all configured scanners.
        scanners:
          type: object
          description: Map of scanner name to risk score (0.0 - 1.0).
          additionalProperties:
            type: number
            format: float
    AnalyzePromptRequest:
      type: object
      required:
      - prompt
      properties:
        prompt:
          type: string
          description: The user prompt to analyze and sanitize.
        scanners_suppress:
          type: array
          description: Optional list of scanner names to skip for this request.
          items:
            type: string
    ScanPromptRequest:
      type: object
      required:
      - prompt
      properties:
        prompt:
          type: string
          description: The user prompt to scan.
        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.