> ## Documentation Index > Fetch the complete documentation index at: https://docs.llmlayer.ai/llms.txt > Use this file to discover all available pages before exploring further. # Answer API - Stream responses in real-time > Stream search results and AI responses in real-time using Server-Sent Events (SSE). Does not support JSON structured output. ## OpenAPI ````yaml post /api/v2/answer_stream openapi: 3.0.0 info: title: LLMLayer API version: 2.0.0 description: >- The Web API for AI Agents - Search, scrape, extract content, crawl websites, and generate AI-powered answers with multiple LLMs servers: - url: https://api.llmlayer.dev security: [] tags: - name: Answer API description: >- Web-enhanced AI responses combining search with multiple LLM models. Supports streaming, custom prompts, and structured JSON output. - name: Web Search description: >- Direct web search across multiple content types (general, news, shopping, videos, images, scholar) without AI processing. - name: Content Extraction description: >- Extract content from websites, PDFs, and YouTube videos in multiple formats. - name: Web Crawling description: >- Map websites and crawl multiple pages with depth control. Supports streaming with markdown output. paths: /api/v2/answer_stream: post: tags: - Answer API summary: Answer API - Stream responses in real-time description: >- Stream search results and AI responses in real-time using Server-Sent Events (SSE). Does not support JSON structured output. operationId: answerStream requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/SearchRequest' responses: '200': description: Server-Sent Events stream content: text/event-stream: schema: type: string description: >- SSE stream with event types: sources, images, answer, usage, done, error examples: sources_event: value: >+ data: {"type":"sources","data":[{"title":"Y Combinator","link":"https://www.ycombinator.com","snippet":"..."}]} images_event: value: >+ data: {"type":"images","data":[{"title":"Image","imageUrl":"https://..."}]} answer_event: value: >+ data: {"type":"answer","content":"This is part of the answer..."} usage_event: value: >+ data: {"type":"usage","input_tokens":1500,"output_tokens":800,"model_cost":0.0025,"llmlayer_cost":0.004} done_event: value: |+ data: {"type":"done","response_time":"3.45"} '400': $ref: '#/components/responses/BadRequest' '401': $ref: '#/components/responses/Unauthorized' '500': $ref: '#/components/responses/InternalServerError' security: - BearerAuth: [] components: schemas: SearchRequest: type: object required: - query - model properties: query: type: string description: The search query or question to answer example: What are the latest developments in quantum computing? model: type: string description: >- LLM model to use (e.g., llmlayer-web, llmlayer-fast, openai/gpt-4o-mini, openai/gpt-5.1) example: llmlayer-web location: type: string default: us description: Country code for localized search results (us, uk, ca, etc.) example: us provider_key: type: string nullable: true description: >- Deprecated. Accepted for backward compatibility but currently ignored by the API. system_prompt: type: string nullable: true description: >- Custom system prompt to override default behavior. Use this to customize how the LLM processes the search results. response_language: type: string default: auto description: >- Language for the response. 'auto' detects from query, or specify language code (en, es, fr, etc.) example: auto answer_type: type: string enum: - markdown - html - json default: markdown description: >- Format of the response. Use 'json' with json_schema for structured output. search_type: type: string enum: - general - news default: general description: Type of web search to perform. 'news' provides recent news articles. json_schema: type: string nullable: true description: >- JSON schema as string for structured responses. Required when answer_type='json'. The LLM will format its response according to this schema. example: >- {"type":"object","properties":{"summary":{"type":"string"},"key_points":{"type":"array","items":{"type":"string"}}}} citations: type: boolean default: false description: Include inline citations [1], [2] in the response text return_sources: type: boolean default: false description: Return the source documents used for answer generation return_images: type: boolean default: false description: Return relevant images from image search. Adds $0.001 to cost. date_filter: type: string enum: - anytime - hour - day - week - month - year default: anytime description: Filter search results by recency. Useful for time-sensitive queries. max_tokens: type: integer default: 1500 minimum: 1 description: Maximum tokens in the LLM response. Affects cost. temperature: type: number default: 0.7 minimum: 0 maximum: 2 description: >- Controls response randomness. 0=deterministic, 2=very creative. Not supported by all models. domain_filter: type: array items: type: string nullable: true description: >- Include or exclude specific domains. Use '-' prefix to exclude (e.g., ['-reddit.com', 'wikipedia.org']) example: - wikipedia.org - '-reddit.com' max_queries: type: integer default: 1 minimum: 1 maximum: 4 description: >- Number of search queries to generate from the user query. More queries = broader search and higher LLMLayer fee. Token-priced models use $0.004 per query; fixed-price LLMLayer models use their model-specific per-query price. example: 3 search_context_size: type: string enum: - low - medium - high default: medium description: >- Amount of search context to extract and pass to LLM. 'high' provides more context but uses more tokens. ErrorResponse: type: object required: - detail properties: detail: type: object required: - error_type - error_code - message properties: error_type: type: string enum: - validation_error - authentication_error - provider_error - rate_limit - internal_error - scraping_error - search_error - map_error description: Category of error error_code: type: string description: Specific error code for programmatic handling example: missing_query message: type: string description: Human-readable error message details: type: object additionalProperties: true nullable: true description: Additional error context and debugging information responses: BadRequest: description: Invalid request parameters content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: missing_query: value: detail: error_type: validation_error error_code: missing_query message: Query parameter cannot be empty missing_json_schema: value: detail: error_type: validation_error error_code: missing_json_schema message: JSON schema is required for JSON response type invalid_max_pages: value: detail: error_type: validation_error error_code: invalid_max_pages message: max_pages must be between 1 and 100 Unauthorized: description: Authentication error - missing or invalid API key content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' example: detail: error_type: authentication_error error_code: missing_llmlayer_api_key message: 'Provide LLMLayer API key via ''Authorization: Bearer ''' InternalServerError: description: Internal server error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' examples: unexpected_error: value: detail: error_type: internal_error error_code: unexpected_error message: An unexpected error occurred. Please try again later scraping_error: value: detail: error_type: scraping_error error_code: url_scrape_failed message: Failed to scrape content from the provided URL details: url: https://www.ycombinator.com error: Connection timeout securitySchemes: BearerAuth: type: http scheme: bearer description: >- Bearer token authentication using your LLMLayer API key. Include in Authorization header as: Bearer YOUR_LLMLAYER_API_KEY ````