> ## Documentation Index > Fetch the complete documentation index at: https://docs.ninjachat.ai/llms.txt > Use this file to discover all available pages before exploring further. # Chat Completions > Generate AI text completions using 26 LLM models. Supports both standard and streaming responses. Cost varies by model tier — see the `model` parameter for pricing details. Also available at the OpenAI-compatible path `/api/v1/chat/completions`. ## OpenAPI ````yaml /openapi.json post /api/v1/chat openapi: 3.1.0 info: title: NinjaChat API version: 1.0.0 description: >- Access 40+ AI models through a unified API — chat, image generation, video generation, and web search. One API key, one endpoint per type, just change the `model` parameter. servers: - url: https://www.ninjachat.ai security: - bearerAuth: [] paths: /api/v1/chat: post: tags: - Endpoints summary: Chat Completions description: >- Generate AI text completions using 26 LLM models. Supports both standard and streaming responses. Cost varies by model tier — see the `model` parameter for pricing details. Also available at the OpenAI-compatible path `/api/v1/chat/completions`. operationId: createChatCompletion requestBody: required: true content: application/json: schema: type: object required: - messages properties: model: type: string default: ninja-1 enum: - gpt-5.4 - gpt-5.4-pro - gpt-5 - gpt-5-mini - o3-mini - claude-sonnet-4.5 - claude-sonnet-4.6 - claude-haiku-4.5 - claude-opus-4.6 - gemini-2.5-pro - gemini-2.5-flash - gemini-3-pro - gemini-3-flash - gemini-3.1-pro - grok-4 - kimi-k2 - kimi-k2.5 - llama-4-scout - llama-4-maverick - deepseek-v3 - mistral-large - qwq-32b - glm-5 - minimax-m2.5 - ninja-1 - uncensored-ai description: >- Model to use. **Ultra ($0.03/req):** `gpt-5.4-pro`, `claude-opus-4.6`. **Premium ($0.015/req):** `gpt-5.4`, `claude-sonnet-4.6`. **Standard ($0.006/req):** `gpt-5`, `o3-mini`, `claude-sonnet-4.5`, `claude-haiku-4.5`, `gemini-2.5-pro`, `gemini-3-pro`, `gemini-3.1-pro`, `grok-4`, `kimi-k2`, `mistral-large`, `llama-4-maverick`, `kimi-k2.5`. **Budget ($0.003/req):** `gpt-5-mini`, `gemini-2.5-flash`, `gemini-3-flash`, `llama-4-scout`, `deepseek-v3`, `qwq-32b`, `glm-5`, `minimax-m2.5`, `ninja-1`, `uncensored-ai`. Or set `auto` to let NinjaChat pick. messages: type: array minItems: 1 maxItems: 50 items: $ref: '#/components/schemas/ChatMessage' description: Conversation history (1–50 messages). temperature: type: number minimum: 0 maximum: 2 default: 0.7 description: >- Sampling temperature. Lower = more precise, higher = more creative. max_tokens: type: integer minimum: 1 maximum: 16384 default: 2048 description: Maximum output tokens. stream: type: boolean default: false description: Enable server-sent events streaming. examples: gpt5: summary: GPT-5 (Standard) value: model: gpt-5 messages: - role: system content: You are a helpful assistant. - role: user content: Hello, what can you do? temperature: 0.7 max_tokens: 2048 claude: summary: Claude Sonnet 4.6 (Premium) value: model: claude-sonnet-4.6 messages: - role: user content: Write a Python function to merge two sorted lists temperature: 0.3 max_tokens: 4096 budget: summary: DeepSeek V3 (Budget) value: model: deepseek-v3 messages: - role: user content: Explain quantum computing in simple terms responses: '200': description: Successful completion. content: application/json: schema: type: object properties: model: type: string example: gpt-5 message: type: object properties: role: type: string example: assistant content: type: string example: I can help with a wide range of topics... usage: type: object properties: prompt_tokens: type: integer example: 42 completion_tokens: type: integer example: 128 total_tokens: type: integer example: 170 cost: $ref: '#/components/schemas/Cost' metadata: type: object properties: latency_ms: type: integer example: 1234 '400': description: Invalid request. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '401': description: Authentication failed. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '402': description: Insufficient credits. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '429': description: Rate limit exceeded. content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' components: schemas: ChatMessage: type: object required: - role - content properties: role: type: string enum: - system - user - assistant description: The role of the message author. content: type: string minLength: 1 maxLength: 100000 description: The message text. Cost: type: object properties: this_request: type: string example: $0.006 description: Cost of this request. ErrorResponse: type: object description: >- OpenAI-compatible error. The top-level `message`, `code`, and `request_id` mirror fields inside `error` for convenience. properties: error: type: object properties: message: type: string description: Human-readable error description. type: type: string description: >- Error category: invalid_request_error, authentication_error, rate_limit_error, insufficient_quota, or api_error. code: type: string description: Machine-readable error code. param: type: string nullable: true description: The request parameter that caused the error, if any. message: type: string description: Same as error.message. code: type: string description: Same as error.code. request_id: type: string description: Unique request ID, useful when contacting support. securitySchemes: bearerAuth: type: http scheme: bearer description: API key starting with nj_sk_ ````