openapi: 3.1.0 info: title: Open WebUI Anthropic Ollama API description: 'REST API exposed by a self-hosted Open WebUI instance. Endpoints include an OpenAI-compatible chat completions surface, an Anthropic-compatible messages endpoint, and a passthrough proxy for native Ollama endpoints. Authentication uses a Bearer token (Open WebUI session token or a per-user API key); each API key inherits the permissions of the user who created it. ' version: 1.0.0 contact: name: Open WebUI Documentation url: https://docs.openwebui.com/ servers: - url: http://localhost:3000 description: Default local Open WebUI deployment - url: https://{host} description: User-deployed Open WebUI instance variables: host: default: openwebui.example.com security: - BearerAuth: [] tags: - name: Ollama paths: /ollama/api/tags: get: tags: - Ollama summary: List Ollama models (passthrough) responses: '200': description: List of available Ollama models from the upstream daemon. content: application/json: schema: type: object additionalProperties: true /ollama/api/generate: post: tags: - Ollama summary: Generate completion via Ollama (passthrough) requestBody: required: true content: application/json: schema: type: object additionalProperties: true properties: model: type: string prompt: type: string stream: type: boolean responses: '200': description: Ollama generation response. content: application/json: schema: type: object additionalProperties: true /ollama/api/chat: post: tags: - Ollama summary: Chat via Ollama (passthrough) requestBody: required: true content: application/json: schema: type: object additionalProperties: true properties: model: type: string messages: type: array items: $ref: '#/components/schemas/Message' responses: '200': description: Ollama chat response. content: application/json: schema: type: object additionalProperties: true components: schemas: Message: type: object properties: role: type: string enum: - system - user - assistant - tool content: type: string required: - role - content securitySchemes: BearerAuth: type: http scheme: bearer description: 'Bearer token: Open WebUI session token or per-user API key. Each API key inherits the permissions of the user who created it. '