> ## Documentation Index > Fetch the complete documentation index at: https://docs.eachlabs.ai/llms.txt > Use this file to discover all available pages before exploring further. # Create Chat Completion > OpenAI-compatible chat completions endpoint backed by Eachlabs LLM Router. Use `Authorization: Bearer ` and point an OpenAI-compatible client at `https://api.eachlabs.ai/v1`. This endpoint uses the OpenAI-compatible error envelope rather than the REST error body described in the global contract notes. ## OpenAPI ````yaml /openapi_specs/models.json post /v1/chat/completions openapi: 3.0.3 info: title: each::labs Official API v1 description: > Official each::labs API V1. This API provides access to our comprehensive AI model catalog and other resources. ## Public contract notes - Public API routes handled by request logging include `X-Request-Id` for support and log correlation. Clients may send `X-Request-Id`; otherwise api-service generates one. Root, health, and metrics endpoints are excluded. - REST error bodies keep the backward-compatible JSON shape used by existing clients. Most errors include at least `error`; some shared error paths also include `status` and `details`. Use the HTTP status code as the primary programmatic signal unless an endpoint documents a richer envelope. - Rate-limit and retry headers are endpoint-dependent. If a response includes `Retry-After`, honor it before retrying; otherwise use bounded exponential backoff for retryable 429/5xx responses. - api-service exposes single workflow trigger through `/v1/workflows/trigger/{workflowID}/{versionID}`. Bulk workflow trigger is not routed through api-service; use the workflows-engine public API directly where bulk trigger is required. version: 1.0.0 contact: name: API Support email: support@eachlabs.ai x-logo: url: ./logo-white.svg altText: each::labs servers: - url: https://api.eachlabs.ai description: Production server security: [] tags: - name: AI Models description: Endpoints for listing and retrieving AI models and other resources. - name: AI Models Prediction description: Endpoints for managing model predictions - name: Uploads description: Endpoints for uploading files that can be used as model inputs. - name: Executions description: Endpoints for listing execution history. - name: Workflows description: Endpoints for triggering workflow executions through api-service. - name: OpenAI Compatibility description: OpenAI-compatible endpoints for LLM Router requests. - name: Webhooks description: > Endpoints for retrieving webhook information and delivery history. **Note:** Currently, webhooks are only supported for Workflows V2. We are actively expanding webhook support to other services and will update this documentation as new integrations become available. paths: /v1/chat/completions: post: tags: - OpenAI Compatibility summary: Create Chat Completion description: > OpenAI-compatible chat completions endpoint backed by Eachlabs LLM Router. Use `Authorization: Bearer ` and point an OpenAI-compatible client at `https://api.eachlabs.ai/v1`. This endpoint uses the OpenAI-compatible error envelope rather than the REST error body described in the global contract notes. operationId: createChatCompletion parameters: - name: X-Eachlabs-Webhook-Url in: header required: false schema: type: string format: uri description: Optional webhook URL for asynchronous result delivery. example: https://your-app.com/webhook requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/ChatCompletionRequest' example: model: openai/gpt-4o-mini messages: - role: user content: Write a one sentence caption. responses: '200': description: >- OpenAI-compatible chat completion. Requests with `stream: true` return Server-Sent Events. content: application/json: schema: $ref: '#/components/schemas/ChatCompletionResponse' text/event-stream: schema: type: string description: | Server-Sent Events stream for requests with `stream: true`. Events use OpenAI-compatible `chat.completion.chunk` payloads and the stream terminates with `data: [DONE]`. example: > data: {"id":"chatcmpl-abc123","object":"chat.completion.chunk","choices":[{"index":0,"delta":{"content":"A cinematic"},"finish_reason":null}]} data: [DONE] '400': description: Invalid request content: application/json: schema: $ref: '#/components/schemas/OpenAIErrorResponse' '401': description: Authentication failed content: application/json: schema: $ref: '#/components/schemas/OpenAIErrorResponse' '402': description: Insufficient balance content: application/json: schema: $ref: '#/components/schemas/OpenAIErrorResponse' '500': description: Server error content: application/json: schema: $ref: '#/components/schemas/OpenAIErrorResponse' security: - BearerAuth: [] components: schemas: ChatCompletionRequest: type: object description: OpenAI-compatible chat completions request body required: - model - messages additionalProperties: true properties: model: type: string description: LLM model identifier example: openai/gpt-4o-mini messages: type: array items: type: object additionalProperties: true description: OpenAI-compatible chat messages example: - role: user content: Write a one sentence caption. stream: type: boolean description: >- Set to `true` to receive OpenAI-compatible SSE chunks (`text/event-stream`) instead of a buffered JSON response. example: false stream_options: type: object nullable: true additionalProperties: true description: >- Optional OpenAI-compatible streaming options. When `include_usage` is true, the stream may include a final usage chunk before `[DONE]`. properties: include_usage: type: boolean description: >- Include token usage in the streamed response when provider usage data is available. example: true ChatCompletionResponse: type: object description: OpenAI-compatible chat completions response properties: id: type: string example: chatcmpl-abc123 object: type: string example: chat.completion created: type: integer format: int64 example: 1773651600 model: type: string example: eachlabs-llm-router choices: type: array items: type: object properties: index: type: integer example: 0 message: type: object properties: role: type: string example: assistant content: type: string example: A cinematic sunset over the ocean. finish_reason: type: string example: stop usage: type: object nullable: true properties: prompt_tokens: type: integer example: 12 completion_tokens: type: integer example: 8 total_tokens: type: integer example: 20 OpenAIErrorResponse: type: object description: OpenAI-compatible error envelope used only by `/v1/chat/completions`. properties: error: type: object properties: message: type: string example: Invalid API key type: type: string example: authentication_error param: type: string example: model code: type: string example: invalid_api_key securitySchemes: BearerAuth: type: http scheme: bearer description: >- API key passed as an Authorization Bearer token for OpenAI-compatible endpoints ````