> ## Documentation Index
> Fetch the complete documentation index at: https://docs.dgrid.ai/llms.txt
> Use this file to discover all available pages before exploring further.
# OpenAI Chat Format
> OpenAI-compatible Chat Completions for standard multi-turn chat, structured output, and tool calling. Model names use the `provider/model-name` format, for example `openai/gpt-4o`. Image-capable models can also return generated images through this endpoint.
This page uses the same `chat/completions` operation as [Create chat completion](/api-reference/chat/create-chat-completion), with the playground above pre-filled for the generic chat schema. The notes below describe how to use this endpoint to request Gemini-backed image generation from an OpenAI-compatible client.
Include an image-generation model in `model` (such as `gemini-2.0-flash-preview-image-generation`), set `stream` as needed, and supply your prompt through `messages`. Optionally include `contents` for additional Gemini-style multimodal context alongside `messages`.
### Provider-specific notes
| Field | Type | Required | Description |
| -------------------- | ------ | -------- | ------------------------------------------------------------------------------------------------------------------- |
| `model` | string | Yes | Image-generation model identifier, e.g. `gemini-2.0-flash-preview-image-generation`. |
| `messages[].content` | string | Yes | Prompt text describing the desired image. |
| `contents` | array | No | Optional Gemini-style content array for additional multimodal context, not part of the standard OpenAI chat schema. |
The `contents` field is a DGrid extension layered on top of the standard chat completions schema — it lets you pass Gemini-native `parts` (such as `inlineData`) alongside the OpenAI-style `messages` array when the target model supports it.
### Example: requesting an image
```json theme={null}
{
"model": "gemini-2.0-flash-preview-image-generation",
"stream": false,
"messages": [
{
"role": "user",
"content": "Generate an image of a futuristic city skyline at sunset."
}
]
}
```
### Response fields
The response follows the standard chat completions shape. The generated image is embedded directly in the assistant message content:
Returned choice entries.
Choice index.
Assistant message object.
Message role, typically `assistant`.
Message content. For image-output models, this is a markdown image reference embedding the generated image as a base64 data URI, e.g. ``.
Finish reason, e.g. `stop`.
Token usage summary.
### Example response
```json 200 theme={null}
{
"id": "chatcmpl-abc123",
"model": "gemini-2.0-flash-preview-image-generation",
"object": "chat.completion",
"created": 1719859200,
"choices": [
{
"index": 0,
"message": {
"role": "assistant",
"content": ""
},
"finish_reason": "stop"
}
],
"usage": {
"prompt_tokens": 12,
"completion_tokens": 0,
"total_tokens": 12
}
}
```
## OpenAPI
````yaml api-reference/openapi.json POST /v1/chat/completions
openapi: 3.1.0
info:
title: DGrid AI Gateway API
description: >-
A single, unified API to access 200+ leading AI models. OpenAI-, Claude-,
and Gemini-compatible endpoints for chat, completions, embeddings, images,
audio, and moderations.
version: 1.0.0
contact:
name: DGrid AI
url: https://dgrid.ai
servers:
- url: https://api.dgrid.ai
description: DGrid AI Gateway
security:
- bearerAuth: []
paths:
/v1/chat/completions:
post:
tags:
- Chat
summary: Create chat completion
description: >-
OpenAI-compatible Chat Completions for standard multi-turn chat,
structured output, and tool calling. Model names use the
`provider/model-name` format, for example `openai/gpt-4o`. Image-capable
models can also return generated images through this endpoint.
operationId: createChatCompletion
requestBody:
required: true
content:
application/json:
schema:
type: object
required:
- model
- messages
properties:
model:
type: string
description: Target model ID in `provider/model-name` format.
example: openai/gpt-4o
messages:
type: array
description: Conversation message list.
items:
type: object
required:
- role
- content
properties:
role:
type: string
enum:
- system
- user
- assistant
- tool
description: Message author role.
content:
type: string
description: Message content.
name:
type: string
description: Optional participant name.
tool_calls:
type: array
description: Tool invocation payloads.
items:
type: object
tool_call_id:
type: string
description: Tool call identifier.
temperature:
type: number
default: 1
description: Sampling temperature.
top_p:
type: number
default: 1
description: Nucleus sampling value.
'n':
type: integer
default: 1
description: Number of choices to generate.
stream:
type: boolean
default: false
description: Enable SSE streaming.
max_tokens:
type: integer
description: Maximum token count.
max_completion_tokens:
type: integer
description: Max completion-only tokens.
presence_penalty:
type: number
default: 0
description: Presence penalty.
frequency_penalty:
type: number
default: 0
description: Frequency penalty.
logit_bias:
type: object
description: Token bias configuration.
stop:
description: Stop sequence string or array.
oneOf:
- type: string
- type: array
items:
type: string
tools:
type: array
description: Tool definitions.
items:
type: object
tool_choice:
description: Tool selection behavior. Defaults to `auto`.
oneOf:
- type: string
- type: object
response_format:
type: object
description: Response schema or JSON mode config.
seed:
type: integer
description: Deterministic seed.
user:
type: string
description: End-user identifier.
example:
model: openai/gpt-4o
messages:
- role: user
content: What is the meaning of life?
responses:
'200':
description: Chat completion result.
content:
application/json:
schema:
type: object
properties:
id:
type: string
description: Completion identifier.
object:
type: string
description: Always `chat.completion`.
created:
type: integer
description: Creation timestamp.
model:
type: string
description: Model that served the request.
choices:
type: array
description: Returned choices.
items:
type: object
properties:
index:
type: integer
description: Choice index.
message:
type: object
description: Assistant message object.
properties:
role:
type: string
description: Response role.
content:
type: string
description: Response text.
reasoning_content:
type: string
description: Reasoning trace for reasoning models.
tool_calls:
type: array
description: Tool call payloads.
items:
type: object
finish_reason:
type: string
description: '`stop`, `length`, `content_filter`, or `tool_calls`.'
usage:
$ref: '#/components/schemas/Usage'
system_fingerprint:
type: string
'400':
$ref: '#/components/responses/BadRequest'
'429':
$ref: '#/components/responses/RateLimited'
components:
schemas:
Usage:
type: object
description: Token usage breakdown.
properties:
prompt_tokens:
type: integer
completion_tokens:
type: integer
total_tokens:
type: integer
prompt_tokens_details:
type: object
properties:
cached_tokens:
type: integer
text_tokens:
type: integer
audio_tokens:
type: integer
image_tokens:
type: integer
completion_tokens_details:
type: object
properties:
text_tokens:
type: integer
audio_tokens:
type: integer
reasoning_tokens:
type: integer
Error:
type: object
properties:
error:
type: object
properties:
message:
type: string
type:
type: string
param:
type: string
code:
type: string
responses:
BadRequest:
description: Invalid request.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
RateLimited:
description: Rate limit exceeded.
content:
application/json:
schema:
$ref: '#/components/schemas/Error'
securitySchemes:
bearerAuth:
type: http
scheme: bearer
description: >-
Your DGrid API key. All endpoints use `Authorization: Bearer
`.
````