Image Generation

TIE provides an OpenAI-compatible image generation endpoint that routes to multiple providers. Any client that works with OpenAI's /v1/images/generations works with TIE by changing the base URL.

All requests require a Bearer token from TIE Auth.

Endpoint

POST /v1/images/generations

Supported Models

Model	Provider	Format
openai/gpt-image-1.5	OpenAI	url or b64_json
openai/dall-e-3	OpenAI	url or b64_json
google/imagen-4.0	Google Imagen (Vertex AI)	b64_json only

Use the provider/model format (e.g. openai/gpt-image-1.5). You can also omit the provider prefix for OpenAI models (e.g. dall-e-3).

Parameters

Send as JSON:

Parameter	Type	Default	Description
model	string	required	Image model to use (e.g. openai/gpt-image-1.5, google/imagen-4.0)
prompt	string	required	Text description of the desired image
n	integer	1	Number of images to generate. OpenAI: 1–10. Google: 1–4.
size	string	null	Image size: 1024x1024, 1792x1024, 1024x1792. For Google models, this maps to aspect ratios (1:1, 16:9, 9:16).
quality	string	null	Image quality (OpenAI only): auto, low, medium, high, hd
response_format	string	b64_json	url or b64_json. Google models always return b64_json regardless of this setting.
style	string	null	Image style (dall-e-3 only): natural, vivid

Examples

OpenAI (gpt-image-1.5)

curl -X POST https://your-tie-host/v1/images/generations \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $TOKEN" \
  -d '{
    "model": "openai/gpt-image-1.5",
    "prompt": "A serene mountain landscape at sunset with a reflective lake",
    "n": 1,
    "size": "1024x1024",
    "quality": "auto"
  }'

Google Imagen

curl -X POST https://your-tie-host/v1/images/generations \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $TOKEN" \
  -d '{
    "model": "google/imagen-4.0",
    "prompt": "A serene mountain landscape at sunset with a reflective lake",
    "n": 1,
    "size": "1024x1024"
  }'

DALL-E 3

curl -X POST https://your-tie-host/v1/images/generations \
  -H "Content-Type: application/json" \
  -H "Authorization: Bearer $TOKEN" \
  -d '{
    "model": "openai/dall-e-3",
    "prompt": "A serene mountain landscape at sunset with a reflective lake",
    "style": "natural"
  }'

Response

The response follows OpenAI's image generation format:

{
  "created": 1711900000,
  "data": [
    {
      "b64_json": "iVBORw0KGgo...",
      "url": null,
      "revised_prompt": "A tranquil mountain landscape during golden hour..."
    }
  ]
}

Field	Type	Description
created	integer	Unix timestamp of when the response was generated
data	array	List of generated images
data[].b64_json	string or null	Base64-encoded image data (when response_format is b64_json)
data[].url	string or null	Temporary URL to the generated image (when response_format is url, OpenAI models only)
data[].revised_prompt	string or null	The prompt that was actually used (OpenAI models may revise your prompt for safety/quality)

Provider Differences

Feature	OpenAI	Google Imagen
Max images per request	10	4
response_format: "url"	Temporary URL returned	Not supported — always returns b64_json
style parameter	Supported (dall-e-3 only)	Ignored
quality parameter	Supported	Ignored
revised_prompt	Returned when prompt is modified	Not returned
Size handling	Passed as-is (e.g. 1024x1024)	Mapped to aspect ratio (e.g. 1:1)

SDK Integration

Since the endpoint is OpenAI-compatible, you can use the standard OpenAI SDK:

Python

from openai import OpenAI

client = OpenAI(
    base_url="https://your-tie-host/v1",
    api_key="your-bearer-token",
)

response = client.images.generate(
    model="openai/gpt-image-1.5",
    prompt="A serene mountain landscape at sunset",
    n=1,
    size="1024x1024",
)

print(response.data[0].b64_json[:50])  # base64 image data

TypeScript / Node.js

import OpenAI from "openai";

const client = new OpenAI({
  baseURL: "https://your-tie-host/v1",
  apiKey: "your-bearer-token",
});

const response = await client.images.generate({
  model: "openai/gpt-image-1.5",
  prompt: "A serene mountain landscape at sunset",
  n: 1,
  size: "1024x1024",
});

console.log(response.data[0].b64_json?.slice(0, 50));

Error Handling

Status	Code	When
400	VALIDATION_ERROR	Unsupported model, n exceeds provider limit, invalid parameters
401	AUTH_TOKEN_MISSING	No Bearer token provided
502	SERVICE_UPSTREAM_ERROR	The upstream provider (OpenAI or Google) returned an error
503	SERVICE_UNAVAILABLE	Required provider credentials not configured (e.g. OPENAI_API_KEY or GCP_PROJECT_ID)