**Cost**: 13 credits per successful call.

Image Replace Background supports two input modes:

1. **JSON URL mode**: send `application/json` with the existing URL field.
2. **Direct upload mode**: send `multipart/form-data` with a local image file in the `image` field. The compatible field name `file` is also accepted for the primary image. Codia checks credits before reading and uploading the file, so insufficient-credit requests return `402` without uploading anything.

Direct upload example:

```bash
curl 'https://openapi.codia.ai/v2/open/image/replace_background' \
  -H 'Authorization: Bearer {codia_api_key}' \
  -F 'image=@./product.png' \
  -F 'prompt=clean white studio background'
```

Keep the foreground subject of an image and synthesize a new background described by a text prompt. Synchronous, single-call. Combines background removal + inpainting + generative rendering in one step.

## What this API is for

Reshooting product photography against new scenes ("on a marble counter", "in front of a sunset window"), reusing portraits across campaigns, or any time you want to keep the subject and change its environment. The subject is preserved; the prompt only steers the new background.

## Request

| Field | Required | Notes |
|---|---|---|
| `image_url` | yes | Public URL of the source image. |
| `prompt` | yes | Natural-language description of the desired new background. Be specific about lighting, surface, and context for best results. |
| `model` | no | Model ID. Defaults to `nano_banana_2`. Also: `nano_banana_pro` (higher fidelity), `ideogram_v3` (alternative aesthetic). |

**Prompt tips**: describe the surface or scene ("clean white marble table"), the lighting ("soft studio lighting from the left"), and the mood. Avoid contradicting the subject's lighting unless you want the subject re-lit (the model may match it).

## Response

Shared `ImageUrlListSuccess` shape — `data.image_urls` is an array of CDN URLs (length 1).

## Billing & limits

- 13 credits per request from the unified Codia Open API balance.
- Synchronous, single-digit-second latency for typical inputs.

## Errors

Standard set — `400` bad input (missing `image_url` or `prompt`), `401`/`403` auth, `402` credits, `429` rate limit, `500` internal.

> **Sync vs. async**
> This synchronous endpoint returns the result inline — the simplest path. For production pipelines that need webhook delivery, automatic retry with idempotency, or explicit task cancellation, call `POST /v2/open/tasks` with `operation=image_replace_background` instead. Inputs and credit cost are identical.

Optional user-supplied key (up to 255 chars). When set, a successful (2xx) response is cached for 7 days. A retry with the same key + identical request body returns the cached response (no extra credit charged); a retry with the same key but a different body returns 409. Use to make POST safe to retry on network failures. For multipart/form-data uploads, requests are compared by form fields and file contents, so a retried upload is replayed even though the client picks a new multipart boundary.

Idempotency-Key

image_url

Text description of the desired new background

prompt

Model that synthesises the new background. Defaults to `nano_banana_2`. All supported models currently cost 13 credits per request.

| Model | Best for | Credits |
| --- | --- | ---: |
| `nano_banana_2` | Fast background swaps (Gemini 3.1 Flash). Good default for most images. | 13 |
| `nano_banana_pro` | Studio-quality 4K backgrounds with realistic lighting and reflections. | 13 |
| `ideogram_v3` | Stylized, illustrative, or text-heavy backgrounds. | 13 |

model

image

Compatible source image file field (deprecated: use `image` instead).

file

Source image URL when not uploading image

code

message

image_urls

data

The request body is malformed or missing required parameters

The API key is missing, invalid, or revoked

Account balance is insufficient or subscription has expired

Account does not have access to this endpoint

Idempotency-Key reused with a different request body.

Rate limited. Wait for the number of seconds in the `Retry-After` header before retrying.

An unexpected error occurred on the server

Keeps the subject and generates a new background from a text prompt.

Replace Background

Input

Output

Related APIs