API Reference

Black Forest Labs FLUX

Gateway FLUX native compatibility route, restricted to flux-3-image. Use the listed model protocols for other FLUX models.

POST https://api.tu-zi.com/flux/v1/flux-3-image

Preview guide

Paste into an AI assistant to help with integration. Documentation and examples only; no real credentials.

# Black Forest Labs FLUX

Gateway FLUX native compatibility route, restricted to flux-3-image. Use the listed model protocols for other FLUX models.

## Endpoint and authentication

`POST https://api.tu-zi.com/flux/v1/flux-3-image`

Transport: json

Use an inference API key. Examples contain placeholders; read credentials from environment variables.

```http
Authorization: Bearer YOUR_API_KEY
Content-Type: application/json
```

## Body parameters

| Field | Type | Required | Description / constraints |
| --- | --- | --- | --- |
| prompt | string | Yes | Image generation prompt. |
| width | integer | No | Image width; the gateway requires a multiple of 32. Form initial value (not an upstream default): 1024 Range in this definition: 256 ~ 1440 |
| height | integer | No | Image height; the gateway requires a multiple of 32. Form initial value (not an upstream default): 1024 Range in this definition: 256 ~ 1440 |
| prompt_upsampling | boolean | No | Whether the upstream provider enhances the prompt. Form initial value (not an upstream default): false |
| seed | integer | No | Random seed. Range in this definition: 0 ~ 4294967295 |
| safety_tolerance | integer | No | Safety tolerance; 0 is the strictest setting. Form initial value (not an upstream default): 2 Range in this definition: 0 ~ 6 |
| output_format | string | No | Output image file format. Form initial value (not an upstream default): "jpeg" Values: "jpeg", "png", "webp" |

## Minimal request example

```json
{
  "prompt": "A white ceramic cup"
}
```

## Before running

Replace https://api.tu-zi.com with this site origin (do not append /v1 twice), and YOUR_MODEL with the exact marketplace model ID. Install requests for Python; use Node.js 20+ and save JavaScript as .mjs. WebSocket samples list their own dependencies.

Create an inference key on the site and set API_KEY in the environment; replace YOUR_API_KEY in cURL. Prepare local input.png/input.wav files for upload examples.

Start with a minimal request, then read the result using the response fields below. For async APIs, a returned task ID requires polling; acceptance does not mean generation has finished.

## Code examples

### curl

```bash
curl --request POST 'https://api.tu-zi.com/flux/v1/flux-3-image' \
  --header 'Authorization: Bearer YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
  "prompt": "A white ceramic cup"
}'
```

### python

```python
import json
import os
import requests

url = "https://api.tu-zi.com/flux/v1/flux-3-image"
headers = json.loads("{\"Authorization\":\"Bearer YOUR_API_KEY\",\"Content-Type\":\"application/json\"}")
headers["Authorization"] = "Bearer " + os.environ["API_KEY"]
payload = json.loads("{\"prompt\":\"A white ceramic cup\"}")
response = requests.request("POST", url, headers=headers, json=payload, timeout=120)
response.raise_for_status()
result = response.json()
if isinstance(result, dict) and (result.get("success") is False or result.get("error")):
    raise RuntimeError(json.dumps(result, ensure_ascii=False))
print(result)  # Also inspect protocol-specific status/code fields.
```

### javascript

```javascript
// Node.js 20+
const url = "https://api.tu-zi.com/flux/v1/flux-3-image";
const headers = {
  "Authorization": "Bearer YOUR_API_KEY",
  "Content-Type": "application/json"
};
headers.Authorization = 'Bearer ' + process.env.API_KEY;
const response = await fetch(url, { method: "POST", headers, body: JSON.stringify({
  "prompt": "A white ceramic cup"
}) });
if (!response.ok) throw new Error(await response.text());
const result = await response.json();
if (result?.success === false || result?.error) throw new Error(JSON.stringify(result));
console.log(result); // Also inspect protocol-specific status/code fields.
```

## Response fields

| Field | Type | Description / constraints |
| --- | --- | --- |
| id | string | Public gateway task ID. |
| polling_url | string | If supplied, verify against the gateway polling endpoint. |

Illustrative response; some endpoints show essential fields only. Optional fields may be absent.

```json
{
  "id": "task_example"
}
```

## Asynchronous workflow

Save the returned id. GET /flux/v1/get_result?id={task_id} returns Pending, Ready or Error. Read result.sample when Ready and error when Error. This gateway result route serves flux-3-image asynchronous tasks; verify effective endpoints for other models.

## Errors and retries

Check HTTP status and protocol-specific errors; do not mix error formats across protocols. For 401/403 check credentials and permissions, for 429 back off, and for 5xx check gateway/upstream status. Error bodies may contain error/message/code depending on the protocol.

Use bounded exponential backoff for reads. Do not blindly retry task creation, generation, or key mutations, to avoid duplicate billing or execution.

## Constraints

Accepts prompt, width, height, seed, prompt_upsampling, safety_tolerance and output_format. Optional model must be flux-3-image. Omitted dimensions default to 1024 in this gateway; each must be a multiple of 32 from 256 to 1440. Unknown fields are rejected. Use Bearer or x-key; do not supply conflicting credentials. This asynchronous endpoint must deliver an image URL. If the upstream returns only Base64, the site must enable Base64-to-URL conversion and have working image storage. Disabled conversion or a storage failure can produce an Error task even when submission returned HTTP 200.

## Documentation source

Definition version: 1

Reviewed: 2026-11-02

Source: https://api.tu-zi.com/en/docs/api/reference-relay-bfl-image

Related protocol guide: https://api.tu-zi.com/docs/api/images

This export contains documentation and examples only, without real credentials, account data or user requests.

Updated 2026-11-02 · Reviewed 2026-11-02

Endpoint and authentication

POST https://api.tu-zi.com/flux/v1/flux-3-image

Transport: json

Use an inference API key. Examples contain placeholders; read credentials from environment variables.

Authorization: Bearer YOUR_API_KEY
Content-Type: application/json

Minimal request example

{
  "prompt": "A white ceramic cup"
}

Before running

Replace https://api.tu-zi.com with this site origin (do not append /v1 twice), and YOUR_MODEL with the exact marketplace model ID. Install requests for Python; use Node.js 20+ and save JavaScript as .mjs. WebSocket samples list their own dependencies.

Create an inference key on the site and set API_KEY in the environment; replace YOUR_API_KEY in cURL. Prepare local input.png/input.wav files for upload examples.

Start with a minimal request, then read the result using the response fields below. For async APIs, a returned task ID requires polling; acceptance does not mean generation has finished.

Constraints

Accepts prompt, width, height, seed, prompt_upsampling, safety_tolerance and output_format. Optional model must be flux-3-image. Omitted dimensions default to 1024 in this gateway; each must be a multiple of 32 from 256 to 1440. Unknown fields are rejected. Use Bearer or x-key; do not supply conflicting credentials. This asynchronous endpoint must deliver an image URL. If the upstream returns only Base64, the site must enable Base64-to-URL conversion and have working image storage. Disabled conversion or a storage failure can produce an Error task even when submission returned HTTP 200.

Body parameters

Field	Type	Required	Description / constraints
prompt	string	Yes	Image generation prompt.
width	integer	No	Image width; the gateway requires a multiple of 32. Form initial value (not an upstream default): 1024 Range in this definition: 256 ~ 1440
height	integer	No	Image height; the gateway requires a multiple of 32. Form initial value (not an upstream default): 1024 Range in this definition: 256 ~ 1440
prompt_upsampling	boolean	No	Whether the upstream provider enhances the prompt. Form initial value (not an upstream default): false
seed	integer	No	Random seed. Range in this definition: 0 ~ 4294967295
safety_tolerance	integer	No	Safety tolerance; 0 is the strictest setting. Form initial value (not an upstream default): 2 Range in this definition: 0 ~ 6
output_format	string	No	Output image file format. Form initial value (not an upstream default): "jpeg" Values: "jpeg", "png", "webp"

Response fields

Field	Type	Description / constraints
id	string	Public gateway task ID.
polling_url	string	If supplied, verify against the gateway polling endpoint.

Illustrative response; some endpoints show essential fields only. Optional fields may be absent.

{
  "id": "task_example"
}

Asynchronous workflow

Save the returned id. GET /flux/v1/get_result?id={task_id} returns Pending, Ready or Error. Read result.sample when Ready and error when Error. This gateway result route serves flux-3-image asynchronous tasks; verify effective endpoints for other models.

Errors and retries

Check HTTP status and protocol-specific errors; do not mix error formats across protocols. For 401/403 check credentials and permissions, for 429 back off, and for 5xx check gateway/upstream status. Error bodies may contain error/message/code depending on the protocol.

Use bounded exponential backoff for reads. Do not blindly retry task creation, generation, or key mutations, to avoid duplicate billing or execution.

Document information and sources

Documentation source

Definition version: 1

Reviewed: 2026-11-02

Source: https://api.tu-zi.com/en/docs/api/reference-relay-bfl-image

Related protocol guide: https://api.tu-zi.com/docs/api/images

This export contains documentation and examples only, without real credentials, account data or user requests.

Request examples

curl --request POST 'https://api.tu-zi.com/flux/v1/flux-3-image' \
  --header 'Authorization: Bearer YOUR_API_KEY' \
  --header 'Content-Type: application/json' \
  --data '{
  "prompt": "A white ceramic cup"
}'

import json
import os
import requests

url = "https://api.tu-zi.com/flux/v1/flux-3-image"
headers = json.loads("{\"Authorization\":\"Bearer YOUR_API_KEY\",\"Content-Type\":\"application/json\"}")
headers["Authorization"] = "Bearer " + os.environ["API_KEY"]
payload = json.loads("{\"prompt\":\"A white ceramic cup\"}")
response = requests.request("POST", url, headers=headers, json=payload, timeout=120)
response.raise_for_status()
result = response.json()
if isinstance(result, dict) and (result.get("success") is False or result.get("error")):
    raise RuntimeError(json.dumps(result, ensure_ascii=False))
print(result)  # Also inspect protocol-specific status/code fields.

// Node.js 20+
const url = "https://api.tu-zi.com/flux/v1/flux-3-image";
const headers = {
  "Authorization": "Bearer YOUR_API_KEY",
  "Content-Type": "application/json"
};
headers.Authorization = 'Bearer ' + process.env.API_KEY;
const response = await fetch(url, { method: "POST", headers, body: JSON.stringify({
  "prompt": "A white ceramic cup"
}) });
if (!response.ok) throw new Error(await response.text());
const result = await response.json();
if (result?.success === false || result?.error) throw new Error(JSON.stringify(result));
console.log(result); // Also inspect protocol-specific status/code fields.