Integrate Figviz diagram generation into your applications via REST API
Figviz exposes a single synchronous endpoint. You send prompts, the request blocks while the images render, and the finished URLs come back in the same response. There is no task ID and nothing to poll.
curl -X POST https://figviz.com/api/v1/generate \
-H "Authorization: Bearer fvk_your_api_key" \
-H "Content-Type: application/json"
POST https://figviz.com/api/v1/generateEvery request goes to this one URL. There are no other public routes.
Pass your secret key as a bearer token. Keys are created and rotated under
Settings > API, where each key is displayed a single time at
creation. Every key begins with the fvk_ prefix.
Authorization: Bearer fvk_xxxxxxxxA key spends real credits from your account balance. Treat it like a password: keep it server-side and never ship it in a browser or mobile bundle.
Send a JSON body with these fields.
| Field | Type | Required | Notes |
|---|---|---|---|
prompt | string | one of the two | A single description to render |
prompts | string[] | one of the two | Up to 4 descriptions for a batch |
quality | string | optional | "1k" (default), "2k", or "4k" |
aspectRatio | string | optional | For example "16:9", "1:1", "4:3" |
Supply prompt for a single image or prompts for a batch. If you send both,
prompts wins and prompt is ignored. Higher resolutions and larger batch sizes
may be gated by your plan.
A 200 returns the stored image URLs plus your updated credit balance.
{
"images": [
{
"url": "https://cdn.figviz.io/generated/abc123.png",
"prompt": "free body diagram of a block on an inclined plane"
}
],
"credits_used": 1,
"credits_remaining": 79
}In a batch, the images array preserves the order of your prompts.
| Quality | Credits |
|---|---|
1k | 1 |
2k | 1 |
4k | 1.5 |
Billing is success-only. If one prompt in a batch fails or cannot be stored, that image is refunded and never appears on your invoice. The API draws from the same pay-as-you-go balance as the web app, and images returned through the API are not watermarked.
import requests
resp = requests.post(
"https://figviz.com/api/v1/generate",
headers={
"Authorization": "Bearer fvk_your_api_key",
"Content-Type": "application/json",
},
const res = await fetch("https://figviz.com/api/v1/generate", {
method: "POST",
headers: {
Authorization: "Bearer fvk_your_api_key",
"Content-Type": "application/json",
},
body: JSON.
curl -X POST https://figviz.com/api/v1/generate \
-H "Authorization: Bearer fvk_your_api_key" \
-H "Content-Type: application/json" \
-d '{
"prompts": [
"rock cycle diagram with arrows",
"labeled food web for a grassland ecosystem",
"titration setup for a high school chemistry lab"
],
"quality": "1k"
}'Failures use conventional HTTP status codes and return a JSON body with a
human-readable error and a machine-readable code.
{
"error": "Insufficient credits. Buy a credit pack at /pricing",
"code": "INSUFFICIENT_CREDITS",
"credits_remaining": 0
}| Status | code | When it happens |
|---|---|---|
400 | INVALID_BODY | The body is missing or is not valid JSON |
400 | PROMPT_REQUIRED | Neither prompt nor prompts was supplied |
400 | TOO_MANY_PROMPTS | More than 4 prompts in one call |
401 | UNAUTHORIZED | The Authorization header is missing or malformed |
401 | INVALID_API_KEY | The key is unknown or has been disabled |
402 | INSUFFICIENT_CREDITS | Balance is too low; credits_remaining is included |
403 | PLAN_LIMIT_EXCEEDED | Batch size is above your plan ceiling |
403 | QUALITY_NOT_ALLOWED | The requested resolution is not on your plan |
500 | GENERATION_FAILED | Every image in the request failed to render |
504 | GENERATION_TIMEOUT | Rendering ran past the five-minute ceiling |
resp = requests.post(url, headers=headers, json=payload)
if resp.status_code == 402:
print("Top up at /pricing, remaining:", resp.json().get("credits_remaining", 0
| Limit | Value |
|---|---|
| Prompts per request | 4 |
| Active keys per account | 5 |
| Render ceiling | 5 minutes per request |
| Resolutions | Subject to your plan |