Font Generation API

Generate custom fonts from a text prompt or a style reference image. Version 3.

Base URL

https://api.lipi.ai/v3

Authentication

All requests require an API key passed in the x-api-key header.

curl https://api.lipi.ai/v3/credits \
  -H "x-api-key: lpi_your_api_key_here"

Keep your key secret

Never expose your API key in client-side code or public repositories. Use environment variables.

Endpoints

POST/v3/font-generate/from-textGenerate a font from a text prompt10 credits

POST/v3/font-generate/from-imageGenerate a font from a style image10 or 30 credits

GET/v3/font-generate/:idPoll job status and download URLs

POST /v3/font-generate/from-text

Generate a font from a prose description. The job runs asynchronously. Poll the returned job_id for the finished font files. Typical processing time is 2 to 5 minutes.

Request fields

Field	Required	Description
prompt	yes	Font description, 1 to 500 characters
font_name	no	Display name for the font (defaults to a generated name)
seed	no	Integer 0 to 4294967295 for reproducible results

Request

curl -X POST https://api.lipi.ai/v3/font-generate/from-text \
  -H "x-api-key: lpi_your_api_key_here" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "gothic blackletter with ornate capitals",
    "font_name": "MyFont",
    "seed": 42
  }'

Response (201)

{
  "job_id": "550e8400-e29b-41d4-a716-446655440000",
  "status": "pending",
  "mode": "text",
  "credits_charged": 10,
  "credits_remaining": 90,
  "free_credits_remaining": 0,
  "poll_url": "/v3/font-generate/550e8400-e29b-41d4-a716-446655440000"
}

POST /v3/font-generate/from-image

Generate a font from a style or handwriting reference image. Set character_set to"standard" (90 glyphs, 10 credits) or "extended" (260 glyphs, 30 credits).

Images larger than 1536px on either dimension are automatically resized (aspect ratio preserved). Maximum request body is 6MB, which is roughly a 4MB raw image. Resize client-side for larger files.

Request fields

Field	Required	Description
style_image	yes	Base64 data URL (data:image/png;base64,...). PNG, JPEG, or WebP
font_name	no	Display name for the font (defaults to a generated name)
character_set	no	"standard" (default, 10 credits) or "extended" (30 credits)

Request

curl -X POST https://api.lipi.ai/v3/font-generate/from-image \
  -H "x-api-key: lpi_your_api_key_here" \
  -H "Content-Type: application/json" \
  -d '{
    "style_image": "data:image/png;base64,iVBORw0KGgo...",
    "font_name": "MyHandwriting",
    "character_set": "standard"
  }'

Response (201)

{
  "job_id": "550e8400-e29b-41d4-a716-446655440000",
  "status": "pending",
  "mode": "image",
  "character_set": "standard",
  "credits_charged": 10,
  "credits_remaining": 90,
  "free_credits_remaining": 0,
  "poll_url": "/v3/font-generate/550e8400-e29b-41d4-a716-446655440000"
}

GET /v3/font-generate/:id

Poll for job completion. Poll every 3 to 5 seconds. Download URLs are valid for 24 hours and are re-issued fresh on every poll, so a job can be re-polled at any time to get working links.

Response (running)

{
  "job_id": "550e8400-e29b-41d4-a716-446655440000",
  "status": "running",
  "mode": "text",
  "progress": 42,
  "stage": "sd_running",
  "font_name": "MyFont",
  "created_at": "2026-05-15T19:00:00Z",
  "completed_at": null
}

Response (succeeded)

{
  "job_id": "550e8400-e29b-41d4-a716-446655440000",
  "status": "succeeded",
  "mode": "text",
  "progress": 100,
  "stage": "completed",
  "font_name": "MyFont",
  "created_at": "2026-05-15T19:00:00Z",
  "completed_at": "2026-05-15T19:03:30Z",
  "download_urls": {
    "otf": "https://fontbuster-job-outputs-prod.s3.amazonaws.com/...",
    "ttf": "https://fontbuster-job-outputs-prod.s3.amazonaws.com/...",
    "woff": "https://fontbuster-job-outputs-prod.s3.amazonaws.com/..."
  },
  "download_urls_expire_at": "2026-05-16T19:03:30Z"
}

OTF, TTF, and WOFF are delivered. WOFF2 is not currently included.

Response (failed)

{
  "job_id": "550e8400-e29b-41d4-a716-446655440000",
  "status": "failed",
  "mode": "text",
  "progress": 0,
  "stage": "failed",
  "font_name": "MyFont",
  "created_at": "2026-05-15T19:00:00Z",
  "completed_at": "2026-05-15T19:01:10Z",
  "error": "Font generation failed: Modal endpoint returned 503",
  "credits_refunded": 10
}

Credits are automatically refunded when a job fails because of an infrastructure error.

Error Codes

Status	Error Code	Description
400	missing_prompt	Empty or missing "prompt" (from-text)
400	missing_image	Missing "style_image" (from-image)
401	invalid_api_key	Missing or invalid API key
402	insufficient_credits	Not enough credits for this generation
403	key_suspended	API key has been suspended
404	not_found	Job not found or not owned by this key
413	payload_too_large	Request body exceeds the 6MB limit
422	prompt_too_long	Prompt exceeds 500 characters
422	invalid_seed	Seed is not an integer in range
422	invalid_image	Not a valid PNG, JPEG, or WebP image
422	invalid_character_set	character_set is not "standard" or "extended"
429	rate_limited	Exceeded rate limit (see retry_after_seconds)
503	service_busy	High demand, retry shortly

Rate Limits

Per Key

60 req/min

Response Header

429 responses include retry_after_seconds

Pricing

Generation type	Credits
Text to font	10
Image to font, standard (90 glyphs)	10
Image to font, extended (260 glyphs)	30

Credits are charged when the job is submitted. A failed job is automatically refunded. A successful generation is not refundable.

Code Examples

Python

import requests
import time

API_KEY = "lpi_your_api_key_here"
BASE = "https://api.lipi.ai/v3"
HEADERS = {"x-api-key": API_KEY, "Content-Type": "application/json"}

# Submit a text-to-font job
resp = requests.post(f"{BASE}/font-generate/from-text", json={
    "prompt": "gothic blackletter with ornate capitals",
    "font_name": "MyFont",
    "seed": 42
}, headers=HEADERS)
job = resp.json()
print(f"Job {job['job_id']} created. Credits remaining: {job['credits_remaining']}")

# Poll for completion
while True:
    time.sleep(4)
    status = requests.get(f"{BASE}/font-generate/{job['job_id']}", headers=HEADERS).json()
    if status["status"] == "succeeded":
        for fmt, url in status["download_urls"].items():
            data = requests.get(url).content
            with open(f"MyFont.{fmt}", "wb") as out:
                out.write(data)
            print(f"Saved MyFont.{fmt}")
        break
    elif status["status"] == "failed":
        print(f"Failed: {status.get('error')}")
        break

Node.js

const fs = require('fs');

const API_KEY = 'lpi_your_api_key_here';
const BASE = 'https://api.lipi.ai/v3';
const headers = { 'x-api-key': API_KEY, 'Content-Type': 'application/json' };

async function generateFont(prompt) {
  const res = await fetch(`${BASE}/font-generate/from-text`, {
    method: 'POST',
    headers,
    body: JSON.stringify({ prompt, font_name: 'MyFont' })
  });
  const job = await res.json();
  console.log(`Job ${job.job_id} created`);

  while (true) {
    await new Promise(r => setTimeout(r, 4000));
    const status = await fetch(`${BASE}/font-generate/${job.job_id}`, { headers }).then(r => r.json());
    if (status.status === 'succeeded') {
      for (const [fmt, url] of Object.entries(status.download_urls)) {
        const buf = Buffer.from(await fetch(url).then(r => r.arrayBuffer()));
        fs.writeFileSync(`MyFont.${fmt}`, buf);
        console.log(`Saved MyFont.${fmt}`);
      }
      return;
    }
    if (status.status === 'failed') throw new Error(status.error);
  }
}

generateFont('gothic blackletter with ornate capitals');

Ready to start?

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