Limits & Quotas

Name: Glyph
Author: Glyph

Every Glyph resource has limits to ensure reliability and fair usage. This page is the single reference for all of them. For rate limit handling strategies and code examples, see Rate Limits.

Rate Limits

Per-minute request limits by tier. Applies to all API endpoints.

Tier	Requests/min	Monthly PDFs	Price
Demo	20	Unlimited (in-memory only)	$0
Free	10	100	$0
Pro	60	1,000	$29/mo
Scale	120	10,000	$129/mo
Enterprise	300	Unlimited	Custom

Session Limits

Sessions are created via /v1/preview or /v1/create and hold the working HTML state.

Constraint	Limit
Session TTL	1 hour from creation
Max modifications per session	50
Max session HTML size	500 KB

When a session expires, all subsequent /v1/modify and /v1/generate calls return SESSION_EXPIRED. Create a new preview to continue.

PDF Generation

Limits for the /v1/generate and /v1/batch/generate endpoints.

Constraint	Limit
Max page count per PDF	50 pages
Max input HTML size	2 MB
Render timeout	30 seconds per PDF
Batch limit	20 documents per request
Monthly PDF cap	Tier-dependent (see table above)

PDFs that exceed the render timeout return a 504 with code PDF_TIMEOUT.

AI Modifications

Limits for the /v1/modify endpoint (both standard and streaming).

Constraint	Limit
Max prompt length	2,000 characters
Max concurrent AI requests per key	3
AI response timeout	60 seconds
Pre-flight validation timeout	5 seconds

The pre-flight check detects impossible or destructive requests early, typically within 2-5 seconds, before committing to a full AI call.

Response Headers

Every API response includes rate limit headers so your application can track usage proactively.

Per-Minute Headers

X-RateLimit-Limit: 60
X-RateLimit-Remaining: 45
X-RateLimit-Reset: 1705320060

Header	Description
`X-RateLimit-Limit`	Maximum requests allowed in the current window
`X-RateLimit-Remaining`	Requests remaining before throttling
`X-RateLimit-Reset`	Unix timestamp (seconds) when the window resets

Monthly PDF Headers

Returned only on /v1/generate responses.

X-Monthly-Limit: 1000
X-Monthly-Used: 150
X-Monthly-Remaining: 850

429 Response

When a limit is exceeded, the response includes a Retry-After header:

HTTP/1.1 429 Too Many Requests
Retry-After: 45
Content-Type: application/json

{
  "error": "Rate limit exceeded",
  "code": "RATE_LIMIT_EXCEEDED",
  "retryAfter": 45,
  "tier": "free",
  "limit": 10,
  "windowMs": 60000
}

Handling Limits

Read the headers after every response and back off when X-RateLimit-Remaining reaches zero.

JavaScript

async function callGlyph(endpoint, body, maxRetries = 3) {
  for (let attempt = 0; attempt < maxRetries; attempt++) {
    const res = await fetch(`https://api.glyph.you${endpoint}`, {
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${API_KEY}`,
        'Content-Type': 'application/json',
      },
      body: JSON.stringify(body),
    });

    // Proactively log remaining quota
    const remaining = res.headers.get('X-RateLimit-Remaining');
    if (remaining !== null && parseInt(remaining) < 5) {
      console.warn(`Glyph: only ${remaining} requests left in this window`);
    }

    if (res.status !== 429) return res.json();

    const retryAfter = parseInt(res.headers.get('Retry-After') || '60', 10);
    console.log(`Rate limited. Waiting ${retryAfter}s before retry...`);
    await new Promise((r) => setTimeout(r, retryAfter * 1000));
  }

  throw new Error('Glyph API: max retries exceeded');
}

Python

import time
import requests

def call_glyph(endpoint: str, body: dict, max_retries: int = 3):
    for attempt in range(max_retries):
        res = requests.post(
            f"https://api.glyph.you{endpoint}",
            headers={
                "Authorization": f"Bearer {API_KEY}",
                "Content-Type": "application/json",
            },
            json=body,
        )

        if res.status_code != 429:
            res.raise_for_status()
            return res.json()

        retry_after = int(res.headers.get("Retry-After", 60))
        print(f"Rate limited. Waiting {retry_after}s...")
        time.sleep(retry_after)

    raise Exception("Glyph API: max retries exceeded")

Upgrading

If you are consistently hitting limits, upgrade your tier in the dashboard under Billing. New limits apply immediately.