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Template · launch-post@1

Launch post template

The launch-post template renders a launch card with a badge, a headline, and a one-line summary, sized for LinkedIn, X, and Open Graph. Send JSON parameters through the remote MCP server, POST /v1/renders, or a signed /i/launch-post.png URL; the default size is 1200×630.

Sizes
1200×630 · 1080×1080 · 1200×1200
Formats
PNG · JPEG · WebP
Version
1.0.0

VectorFast Render is in early access. Billing is not connected yet, and API keys are issued to waitlist members as access opens. Join the waitlist

Preview

Rendered by VectorFast Render from this template's English and Chinese example parameters, through the same signed URLs your own pages would use.

Preview images are signed on the server and are not available in this environment.

Ask your agent

Paste the prompt into Claude, Cursor, or another agent connected to the VectorFast Render MCP server. The JSON is the render tool call it should turn into.
Prompt
We just shipped scheduled renders. Make a launch image for LinkedIn and X: headline "Scheduled renders are live", one line saying images now render from CI on every release, and a "New" badge.
MCP render call
{
  "name": "render",
  "arguments": {
    "template": "launch-post",
    "params": {
      "title": "Scheduled renders are live",
      "subtitle": "On-brand images now render from CI on every release.",
      "badge": "New"
    },
    "width": 1200,
    "height": 630
  }
}

Connect Claude to VectorFast Render

Parameters

Read from the schema that POST /v1/renders validates. String values are trimmed; anything over a limit is rejected with invalid_params.
Launch post template parameters
ParamTypeRequiredLimitNotes
titlestringYes≤ 120 charsHeadline. The font size steps down as it gets longer.
subtitlestringNo≤ 200 charsOne-line summary under the headline.
badgestringNo≤ 24 charsShort pill above the headline, such as "New" or "Beta".

Render it from code

The REST call needs an API key in Authorization: Bearer. Its response includes a signed url you can store and reuse as an og:image. The Node.js function shows the signing algorithm the server verifies; per-key signing secrets are not issued yet in early access, and the secret must stay on your server.
curl · POST /v1/renders
curl https://vectorfast.ai/v1/renders \
  -H "Authorization: Bearer $VECTORFAST_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "template": "launch-post@1",
  "format": "png",
  "width": 1200,
  "height": 630,
  "params": {
    "title": "Scheduled renders are live",
    "subtitle": "On-brand images now render from CI on every release.",
    "badge": "New"
  }
}'
Node.js · signed URL (server-side only)
import { createHmac } from 'node:crypto'

// Server-side only. Never ship the signing secret to a browser, a mobile app or a repo.
const SIGNING_SECRET = process.env.VECTORFAST_SIGNING_SECRET

function encode(value) {
  return encodeURIComponent(value).replace(/[!'()*]/g, c => '%' + c.charCodeAt(0).toString(16).toUpperCase())
}

export function signRenderUrl({ template, format = 'png', params, brand, width, height, keyId }, secret = SIGNING_SECRET) {
  const query = {}
  for (const [key, value] of Object.entries(params)) {
    if (value === undefined || value === null)
      continue
    query[key] = typeof value === 'string' ? value : Array.isArray(value) ? JSON.stringify(value) : String(value)
  }
  if (brand) query.brand = brand
  if (keyId) query.k = keyId
  if (width) query.w = String(width)
  if (height) query.h = String(height)

  const canonical = Object.entries(query)
    .map(([key, value]) => [encode(key), encode(value)])
    .sort((a, b) => (a[0] < b[0] ? -1 : a[0] > b[0] ? 1 : a[1] < b[1] ? -1 : a[1] > b[1] ? 1 : 0))
    .map(([key, value]) => key + '=' + value)
    .join('&')
  const path = '/i/' + template + '.' + format
  const sig = createHmac('sha256', secret).update(path + '?' + canonical).digest('base64url')
  return 'https://vectorfast.ai' + path + '?' + (canonical ? canonical + '&' : '') + 'sig=' + sig
}

const url = signRenderUrl({
  template: 'launch-post',
  format: 'png',
  width: 1200,
  height: 630,
  params: {
    "title": "Introducing scheduled renders",
    "subtitle": "Ship on-brand images from your CI, every time a release goes out.",
    "badge": "New"
  },
})

How signed URLs work

Launch post template FAQ

Which sizes does the launch-post template support?
1200×630, 1080×1080, 1200×1200. The default is 1200×630; pass width and height to pick another supported size.
Which parameters are required?
title. Every other parameter is optional and has a rendering default.
Does rendering the same parameters twice cost twice?
No. The same template version, parameters, brand kit version, format, and size produce the same cache key, so a repeat request is served from cache instead of rendering again. Billing is not connected yet in early access.

Updated · Markdown version