Examples

curl, Node and Python examples for common tasks.

# Render and save a PNG

Render a small funnel and write the PNG to disk.

curl https://sankeykit.com/api/v1/render \
  -H "Authorization: Bearer sk_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "flows": [
      { "source": "Visitors", "target": "Signups", "value": 120 },
      { "source": "Signups", "target": "Paid", "value": 30 }
    ],
    "options": { "format": "png" }
  }' \
  -o chart.png

import { writeFile } from 'node:fs/promises';

const res = await fetch('https://sankeykit.com/api/v1/render', {
  method: 'POST',
  headers: {
    Authorization: `Bearer ${process.env.SANKEYKIT_API_KEY}`,
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    flows: [
      { source: 'Visitors', target: 'Signups', value: 120 },
      { source: 'Signups', target: 'Paid', value: 30 }
    ],
    options: { format: 'png' }
  })
});

if (!res.ok) {
  const body = await res.json();
  throw new Error(`Render failed (${res.status}): ${body.error ?? body.message}`);
}

await writeFile('chart.png', Buffer.from(await res.arrayBuffer()));
console.log('Saved chart.png');

import os
import requests

res = requests.post(
    "https://sankeykit.com/api/v1/render",
    headers={"Authorization": f"Bearer {os.environ['SANKEYKIT_API_KEY']}"},
    json={
        "flows": [
            {"source": "Visitors", "target": "Signups", "value": 120},
            {"source": "Signups", "target": "Paid", "value": 30},
        ],
        "options": {"format": "png"},
    },
)

if not res.ok:
    body = res.json()
    raise RuntimeError(f"Render failed ({res.status_code}): {body.get('error') or body.get('message')}")

with open("chart.png", "wb") as f:
    f.write(res.content)
print("Saved chart.png")

# Handling 429 and retrying

Read the Retry-After header (seconds) and wait before retrying, instead of hammering the endpoint.

# -i shows headers so you can read Retry-After on a 429
curl -i https://sankeykit.com/api/v1/render \
  -H "Authorization: Bearer sk_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "flows": [{ "source": "a", "target": "b", "value": 1 }] }'

async function renderWithRetry(body, attempt = 0) {
  const res = await fetch('https://sankeykit.com/api/v1/render', {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${process.env.SANKEYKIT_API_KEY}`,
      'Content-Type': 'application/json'
    },
    body: JSON.stringify(body)
  });

  if (res.status === 429 && attempt < 3) {
    const retryAfter = Number(res.headers.get('retry-after') ?? 30);
    console.log(`Quota exceeded, retrying in ${retryAfter}s`);
    await new Promise((r) => setTimeout(r, retryAfter * 1000));
    return renderWithRetry(body, attempt + 1);
  }

  return res;
}

import time
import requests

def render_with_retry(body, attempt=0):
    res = requests.post(
        "https://sankeykit.com/api/v1/render",
        headers={"Authorization": f"Bearer {API_KEY}"},
        json=body,
    )
    if res.status_code == 429 and attempt < 3:
        retry_after = int(res.headers.get("retry-after", 30))
        print(f"Quota exceeded, retrying in {retry_after}s")
        time.sleep(retry_after)
        return render_with_retry(body, attempt + 1)
    return res

# Reading remaining quota

Every response — success or error — includes the X-RateLimit-* headers.

curl -s -D - https://sankeykit.com/api/v1/render \
  -H "Authorization: Bearer sk_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{ "flows": [{ "source": "a", "target": "b", "value": 1 }] }' \
  -o /dev/null | grep -i x-ratelimit

const res = await fetch('https://sankeykit.com/api/v1/render', {
  method: 'POST',
  headers: {
    Authorization: `Bearer ${process.env.SANKEYKIT_API_KEY}`,
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({ flows: [{ source: 'a', target: 'b', value: 1 }] })
});

const remaining = res.headers.get('x-ratelimit-remaining');
const limit = res.headers.get('x-ratelimit-limit');
const resetsAt = new Date(Number(res.headers.get('x-ratelimit-reset')) * 1000);
console.log(`${remaining}/${limit} renders left, resets ${resetsAt.toISOString()}`);

import os
import requests

res = requests.post(
    "https://sankeykit.com/api/v1/render",
    headers={"Authorization": f"Bearer {os.environ['SANKEYKIT_API_KEY']}"},
    json={"flows": [{"source": "a", "target": "b", "value": 1}]},
)

remaining = res.headers.get("x-ratelimit-remaining")
limit = res.headers.get("x-ratelimit-limit")
resets_at = res.headers.get("x-ratelimit-reset")
print(f"{remaining}/{limit} renders left, resets at {resets_at}")