Why Automate Instagram Posting with an AI Agent?

Instagram is the second most-used social platform for brand marketing, yet its API has a reputation for being restrictive and complex. Manual posting works fine for a solo creator — but once you're managing multiple accounts, scheduling Reels, or running campaigns across platforms, the workflow breaks down fast.

This is where OpenClaw — an open-source autonomous AI agent — combined with Postpost changes the game. Instead of writing API calls or clicking through dashboards, you describe what you want in plain English and the AI handles everything: scheduling, media uploads, cross-platform posting, and even respecting Instagram's complex media limits automatically.

What you'll learn in this guide:

• How to connect your Instagram Business account to Postpost via OAuth
• How to post photos, carousels, Reels, and Stories via OpenClaw
• Instagram's media limits — sizes, durations, formats — all in one place
• The complete flow: OpenClaw → Postpost → Meta Graph API

What Is OpenClaw?

OpenClaw is an open-source autonomous AI agent that connects to external services via MCP (Model Context Protocol). Think of it as an AI assistant that can take actions — not just answer questions. When connected to Postpost's MCP server, OpenClaw gains the ability to:

Step 1: Connect Instagram to Postpost (OAuth Setup)

Before OpenClaw can post to Instagram, you need to connect your Instagram Business account to Postpost. This is a one-time setup done through the Postpost dashboard.

OAuth Connection Walkthrough

1. Open the Postpost Dashboard — Navigate to app.postpost.dev and log in to your account.
2. Go to Connections — Click "Connections" in the left sidebar, then click "+ Add Connection".
3. Select Instagram — Choose Instagram from the platform list. You'll see the OAuth consent screen.
4. Authorize with Facebook — Click "Continue with Facebook". Meta's OAuth flow will ask you to:
   • Select the Facebook Page linked to your Instagram Business account
   • Grant permissions for content publishing, media management, and account insights
5. Confirm & Done — Once authorized, your Instagram account appears in the Connections list with its platform ID (e.g., instagram-17841400123456789). You'll need this ID for API calls and OpenClaw configuration.

Step 2: Set Up OpenClaw with Postpost MCP

With Instagram connected, you now configure OpenClaw to communicate with Postpost. See the full MCP client setup guide for detailed instructions. There are two approaches:

{
  "mcpServers": {
    "postpost": {
      "type": "http",
      "url": "https://mcp.postpost.dev",
      "headers": {
        "Authorization": "Bearer sk_YOUR_API_KEY"
      }
    }
  }
}

curl -X POST \
  https://api.postpost.dev/api/v1/create-post \
  -H "x-postpost-key: sk_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"content": "Hello!",
       "platforms": ["instagram-ID"]}'

For OpenClaw specifically, the REST API approach is recommended. It's simpler, has no session state to manage, and is easier to debug. MCP shines when you're working interactively with Claude Code or Cursor in your IDE.

Posting to Instagram: Content Types Explained

Instagram supports four distinct content types through the Meta Graph API. Each has different media requirements, character limits, and behavior. For the complete technical reference, see the Instagram platform documentation. Let's break down each one.

📸 Photo Posts (Single Image)

The simplest content type. One image with a caption. Note that Instagram requires JPEG format only — PNG files will be rejected by the API. See the media upload guide for the full upload workflow.

JavaScript

// Step 1: Create the post
const response = await fetch('https://api.postpost.dev/api/v1/create-post', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'x-postpost-key': 'sk_YOUR_API_KEY'
  },
  body: JSON.stringify({
    content: 'Launching our new product line today! 🚀\n\nAfter months of development, we\'re thrilled to share what we\'ve been working on.\n\n#launch #startup #newproduct',
    platforms: ['instagram-17841400123456789'],
    scheduledTime: '2026-03-25T09:00:00Z'
  })
});
const { postGroupId } = await response.json();
// Step 2: Get presigned upload URL
const uploadRes = await fetch(
https://api.postpost.dev/api/v1/upload-media/${postGroupId}?filename=product-hero.jpg,
{ headers: { ‘x-postpost-key’: ‘sk_YOUR_API_KEY’ } }
);
const { uploadUrl } = await uploadRes.json();
// Step 3: Upload the image
await fetch(uploadUrl, {
method: ‘PUT’,
headers: { ‘Content-Type’: ‘image/jpeg’ },
body: imageBuffer
});

Python

import requests
API_KEY = ‘sk_YOUR_API_KEY’
BASE = ‘https://api.postpost.dev/api/v1’
headers = {‘Content-Type’: ‘application/json’, ‘x-postpost-key’: API_KEY}
Step 1: Create post
resp = requests.post(f’{BASE}/create-post’, headers=headers, json={
‘content’: ‘Launching our new product line today! 🚀’,
‘platforms’: [‘instagram-17841400123456789’],
‘scheduledTime’: ‘2026-03-25T09:00:00Z’
})
post_group_id = resp.json()[‘postGroupId’]
Step 2: Get upload URL
upload_resp = requests.get(
f’{BASE}/upload-media/{post_group_id}?filename=hero.jpg’,
headers={‘x-postpost-key’: API_KEY}
)
upload_url = upload_resp.json()[‘uploadUrl’]
Step 3: Upload image
with open(‘hero.jpg’, ‘rb’) as f:
requests.put(upload_url, headers={‘Content-Type’: ‘image/jpeg’}, data=f)

🎠 Carousel Posts (2–10 Images)

Carousels let you share up to 10 images in a single swipeable post. They're great for step-by-step guides, product showcases, or before/after comparisons.

// Create a carousel with multiple images
const response = await fetch('https://api.postpost.dev/api/v1/create-post', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'x-postpost-key': 'sk_YOUR_API_KEY'
  },
  body: JSON.stringify({
    content: '5 design principles every startup should follow 👇\n\nSwipe through for the complete breakdown.\n\n#design #startup #ux',
    platforms: ['instagram-17841400123456789'],
    scheduledTime: '2026-03-26T14:00:00Z'
  })
});

const { postGroupId } = await response.json();

// Upload each image (2-10 images)
const images = ['slide1.jpg', 'slide2.jpg', 'slide3.jpg', 'slide4.jpg', 'slide5.jpg'];

for (const filename of images) {
  const uploadRes = await fetch(
    `https://api.postpost.dev/api/v1/upload-media/${postGroupId}?filename=${filename}`,
    { headers: { 'x-postpost-key': 'sk_YOUR_API_KEY' } }
  );
  const { uploadUrl } = await uploadRes.json();
  const imageData = fs.readFileSync(filename);
  await fetch(uploadUrl, {
    method: 'PUT',
    headers: { 'Content-Type': 'image/jpeg' },
    body: imageData
  });
}

🎬 Reels (Video Posts)

Reels are Instagram's primary video format and get significantly more reach than static posts. The API supports videos up to 15 minutes, but only videos between 5 and 90 seconds are eligible for the Reels tab and Explore page.

const response = await fetch('https://api.postpost.dev/api/v1/create-post', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'x-postpost-key': 'sk_YOUR_API_KEY'
  },
  body: JSON.stringify({
    content: 'Quick tutorial: How to set up CI/CD in 60 seconds ⚡\n\n#devops #tutorial #coding',
    platforms: ['instagram-17841400123456789'],
    platformSettings: {
      instagram: {
        videoType: 'REELS'  // This is the default
      }
    },
    scheduledTime: '2026-03-27T12:00:00Z'
  })
});

const { postGroupId } = await response.json();

// Upload video file (MP4 recommended, max 300 MB)
const uploadRes = await fetch(
  `https://api.postpost.dev/api/v1/upload-media/${postGroupId}?filename=tutorial.mp4`,
  { headers: { 'x-postpost-key': 'sk_YOUR_API_KEY' } }
);
const { uploadUrl } = await uploadRes.json();
await fetch(uploadUrl, {
  method: 'PUT',
  headers: { 'Content-Type': 'video/mp4' },
  body: videoBuffer
});

📱 Stories (Ephemeral Content)

Stories disappear after 24 hours and appear at the top of followers' feeds. They're ideal for time-sensitive announcements, behind-the-scenes content, or quick updates.

import requests

response = requests.post(
    'https://api.postpost.dev/api/v1/create-post',
    headers={
        'Content-Type': 'application/json',
        'x-postpost-key': 'sk_YOUR_API_KEY'
    },
    json={
        'content': '🔥 Big announcement dropping tomorrow!',
        'platforms': ['instagram-17841400123456789'],
        'platformSettings': {
            'instagram': {
                'videoType': 'STORIES'  # Key setting for Stories
            }
        },
        'scheduledTime': '2026-03-27T18:00:00Z'
    }
)
print(response.json())
# {"success": true, "postGroupId": "abc123..."}

Instagram Media Limits — The Complete Reference

One of the most common causes of failed Instagram posts is exceeding media limits. Here's everything you need to know in one place:

How It Works: OpenClaw → Postpost → Meta Graph API

Understanding the architecture helps you debug issues and build trust in the automation pipeline. Here's the complete flow:

Why This Architecture Matters

Postpost uses Meta's official Graph API for all Instagram operations. Your content flows through secure, authenticated API endpoints — the same ones used by Meta's own tools. No browser automation, no scraping, no risk of account suspension.

Using OpenClaw: Real Conversation Examples

Here's what it actually looks like when you use OpenClaw with Postpost to manage Instagram:

Best Practices for Instagram Automation

Getting Started in 5 Minutes

Ready to automate your Instagram posting? Here's the fastest path:

1. Create a Postpost account — free trial available on the Pro plan
2. Connect Instagram — Go to Connections → Add → Instagram → Authorize via Facebook
3. Get your API key — Settings → API Keys → Create Key (authentication docs)
4. Configure OpenClaw — Add Postpost as an MCP server or use the REST API directly
5. Start posting — Tell OpenClaw what to post and when

Frequently Asked Questions

Further Reading

• Instagram Platform Reference — Complete API documentation
• OpenClaw Integration Guide — Detailed MCP setup
• Media Upload Workflow — Step-by-step upload guide
• MCP Client Setup — Claude Code, Cursor, and more
• Scheduling Guide — Timezone handling and best practices