Publisher

Schedule content to connected Instagram accounts via Zernio and manage account connections. Handles media upload, caption writing, timing, and account health.

Base URL: https://zernio.com/api/v1 Auth header: Authorization: Bearer $ZERNIO_API_KEY

---

Account Management

Connect Account

Direct the user to connect their Instagram account through Zernio's web dashboard:

1. Go to zernio.com and log in.
2. Navigate to the accounts/connections section.
3. Follow the OAuth flow to connect an Instagram account.

Zernio handles the Instagram authentication — there is no API endpoint to provision accounts. All connections happen through the dashboard.

Verify Connection

GET /accounts
Authorization: Bearer $ZERNIO_API_KEY

Returns an array of connected accounts. Confirm the expected account appears. Note the _id for scheduling.

Account Health

• Disconnected accounts — OAuth tokens can expire. Re-authorize via dashboard.
• Engagement drops — may indicate algorithm penalties.
• Account restrictions — content policy violations on the platform side.

Multiple Accounts

Each account appears in GET /accounts. Connect one at a time and verify each.

---

Scheduling

Step 1 — Verify Account

GET /accounts
Authorization: Bearer $ZERNIO_API_KEY

Only schedule to accounts that appear in this list.

Step 2 — Upload Media

Get presigned URL:

POST /media/presign
Authorization: Bearer $ZERNIO_API_KEY

{
  "filename": "video.mp4",
  "contentType": "video/mp4"
}

Upload file to presigned URL:

PUT [uploadUrl]
Content-Type: video/mp4

[raw file bytes]

Use the publicUrl when creating the post.

Step 3 — Write Caption

• Keep it short — 1-3 lines max.
• Include a CTA — "Link in bio", "DM me [keyword]", etc.
• Use 3-5 relevant hashtags — niche-specific, not generic.
• Match the character's voice from the channel spec.

Step 4 — Create Post

POST /posts
Authorization: Bearer $ZERNIO_API_KEY

{
  "content": "[CAPTION]",
  "mediaItems": ["[PUBLIC_URL]"],
  "platforms": [
    {
      "accountId": "[ACCOUNT_ID]",
      "platform": "instagram",
      "platformSpecificData": {
        "contentType": "reel"
      }
    }
  ],
  "scheduledFor": "2026-04-10T14:00:00.000Z",
  "timezone": "America/New_York",
  "publishNow": false
}

Set publishNow: true to post immediately.

Step 5 — Confirm

GET /posts
Authorization: Bearer $ZERNIO_API_KEY

Update: PUT /posts/:id | Cancel: DELETE /posts/:id

Timing

• Post 1-2x per day per account.
• Space posts 8-12 hours apart if posting twice.
• Default to 9am and 6pm in the account's timezone.

Key Behaviors

• Never schedule to an account not in GET /accounts.
• Always upload media first via presign flow.
• Scheduling and post creation happen in one call.
• Don't batch-schedule 30 days — schedule 3-7 days ahead max.