Schedule Posts

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

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

Walkthrough

Step 1 — Verify Account Connection

Before scheduling, confirm the target account is connected:

GET /accounts
Authorization: Bearer $ZERNIO_API_KEY

Find the account in the response and note its _id and platform. Only schedule to accounts that appear in this list.

Step 2 — Upload Media

Upload video using Zernio's presigned URL flow:

2a — Get a presigned upload URL:

POST /media/presign
Authorization: Bearer $ZERNIO_API_KEY

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

Returns { "uploadUrl": "https://...", "publicUrl": "https://..." }.

2b — Upload the file to the presigned URL:

PUT [uploadUrl]
Content-Type: video/mp4

[raw file bytes]

2c — Use the publicUrl as the media reference when creating the post.

Step 3 — Write Caption

Generate a caption based on the video content and channel strategy:

• 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 — refer to the channel spec.

Step 4 — Create and Schedule Post

Create a post with scheduling in a single call:

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
}

• scheduledFor — ISO 8601 timestamp for when to publish.
• timezone — IANA timezone string.
• publishNow — set to true to post immediately instead of scheduling.
• platformSpecificData.contentType — set to "reel" for Instagram Reels.

To publish immediately, set publishNow: true and omit scheduledFor.

Step 5 — Confirm

Verify the post was created:

GET /posts
Authorization: Bearer $ZERNIO_API_KEY

Check that your post appears with the correct scheduled time and status.

To update a scheduled post before it publishes:

PUT /posts/:id
Authorization: Bearer $ZERNIO_API_KEY

{
  "content": "[UPDATED_CAPTION]",
  "scheduledFor": "2026-04-10T18:00:00.000Z"
}

To cancel a scheduled post:

DELETE /posts/:id
Authorization: Bearer $ZERNIO_API_KEY

Timing

• Post 1-2x per day per account. More than that risks algorithm penalties.
• Space posts 8-12 hours apart if posting twice.
• Best times vary by niche — use analytics data if available, otherwise default to 9am and 6pm in the account's timezone.

Key Behaviors

• Never schedule to an account that isn't in GET /accounts.
• Always upload media first via the presign flow, then reference the publicUrl in the post.
• Scheduling and post creation happen in one call — there is no separate schedule endpoint.
• Captions should match the channel character's voice.
• Don't batch-schedule 30 days at once — schedule 3-7 days ahead max so you can adjust based on performance.
• Zernio handles billing separately — there is no per-post credit charge through the API.