Connect Zapier to posterly and put your social posting on autopilot

How the Zapier connection works

posterly does not have a native Zapier app yet, and you do not need one. Zapier's built-in "Webhooks by Zapier" action can call the posterly REST API directly, which gives you everything a native app would: create posts, schedule them, list accounts, and upload media. Going the other direction, posterly's outbound webhooks can start any Zap the moment a post publishes or fails.

Get your posterly API key

In your posterly dashboard, open Settings and go to the API section to generate a key. API access starts at $3/month on individual plans, with Agency API at $29/month. Copy the key somewhere safe, you will paste it into Zapier as an Authorization header.

Create a post from a Zap

Add a "Webhooks by Zapier" action to your Zap and choose the POST method. Point it at https://www.poster.ly/api/v1/posts, set the payload type to JSON, and add a header: Authorization: Bearer YOUR_API_KEY. That single action can publish immediately or schedule for later, to any platform you have connected.

Map your fields into the request body

In the JSON body, set caption to your post text (map it from the trigger step, a spreadsheet row, an RSS item, a form response), account_id to the connected account you are posting to (list your account ids once with GET /api/v1/accounts), and scheduled_at to an ISO timestamp if you want it scheduled instead of published now. Each request targets one account, so add an action step per account (or a Looping step) to fan the same caption out to more platforms. Add media by passing image or video URLs in media_urls, posterly fetches and validates them against each platform's requirements.

Trigger Zaps when posts publish

For the reverse direction, create an outbound webhook in posterly by calling POST https://www.poster.ly/api/v1/webhooks with the events you care about, such as post.published and post.failed. Use a Zapier "Catch Hook" trigger URL as the destination. Now every publish event starts a Zap: log it to a sheet, ping Slack, update your CRM, whatever comes next in your workflow.

Verify webhook signatures

Every webhook posterly sends is HMAC-signed with your webhook secret using SHA-256, delivered in the X-posterly-Signature header. For most Zaps the unique catch-hook URL is protection enough, but if you route events into anything sensitive, add a code step that recomputes the signature and rejects mismatches.

Workflows people actually build

The most common patterns: new blog post via RSS becomes a scheduled promo across X, LinkedIn, and Facebook; a new row in Google Sheets becomes a queued post; a failed publish sends a Slack alert with the error; a published post writes its live URL back into Notion or Airtable.

What about a native Zapier app?

A native posterly app in the Zapier directory is on the roadmap. Until it ships, the webhook approach above is fully supported, uses the same API our own MCP server and CLI use, and will keep working after the native app arrives.