API and MCP
Build on Postocial with APIs, webhooks and MCP
Create and schedule posts or manage contacts and conversations from your own code, react to post and messaging events with signed webhooks, start Zaps from messaging events, or let your AI assistant work in Postocial through the MCP server.
Every plan includes the Publishing API, publishing webhooks and the MCP server. Messaging and link in bio are on Premium and higher plans. They add the Messaging and Link in Bio APIs, messaging webhooks and Zapier triggers.
REST APIs
Three REST APIs
One for publishing, one for messaging and one for link in bio, all authenticated with workspace API keys.
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Publishing API
The calendar, from code.
- Accounts and posts
- Scheduling and approvals
- Media and tags
- Analytics
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Messaging API
Your contacts, conversations and campaigns, from code, on Premium and higher plans.
- Contacts, tags, segments and pipeline stages
- Conversations: assign, close, pause the bot, block
- Send messages and approved WhatsApp templates
- Broadcasts, and automations on or off
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Link in Bio API
Your bio pages and links, from code, on Premium and higher plans.
- Pages, blocks and themes
- Short links and QR codes
- Analytics, form submissions and pixels
- Read your custom domains
- New pages and links start paused until you publish them
Authentication
Workspace API keys with fine-grained permissions
Workspace admins create API keys for the whole workspace. A key acts with the rights of the admin who created it, narrowed to the permissions you choose. If that admin leaves the workspace or stops being an admin, the key stops working, so create integration keys from an admin account that will stay.
- Created by workspace admins under Integrations > REST API
- Fine-grained permissions on every key
- 60 requests per minute per key
- A separate key per integration keeps access easy to manage
Webhooks
Signed webhooks for publishing events
Subscribe to these events and Postocial sends a signed request to your endpoint. Check the signature before you act on it. You can rotate the signing secret with a grace period for the old one, and create or update endpoints from your own code with the webhook management API.
| Event | Sent when | Use it to |
|---|---|---|
| Post scheduled | A post is scheduled | Mirror the content calendar in your project tool |
| Post published | A post goes live | Tell the team, or update a client report |
| Post failed | A post could not be published | Alert the right person so they can fix and reschedule it |
| Post deleted | A post is deleted or moved to the trash | Remove it from your own content records |
| Account added | A social account is connected | Start your onboarding checklist for a new client |
| Account updated | A connected account changes | Keep your own records of connected accounts in sync |
| Account deleted | A social account is removed | Stop reports and clean up for that account |
Payload formats and signature details are in the API documentation.
Messaging webhooks
Webhooks for contacts, chats and campaigns
On Premium and higher plans, send messaging events to the same endpoint or to a new one. Limit an endpoint to one channel, such as WhatsApp, Messenger, Instagram or SMS, check its delivery history, resend a delivery and send test events.
| Group | Sent when | Use it to |
|---|---|---|
| Contacts | A contact is created, updated, tagged or untagged, moves to another pipeline stage, or reaches a date such as a birthday | Keep your CRM or mailing list in sync |
| Conversations | A message arrives, with the ad that started the chat, or a conversation is assigned or closed | Log sales and support activity in your own tools |
| Message delivery | A message is sent, delivered, read or fails, where the channel reports it | Follow up when an important message does not arrive |
| Automations | An automation starts, completes or fails | Alert the team when a flow breaks |
| Broadcasts | A broadcast is sent, completes or fails | Share campaign results with the team |
| Payments | A payment succeeds, fails or is refunded | Update orders and invoices in your own system |
| Bookings | A booking is created, rescheduled or cancelled | Mirror appointments in your CRM |
| Store | An order is created, paid, fulfilled, cancelled or refunded, a payment fails, a checkout is abandoned, a product is back in stock or running low, or a customer reaches an order or spending milestone | Pass order updates to your fulfillment tools |
Treat these payloads as customer data: they can include a contact's name and phone number and the text of their messages.
No-code automation
Automate without writing code
Start a Zap from messaging events, such as a new contact or an inbound message, or call the REST API from n8n with its HTTP Request node.
- Zapier triggers for messaging events, on Premium and higher plans
- n8n through its HTTP Request node
- Signed webhooks for everything else
MCP server
Connect your AI assistant with MCP
Postocial runs an MCP server at https://app.postocial.com/mcp. Your assistant signs in to Postocial, picks one workspace and can then list your accounts, draft, schedule and queue posts, add media and read your analytics, limited by your role.
| Client | How to connect | Guide |
|---|---|---|
| Claude | Settings > Connectors > Add custom connector, paste the server URL and leave the OAuth client ID and secret empty. | Claude guide |
| ChatGPT | Settings > Apps & Connectors > Advanced settings > Developer mode, then Create: paste the URL, choose OAuth and tick I trust this application. | ChatGPT guide |
| Claude Code | Run claude mcp add --transport http postocial https://app.postocial.com/mcp, then open /mcp and choose Authenticate. | Claude Code guide |
| Cursor | Settings > MCP, or add the URL to ~/.cursor/mcp.json. | Cursor guide |
| VS Code | Add the server to .vscode/mcp.json, then use it in Copilot Chat agent mode. | VS Code guide |
| Other MCP clients | Where the app supports OAuth, add the server URL, leave any client ID and secret empty and sign in. Otherwise, send a personal access token in an Authorization: Bearer header. | MCP overview |
Ideas
What teams build on Postocial
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Publish from your CMS
Create a post when an article, product or listing goes live in your own system.
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Client reporting
Pull analytics into your own dashboards and reports on a schedule.
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Alerts on failures
Use the post failed webhook to notify the right person, so they can fix and reschedule.
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Onboarding automation
Kick off your onboarding checklist when the account added webhook fires.
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Media from your storage
Upload images and videos through the API instead of dragging them in by hand.
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Planning with an assistant
Ask Claude or ChatGPT to draft next week's posts and schedule them through MCP.
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Sync contacts from your systems
On Premium and higher plans, create or update contacts, tags and pipeline stages from your own app, then let automations follow up.
FAQ
API and MCP questions
Is the API included in every plan?
Yes for publishing: the Publishing API, webhooks for publishing events and the MCP server are part of every plan. The Messaging API, messaging webhooks and Zapier triggers need messaging, and the Link in Bio API needs link in bio. Messaging and link in bio are on Premium and higher plans.
What is the rate limit?
Each API key can make 60 requests per minute, and each IP address 300 across all keys. Use a separate key for each integration so one busy job does not use up another's limit. After a 429 response, wait as many seconds as its Retry-After header says before you retry.
How do I know a webhook came from Postocial?
Every webhook is signed. Check the signature before you act on a payload; the API documentation explains how.
Can I send WhatsApp messages through the API?
Yes, with the Messaging API on Premium and higher plans. Messages go out on the contact's channel, and once 24 hours have passed since the customer's last message, you send an approved template. Sends to blocked or opted-out contacts are refused. Meta bills WhatsApp messages to your WhatsApp Business account.
What can an AI assistant do through MCP?
After it signs in, the assistant works in the one workspace you pick. It can list your accounts, draft, schedule and queue posts, add media and read your analytics, and it can only do what your role allows. Posts it schedules still wait for approval when your workspace requires it.
Do I give my password to the AI assistant?
No. Supported clients open a Postocial sign-in where you pick the workspace. Clients that cannot sign in use a personal access token instead, which you should keep as secret as a password.
Where is the documentation?
The API documentation covers the Publishing, Messaging and Link in Bio APIs, authentication and webhooks. The partner pages in the documentation are for platform partners and are not part of Postocial plans.
Start building on Postocial
Create a workspace, generate an API key and connect your assistant during the free trial.
Free for 7 days. Card required; cancel before the trial ends and you will not be charged.