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Integrations

Post to social media from n8n

There are two ways to use OmniSocials from n8n:

1. HTTP Request node. Your workflow calls the REST API with fixed fields. Use it when every run does the same thing, for example "new RSS item, schedule a LinkedIn post".
2. AI Agent with the MCP Client Tool node. An agent gets the OmniSocials MCP tools and decides what to call. Use it when a model should write the caption, pick the accounts, or choose a time.

Both use the same API key and the same n8n credential.

Before you start

• An OmniSocials account with at least one social account connected (Settings → Organisation → Workspaces). Accounts cannot be connected through the API.
• An API key from Settings → API. Give it posts:write and accounts:read, plus media:write if the workflow uploads files. See Authentication.
• n8n Cloud or a self-hosted n8n instance.

Store the API key in n8n

Create the credential once. Both nodes on this page use it.

1. In n8n, create a new credential and pick the Bearer Auth type.
2. In Bearer Token, paste your key: omsk_live_<YOUR_KEY>.
3. Name it something like "OmniSocials API" and save.

n8n sends it as Authorization: Bearer omsk_live_<YOUR_KEY> on every request. Keep the key in this credential, not in a node's headers or body, so it never shows up in exported workflows.

Option 1: create a post with the HTTP Request node

Add an HTTP Request node after your trigger and set:

Parameter	Value
Method	POST
URL	https://api.omnisocials.com/v1/posts/create
Authentication	Generic Credential Type
Generic Auth Type	Bearer Auth, then pick the "OmniSocials API" credential
Send Body	On
Body Content Type	JSON
Specify Body	Using JSON

Paste this into the JSON field:

JSON
{
  "content": { "default": "New on the blog: how we plan a month of posts in one hour." },
  "accounts": ["linkedin", "x"],
  "schedule_at": "2026-11-02T09:00:00Z",
  "media_urls": ["https://example.com/cover.jpg"],
  "source": "n8n"
}

Run the node. A 201 response returns the new post in data, with its id and a status of scheduled.

Map data from earlier nodes

Switch the JSON field to an expression to fill it from the previous node. Wrap text values in JSON.stringify(), so quotes and line breaks in a caption cannot break the JSON:

Text
{
  "content": { "default": {{ JSON.stringify($json.caption) }} },
  "accounts": ["linkedin", "x"],
  "schedule_at": "{{ $now.plus({ hours: 1 }).toISO() }}",
  "media_urls": [{{ JSON.stringify($json.image_url) }}],
  "source": "n8n"
}

Body fields

The fields you will use most. The full list, including per-platform options, is in the API reference and Creating posts.

Field	Type	What it does
content	object	Required. default is the text for every account. Add a platform key such as instagram or linkedin to give that platform its own text.
accounts	array of strings	Required. Platform names such as "instagram", or account IDs from GET /v1/accounts such as "844008_instagram".
schedule_at	string	ISO 8601 date and time, in the future. The post publishes then.
publish_now	boolean	true publishes right away. It wins over schedule_at.
media_urls	array of URLs	Public image or video URLs. OmniSocials downloads them. Instagram and TikTok posts need at least one.
source	string	Optional label for where the post came from.

Leave out both schedule_at and publish_now to save the post as a draft. Send publish_now as a real boolean (true), never as the string "false".

Option 2: let an AI Agent post through MCP

The MCP Client Tool node connects an n8n AI Agent to the hosted OmniSocials MCP server at https://mcp.omnisocials.com. The agent then sees tools like list_accounts, create_post, upload_media, and get_best_times. See MCP server for the full tool list.

Build the workflow:

1. Add a Chat Trigger node. It shows as "When chat message received" on the canvas.
2. Add an AI Agent node after it. Leave Source for Prompt (User Message) on Connected Chat Trigger Node.
3. Connect a chat model sub-node to the agent, for example OpenAI or Anthropic.
4. On the agent's tool connector, add an MCP Client Tool node and set:

Parameter	Value
Endpoint	https://mcp.omnisocials.com
Server Transport	HTTP Streamable
Authentication	Bearer Auth, then pick the "OmniSocials API" credential
Tools to Include	Selected, then pick the tools the agent needs. Or All.

5. Optional: under the agent's Options, add a System Message, for example:

Text
You manage social media through OmniSocials. Call list_accounts before you create a post.
Create posts as drafts unless the user asks you to schedule or publish them.

6. Open the chat and ask: "List my connected social accounts on OmniSocials". The agent should call list_accounts and answer with your accounts.

The tools respect the key's scopes. A key without posts:write still lists create_post, but calling it returns 403. Pick Selected in Tools to Include to keep the agent to the tools it needs, for example list_accounts, create_post, and list_posts.

Troubleshooting

Response	Cause	Fix
401	The key is wrong or revoked.	Check the Bearer Token in the credential.
402 on the MCP server	The organisation has no active plan.	Check billing in Settings → Organisation.
403	The key misses a scope.	Create a new key with the scope. Scopes cannot be edited.
400 with validation_error	A field is missing or invalid, for example an unknown account or a past schedule_at.	Read error.message, it names the field.
429	Rate limit.	Wait for Retry-After seconds, then retry.

See Rate limits and errors for every status code.

Next steps

• Creating posts covers per-platform text, post types, and updates.
• Media covers uploads, formats, and size limits.
• Webhooks can start an n8n workflow when a post publishes or fails.