n8n integration

Two nodes, one credential. Schedule posts, generate captions and react to events — all from an n8n workflow.

The post mate n8n integration gives you two native nodes:

Node	Type	What it does
Post Mate	Action	Call any /v1 endpoint — schedule posts, generate AI captions, read analytics, manage webhooks
Post Mate Trigger	Webhook	Start a workflow the instant a post publishes, fails, gets approved, or crosses an engagement threshold

The nodes are published as n8n-nodes-post-mate on npm.

Installation

n8n Cloud or Desktop

Open Settings → Community Nodes
Click Install
Enter n8n-nodes-post-mate
Restart n8n when prompted

Self-hosted

npm install n8n-nodes-post-mate
# restart n8n

Credentials

In post mate, go to Settings → API and click New key
Choose scope Full (REST API) — the key starts with pm_live_…
Copy it (shown once)
In n8n, add a new credential → Post Mate API
Paste the key into API Key
Leave Base URL as https://post-mate.com (change only for self-hosted post mate)
Click Test credential — you should see a green tick

One credential works across every Post Mate and Post Mate Trigger node in all your workflows.

Post Mate node — quick start

Add a Post Mate node to any workflow
Select your credential
Choose Resource → Post, Operation → Get Many
Run — you'll see your scheduled posts as JSON items

Resources and operations

Post

Operation	What it does
Schedule / Create	Create a post (publishes immediately if no date set)
Get	Fetch one post by ID
Get Many	List posts, optionally filtered by status
Cancel	Delete a draft or scheduled post
Approve	Approve a `pending_approval` post
Request Changes	Send a post back to draft with an optional note

Schedule / Create fields:

Field	Required	Notes
Type	✓	text / image / video / story
Caption	—	Main caption, up to 10 000 chars
Social Account IDs	✓	Comma-separated UUIDs — get them from Account → Get Many
Scheduled At	—	ISO 8601. Leave blank to publish now.
Timezone	—	Defaults to UTC
Media Keys (JSON)	—	Array from the Media → Upload operation

Caption (AI)

Operation	What it does
Generate	Returns 5 caption variants for a topic
Hashtags	Suggests ranked hashtags for a caption or topic
Translate	Translates a caption while preserving voice

AI operations share the same monthly quota as the post mate dashboard. Rate limit: 20 requests per minute per API key.

Account

Operation	What it does
Get Many	List all connected social accounts with their IDs

Run this once to find the account UUIDs you need for scheduling.

Analytics

Operation	What it does
Get	Fetch engagement metrics for the last N days (default 30, max 180)

Media

Operation	What it does
Upload	Upload a binary file (max 50 MB) and get back a key for use in posts

Connect a Read Binary File, HTTP Request, or Google Drive node before Post Mate to supply the binary data.

Webhook

Operation	What it does
List	List all registered webhook endpoints
Create	Register a new webhook (idempotent by URL + events)
Test (Ping)	Send a test ping and see the response immediately
Delete	Remove a webhook

Metric Alert

Operation	What it does
List	List all threshold rules
Create	Create a rule that fires `post.metric_threshold` once
Delete	Remove a rule

Post Mate Trigger — quick start

Add a Post Mate Trigger node at the start of a workflow
Select your credential
Pick one or more Events (e.g. Post Published, Post Failed)
Activate the workflow
The node automatically registers itself in post mate via POST /v1/webhooks
When the workflow is deactivated, the webhook is removed automatically

Trigger events

Event	When it fires
Post Published	A post successfully publishes to a network
Post Failed	A post fails after all retry attempts
Post Scheduled	A post enters the scheduled queue
Post Approved	A pending-approval post is approved
Post Changes Requested	A reviewer sends a post back to draft
Post Metric Threshold	A post crosses a configured metric alert

The trigger node verifies the X-PostMate-Signature header automatically on every incoming request. Requests with an invalid signature or a timestamp older than 5 minutes are rejected with 401 and do not trigger the workflow.

To disable verification during development behind an isolated network, open the node's Options and enable Skip Signature Verification.

Workflow recipes

Blog post → all networks

RSS Feed → Post Mate (Caption: Generate) → Post Mate (Post: Schedule)

Failure → Slack alert

Post Mate Trigger (post.failed) → Slack (send message)

Approve posts from Slack

Post Mate Trigger (post.changes_requested)
  → Slack (ask for approval)

Slack Trigger (button clicked: "Approve")
  → Post Mate (Post: Approve)

Daily metrics → Google Sheets

Schedule Trigger (08:00 every day)
  → Post Mate (Analytics: Get)
  → Google Sheets (append row)

Viral alert → notify team

Post Mate Trigger (post.metric_threshold)
  → Slack (notify #content with post link + metric value)

Troubleshooting

Credential test fails with 401 The key is invalid or has been revoked. Create a new one under Settings → API. Make sure the scope is Full (REST API), not MCP-only.

Credential test fails with 402 Your trial ended or your subscription is inactive. Upgrade at Settings → Billing.

Trigger node doesn't fire Check that the workflow is Active (toggle in the top-right). If it's active but events aren't arriving, use Webhook → Test (Ping) in a Post Mate action node to verify the endpoint responds.

Duplicate webhooks in Settings → API The trigger node deduplicates by URL + event list on every activation, so duplicates shouldn't accumulate. If you see stale entries, delete them manually or via Webhook → Delete.

Rate limit errors (429) Post Mate allows 60 API requests per minute per key (20/min for AI operations). Add a Wait node between high-volume steps or split large batches across multiple executions.

Plan

The n8n integration uses the same API key and plan as the REST API: Pro plan or an active trial. One key works for n8n, MCP, and direct REST calls — rotate it any time from Settings → API.