Automate social media posting with n8n

Agent node or plain API calls? Use the agent when the decision varies: which networks suit this item, how the caption should change, whether it is worth posting. When the logic is fixed (every post goes to the same four accounts), skip the model and call the social media API from an HTTP Request node: POST to app.posteverywhere.ai/api/v1/posts with content, account_ids and scheduled_for. Deterministic is cheaper and more predictable, and many teams run both.

Rate limits. Each API key gets 60 requests a minute and 1,000 an hour, on every plan. Bulk create takes up to 50 posts per call, but each post also counts, so a 50-post batch uses 51 of the minute’s 60. Space big batches with a Wait node, and see the rate limit guide.

Webhooks arrive at least once. PostEverywhere retries a delivery up to six attempts, so the same event can reach your Webhook node twice. Deduplicate on the X-PostEverywhere-Event-Id header and check the HMAC signature in X-PostEverywhere-Signature before acting. Verifying signatures has the code.

Unattended runs publish without a review. A chat window shows you each tool call; a scheduled workflow does not. While you test, tell the agent to save drafts or schedule for later rather than publish now. Scheduled posts can be edited or deleted until they go out; a published post usually cannot be recalled, because most platform APIs do not allow it.

The node will not connect. Check the endpoint has no trailing path, that the credential is Bearer with the full key, and that your PostEverywhere subscription is active. The server refuses calls from an inactive workspace instead of failing quietly.

The agent calls the wrong tool. Name the outcome in the system message (“schedule, never publish now”, “drafts only”). A large tool list rewards clear instructions. You can also limit which tools the node exposes if your version offers that option.