Quick overview
This workflow runs every Monday to generate a week of social media posts with OpenAI, then schedules them at preselected high-reach time slots through PostFast for the social accounts you choose.
How it works
- Runs every Monday morning on a schedule trigger.
- Loads your brand name, voice, topics, number of posts, and a platform filter for which networks to target.
- Fetches all connected social accounts from PostFast and keeps only accounts that are connected and match the chosen platforms.
- Uses OpenAI to write the requested number of posts in the defined brand voice and returns them as structured JSON.
- Assigns each post to the next available “best time” slot (UTC) and expands the plan so each post is scheduled for each selected PostFast account.
- Creates scheduled posts in PostFast with APPROVED status so they publish automatically at the assigned times.
Setup
- Install and enable the PostFast community node (n8n-nodes-postfast) if your n8n instance does not already allow verified community nodes.
- Add a PostFast API key credential and connect the social accounts you want to schedule to in your PostFast dashboard.
- Add an OpenAI credential for the OpenAI node.
- Update the configuration values (brandName, brandVoice, topics, postsPerWeek, and platformFilter) to match your needs and ensure the platform names match your PostFast account platforms.
Requirements
- A PostFast account (postfa.st) with an API key from Dashboard > API
- An OpenAI API key
- The verified PostFast community node (n8n-nodes-postfast) enabled on your instance
Customization
- Change the posting time slots in the "Assign data-backed time slots" Code node
- Adjust tone, length, hashtags or language in the OpenAI prompt
- Change postsPerWeek or target different networks via the platformFilter value
Additional info
The posting time slots are not guesses: they come from PostFast's analysis of 36,000+ real scheduled posts (22,890 Instagram and 13,758 TikTok), published at postfa.st/blog/best-time-to-post-on-instagram. This template is built and maintained by the PostFast team, the makers of the verified n8n-nodes-postfast community node. PostFast supports 11 networks; the default platform filter targets text-friendly ones, since Instagram, TikTok, Pinterest and YouTube require media on every post.