Post Mate icon

Post Mate

Schedule posts, generate captions and manage social media across 13 networks

Actions19

Caption (AI) → Generate

AI-generated

Summary

Generates AI caption variants via the Post Mate API (POST /api/v1/ai/caption) from an optional topic, tone, target platforms and a character limit.

Inputs

  • Topic — Topic seed for the captions. Only sent if non-empty; leave blank to let the service pick ambient angles.
  • Platforms — Multi-select of Instagram, TikTok, LinkedIn, X, Threads, YouTube, Facebook, Bluesky, Pinterest. Used to tune tone and length. Only sent if at least one is selected.
  • Tone — Friendly (default), Witty, Punchy, Professional or Storyteller. Sent as 'tone'.
  • Max Characters — Character limit per caption, 50–2200, default 220. Sent as 'max_chars'.

Output shape

One output item per input item, whose json is the API response body as returned. If the API returns an array, each element becomes a separate item.

The node's action label says it returns 5 caption variants, but the response schema is defined by the Post Mate API, not the node source. Requires Post Mate API credentials (Bearer API key). With Continue On Fail enabled, errors are returned as {error: message} items.

Examples

Example 1: Draft short witty captions for a product launch on X and Threads

Topic='New feature launch', Platforms=[x, threads], Tone=Witty, Max Characters=200

Example 2: Generate professional LinkedIn copy

Topic='Q3 hiring update', Platforms=[linkedin], Tone=Professional, Max Characters=1200

Example 3: Get open-ended caption ideas without a topic

Leave Topic blank, Tone=Friendly, defaults for the rest

Links

Discussion