A tool that writes a different caption for each social network from one idea

PostWire takes one idea and writes a separate, native post for each network you tick — a hook-first TikTok caption, a short Instagram caption, a YouTube title with description and tags, a first-person LinkedIn post, a Bluesky post under 300 characters — then publishes or schedules them. It does it in one step in the dashboard (Write the posts), in one call over the REST API (POST /api/generate) and as the generate_posts tool in Claude or any MCP client.

Most schedulers give you one text box and let you edit a copy per network by hand. As of Oct 2026, we couldn't find another hosted API that writes a different native post per network from one prompt, in one call (22 tools reviewed on Sept 26, 2026). Many tools publish to several networks and have AI assistants; the difference is the per-network writing in one request.

PostWire's composer showing a first-person LinkedIn draft (1,106 of 3,000 characters) and a short Instagram caption with hashtags, both written from one idea about a 6:15am yoga class
One idea (a 6:15am yoga class) in; a first-person LinkedIn post and a short Instagram caption out, each with its own character counter.

Updated . Written from PostWire's own code; vendor prices read on Oct 3, 2026. Live networks: TikTok, Instagram, YouTube, LinkedIn (personal profiles), Facebook Pages, Bluesky, Mastodon, Telegram, Discord, and X on paid plans.

Step by step

  1. Create a free PostWire account

    Open postwire.io/dashboard.html, type your email and press Create my free account. PostWire emails you a link to confirm the address; connecting accounts and publishing unlock once it is confirmed. No password and no card (free plan: 1 business, 20 posts a month, 5 AI drafts a day (about 20 a month), 2 networks per post, 3 scheduled posts at a time — every network connects free, no card).

  2. Write the idea in one or two sentences

    In Compose → Your idea. Facts, numbers and a link make better posts than adjectives. Optional: a Brand voice under More options ("plain-spoken, no exclamation marks").

  3. Tick the networks and press Write the posts

    PostWire writes one draft per network, each inside that network's limits (TikTok and Instagram 2,200 characters, YouTube title 100, LinkedIn 3,000, Facebook 2,000, Bluesky 300, Mastodon 500, Telegram 4,000, Discord 2,000). Writing six networks takes about 20–25 seconds.

  4. Adjust any draft

    Each draft has ↻ Regenerate, – Shorten, + Expand, Formal and Casual, plus free editing and a character counter.

  5. Publish or schedule them together

    Publish now, or Schedule → Add to queue. TikTok, YouTube and Instagram need a photo or video — no photo to hand? Make an image from this post turns the words into a 4:5 or 9:16 image.

Tools whose AI adapts a post to each network

Several schedulers now tailor text per network with AI. What differs is how many networks you get in one step, and whether the same thing works from an API, n8n or an AI assistant.

ToolAdapts the text per networkAll networks in one stepSame from an API / n8n / MCPFree plan
PostWireYes — a native draft per network (caption, YouTube title + tags, LinkedIn long-form, Bluesky ≤300)Yes — one press, one API call or one MCP toolYes — POST /api/generate, the n8n node's Smart Distribute, generate_postsYes — 1 business, 20 posts a month, 5 AI drafts a day (about 20 a month), 2 networks per post, 3 scheduled posts at a time — every network connects free, no card
Buffer AI AssistantYes — "turn a single post into multiple formats and styles tailored to each social media platform"Not listedNot listedYes — 3 channels (buffer.com/pricing)
Metricool AI assistantYes — "posts can be adapted to each social platform" with shortcutsNot listedNot listedYes (metricool.com/pricing)

Read on each vendor's own page on Oct 3, 2026 (links below). "Not listed" = we could not find it on their page. Monthly billing in USD unless noted. "Not listed" means we could not find it on their page, not that it is missing.

Where PostWire is ahead

  • Every network in one step — one press, one API call (POST /api/generate) or one MCP tool (generate_posts). Buffer's and Metricool's pages describe their AI adapting the post inside their editors.
  • The same writer in n8n, Make and AI agents, so an automated workflow gets a native post per network with no prompt per network to maintain.
  • Each network's limits kept: Bluesky under 300 characters, a YouTube title up to 100, at most 30 Instagram hashtags, X counted the way X counts — checked before anything is published.
Sources, all read on Oct 3, 2026:

The same thing over the API, n8n or MCP

REST — two calls: write, then publish what you approved.

curl -X POST https://postwire.io/api/generate \
  -H "Authorization: Bearer pw_live_…" -H "Content-Type: application/json" \
  -d '{"prompt":"We cut onboarding from 9 steps to 3","platforms":["linkedin","bluesky","instagram"]}'
# → { "drafts": { "linkedin": {"text": "…"}, "bluesky": {"text": "…"}, "instagram": {"text": "…"} } }

curl -X POST https://postwire.io/api/post \
  -H "Authorization: Bearer pw_live_…" -H "Content-Type: application/json" \
  -d '{"platforms":["linkedin","bluesky","instagram"],"per_platform":{…the drafts…},"photo_url":"https://…/card.jpg"}'

n8n — the PostWire node's Publish operation with Content = Smart Distribute: Write a Native Post per Network (guide). Claude / MCP — ask "turn this into posts for LinkedIn and Bluesky"; the assistant calls generate_posts, shows the drafts, and only publishes with post_to_social after you approve (guide).

What changes from network to network

  • TikTok: the first line is the hook; a few hashtags in the caption.
  • Instagram: a short caption, hashtags at the end (at most 30 are kept).
  • YouTube: a title (up to 100 characters), a description and SEO tags.
  • LinkedIn: a longer first-person post; only about the first 210 characters show before "see more".
  • Bluesky: 300 characters, links included.
  • Mastodon: 500 characters on most servers, CamelCase hashtags.

The full table is on social media post sizes.

Questions people ask

Is there a tool that writes a different post for each social network?

Yes. PostWire writes a separate native post for each network you choose from one idea, in one step (dashboard), one call (POST /api/generate) or one MCP tool (generate_posts), and then publishes or schedules them.

Can I edit the drafts before they are published?

Yes. Nothing is published until you press Publish now or Schedule (or approve it in the chat). Each draft can be edited, shortened, expanded, made more formal or casual, or regenerated.

Which networks get their own version?

TikTok, Instagram, YouTube, LinkedIn (personal profiles), Facebook Pages, Bluesky, Mastodon, Telegram and Discord.

How many AI drafts can I write for free?

The free plan includes 5 AI drafts a day (about 20 a month) and 20 published posts a month for one business. Starter ($9) raises that to 60 drafts a day (about 30 a month) and 1,000 posts; past the month, AI credit packs add more.

Does it learn what works for my audience?

The What works page compares each published post with your own median on the same network and shows your best posts; on paid plans, Replicate turns a winning post into new drafts for each network.