Move from Buffer to PostWire in an afternoon

Buffer — their docs' example

mutation CreatePost {
  createPost(input: {
    text: "Hello there, this is another one!",
    channelId: "some_channel_id",
    schedulingType: automatic,
    mode: customScheduled,
    dueAt: "2026-03-26T10:28:47.545Z"
  }) {
    ... on PostActionSuccess {
      post {
        id
        text
        assets {
          id
          mimeType
        }
      }
    }
    ... on MutationError {
      message
    }
  }
}

From developers.buffer.com, read Oct 9, 2026.

PostWire — REST (the converter's output, with linkedin ticked)

curl -X POST https://postwire.io/api/schedule \
  -H "Authorization: Bearer $POSTWIRE_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
  "platforms": [
    "linkedin"
  ],
  "text": "Hello there, this is another one!",
  "run_at": "2026-03-26T10:28:47.545Z"
}'

channelId (a Buffer channel) → brand_id: create one PostWire brand per client (POST /api/brands) and send its id; with a single brand you can leave brand_id out run_at is in the past: PostWire refuses a schedule in the past — set a future time

PostWire — n8n node

PostWire node
  Resource:   Post
  Operation:  Schedule
  Networks:   linkedin
  Content:    Same Text on Every Network
  Text:       Hello there, this is another one!
  When:       At a Specific Time
  Publish At: 2026-03-26T10:28:47.545Z
  Options → Brand: the client's brand

PostWire — MCP (Claude, ChatGPT, any agent)

schedule_post({
  "platforms": [
    "linkedin"
  ],
  "text": "Hello there, this is another one!",
  "run_at": "2026-03-26T10:28:47.545Z"
})

# or ask your agent: "Schedule this on LinkedIn for 2026-03-26T10:28:47.545Z"