Posting - Postsiva

Publish to one or more connected platforms with a single JSON body. Postsiva merges unified fields (shared defaults) with platform override objects (linkedin, facebook, etc.) when you need per-network copy or targeting.

For every field Postsiva accepts (per platform), see the complete Posting parameters reference. For UI + OAuth + API key setup, see Complete setup.

Base URL & auth

https://backend.postsiva.com

curl -X POST "https://backend.postsiva.com/unified/post/text" \
  -H "X-API-Key: psk_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"platforms":["linkedin"],"default_text":"Hello from Postsiva!"}'

Header	Required	Notes
`X-API-Key`	Yes (or Bearer)	Workspace is resolved from the key. See Authentication.
`Authorization: Bearer …`	Alternative	JWT session or `psk_live_…` key
`X-Workspace-Id`	JWT only	Required with JWT; optional with API key (must match key workspace)
`Content-Type`	Yes	`application/json`

Connect accounts first via OAuth. Upload images and videos via Media and pass returned media_id values in post bodies.

Endpoints

Method	Path	Post type
`POST`	`/unified/post/text`	Text only
`POST`	`/unified/post/image`	Single image
`POST`	`/unified/post/carousel`	2–20 images
`POST`	`/unified/post/video`	Video

Each path accepts the same cross-cutting fields; type-specific fields are validated per route.

Common body fields

These apply to all four post types unless noted.

Field	Type	Required	Description
`platforms`	`string[]`	Yes	One or more: `linkedin`, `facebook`, `instagram`, `threads`, `tiktok`, `youtube`, `pinterest`, `bluesky` (availability varies by post type)
`default_text`	`string`	Text: yes; others: optional	Default caption/text (max 3000). Used unless a platform override replaces it
`visibility`	`string`	No	`PUBLIC` (default) or `CONNECTIONS` — LinkedIn
`scheduled_time`	`string`	No	ISO 8601 UTC, e.g. `2026-07-10T14:30:00Z`
`draft`	`boolean`	No	`false` (default). If `true` and `draft_platforms` omitted, all platforms save as draft
`draft_platforms`	`string[]`	No	Subset of `platforms` to save as draft; others publish immediately
`board_id`	`string`	No	Top-level Pinterest board id fallback

Platform override objects

Nest platform-specific fields under the platform key. Overrides win over unified defaults for that network only.

Key	Common fields
`linkedin`	`linkedin_text`, `linkedin_page_ids`, `post_to_personal`, `linkedin_page_texts`, `linkedin_page_images`, `visibility`, `scheduled_time`, `thumbnail_image_id`, `generate_thumbnail_from_content`
`facebook`	`facebook_page_ids` (required when `facebook` is in `platforms`), `facebook_page_texts`, `facebook_page_images`, `scheduled_time`
`instagram`	`instagram_text`, `instagram_image_id`, `scheduled_time`
`threads`	`threads_text` (max 500), `threads_image_id`
`tiktok`	`tiktok_text`, `tiktok_title`, `privacy_level`, `disable_comment`, `auto_add_music`, `cover_index`
`youtube`	`youtube_title` (required for YouTube video), `youtube_description`, `youtube_playlist_id`, `thumbnail_image_id`
`pinterest`	`board_id` (required for pin), `pinterest_text`, `pinterest_description`, `pinterest_image_id`

LinkedIn targeting

Field	Description
`linkedin.linkedin_page_ids`	Org/page IDs to post to. Omit = personal profile only
`linkedin.post_to_personal`	When pages are set: omitted/`false` = pages only; `true` = personal and each page
`linkedin.linkedin_text`	Text for personal profile; fallback for pages not in `linkedin_page_texts`
`linkedin.linkedin_page_texts`	Map of `page_id → text` for per-page copy

Facebook pages

Facebook posts always target Pages (not personal profiles). You must supply page IDs:

{
  "platforms": ["facebook"],
  "default_text": "Weekly update",
  "facebook": {
    "facebook_page_ids": ["123456789012345"],
    "facebook_page_texts": {
      "123456789012345": "Custom copy for this page"
    }
  }
}

POST /unified/post/text

Text-only posts. Supported platforms: linkedin, facebook, threads, bluesky.

Field	Required	Notes
`default_text`	Yes	1–3000 characters
`platforms`	Yes	Min length 1

curl -X POST "https://backend.postsiva.com/unified/post/text" \
  -H "X-API-Key: psk_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "platforms": ["linkedin", "threads"],
    "default_text": "Shipping a new API docs site today.",
    "linkedin": {
      "linkedin_page_ids": ["10987654321"],
      "linkedin_text": "LinkedIn-specific angle on the launch."
    },
    "threads": {
      "threads_text": "Short Threads version (max 500)."
    }
  }'

POST /unified/post/image

Single-image posts. Provide default_image_id OR default_image_url (at least one required).

Field	Required	Notes
`default_image_id`	One of id/url	UUID from POST /media/upload
`default_image_url`	One of id/url	Public HTTPS image URL
`platforms`	Yes	e.g. `linkedin`, `facebook`, `instagram`, `threads`, `tiktok`, `pinterest`

{
  "platforms": ["instagram", "linkedin"],
  "default_image_id": "a1b2c3d4-e5f6-7890-abcd-ef1234567890",
  "default_text": "Product screenshot",
  "pinterest": {
    "board_id": "9876543210987654321",
    "pinterest_text": "Pin title"
  }
}

Threads and Bluesky accept default_image_url / video_url — Postsiva uploads the file first, then posts using the returned media_id. Carousel posts still require image_ids from Media.

POST /unified/post/carousel

Multi-image carousel. image_ids required: 2–20 UUIDs from media upload.

Field	Required	Notes
`image_ids`	Yes	Array of 2–20 `media_id` values
`platforms`	Yes	`linkedin`, `facebook`, `instagram`, `threads`, `tiktok`, `pinterest`

{
  "platforms": ["instagram", "facebook"],
  "image_ids": [
    "11111111-1111-1111-1111-111111111111",
    "22222222-2222-2222-2222-222222222222"
  ],
  "default_text": "Swipe through our launch gallery",
  "facebook": {
    "facebook_page_ids": ["123456789012345"]
  }
}

POST /unified/post/video

Video posts. Provide video_id OR video_url (at least one required).

Field	Required	Notes
`video_id`	One of id/url	From POST /media/upload (`media_type=video`)
`video_url`	One of id/url	Direct HTTPS video URL
`platforms`	Yes	`linkedin`, `facebook`, `instagram`, `threads`, `tiktok`, `youtube`, `pinterest`, `bluesky`
`youtube.youtube_title`	YouTube only	Required when `youtube` is in `platforms` (or use `default_text` as title fallback)
`pinterest.board_id`	Pinterest only	Required when `pinterest` is in `platforms`

{
  "platforms": ["youtube", "linkedin"],
  "video_id": "33333333-3333-3333-3333-333333333333",
  "default_text": "Demo walkthrough",
  "youtube": {
    "youtube_title": "Postsiva API demo — full walkthrough",
    "youtube_description": "How to publish from one JSON body."
  },
  "linkedin": {
    "linkedin_page_ids": ["10987654321"],
    "post_to_personal": true
  }
}

Drafts and scheduling

Mode	How
Publish now	Omit `draft`, `draft_platforms`, and `scheduled_time`
Save all as draft	`"draft": true`
Mixed draft + publish	`"draft_platforms": ["linkedin"]` with `platforms: ["linkedin","facebook"]` — LinkedIn draft, Facebook publishes
Schedule	Set `scheduled_time` (ISO UTC) on the body or inside a platform override

Schedule-only workflows without immediate publish can also use POST /unified/scheduled-posts (same body shape, scheduled_time required, draft not allowed on that route).

When drafts are saved, you receive draft objects instead of live post IDs. Publish drafts from the Postsiva app or scheduled-posts APIs.

Response shapes

Single platform

{
  "success": true,
  "message": "Post created",
  "post": {
    "platform": "linkedin",
    "post_id": "urn:li:share:7123456789012345678",
    "permalink": "https://www.linkedin.com/feed/update/..."
  }
}

Multiple platforms

Each platform runs in parallel. Partial success is possible.

{
  "results": [
    {
      "platform": "linkedin",
      "success": true,
      "message": "Posted",
      "post": { "post_id": "urn:li:share:7123456789012345678" }
    },
    {
      "platform": "facebook",
      "success": false,
      "message": "Page token expired",
      "error": "OAUTH_ERROR"
    }
  ]
}

Draft responses

{
  "success": true,
  "message": "Saved as drafts",
  "drafts": [
    {
      "platform": "linkedin",
      "draft_id": "d4e5f6a7-b8c9-0123-def0-456789abcdef",
      "status": "draft"
    }
  ]
}

Mixed draft + publish

{
  "success": true,
  "message": "Drafts and posts completed",
  "drafts": [{ "platform": "linkedin", "draft_id": "..." }],
  "results": [{ "platform": "facebook", "success": true, "post": { "post_id": "..." } }]
}

MCP equivalent

Use the publish tool on Unified MCP with the same fields (post_type, platforms, default_text, media ids, draft, scheduled_time, platform_overrides_json).

https://mcp.postsiva.com/mcp

Auth: X-API-Key: psk_live_… or ?apikey=psk_live_…

Posting parameters (complete) — all LinkedIn / Facebook / IG / TikTok / YouTube / Threads / Pinterest fields
Complete setup — connect accounts in UI or via API, then automate
Media upload — get media_id before image/video/carousel posts
OAuth — connect platforms before posting
Posts — read published content and stats
Authentication — API key scopes and plan gates

​Base URL & auth

​Endpoints

​Common body fields

​Platform override objects

​LinkedIn targeting

​Facebook pages

​POST /unified/post/text

​POST /unified/post/image

​POST /unified/post/carousel

​POST /unified/post/video

​Drafts and scheduling

​Response shapes

​Single platform

​Multiple platforms

​Draft responses

​Mixed draft + publish

​MCP equivalent

​Related

Base URL & auth

Endpoints

Common body fields

Platform override objects

LinkedIn targeting

Facebook pages

POST /unified/post/text

POST /unified/post/image

POST /unified/post/carousel

POST /unified/post/video

Drafts and scheduling

Response shapes

Single platform

Multiple platforms

Draft responses

Mixed draft + publish

MCP equivalent

Related